Index: head/sys/amd64/amd64/pmap.c =================================================================== --- head/sys/amd64/amd64/pmap.c (revision 100377) +++ head/sys/amd64/amd64/pmap.c (revision 100378) @@ -1,3529 +1,3527 @@ /* * Copyright (c) 1991 Regents of the University of California. * All rights reserved. * Copyright (c) 1994 John S. Dyson * All rights reserved. * Copyright (c) 1994 David Greenman * All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department and William Jolitz of UUNET Technologies Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)pmap.c 7.7 (Berkeley) 5/12/91 * $FreeBSD$ */ /* * Manages physical address maps. * * In addition to hardware address maps, this * module is called upon to provide software-use-only * maps which may or may not be stored in the same * form as hardware maps. These pseudo-maps are * used to store intermediate results from copy * operations to and from address spaces. * * Since the information managed by this module is * also stored by the logical address mapping module, * this module may throw away valid virtual-to-physical * mappings at almost any time. However, invalidations * of virtual-to-physical mappings must be done as * requested. * * In order to cope with hardware architectures which * make virtual-to-physical map invalidates expensive, * this module may delay invalidate or reduced protection * operations until such time as they are actually * necessary. This module is given full information as * to which processors are currently using which maps, * and to when physical maps must be made correct. */ #include "opt_pmap.h" #include "opt_msgbuf.h" #include "opt_kstack_pages.h" #include #include #include #include #include #include #include #include #include #include #include #include #ifdef SMP #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(SMP) || defined(APIC_IO) #include #include #include #include #endif /* SMP || APIC_IO */ #define PMAP_KEEP_PDIRS #ifndef PMAP_SHPGPERPROC #define PMAP_SHPGPERPROC 200 #endif #if defined(DIAGNOSTIC) #define PMAP_DIAGNOSTIC #endif #define MINPV 2048 #if !defined(PMAP_DIAGNOSTIC) #define PMAP_INLINE __inline #else #define PMAP_INLINE #endif /* * Get PDEs and PTEs for user/kernel address space */ #define pmap_pde(m, v) (&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT])) #define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT]) #define pmap_pde_v(pte) ((*(int *)pte & PG_V) != 0) #define pmap_pte_w(pte) ((*(int *)pte & PG_W) != 0) #define pmap_pte_m(pte) ((*(int *)pte & PG_M) != 0) #define pmap_pte_u(pte) ((*(int *)pte & PG_A) != 0) #define pmap_pte_v(pte) ((*(int *)pte & PG_V) != 0) #define pmap_pte_set_w(pte, v) ((v)?(*(int *)pte |= PG_W):(*(int *)pte &= ~PG_W)) #define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v))) /* * Given a map and a machine independent protection code, * convert to a vax protection code. */ #define pte_prot(m, p) (protection_codes[p]) static int protection_codes[8]; struct pmap kernel_pmap_store; LIST_HEAD(pmaplist, pmap); struct pmaplist allpmaps; vm_offset_t avail_start; /* PA of first available physical page */ vm_offset_t avail_end; /* PA of last available physical page */ vm_offset_t virtual_avail; /* VA of first avail page (after kernel bss) */ vm_offset_t virtual_end; /* VA of last avail page (end of kernel AS) */ static boolean_t pmap_initialized = FALSE; /* Has pmap_init completed? */ static int pgeflag; /* PG_G or-in */ static int pseflag; /* PG_PS or-in */ static vm_object_t kptobj; static int nkpt; vm_offset_t kernel_vm_end; extern u_int32_t KERNend; /* * Data for the pv entry allocation mechanism */ static uma_zone_t pvzone; static struct vm_object pvzone_obj; static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0; static int pmap_pagedaemon_waken = 0; /* * All those kernel PT submaps that BSD is so fond of */ pt_entry_t *CMAP1 = 0; static pt_entry_t *CMAP2, *CMAP3, *ptmmap; caddr_t CADDR1 = 0, ptvmmap = 0; static caddr_t CADDR2, CADDR3; static pt_entry_t *msgbufmap; struct msgbuf *msgbufp = 0; /* * Crashdump maps. */ static pt_entry_t *pt_crashdumpmap; static caddr_t crashdumpmap; #ifdef SMP extern pt_entry_t *SMPpt; #endif static pt_entry_t *PMAP1 = 0; static pt_entry_t *PADDR1 = 0; static PMAP_INLINE void free_pv_entry(pv_entry_t pv); static pt_entry_t *get_ptbase(pmap_t pmap); static pv_entry_t get_pv_entry(void); static void i386_protection_init(void); static __inline void pmap_changebit(vm_page_t m, int bit, boolean_t setem); static void pmap_remove_all(vm_page_t m); static vm_page_t pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_page_t mpte); static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t sva); static void pmap_remove_page(struct pmap *pmap, vm_offset_t va); static int pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va); static boolean_t pmap_testbit(vm_page_t m, int bit); static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m); static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va); static int pmap_release_free_page(pmap_t pmap, vm_page_t p); static vm_page_t _pmap_allocpte(pmap_t pmap, unsigned ptepindex); static pt_entry_t *pmap_pte_quick(pmap_t pmap, vm_offset_t va); static vm_page_t pmap_page_lookup(vm_object_t object, vm_pindex_t pindex); static int pmap_unuse_pt(pmap_t, vm_offset_t, vm_page_t); static vm_offset_t pmap_kmem_choose(vm_offset_t addr); static void *pmap_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait); static pd_entry_t pdir4mb; /* * Routine: pmap_pte * Function: * Extract the page table entry associated * with the given map/virtual_address pair. */ PMAP_INLINE pt_entry_t * pmap_pte(pmap, va) register pmap_t pmap; vm_offset_t va; { pd_entry_t *pdeaddr; if (pmap) { pdeaddr = pmap_pde(pmap, va); if (*pdeaddr & PG_PS) return pdeaddr; if (*pdeaddr) { return get_ptbase(pmap) + i386_btop(va); } } return (0); } /* * Move the kernel virtual free pointer to the next * 4MB. This is used to help improve performance * by using a large (4MB) page for much of the kernel * (.text, .data, .bss) */ static vm_offset_t pmap_kmem_choose(vm_offset_t addr) { vm_offset_t newaddr = addr; #ifndef DISABLE_PSE if (cpu_feature & CPUID_PSE) newaddr = (addr + (NBPDR - 1)) & ~(NBPDR - 1); #endif return newaddr; } /* * Bootstrap the system enough to run with virtual memory. * * On the i386 this is called after mapping has already been enabled * and just syncs the pmap module with what has already been done. * [We can't call it easily with mapping off since the kernel is not * mapped with PA == VA, hence we would have to relocate every address * from the linked base (virtual) address "KERNBASE" to the actual * (physical) address starting relative to 0] */ void pmap_bootstrap(firstaddr, loadaddr) vm_offset_t firstaddr; vm_offset_t loadaddr; { vm_offset_t va; pt_entry_t *pte; int i; avail_start = firstaddr; /* * XXX The calculation of virtual_avail is wrong. It's NKPT*PAGE_SIZE too * large. It should instead be correctly calculated in locore.s and * not based on 'first' (which is a physical address, not a virtual * address, for the start of unused physical memory). The kernel * page tables are NOT double mapped and thus should not be included * in this calculation. */ virtual_avail = (vm_offset_t) KERNBASE + firstaddr; virtual_avail = pmap_kmem_choose(virtual_avail); virtual_end = VM_MAX_KERNEL_ADDRESS; /* * Initialize protection array. */ i386_protection_init(); /* * Initialize the kernel pmap (which is statically allocated). */ kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + (u_int)IdlePTD); kernel_pmap->pm_active = -1; /* don't allow deactivation */ TAILQ_INIT(&kernel_pmap->pm_pvlist); LIST_INIT(&allpmaps); LIST_INSERT_HEAD(&allpmaps, kernel_pmap, pm_list); nkpt = NKPT; /* * Reserve some special page table entries/VA space for temporary * mapping of pages. */ #define SYSMAP(c, p, v, n) \ v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n); va = virtual_avail; pte = (pt_entry_t *) pmap_pte(kernel_pmap, va); /* * CMAP1/CMAP2 are used for zeroing and copying pages. * CMAP3 is used for the idle process page zeroing. */ SYSMAP(caddr_t, CMAP1, CADDR1, 1) SYSMAP(caddr_t, CMAP2, CADDR2, 1) SYSMAP(caddr_t, CMAP3, CADDR3, 1) /* * Crashdump maps. */ SYSMAP(caddr_t, pt_crashdumpmap, crashdumpmap, MAXDUMPPGS); /* * ptvmmap is used for reading arbitrary physical pages via /dev/mem. * XXX ptmmap is not used. */ SYSMAP(caddr_t, ptmmap, ptvmmap, 1) /* * msgbufp is used to map the system message buffer. * XXX msgbufmap is not used. */ SYSMAP(struct msgbuf *, msgbufmap, msgbufp, atop(round_page(MSGBUF_SIZE))) /* * ptemap is used for pmap_pte_quick */ SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1); virtual_avail = va; *CMAP1 = *CMAP2 = 0; for (i = 0; i < NKPT; i++) PTD[i] = 0; pgeflag = 0; #ifndef DISABLE_PG_G if (cpu_feature & CPUID_PGE) pgeflag = PG_G; #endif /* * Initialize the 4MB page size flag */ pseflag = 0; /* * The 4MB page version of the initial * kernel page mapping. */ pdir4mb = 0; #ifndef DISABLE_PSE if (cpu_feature & CPUID_PSE) { pd_entry_t ptditmp; /* * Note that we have enabled PSE mode */ pseflag = PG_PS; ptditmp = *(PTmap + i386_btop(KERNBASE)); ptditmp &= ~(NBPDR - 1); ptditmp |= PG_V | PG_RW | PG_PS | PG_U | pgeflag; pdir4mb = ptditmp; } #endif #ifndef SMP /* * Turn on PGE/PSE. SMP does this later on since the * 4K page tables are required for AP boot (for now). * XXX fixme. */ pmap_set_opt(); #endif #ifdef SMP if (cpu_apic_address == 0) panic("pmap_bootstrap: no local apic! (non-SMP hardware?)"); /* local apic is mapped on last page */ SMPpt[NPTEPG - 1] = (pt_entry_t)(PG_V | PG_RW | PG_N | pgeflag | (cpu_apic_address & PG_FRAME)); #endif invltlb(); } /* * Enable 4MB page mode for MP startup. Turn on PG_G support. * BSP will run this after all the AP's have started up. */ void pmap_set_opt(void) { pt_entry_t *pte; vm_offset_t va, endva; if (pgeflag && (cpu_feature & CPUID_PGE)) { load_cr4(rcr4() | CR4_PGE); invltlb(); /* Insurance */ } #ifndef DISABLE_PSE if (pseflag && (cpu_feature & CPUID_PSE)) { load_cr4(rcr4() | CR4_PSE); invltlb(); /* Insurance */ } #endif if (PCPU_GET(cpuid) == 0) { #ifndef DISABLE_PSE if (pdir4mb) { kernel_pmap->pm_pdir[KPTDI] = PTD[KPTDI] = pdir4mb; invltlb(); /* Insurance */ } #endif if (pgeflag) { /* Turn on PG_G for text, data, bss pages. */ va = (vm_offset_t)btext; #ifndef DISABLE_PSE if (pseflag && (cpu_feature & CPUID_PSE)) { if (va < KERNBASE + (1 << PDRSHIFT)) va = KERNBASE + (1 << PDRSHIFT); } #endif endva = KERNBASE + KERNend; while (va < endva) { pte = vtopte(va); if (*pte) *pte |= pgeflag; va += PAGE_SIZE; } invltlb(); /* Insurance */ } /* * We do not need to broadcast the invltlb here, because * each AP does it the moment it is released from the boot * lock. See ap_init(). */ } } void * pmap_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait) { *flags = UMA_SLAB_PRIV; return (void *)kmem_alloc(kernel_map, bytes); } /* * Initialize the pmap module. * Called by vm_init, to initialize any structures that the pmap * system needs to map virtual memory. * pmap_init has been enhanced to support in a fairly consistant * way, discontiguous physical memory. */ void pmap_init(phys_start, phys_end) vm_offset_t phys_start, phys_end; { int i; int initial_pvs; /* * object for kernel page table pages */ kptobj = vm_object_allocate(OBJT_DEFAULT, NKPDE); /* * Allocate memory for random pmap data structures. Includes the * pv_head_table. */ for(i = 0; i < vm_page_array_size; i++) { vm_page_t m; m = &vm_page_array[i]; TAILQ_INIT(&m->md.pv_list); m->md.pv_list_count = 0; } /* * init the pv free list */ initial_pvs = vm_page_array_size; if (initial_pvs < MINPV) initial_pvs = MINPV; pvzone = uma_zcreate("PV ENTRY", sizeof (struct pv_entry), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM); uma_zone_set_allocf(pvzone, pmap_allocf); uma_prealloc(pvzone, initial_pvs); /* * Now it is safe to enable pv_table recording. */ pmap_initialized = TRUE; } /* * Initialize the address space (zone) for the pv_entries. Set a * high water mark so that the system can recover from excessive * numbers of pv entries. */ void pmap_init2() { int shpgperproc = PMAP_SHPGPERPROC; TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc); pv_entry_max = shpgperproc * maxproc + vm_page_array_size; TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max); pv_entry_high_water = 9 * (pv_entry_max / 10); uma_zone_set_obj(pvzone, &pvzone_obj, pv_entry_max); } /*************************************************** * Low level helper routines..... ***************************************************/ #if defined(PMAP_DIAGNOSTIC) /* * This code checks for non-writeable/modified pages. * This should be an invalid condition. */ static int pmap_nw_modified(pt_entry_t ptea) { int pte; pte = (int) ptea; if ((pte & (PG_M|PG_RW)) == PG_M) return 1; else return 0; } #endif /* * this routine defines the region(s) of memory that should * not be tested for the modified bit. */ static PMAP_INLINE int pmap_track_modified(vm_offset_t va) { if ((va < kmi.clean_sva) || (va >= kmi.clean_eva)) return 1; else return 0; } #ifdef I386_CPU /* * i386 only has "invalidate everything" and no SMP to worry about. */ PMAP_INLINE void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } PMAP_INLINE void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } PMAP_INLINE void pmap_invalidate_all(pmap_t pmap) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } #else /* !I386_CPU */ #ifdef SMP /* * For SMP, these functions have to use the IPI mechanism for coherence. */ void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { u_int cpumask; u_int other_cpus; critical_enter(); /* * We need to disable interrupt preemption but MUST NOT have * interrupts disabled here. * XXX we may need to hold schedlock to get a coherent pm_active */ if (pmap->pm_active == -1 || pmap->pm_active == all_cpus) { invlpg(va); smp_invlpg(va); } else { cpumask = PCPU_GET(cpumask); other_cpus = PCPU_GET(other_cpus); if (pmap->pm_active & cpumask) invlpg(va); if (pmap->pm_active & other_cpus) smp_masked_invlpg(pmap->pm_active & other_cpus, va); } critical_exit(); } void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { u_int cpumask; u_int other_cpus; vm_offset_t addr; critical_enter(); /* * We need to disable interrupt preemption but MUST NOT have * interrupts disabled here. * XXX we may need to hold schedlock to get a coherent pm_active */ if (pmap->pm_active == -1 || pmap->pm_active == all_cpus) { for (addr = sva; addr < eva; addr += PAGE_SIZE) invlpg(addr); smp_invlpg_range(sva, eva); } else { cpumask = PCPU_GET(cpumask); other_cpus = PCPU_GET(other_cpus); if (pmap->pm_active & cpumask) for (addr = sva; addr < eva; addr += PAGE_SIZE) invlpg(addr); if (pmap->pm_active & other_cpus) smp_masked_invlpg_range(pmap->pm_active & other_cpus, sva, eva); } critical_exit(); } void pmap_invalidate_all(pmap_t pmap) { u_int cpumask; u_int other_cpus; critical_enter(); /* * We need to disable interrupt preemption but MUST NOT have * interrupts disabled here. * XXX we may need to hold schedlock to get a coherent pm_active */ if (pmap->pm_active == -1 || pmap->pm_active == all_cpus) { invltlb(); smp_invltlb(); } else { cpumask = PCPU_GET(cpumask); other_cpus = PCPU_GET(other_cpus); if (pmap->pm_active & cpumask) invltlb(); if (pmap->pm_active & other_cpus) smp_masked_invltlb(pmap->pm_active & other_cpus); } critical_exit(); } #else /* !SMP */ /* * Normal, non-SMP, 486+ invalidation functions. * We inline these within pmap.c for speed. */ PMAP_INLINE void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { if (pmap == kernel_pmap || pmap->pm_active) invlpg(va); } PMAP_INLINE void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { vm_offset_t addr; if (pmap == kernel_pmap || pmap->pm_active) for (addr = sva; addr < eva; addr += PAGE_SIZE) invlpg(addr); } PMAP_INLINE void pmap_invalidate_all(pmap_t pmap) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } #endif /* !SMP */ #endif /* !I386_CPU */ /* * Return an address which is the base of the Virtual mapping of * all the PTEs for the given pmap. Note this doesn't say that * all the PTEs will be present or that the pages there are valid. * The PTEs are made available by the recursive mapping trick. * It will map in the alternate PTE space if needed. */ static pt_entry_t * get_ptbase(pmap) pmap_t pmap; { pd_entry_t frame; /* are we current address space or kernel? */ if (pmap == kernel_pmap) return PTmap; frame = pmap->pm_pdir[PTDPTDI] & PG_FRAME; if (frame == (PTDpde & PG_FRAME)) return PTmap; /* otherwise, we are alternate address space */ if (frame != (APTDpde & PG_FRAME)) { APTDpde = (pd_entry_t) (frame | PG_RW | PG_V); pmap_invalidate_all(kernel_pmap); /* XXX Bandaid */ } return APTmap; } /* * Super fast pmap_pte routine best used when scanning * the pv lists. This eliminates many coarse-grained * invltlb calls. Note that many of the pv list * scans are across different pmaps. It is very wasteful * to do an entire invltlb for checking a single mapping. */ static pt_entry_t * pmap_pte_quick(pmap, va) register pmap_t pmap; vm_offset_t va; { pd_entry_t pde, newpf; pde = pmap->pm_pdir[va >> PDRSHIFT]; if (pde != 0) { pd_entry_t frame = pmap->pm_pdir[PTDPTDI] & PG_FRAME; unsigned index = i386_btop(va); /* are we current address space or kernel? */ if (pmap == kernel_pmap || frame == (PTDpde & PG_FRAME)) return PTmap + index; newpf = pde & PG_FRAME; if (((*PMAP1) & PG_FRAME) != newpf) { *PMAP1 = newpf | PG_RW | PG_V; pmap_invalidate_page(kernel_pmap, (vm_offset_t)PADDR1); } return PADDR1 + (index & (NPTEPG - 1)); } return (0); } /* * Routine: pmap_extract * Function: * Extract the physical page address associated * with the given map/virtual_address pair. */ vm_offset_t pmap_extract(pmap, va) register pmap_t pmap; vm_offset_t va; { vm_offset_t rtval; /* XXX FIXME */ vm_offset_t pdirindex; if (pmap == 0) return 0; pdirindex = va >> PDRSHIFT; rtval = pmap->pm_pdir[pdirindex]; if (rtval != 0) { pt_entry_t *pte; if ((rtval & PG_PS) != 0) { rtval &= ~(NBPDR - 1); rtval |= va & (NBPDR - 1); return rtval; } pte = get_ptbase(pmap) + i386_btop(va); rtval = ((*pte & PG_FRAME) | (va & PAGE_MASK)); return rtval; } return 0; } /*************************************************** * Low level mapping routines..... ***************************************************/ /* * Add a wired page to the kva. * Note: not SMP coherent. */ PMAP_INLINE void pmap_kenter(vm_offset_t va, vm_offset_t pa) { pt_entry_t *pte; pte = vtopte(va); *pte = pa | PG_RW | PG_V | pgeflag; } /* * Remove a page from the kernel pagetables. * Note: not SMP coherent. */ PMAP_INLINE void pmap_kremove(vm_offset_t va) { pt_entry_t *pte; pte = vtopte(va); *pte = 0; } /* * Used to map a range of physical addresses into kernel * virtual address space. * * The value passed in '*virt' is a suggested virtual address for * the mapping. Architectures which can support a direct-mapped * physical to virtual region can return the appropriate address * within that region, leaving '*virt' unchanged. Other * architectures should map the pages starting at '*virt' and * update '*virt' with the first usable address after the mapped * region. */ vm_offset_t pmap_map(vm_offset_t *virt, vm_offset_t start, vm_offset_t end, int prot) { vm_offset_t va, sva; va = sva = *virt; while (start < end) { pmap_kenter(va, start); va += PAGE_SIZE; start += PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); *virt = va; return (sva); } /* * Add a list of wired pages to the kva * this routine is only used for temporary * kernel mappings that do not need to have * page modification or references recorded. * Note that old mappings are simply written * over. The page *must* be wired. * Note: SMP coherent. Uses a ranged shootdown IPI. */ void pmap_qenter(vm_offset_t sva, vm_page_t *m, int count) { vm_offset_t va; va = sva; while (count-- > 0) { pmap_kenter(va, VM_PAGE_TO_PHYS(*m)); va += PAGE_SIZE; m++; } pmap_invalidate_range(kernel_pmap, sva, va); } /* * This routine tears out page mappings from the * kernel -- it is meant only for temporary mappings. * Note: SMP coherent. Uses a ranged shootdown IPI. */ void pmap_qremove(vm_offset_t sva, int count) { vm_offset_t va; va = sva; while (count-- > 0) { pmap_kremove(va); va += PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); } static vm_page_t pmap_page_lookup(vm_object_t object, vm_pindex_t pindex) { vm_page_t m; retry: m = vm_page_lookup(object, pindex); if (m && vm_page_sleep_busy(m, FALSE, "pplookp")) goto retry; return m; } /* * Create the kernel stack (including pcb for i386) for a new thread. * This routine directly affects the fork perf for a process and * create performance for a thread. */ void pmap_new_thread(struct thread *td) { int i; vm_page_t ma[KSTACK_PAGES]; vm_object_t ksobj; vm_page_t m; vm_offset_t ks; /* * allocate object for the kstack */ ksobj = vm_object_allocate(OBJT_DEFAULT, KSTACK_PAGES); td->td_kstack_obj = ksobj; /* get a kernel virtual address for the kstack for this thread */ #ifdef KSTACK_GUARD ks = kmem_alloc_nofault(kernel_map, (KSTACK_PAGES + 1) * PAGE_SIZE); if (ks == 0) panic("pmap_new_thread: kstack allocation failed"); if (*vtopte(ks) != 0) pmap_qremove(ks, 1); ks += PAGE_SIZE; td->td_kstack = ks; #else /* get a kernel virtual address for the kstack for this thread */ ks = kmem_alloc_nofault(kernel_map, KSTACK_PAGES * PAGE_SIZE); if (ks == 0) panic("pmap_new_thread: kstack allocation failed"); td->td_kstack = ks; #endif /* * For the length of the stack, link in a real page of ram for each * page of stack. */ for (i = 0; i < KSTACK_PAGES; i++) { /* * Get a kernel stack page */ m = vm_page_grab(ksobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); ma[i] = m; /* * Wire the page */ m->wire_count++; cnt.v_wire_count++; vm_page_wakeup(m); vm_page_flag_clear(m, PG_ZERO); vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE); m->valid = VM_PAGE_BITS_ALL; } pmap_qenter(ks, ma, KSTACK_PAGES); } /* * Dispose the kernel stack for a thread that has exited. * This routine directly impacts the exit perf of a process and thread. */ void pmap_dispose_thread(td) struct thread *td; { int i; vm_object_t ksobj; vm_offset_t ks; vm_page_t m; ksobj = td->td_kstack_obj; ks = td->td_kstack; pmap_qremove(ks, KSTACK_PAGES); for (i = 0; i < KSTACK_PAGES; i++) { m = vm_page_lookup(ksobj, i); if (m == NULL) panic("pmap_dispose_thread: kstack already missing?"); vm_page_lock_queues(); vm_page_busy(m); vm_page_unwire(m, 0); vm_page_free(m); vm_page_unlock_queues(); } /* * Free the space that this stack was mapped to in the kernel * address map. */ #ifdef KSTACK_GUARD kmem_free(kernel_map, ks - PAGE_SIZE, (KSTACK_PAGES + 1) * PAGE_SIZE); #else kmem_free(kernel_map, ks, KSTACK_PAGES * PAGE_SIZE); #endif vm_object_deallocate(ksobj); } /* * Allow the Kernel stack for a thread to be prejudicially paged out. */ void pmap_swapout_thread(td) struct thread *td; { int i; vm_object_t ksobj; vm_offset_t ks; vm_page_t m; ksobj = td->td_kstack_obj; ks = td->td_kstack; pmap_qremove(ks, KSTACK_PAGES); for (i = 0; i < KSTACK_PAGES; i++) { m = vm_page_lookup(ksobj, i); if (m == NULL) panic("pmap_swapout_thread: kstack already missing?"); vm_page_lock_queues(); vm_page_dirty(m); vm_page_unwire(m, 0); vm_page_unlock_queues(); } } /* * Bring the kernel stack for a specified thread back in. */ void pmap_swapin_thread(td) struct thread *td; { int i, rv; vm_page_t ma[KSTACK_PAGES]; vm_object_t ksobj; vm_offset_t ks; vm_page_t m; ksobj = td->td_kstack_obj; ks = td->td_kstack; for (i = 0; i < KSTACK_PAGES; i++) { m = vm_page_grab(ksobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); if (m->valid != VM_PAGE_BITS_ALL) { rv = vm_pager_get_pages(ksobj, &m, 1, 0); if (rv != VM_PAGER_OK) panic("pmap_swapin_thread: cannot get kstack for proc: %d\n", td->td_proc->p_pid); m = vm_page_lookup(ksobj, i); m->valid = VM_PAGE_BITS_ALL; } ma[i] = m; vm_page_lock_queues(); vm_page_wire(m); vm_page_wakeup(m); vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE); vm_page_unlock_queues(); } pmap_qenter(ks, ma, KSTACK_PAGES); } /*************************************************** * Page table page management routines..... ***************************************************/ /* * This routine unholds page table pages, and if the hold count * drops to zero, then it decrements the wire count. */ static int _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m) { while (vm_page_sleep_busy(m, FALSE, "pmuwpt")) ; if (m->hold_count == 0) { vm_offset_t pteva; /* * unmap the page table page */ pmap->pm_pdir[m->pindex] = 0; --pmap->pm_stats.resident_count; if ((pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde & PG_FRAME)) { /* * Do a invltlb to make the invalidated mapping * take effect immediately. */ pteva = VM_MAXUSER_ADDRESS + i386_ptob(m->pindex); pmap_invalidate_page(pmap, pteva); } if (pmap->pm_ptphint == m) pmap->pm_ptphint = NULL; /* * If the page is finally unwired, simply free it. */ --m->wire_count; if (m->wire_count == 0) { vm_page_flash(m); vm_page_busy(m); vm_page_free_zero(m); --cnt.v_wire_count; } return 1; } return 0; } static PMAP_INLINE int pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m) { vm_page_unhold(m); if (m->hold_count == 0) return _pmap_unwire_pte_hold(pmap, m); else return 0; } /* * After removing a page table entry, this routine is used to * conditionally free the page, and manage the hold/wire counts. */ static int pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t mpte) { unsigned ptepindex; if (va >= VM_MAXUSER_ADDRESS) return 0; if (mpte == NULL) { ptepindex = (va >> PDRSHIFT); if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == ptepindex)) { mpte = pmap->pm_ptphint; } else { mpte = pmap_page_lookup(pmap->pm_pteobj, ptepindex); pmap->pm_ptphint = mpte; } } return pmap_unwire_pte_hold(pmap, mpte); } void pmap_pinit0(pmap) struct pmap *pmap; { pmap->pm_pdir = (pd_entry_t *)kmem_alloc_pageable(kernel_map, PAGE_SIZE); pmap_kenter((vm_offset_t)pmap->pm_pdir, (vm_offset_t)IdlePTD); #ifndef I386_CPU invlpg((vm_offset_t)pmap->pm_pdir); #else invltlb(); #endif pmap->pm_ptphint = NULL; pmap->pm_active = 0; TAILQ_INIT(&pmap->pm_pvlist); bzero(&pmap->pm_stats, sizeof pmap->pm_stats); LIST_INSERT_HEAD(&allpmaps, pmap, pm_list); } /* * Initialize a preallocated and zeroed pmap structure, * such as one in a vmspace structure. */ void pmap_pinit(pmap) register struct pmap *pmap; { vm_page_t ptdpg; /* * No need to allocate page table space yet but we do need a valid * page directory table. */ if (pmap->pm_pdir == NULL) pmap->pm_pdir = (pd_entry_t *)kmem_alloc_pageable(kernel_map, PAGE_SIZE); /* * allocate object for the ptes */ if (pmap->pm_pteobj == NULL) pmap->pm_pteobj = vm_object_allocate(OBJT_DEFAULT, PTDPTDI + 1); /* * allocate the page directory page */ ptdpg = vm_page_grab(pmap->pm_pteobj, PTDPTDI, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); ptdpg->wire_count = 1; ++cnt.v_wire_count; vm_page_flag_clear(ptdpg, PG_MAPPED | PG_BUSY); /* not usually mapped*/ ptdpg->valid = VM_PAGE_BITS_ALL; pmap_qenter((vm_offset_t) pmap->pm_pdir, &ptdpg, 1); if ((ptdpg->flags & PG_ZERO) == 0) bzero(pmap->pm_pdir, PAGE_SIZE); LIST_INSERT_HEAD(&allpmaps, pmap, pm_list); /* Wire in kernel global address entries. */ /* XXX copies current process, does not fill in MPPTDI */ bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * PTESIZE); #ifdef SMP pmap->pm_pdir[MPPTDI] = PTD[MPPTDI]; #endif /* install self-referential address mapping entry */ pmap->pm_pdir[PTDPTDI] = VM_PAGE_TO_PHYS(ptdpg) | PG_V | PG_RW | PG_A | PG_M; pmap->pm_active = 0; pmap->pm_ptphint = NULL; TAILQ_INIT(&pmap->pm_pvlist); bzero(&pmap->pm_stats, sizeof pmap->pm_stats); } /* * Wire in kernel global address entries. To avoid a race condition * between pmap initialization and pmap_growkernel, this procedure * should be called after the vmspace is attached to the process * but before this pmap is activated. */ void pmap_pinit2(pmap) struct pmap *pmap; { /* XXX: Remove this stub when no longer called */ } static int pmap_release_free_page(pmap_t pmap, vm_page_t p) { pd_entry_t *pde = pmap->pm_pdir; /* * This code optimizes the case of freeing non-busy * page-table pages. Those pages are zero now, and * might as well be placed directly into the zero queue. */ if (vm_page_sleep_busy(p, FALSE, "pmaprl")) return 0; vm_page_busy(p); /* * Remove the page table page from the processes address space. */ pde[p->pindex] = 0; pmap->pm_stats.resident_count--; if (p->hold_count) { panic("pmap_release: freeing held page table page"); } /* * Page directory pages need to have the kernel * stuff cleared, so they can go into the zero queue also. */ if (p->pindex == PTDPTDI) { bzero(pde + KPTDI, nkpt * PTESIZE); #ifdef SMP pde[MPPTDI] = 0; #endif pde[APTDPTDI] = 0; pmap_kremove((vm_offset_t) pmap->pm_pdir); } if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == p->pindex)) pmap->pm_ptphint = NULL; p->wire_count--; cnt.v_wire_count--; vm_page_free_zero(p); return 1; } /* * this routine is called if the page table page is not * mapped correctly. */ static vm_page_t _pmap_allocpte(pmap, ptepindex) pmap_t pmap; unsigned ptepindex; { vm_offset_t pteva, ptepa; /* XXXPA */ vm_page_t m; /* * Find or fabricate a new pagetable page */ m = vm_page_grab(pmap->pm_pteobj, ptepindex, VM_ALLOC_ZERO | VM_ALLOC_RETRY); KASSERT(m->queue == PQ_NONE, ("_pmap_allocpte: %p->queue != PQ_NONE", m)); if (m->wire_count == 0) cnt.v_wire_count++; m->wire_count++; /* * Increment the hold count for the page table page * (denoting a new mapping.) */ m->hold_count++; /* * Map the pagetable page into the process address space, if * it isn't already there. */ pmap->pm_stats.resident_count++; ptepa = VM_PAGE_TO_PHYS(m); pmap->pm_pdir[ptepindex] = (pd_entry_t) (ptepa | PG_U | PG_RW | PG_V | PG_A | PG_M); /* * Set the page table hint */ pmap->pm_ptphint = m; /* * Try to use the new mapping, but if we cannot, then * do it with the routine that maps the page explicitly. */ if ((m->flags & PG_ZERO) == 0) { if ((pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde & PG_FRAME)) { pteva = VM_MAXUSER_ADDRESS + i386_ptob(ptepindex); bzero((caddr_t) pteva, PAGE_SIZE); } else { pmap_zero_page(m); } } m->valid = VM_PAGE_BITS_ALL; vm_page_flag_clear(m, PG_ZERO); vm_page_flag_set(m, PG_MAPPED); vm_page_wakeup(m); return m; } static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va) { unsigned ptepindex; pd_entry_t ptepa; vm_page_t m; /* * Calculate pagetable page index */ ptepindex = va >> PDRSHIFT; /* * Get the page directory entry */ ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex]; /* * This supports switching from a 4MB page to a * normal 4K page. */ if (ptepa & PG_PS) { pmap->pm_pdir[ptepindex] = 0; ptepa = 0; pmap_invalidate_all(kernel_pmap); } /* * If the page table page is mapped, we just increment the * hold count, and activate it. */ if (ptepa) { /* * In order to get the page table page, try the * hint first. */ if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == ptepindex)) { m = pmap->pm_ptphint; } else { m = pmap_page_lookup(pmap->pm_pteobj, ptepindex); pmap->pm_ptphint = m; } m->hold_count++; return m; } /* * Here if the pte page isn't mapped, or if it has been deallocated. */ return _pmap_allocpte(pmap, ptepindex); } /*************************************************** * Pmap allocation/deallocation routines. ***************************************************/ /* * Release any resources held by the given physical map. * Called when a pmap initialized by pmap_pinit is being released. * Should only be called if the map contains no valid mappings. */ void pmap_release(pmap_t pmap) { vm_page_t p,n,ptdpg; vm_object_t object = pmap->pm_pteobj; int curgeneration; #if defined(DIAGNOSTIC) if (object->ref_count != 1) panic("pmap_release: pteobj reference count != 1"); #endif ptdpg = NULL; LIST_REMOVE(pmap, pm_list); retry: curgeneration = object->generation; for (p = TAILQ_FIRST(&object->memq); p != NULL; p = n) { n = TAILQ_NEXT(p, listq); if (p->pindex == PTDPTDI) { ptdpg = p; continue; } while (1) { if (!pmap_release_free_page(pmap, p) && (object->generation != curgeneration)) goto retry; } } if (ptdpg && !pmap_release_free_page(pmap, ptdpg)) goto retry; } static int kvm_size(SYSCTL_HANDLER_ARGS) { unsigned long ksize = VM_MAX_KERNEL_ADDRESS - KERNBASE; return sysctl_handle_long(oidp, &ksize, 0, req); } SYSCTL_PROC(_vm, OID_AUTO, kvm_size, CTLTYPE_LONG|CTLFLAG_RD, 0, 0, kvm_size, "IU", "Size of KVM"); static int kvm_free(SYSCTL_HANDLER_ARGS) { unsigned long kfree = VM_MAX_KERNEL_ADDRESS - kernel_vm_end; return sysctl_handle_long(oidp, &kfree, 0, req); } SYSCTL_PROC(_vm, OID_AUTO, kvm_free, CTLTYPE_LONG|CTLFLAG_RD, 0, 0, kvm_free, "IU", "Amount of KVM free"); /* * grow the number of kernel page table entries, if needed */ void pmap_growkernel(vm_offset_t addr) { struct pmap *pmap; int s; vm_offset_t ptppaddr; vm_page_t nkpg; pd_entry_t newpdir; s = splhigh(); if (kernel_vm_end == 0) { kernel_vm_end = KERNBASE; nkpt = 0; while (pdir_pde(PTD, kernel_vm_end)) { kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); nkpt++; } } addr = (addr + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); while (kernel_vm_end < addr) { if (pdir_pde(PTD, kernel_vm_end)) { kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); continue; } /* * This index is bogus, but out of the way */ - nkpg = vm_page_alloc(kptobj, nkpt, VM_ALLOC_SYSTEM); + nkpg = vm_page_alloc(kptobj, nkpt, + VM_ALLOC_SYSTEM | VM_ALLOC_WIRED); if (!nkpg) panic("pmap_growkernel: no memory to grow kernel"); nkpt++; - vm_page_lock_queues(); - vm_page_wire(nkpg); - vm_page_unlock_queues(); pmap_zero_page(nkpg); ptppaddr = VM_PAGE_TO_PHYS(nkpg); newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M); pdir_pde(PTD, kernel_vm_end) = newpdir; LIST_FOREACH(pmap, &allpmaps, pm_list) { *pmap_pde(pmap, kernel_vm_end) = newpdir; } kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); } splx(s); } /*************************************************** * page management routines. ***************************************************/ /* * free the pv_entry back to the free list */ static PMAP_INLINE void free_pv_entry(pv_entry_t pv) { pv_entry_count--; uma_zfree(pvzone, pv); } /* * get a new pv_entry, allocating a block from the system * when needed. * the memory allocation is performed bypassing the malloc code * because of the possibility of allocations at interrupt time. */ static pv_entry_t get_pv_entry(void) { pv_entry_count++; if (pv_entry_high_water && (pv_entry_count > pv_entry_high_water) && (pmap_pagedaemon_waken == 0)) { pmap_pagedaemon_waken = 1; wakeup (&vm_pages_needed); } return uma_zalloc(pvzone, M_NOWAIT); } /* * This routine is very drastic, but can save the system * in a pinch. */ void pmap_collect() { int i; vm_page_t m; static int warningdone = 0; if (pmap_pagedaemon_waken == 0) return; if (warningdone < 5) { printf("pmap_collect: collecting pv entries -- suggest increasing PMAP_SHPGPERPROC\n"); warningdone++; } for(i = 0; i < vm_page_array_size; i++) { m = &vm_page_array[i]; if (m->wire_count || m->hold_count || m->busy || (m->flags & (PG_BUSY | PG_UNMANAGED))) continue; pmap_remove_all(m); } pmap_pagedaemon_waken = 0; } /* * If it is the first entry on the list, it is actually * in the header and we must copy the following entry up * to the header. Otherwise we must search the list for * the entry. In either case we free the now unused entry. */ static int pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va) { pv_entry_t pv; int rtval; int s; s = splvm(); if (m->md.pv_list_count < pmap->pm_stats.resident_count) { TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { if (pmap == pv->pv_pmap && va == pv->pv_va) break; } } else { TAILQ_FOREACH(pv, &pmap->pm_pvlist, pv_plist) { if (va == pv->pv_va) break; } } rtval = 0; if (pv) { rtval = pmap_unuse_pt(pmap, va, pv->pv_ptem); TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); m->md.pv_list_count--; if (TAILQ_FIRST(&m->md.pv_list) == NULL) vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist); free_pv_entry(pv); } splx(s); return rtval; } /* * Create a pv entry for page at pa for * (pmap, va). */ static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m) { int s; pv_entry_t pv; s = splvm(); pv = get_pv_entry(); pv->pv_va = va; pv->pv_pmap = pmap; pv->pv_ptem = mpte; TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list); m->md.pv_list_count++; splx(s); } /* * pmap_remove_pte: do the things to unmap a page in a process */ static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va) { pt_entry_t oldpte; vm_page_t m; oldpte = atomic_readandclear_int(ptq); if (oldpte & PG_W) pmap->pm_stats.wired_count -= 1; /* * Machines that don't support invlpg, also don't support * PG_G. */ if (oldpte & PG_G) pmap_invalidate_page(kernel_pmap, va); pmap->pm_stats.resident_count -= 1; if (oldpte & PG_MANAGED) { m = PHYS_TO_VM_PAGE(oldpte); if (oldpte & PG_M) { #if defined(PMAP_DIAGNOSTIC) if (pmap_nw_modified((pt_entry_t) oldpte)) { printf( "pmap_remove: modified page not writable: va: 0x%x, pte: 0x%x\n", va, oldpte); } #endif if (pmap_track_modified(va)) vm_page_dirty(m); } if (oldpte & PG_A) vm_page_flag_set(m, PG_REFERENCED); return pmap_remove_entry(pmap, m, va); } else { return pmap_unuse_pt(pmap, va, NULL); } return 0; } /* * Remove a single page from a process address space */ static void pmap_remove_page(pmap_t pmap, vm_offset_t va) { register pt_entry_t *ptq; /* * if there is no pte for this address, just skip it!!! */ if (*pmap_pde(pmap, va) == 0) { return; } /* * get a local va for mappings for this pmap. */ ptq = get_ptbase(pmap) + i386_btop(va); if (*ptq) { (void) pmap_remove_pte(pmap, ptq, va); pmap_invalidate_page(pmap, va); } return; } /* * Remove the given range of addresses from the specified map. * * It is assumed that the start and end are properly * rounded to the page size. */ void pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { register pt_entry_t *ptbase; vm_offset_t pdnxt; pd_entry_t ptpaddr; vm_offset_t sindex, eindex; int anyvalid; if (pmap == NULL) return; if (pmap->pm_stats.resident_count == 0) return; /* * special handling of removing one page. a very * common operation and easy to short circuit some * code. */ if ((sva + PAGE_SIZE == eva) && ((pmap->pm_pdir[(sva >> PDRSHIFT)] & PG_PS) == 0)) { pmap_remove_page(pmap, sva); return; } anyvalid = 0; /* * Get a local virtual address for the mappings that are being * worked with. */ ptbase = get_ptbase(pmap); sindex = i386_btop(sva); eindex = i386_btop(eva); for (; sindex < eindex; sindex = pdnxt) { unsigned pdirindex; /* * Calculate index for next page table. */ pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1)); if (pmap->pm_stats.resident_count == 0) break; pdirindex = sindex / NPDEPG; ptpaddr = pmap->pm_pdir[pdirindex]; if ((ptpaddr & PG_PS) != 0) { pmap->pm_pdir[pdirindex] = 0; pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE; anyvalid++; continue; } /* * Weed out invalid mappings. Note: we assume that the page * directory table is always allocated, and in kernel virtual. */ if (ptpaddr == 0) continue; /* * Limit our scan to either the end of the va represented * by the current page table page, or to the end of the * range being removed. */ if (pdnxt > eindex) { pdnxt = eindex; } for (; sindex != pdnxt; sindex++) { vm_offset_t va; if (ptbase[sindex] == 0) { continue; } va = i386_ptob(sindex); anyvalid++; if (pmap_remove_pte(pmap, ptbase + sindex, va)) break; } } if (anyvalid) pmap_invalidate_all(pmap); } /* * Routine: pmap_remove_all * Function: * Removes this physical page from * all physical maps in which it resides. * Reflects back modify bits to the pager. * * Notes: * Original versions of this routine were very * inefficient because they iteratively called * pmap_remove (slow...) */ static void pmap_remove_all(vm_page_t m) { register pv_entry_t pv; pt_entry_t *pte, tpte; int s; #if defined(PMAP_DIAGNOSTIC) /* * XXX this makes pmap_page_protect(NONE) illegal for non-managed * pages! */ if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) { panic("pmap_page_protect: illegal for unmanaged page, va: 0x%x", VM_PAGE_TO_PHYS(m)); } #endif s = splvm(); while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) { pv->pv_pmap->pm_stats.resident_count--; pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); tpte = atomic_readandclear_int(pte); if (tpte & PG_W) pv->pv_pmap->pm_stats.wired_count--; if (tpte & PG_A) vm_page_flag_set(m, PG_REFERENCED); /* * Update the vm_page_t clean and reference bits. */ if (tpte & PG_M) { #if defined(PMAP_DIAGNOSTIC) if (pmap_nw_modified((pt_entry_t) tpte)) { printf( "pmap_remove_all: modified page not writable: va: 0x%x, pte: 0x%x\n", pv->pv_va, tpte); } #endif if (pmap_track_modified(pv->pv_va)) vm_page_dirty(m); } pmap_invalidate_page(pv->pv_pmap, pv->pv_va); TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist); TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); m->md.pv_list_count--; pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem); free_pv_entry(pv); } vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); splx(s); } /* * Set the physical protection on the * specified range of this map as requested. */ void pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot) { register pt_entry_t *ptbase; vm_offset_t pdnxt; pd_entry_t ptpaddr; vm_offset_t sindex, eindex; int anychanged; if (pmap == NULL) return; if ((prot & VM_PROT_READ) == VM_PROT_NONE) { pmap_remove(pmap, sva, eva); return; } if (prot & VM_PROT_WRITE) return; anychanged = 0; ptbase = get_ptbase(pmap); sindex = i386_btop(sva); eindex = i386_btop(eva); for (; sindex < eindex; sindex = pdnxt) { unsigned pdirindex; pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1)); pdirindex = sindex / NPDEPG; ptpaddr = pmap->pm_pdir[pdirindex]; if ((ptpaddr & PG_PS) != 0) { pmap->pm_pdir[pdirindex] &= ~(PG_M|PG_RW); pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE; anychanged++; continue; } /* * Weed out invalid mappings. Note: we assume that the page * directory table is always allocated, and in kernel virtual. */ if (ptpaddr == 0) continue; if (pdnxt > eindex) { pdnxt = eindex; } for (; sindex != pdnxt; sindex++) { pt_entry_t pbits; vm_page_t m; pbits = ptbase[sindex]; if (pbits & PG_MANAGED) { m = NULL; if (pbits & PG_A) { m = PHYS_TO_VM_PAGE(pbits); vm_page_flag_set(m, PG_REFERENCED); pbits &= ~PG_A; } if (pbits & PG_M) { if (pmap_track_modified(i386_ptob(sindex))) { if (m == NULL) m = PHYS_TO_VM_PAGE(pbits); vm_page_dirty(m); pbits &= ~PG_M; } } } pbits &= ~PG_RW; if (pbits != ptbase[sindex]) { ptbase[sindex] = pbits; anychanged = 1; } } } if (anychanged) pmap_invalidate_all(pmap); } /* * Insert the given physical page (p) at * the specified virtual address (v) in the * target physical map with the protection requested. * * If specified, the page will be wired down, meaning * that the related pte can not be reclaimed. * * NB: This is the only routine which MAY NOT lazy-evaluate * or lose information. That is, this routine must actually * insert this page into the given map NOW. */ void pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, boolean_t wired) { vm_offset_t pa; register pt_entry_t *pte; vm_offset_t opa; pt_entry_t origpte, newpte; vm_page_t mpte; if (pmap == NULL) return; va &= PG_FRAME; #ifdef PMAP_DIAGNOSTIC if (va > VM_MAX_KERNEL_ADDRESS) panic("pmap_enter: toobig"); if ((va >= UPT_MIN_ADDRESS) && (va < UPT_MAX_ADDRESS)) panic("pmap_enter: invalid to pmap_enter page table pages (va: 0x%x)", va); #endif mpte = NULL; /* * In the case that a page table page is not * resident, we are creating it here. */ if (va < VM_MAXUSER_ADDRESS) { mpte = pmap_allocpte(pmap, va); } #if 0 && defined(PMAP_DIAGNOSTIC) else { pd_entry_t *pdeaddr = pmap_pde(pmap, va); origpte = *pdeaddr; if ((origpte & PG_V) == 0) { panic("pmap_enter: invalid kernel page table page, pdir=%p, pde=%p, va=%p\n", pmap->pm_pdir[PTDPTDI], origpte, va); } } #endif pte = pmap_pte(pmap, va); /* * Page Directory table entry not valid, we need a new PT page */ if (pte == NULL) { panic("pmap_enter: invalid page directory, pdir=%p, va=0x%x\n", (void *)pmap->pm_pdir[PTDPTDI], va); } pa = VM_PAGE_TO_PHYS(m) & PG_FRAME; origpte = *(vm_offset_t *)pte; opa = origpte & PG_FRAME; if (origpte & PG_PS) panic("pmap_enter: attempted pmap_enter on 4MB page"); /* * Mapping has not changed, must be protection or wiring change. */ if (origpte && (opa == pa)) { /* * Wiring change, just update stats. We don't worry about * wiring PT pages as they remain resident as long as there * are valid mappings in them. Hence, if a user page is wired, * the PT page will be also. */ if (wired && ((origpte & PG_W) == 0)) pmap->pm_stats.wired_count++; else if (!wired && (origpte & PG_W)) pmap->pm_stats.wired_count--; #if defined(PMAP_DIAGNOSTIC) if (pmap_nw_modified((pt_entry_t) origpte)) { printf( "pmap_enter: modified page not writable: va: 0x%x, pte: 0x%x\n", va, origpte); } #endif /* * Remove extra pte reference */ if (mpte) mpte->hold_count--; if ((prot & VM_PROT_WRITE) && (origpte & PG_V)) { if ((origpte & PG_RW) == 0) { *pte |= PG_RW; pmap_invalidate_page(pmap, va); } return; } /* * We might be turning off write access to the page, * so we go ahead and sense modify status. */ if (origpte & PG_MANAGED) { if ((origpte & PG_M) && pmap_track_modified(va)) { vm_page_t om; om = PHYS_TO_VM_PAGE(opa); vm_page_dirty(om); } pa |= PG_MANAGED; } goto validate; } /* * Mapping has changed, invalidate old range and fall through to * handle validating new mapping. */ if (opa) { int err; err = pmap_remove_pte(pmap, pte, va); if (err) panic("pmap_enter: pte vanished, va: 0x%x", va); } /* * Enter on the PV list if part of our managed memory. Note that we * raise IPL while manipulating pv_table since pmap_enter can be * called at interrupt time. */ if (pmap_initialized && (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) { pmap_insert_entry(pmap, va, mpte, m); pa |= PG_MANAGED; } /* * Increment counters */ pmap->pm_stats.resident_count++; if (wired) pmap->pm_stats.wired_count++; validate: /* * Now validate mapping with desired protection/wiring. */ newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | PG_V); if (wired) newpte |= PG_W; if (va < VM_MAXUSER_ADDRESS) newpte |= PG_U; if (pmap == kernel_pmap) newpte |= pgeflag; /* * if the mapping or permission bits are different, we need * to update the pte. */ if ((origpte & ~(PG_M|PG_A)) != newpte) { *pte = newpte | PG_A; /*if (origpte)*/ { pmap_invalidate_page(pmap, va); } } } /* * this code makes some *MAJOR* assumptions: * 1. Current pmap & pmap exists. * 2. Not wired. * 3. Read access. * 4. No page table pages. * 5. Tlbflush is deferred to calling procedure. * 6. Page IS managed. * but is *MUCH* faster than pmap_enter... */ static vm_page_t pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_page_t mpte) { pt_entry_t *pte; vm_offset_t pa; /* * In the case that a page table page is not * resident, we are creating it here. */ if (va < VM_MAXUSER_ADDRESS) { unsigned ptepindex; pd_entry_t ptepa; /* * Calculate pagetable page index */ ptepindex = va >> PDRSHIFT; if (mpte && (mpte->pindex == ptepindex)) { mpte->hold_count++; } else { retry: /* * Get the page directory entry */ ptepa = pmap->pm_pdir[ptepindex]; /* * If the page table page is mapped, we just increment * the hold count, and activate it. */ if (ptepa) { if (ptepa & PG_PS) panic("pmap_enter_quick: unexpected mapping into 4MB page"); if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == ptepindex)) { mpte = pmap->pm_ptphint; } else { mpte = pmap_page_lookup(pmap->pm_pteobj, ptepindex); pmap->pm_ptphint = mpte; } if (mpte == NULL) goto retry; mpte->hold_count++; } else { mpte = _pmap_allocpte(pmap, ptepindex); } } } else { mpte = NULL; } /* * This call to vtopte makes the assumption that we are * entering the page into the current pmap. In order to support * quick entry into any pmap, one would likely use pmap_pte_quick. * But that isn't as quick as vtopte. */ pte = vtopte(va); if (*pte) { if (mpte) pmap_unwire_pte_hold(pmap, mpte); return 0; } /* * Enter on the PV list if part of our managed memory. Note that we * raise IPL while manipulating pv_table since pmap_enter can be * called at interrupt time. */ if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) pmap_insert_entry(pmap, va, mpte, m); /* * Increment counters */ pmap->pm_stats.resident_count++; pa = VM_PAGE_TO_PHYS(m); /* * Now validate mapping with RO protection */ if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) *pte = pa | PG_V | PG_U; else *pte = pa | PG_V | PG_U | PG_MANAGED; return mpte; } /* * Make a temporary mapping for a physical address. This is only intended * to be used for panic dumps. */ void * pmap_kenter_temporary(vm_offset_t pa, int i) { vm_offset_t va; va = (vm_offset_t)crashdumpmap + (i * PAGE_SIZE); pmap_kenter(va, pa); #ifndef I386_CPU invlpg(va); #else invltlb(); #endif return ((void *)crashdumpmap); } #define MAX_INIT_PT (96) /* * pmap_object_init_pt preloads the ptes for a given object * into the specified pmap. This eliminates the blast of soft * faults on process startup and immediately after an mmap. */ void pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_object_t object, vm_pindex_t pindex, vm_size_t size, int limit) { vm_offset_t tmpidx; int psize; vm_page_t p, mpte; int objpgs; if (pmap == NULL || object == NULL) return; /* * This code maps large physical mmap regions into the * processor address space. Note that some shortcuts * are taken, but the code works. */ if (pseflag && (object->type == OBJT_DEVICE) && ((addr & (NBPDR - 1)) == 0) && ((size & (NBPDR - 1)) == 0)) { int i; vm_page_t m[1]; unsigned int ptepindex; int npdes; pd_entry_t ptepa; if (pmap->pm_pdir[ptepindex = (addr >> PDRSHIFT)]) return; retry: p = vm_page_lookup(object, pindex); if (p && vm_page_sleep_busy(p, FALSE, "init4p")) goto retry; if (p == NULL) { p = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL); if (p == NULL) return; m[0] = p; if (vm_pager_get_pages(object, m, 1, 0) != VM_PAGER_OK) { vm_page_free(p); return; } p = vm_page_lookup(object, pindex); vm_page_wakeup(p); } ptepa = VM_PAGE_TO_PHYS(p); if (ptepa & (NBPDR - 1)) { return; } p->valid = VM_PAGE_BITS_ALL; pmap->pm_stats.resident_count += size >> PAGE_SHIFT; npdes = size >> PDRSHIFT; for(i = 0; i < npdes; i++) { pmap->pm_pdir[ptepindex] = ptepa | PG_U | PG_RW | PG_V | PG_PS; ptepa += NBPDR; ptepindex += 1; } vm_page_flag_set(p, PG_MAPPED); pmap_invalidate_all(kernel_pmap); return; } psize = i386_btop(size); if ((object->type != OBJT_VNODE) || ((limit & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) && (object->resident_page_count > MAX_INIT_PT))) { return; } if (psize + pindex > object->size) { if (object->size < pindex) return; psize = object->size - pindex; } mpte = NULL; /* * if we are processing a major portion of the object, then scan the * entire thing. */ if (psize > (object->resident_page_count >> 2)) { objpgs = psize; for (p = TAILQ_FIRST(&object->memq); ((objpgs > 0) && (p != NULL)); p = TAILQ_NEXT(p, listq)) { if (p->pindex < pindex || p->pindex - pindex >= psize) { continue; } tmpidx = p->pindex - pindex; /* * don't allow an madvise to blow away our really * free pages allocating pv entries. */ if ((limit & MAP_PREFAULT_MADVISE) && cnt.v_free_count < cnt.v_free_reserved) { break; } if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if ((p->queue - p->pc) == PQ_CACHE) vm_page_deactivate(p); vm_page_busy(p); mpte = pmap_enter_quick(pmap, addr + i386_ptob(tmpidx), p, mpte); vm_page_flag_set(p, PG_MAPPED); vm_page_wakeup(p); } objpgs -= 1; } } else { /* * else lookup the pages one-by-one. */ for (tmpidx = 0; tmpidx < psize; tmpidx += 1) { /* * don't allow an madvise to blow away our really * free pages allocating pv entries. */ if ((limit & MAP_PREFAULT_MADVISE) && cnt.v_free_count < cnt.v_free_reserved) { break; } p = vm_page_lookup(object, tmpidx + pindex); if (p && ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if ((p->queue - p->pc) == PQ_CACHE) vm_page_deactivate(p); vm_page_busy(p); mpte = pmap_enter_quick(pmap, addr + i386_ptob(tmpidx), p, mpte); vm_page_flag_set(p, PG_MAPPED); vm_page_wakeup(p); } } } return; } /* * pmap_prefault provides a quick way of clustering * pagefaults into a processes address space. It is a "cousin" * of pmap_object_init_pt, except it runs at page fault time instead * of mmap time. */ #define PFBAK 4 #define PFFOR 4 #define PAGEORDER_SIZE (PFBAK+PFFOR) static int pmap_prefault_pageorder[] = { -PAGE_SIZE, PAGE_SIZE, -2 * PAGE_SIZE, 2 * PAGE_SIZE, -3 * PAGE_SIZE, 3 * PAGE_SIZE -4 * PAGE_SIZE, 4 * PAGE_SIZE }; void pmap_prefault(pmap, addra, entry) pmap_t pmap; vm_offset_t addra; vm_map_entry_t entry; { int i; vm_offset_t starta; vm_offset_t addr; vm_pindex_t pindex; vm_page_t m, mpte; vm_object_t object; if (!curthread || (pmap != vmspace_pmap(curthread->td_proc->p_vmspace))) return; object = entry->object.vm_object; starta = addra - PFBAK * PAGE_SIZE; if (starta < entry->start) { starta = entry->start; } else if (starta > addra) { starta = 0; } mpte = NULL; for (i = 0; i < PAGEORDER_SIZE; i++) { vm_object_t lobject; pt_entry_t *pte; addr = addra + pmap_prefault_pageorder[i]; if (addr > addra + (PFFOR * PAGE_SIZE)) addr = 0; if (addr < starta || addr >= entry->end) continue; if ((*pmap_pde(pmap, addr)) == NULL) continue; pte = vtopte(addr); if (*pte) continue; pindex = ((addr - entry->start) + entry->offset) >> PAGE_SHIFT; lobject = object; for (m = vm_page_lookup(lobject, pindex); (!m && (lobject->type == OBJT_DEFAULT) && (lobject->backing_object)); lobject = lobject->backing_object) { if (lobject->backing_object_offset & PAGE_MASK) break; pindex += (lobject->backing_object_offset >> PAGE_SHIFT); m = vm_page_lookup(lobject->backing_object, pindex); } /* * give-up when a page is not in memory */ if (m == NULL) break; if (((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (m->busy == 0) && (m->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if ((m->queue - m->pc) == PQ_CACHE) { vm_page_deactivate(m); } vm_page_busy(m); mpte = pmap_enter_quick(pmap, addr, m, mpte); vm_page_flag_set(m, PG_MAPPED); vm_page_wakeup(m); } } } /* * Routine: pmap_change_wiring * Function: Change the wiring attribute for a map/virtual-address * pair. * In/out conditions: * The mapping must already exist in the pmap. */ void pmap_change_wiring(pmap, va, wired) register pmap_t pmap; vm_offset_t va; boolean_t wired; { register pt_entry_t *pte; if (pmap == NULL) return; pte = pmap_pte(pmap, va); if (wired && !pmap_pte_w(pte)) pmap->pm_stats.wired_count++; else if (!wired && pmap_pte_w(pte)) pmap->pm_stats.wired_count--; /* * Wiring is not a hardware characteristic so there is no need to * invalidate TLB. */ pmap_pte_set_w(pte, wired); } /* * Copy the range specified by src_addr/len * from the source map to the range dst_addr/len * in the destination map. * * This routine is only advisory and need not do anything. */ void pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len, vm_offset_t src_addr) { vm_offset_t addr; vm_offset_t end_addr = src_addr + len; vm_offset_t pdnxt; pd_entry_t src_frame, dst_frame; vm_page_t m; if (dst_addr != src_addr) return; src_frame = src_pmap->pm_pdir[PTDPTDI] & PG_FRAME; if (src_frame != (PTDpde & PG_FRAME)) return; dst_frame = dst_pmap->pm_pdir[PTDPTDI] & PG_FRAME; for (addr = src_addr; addr < end_addr; addr = pdnxt) { pt_entry_t *src_pte, *dst_pte; vm_page_t dstmpte, srcmpte; pd_entry_t srcptepaddr; unsigned ptepindex; if (addr >= UPT_MIN_ADDRESS) panic("pmap_copy: invalid to pmap_copy page tables\n"); /* * Don't let optional prefaulting of pages make us go * way below the low water mark of free pages or way * above high water mark of used pv entries. */ if (cnt.v_free_count < cnt.v_free_reserved || pv_entry_count > pv_entry_high_water) break; pdnxt = ((addr + PAGE_SIZE*NPTEPG) & ~(PAGE_SIZE*NPTEPG - 1)); ptepindex = addr >> PDRSHIFT; srcptepaddr = src_pmap->pm_pdir[ptepindex]; if (srcptepaddr == 0) continue; if (srcptepaddr & PG_PS) { if (dst_pmap->pm_pdir[ptepindex] == 0) { dst_pmap->pm_pdir[ptepindex] = srcptepaddr; dst_pmap->pm_stats.resident_count += NBPDR / PAGE_SIZE; } continue; } srcmpte = vm_page_lookup(src_pmap->pm_pteobj, ptepindex); if ((srcmpte == NULL) || (srcmpte->hold_count == 0) || (srcmpte->flags & PG_BUSY)) continue; if (pdnxt > end_addr) pdnxt = end_addr; /* * Have to recheck this before every avtopte() call below * in case we have blocked and something else used APTDpde. */ if (dst_frame != (APTDpde & PG_FRAME)) { APTDpde = dst_frame | PG_RW | PG_V; pmap_invalidate_all(kernel_pmap); /* XXX Bandaid */ } src_pte = vtopte(addr); dst_pte = avtopte(addr); while (addr < pdnxt) { pt_entry_t ptetemp; ptetemp = *src_pte; /* * we only virtual copy managed pages */ if ((ptetemp & PG_MANAGED) != 0) { /* * We have to check after allocpte for the * pte still being around... allocpte can * block. */ dstmpte = pmap_allocpte(dst_pmap, addr); if ((*dst_pte == 0) && (ptetemp = *src_pte)) { /* * Clear the modified and * accessed (referenced) bits * during the copy. */ m = PHYS_TO_VM_PAGE(ptetemp); *dst_pte = ptetemp & ~(PG_M | PG_A); dst_pmap->pm_stats.resident_count++; pmap_insert_entry(dst_pmap, addr, dstmpte, m); } else { pmap_unwire_pte_hold(dst_pmap, dstmpte); } if (dstmpte->hold_count >= srcmpte->hold_count) break; } addr += PAGE_SIZE; src_pte++; dst_pte++; } } } #ifdef SMP /* * pmap_zpi_switchin*() * * These functions allow us to avoid doing IPIs alltogether in certain * temporary page-mapping situations (page zeroing). Instead to deal * with being preempted and moved onto a different cpu we invalidate * the page when the scheduler switches us in. This does not occur * very often so we remain relatively optimal with very little effort. */ static void pmap_zpi_switchin12(void) { invlpg((u_int)CADDR1); invlpg((u_int)CADDR2); } static void pmap_zpi_switchin2(void) { invlpg((u_int)CADDR2); } static void pmap_zpi_switchin3(void) { invlpg((u_int)CADDR3); } #endif /* * pmap_zero_page zeros the specified hardware page by mapping * the page into KVM and using bzero to clear its contents. */ void pmap_zero_page(vm_page_t m) { vm_offset_t phys; phys = VM_PAGE_TO_PHYS(m); if (*CMAP2) panic("pmap_zero_page: CMAP2 busy"); *CMAP2 = PG_V | PG_RW | phys | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin2; #endif invlpg((u_int)CADDR2); #endif #if defined(I686_CPU) if (cpu_class == CPUCLASS_686) i686_pagezero(CADDR2); else #endif bzero(CADDR2, PAGE_SIZE); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP2 = 0; } /* * pmap_zero_page_area zeros the specified hardware page by mapping * the page into KVM and using bzero to clear its contents. * * off and size may not cover an area beyond a single hardware page. */ void pmap_zero_page_area(vm_page_t m, int off, int size) { vm_offset_t phys; phys = VM_PAGE_TO_PHYS(m); if (*CMAP2) panic("pmap_zero_page: CMAP2 busy"); *CMAP2 = PG_V | PG_RW | phys | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin2; #endif invlpg((u_int)CADDR2); #endif #if defined(I686_CPU) if (cpu_class == CPUCLASS_686 && off == 0 && size == PAGE_SIZE) i686_pagezero(CADDR2); else #endif bzero((char *)CADDR2 + off, size); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP2 = 0; } /* * pmap_zero_page_idle zeros the specified hardware page by mapping * the page into KVM and using bzero to clear its contents. This * is intended to be called from the vm_pagezero process only and * outside of Giant. */ void pmap_zero_page_idle(vm_page_t m) { vm_offset_t phys; phys = VM_PAGE_TO_PHYS(m); if (*CMAP3) panic("pmap_zero_page: CMAP3 busy"); *CMAP3 = PG_V | PG_RW | phys | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin3; #endif invlpg((u_int)CADDR3); #endif #if defined(I686_CPU) if (cpu_class == CPUCLASS_686) i686_pagezero(CADDR3); else #endif bzero(CADDR3, PAGE_SIZE); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP3 = 0; } /* * pmap_copy_page copies the specified (machine independent) * page by mapping the page into virtual memory and using * bcopy to copy the page, one machine dependent page at a * time. */ void pmap_copy_page(vm_page_t src, vm_page_t dst) { if (*CMAP1) panic("pmap_copy_page: CMAP1 busy"); if (*CMAP2) panic("pmap_copy_page: CMAP2 busy"); *CMAP1 = PG_V | VM_PAGE_TO_PHYS(src) | PG_A; *CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(dst) | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin12; #endif invlpg((u_int)CADDR1); invlpg((u_int)CADDR2); #endif bcopy(CADDR1, CADDR2, PAGE_SIZE); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP1 = 0; *CMAP2 = 0; } /* * Routine: pmap_pageable * Function: * Make the specified pages (by pmap, offset) * pageable (or not) as requested. * * A page which is not pageable may not take * a fault; therefore, its page table entry * must remain valid for the duration. * * This routine is merely advisory; pmap_enter * will specify that these pages are to be wired * down (or not) as appropriate. */ void pmap_pageable(pmap, sva, eva, pageable) pmap_t pmap; vm_offset_t sva, eva; boolean_t pageable; { } /* * Returns true if the pmap's pv is one of the first * 16 pvs linked to from this page. This count may * be changed upwards or downwards in the future; it * is only necessary that true be returned for a small * subset of pmaps for proper page aging. */ boolean_t pmap_page_exists_quick(pmap, m) pmap_t pmap; vm_page_t m; { pv_entry_t pv; int loops = 0; int s; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return FALSE; s = splvm(); TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { if (pv->pv_pmap == pmap) { splx(s); return TRUE; } loops++; if (loops >= 16) break; } splx(s); return (FALSE); } #define PMAP_REMOVE_PAGES_CURPROC_ONLY /* * Remove all pages from specified address space * this aids process exit speeds. Also, this code * is special cased for current process only, but * can have the more generic (and slightly slower) * mode enabled. This is much faster than pmap_remove * in the case of running down an entire address space. */ void pmap_remove_pages(pmap, sva, eva) pmap_t pmap; vm_offset_t sva, eva; { pt_entry_t *pte, tpte; vm_page_t m; pv_entry_t pv, npv; int s; #ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY if (!curthread || (pmap != vmspace_pmap(curthread->td_proc->p_vmspace))) { printf("warning: pmap_remove_pages called with non-current pmap\n"); return; } #endif s = splvm(); for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) { if (pv->pv_va >= eva || pv->pv_va < sva) { npv = TAILQ_NEXT(pv, pv_plist); continue; } #ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY pte = vtopte(pv->pv_va); #else pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); #endif tpte = *pte; if (tpte == 0) { printf("TPTE at %p IS ZERO @ VA %08x\n", pte, pv->pv_va); panic("bad pte"); } /* * We cannot remove wired pages from a process' mapping at this time */ if (tpte & PG_W) { npv = TAILQ_NEXT(pv, pv_plist); continue; } m = PHYS_TO_VM_PAGE(tpte); KASSERT(m->phys_addr == (tpte & PG_FRAME), ("vm_page_t %p phys_addr mismatch %08x %08x", m, m->phys_addr, tpte)); KASSERT(m < &vm_page_array[vm_page_array_size], ("pmap_remove_pages: bad tpte %x", tpte)); pv->pv_pmap->pm_stats.resident_count--; *pte = 0; /* * Update the vm_page_t clean and reference bits. */ if (tpte & PG_M) { vm_page_dirty(m); } npv = TAILQ_NEXT(pv, pv_plist); TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist); m->md.pv_list_count--; TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); if (TAILQ_FIRST(&m->md.pv_list) == NULL) { vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); } pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem); free_pv_entry(pv); } splx(s); pmap_invalidate_all(pmap); } /* * pmap_testbit tests bits in pte's * note that the testbit/changebit routines are inline, * and a lot of things compile-time evaluate. */ static boolean_t pmap_testbit(m, bit) vm_page_t m; int bit; { pv_entry_t pv; pt_entry_t *pte; int s; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return FALSE; if (TAILQ_FIRST(&m->md.pv_list) == NULL) return FALSE; s = splvm(); TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { /* * if the bit being tested is the modified bit, then * mark clean_map and ptes as never * modified. */ if (bit & (PG_A|PG_M)) { if (!pmap_track_modified(pv->pv_va)) continue; } #if defined(PMAP_DIAGNOSTIC) if (!pv->pv_pmap) { printf("Null pmap (tb) at va: 0x%x\n", pv->pv_va); continue; } #endif pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); if (*pte & bit) { splx(s); return TRUE; } } splx(s); return (FALSE); } /* * this routine is used to modify bits in ptes */ static __inline void pmap_changebit(vm_page_t m, int bit, boolean_t setem) { register pv_entry_t pv; register pt_entry_t *pte; int s; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return; s = splvm(); /* * Loop over all current mappings setting/clearing as appropos If * setting RO do we need to clear the VAC? */ TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { /* * don't write protect pager mappings */ if (!setem && (bit == PG_RW)) { if (!pmap_track_modified(pv->pv_va)) continue; } #if defined(PMAP_DIAGNOSTIC) if (!pv->pv_pmap) { printf("Null pmap (cb) at va: 0x%x\n", pv->pv_va); continue; } #endif pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); if (setem) { *pte |= bit; pmap_invalidate_page(pv->pv_pmap, pv->pv_va); } else { pt_entry_t pbits = *pte; if (pbits & bit) { if (bit == PG_RW) { if (pbits & PG_M) { vm_page_dirty(m); } *pte = pbits & ~(PG_M|PG_RW); } else { *pte = pbits & ~bit; } pmap_invalidate_page(pv->pv_pmap, pv->pv_va); } } } splx(s); } /* * pmap_page_protect: * * Lower the permission for all mappings to a given page. */ void pmap_page_protect(vm_page_t m, vm_prot_t prot) { if ((prot & VM_PROT_WRITE) == 0) { if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) { pmap_changebit(m, PG_RW, FALSE); } else { pmap_remove_all(m); } } } vm_offset_t pmap_phys_address(ppn) int ppn; { return (i386_ptob(ppn)); } /* * pmap_ts_referenced: * * Return a count of reference bits for a page, clearing those bits. * It is not necessary for every reference bit to be cleared, but it * is necessary that 0 only be returned when there are truly no * reference bits set. * * XXX: The exact number of bits to check and clear is a matter that * should be tested and standardized at some point in the future for * optimal aging of shared pages. */ int pmap_ts_referenced(vm_page_t m) { register pv_entry_t pv, pvf, pvn; pt_entry_t *pte; int s; int rtval = 0; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return (rtval); s = splvm(); if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) { pvf = pv; do { pvn = TAILQ_NEXT(pv, pv_list); TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list); if (!pmap_track_modified(pv->pv_va)) continue; pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); if (pte && (*pte & PG_A)) { *pte &= ~PG_A; pmap_invalidate_page(pv->pv_pmap, pv->pv_va); rtval++; if (rtval > 4) { break; } } } while ((pv = pvn) != NULL && pv != pvf); } splx(s); return (rtval); } /* * pmap_is_modified: * * Return whether or not the specified physical page was modified * in any physical maps. */ boolean_t pmap_is_modified(vm_page_t m) { return pmap_testbit(m, PG_M); } /* * Clear the modify bits on the specified physical page. */ void pmap_clear_modify(vm_page_t m) { pmap_changebit(m, PG_M, FALSE); } /* * pmap_clear_reference: * * Clear the reference bit on the specified physical page. */ void pmap_clear_reference(vm_page_t m) { pmap_changebit(m, PG_A, FALSE); } /* * Miscellaneous support routines follow */ static void i386_protection_init() { register int *kp, prot; kp = protection_codes; for (prot = 0; prot < 8; prot++) { switch (prot) { case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_NONE: /* * Read access is also 0. There isn't any execute bit, * so just make it readable. */ case VM_PROT_READ | VM_PROT_NONE | VM_PROT_NONE: case VM_PROT_READ | VM_PROT_NONE | VM_PROT_EXECUTE: case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_EXECUTE: *kp++ = 0; break; case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_NONE: case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_EXECUTE: case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_NONE: case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE: *kp++ = PG_RW; break; } } } /* * Map a set of physical memory pages into the kernel virtual * address space. Return a pointer to where it is mapped. This * routine is intended to be used for mapping device memory, * NOT real memory. */ void * pmap_mapdev(pa, size) vm_offset_t pa; vm_size_t size; { vm_offset_t va, tmpva, offset; pt_entry_t *pte; offset = pa & PAGE_MASK; size = roundup(offset + size, PAGE_SIZE); GIANT_REQUIRED; va = kmem_alloc_pageable(kernel_map, size); if (!va) panic("pmap_mapdev: Couldn't alloc kernel virtual memory"); pa = pa & PG_FRAME; for (tmpva = va; size > 0; ) { pte = vtopte(tmpva); *pte = pa | PG_RW | PG_V | pgeflag; size -= PAGE_SIZE; tmpva += PAGE_SIZE; pa += PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, va, tmpva); return ((void *)(va + offset)); } void pmap_unmapdev(va, size) vm_offset_t va; vm_size_t size; { vm_offset_t base, offset, tmpva; pt_entry_t *pte; base = va & PG_FRAME; offset = va & PAGE_MASK; size = roundup(offset + size, PAGE_SIZE); for (tmpva = base; tmpva < (base + size); tmpva += PAGE_SIZE) { pte = vtopte(tmpva); *pte = 0; } pmap_invalidate_range(kernel_pmap, va, tmpva); kmem_free(kernel_map, base, size); } /* * perform the pmap work for mincore */ int pmap_mincore(pmap, addr) pmap_t pmap; vm_offset_t addr; { pt_entry_t *ptep, pte; vm_page_t m; int val = 0; ptep = pmap_pte(pmap, addr); if (ptep == 0) { return 0; } if ((pte = *ptep) != 0) { vm_offset_t pa; val = MINCORE_INCORE; if ((pte & PG_MANAGED) == 0) return val; pa = pte & PG_FRAME; m = PHYS_TO_VM_PAGE(pa); /* * Modified by us */ if (pte & PG_M) val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER; /* * Modified by someone */ else if (m->dirty || pmap_is_modified(m)) val |= MINCORE_MODIFIED_OTHER; /* * Referenced by us */ if (pte & PG_A) val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER; /* * Referenced by someone */ else if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) { val |= MINCORE_REFERENCED_OTHER; vm_page_flag_set(m, PG_REFERENCED); } } return val; } void pmap_activate(struct thread *td) { struct proc *p = td->td_proc; pmap_t pmap; u_int32_t cr3; pmap = vmspace_pmap(td->td_proc->p_vmspace); #if defined(SMP) pmap->pm_active |= PCPU_GET(cpumask); #else pmap->pm_active |= 1; #endif #if defined(SWTCH_OPTIM_STATS) tlb_flush_count++; #endif cr3 = vtophys(pmap->pm_pdir); /* XXXKSE this is wrong. * pmap_activate is for the current thread on the current cpu */ if (p->p_flag & P_KSES) { /* Make sure all other cr3 entries are updated. */ /* what if they are running? XXXKSE (maybe abort them) */ FOREACH_THREAD_IN_PROC(p, td) { td->td_pcb->pcb_cr3 = cr3; } } else { td->td_pcb->pcb_cr3 = cr3; } load_cr3(cr3); } vm_offset_t pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size) { if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) { return addr; } addr = (addr + (NBPDR - 1)) & ~(NBPDR - 1); return addr; } #if defined(PMAP_DEBUG) pmap_pid_dump(int pid) { pmap_t pmap; struct proc *p; int npte = 0; int index; sx_slock(&allproc_lock); LIST_FOREACH(p, &allproc, p_list) { if (p->p_pid != pid) continue; if (p->p_vmspace) { int i,j; index = 0; pmap = vmspace_pmap(p->p_vmspace); for (i = 0; i < NPDEPG; i++) { pd_entry_t *pde; pt_entry_t *pte; vm_offset_t base = i << PDRSHIFT; pde = &pmap->pm_pdir[i]; if (pde && pmap_pde_v(pde)) { for (j = 0; j < NPTEPG; j++) { vm_offset_t va = base + (j << PAGE_SHIFT); if (va >= (vm_offset_t) VM_MIN_KERNEL_ADDRESS) { if (index) { index = 0; printf("\n"); } sx_sunlock(&allproc_lock); return npte; } pte = pmap_pte_quick(pmap, va); if (pte && pmap_pte_v(pte)) { pt_entry_t pa; vm_page_t m; pa = *pte; m = PHYS_TO_VM_PAGE(pa); printf("va: 0x%x, pt: 0x%x, h: %d, w: %d, f: 0x%x", va, pa, m->hold_count, m->wire_count, m->flags); npte++; index++; if (index >= 2) { index = 0; printf("\n"); } else { printf(" "); } } } } } } } sx_sunlock(&allproc_lock); return npte; } #endif #if defined(DEBUG) static void pads(pmap_t pm); void pmap_pvdump(vm_offset_t pa); /* print address space of pmap*/ static void pads(pm) pmap_t pm; { int i, j; vm_offset_t va; pt_entry_t *ptep; if (pm == kernel_pmap) return; for (i = 0; i < NPDEPG; i++) if (pm->pm_pdir[i]) for (j = 0; j < NPTEPG; j++) { va = (i << PDRSHIFT) + (j << PAGE_SHIFT); if (pm == kernel_pmap && va < KERNBASE) continue; if (pm != kernel_pmap && va > UPT_MAX_ADDRESS) continue; ptep = pmap_pte_quick(pm, va); if (pmap_pte_v(ptep)) printf("%x:%x ", va, *ptep); }; } void pmap_pvdump(pa) vm_offset_t pa; { pv_entry_t pv; vm_page_t m; printf("pa %x", pa); m = PHYS_TO_VM_PAGE(pa); TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { printf(" -> pmap %p, va %x", (void *)pv->pv_pmap, pv->pv_va); pads(pv->pv_pmap); } printf(" "); } #endif Index: head/sys/i386/i386/pmap.c =================================================================== --- head/sys/i386/i386/pmap.c (revision 100377) +++ head/sys/i386/i386/pmap.c (revision 100378) @@ -1,3529 +1,3527 @@ /* * Copyright (c) 1991 Regents of the University of California. * All rights reserved. * Copyright (c) 1994 John S. Dyson * All rights reserved. * Copyright (c) 1994 David Greenman * All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department and William Jolitz of UUNET Technologies Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)pmap.c 7.7 (Berkeley) 5/12/91 * $FreeBSD$ */ /* * Manages physical address maps. * * In addition to hardware address maps, this * module is called upon to provide software-use-only * maps which may or may not be stored in the same * form as hardware maps. These pseudo-maps are * used to store intermediate results from copy * operations to and from address spaces. * * Since the information managed by this module is * also stored by the logical address mapping module, * this module may throw away valid virtual-to-physical * mappings at almost any time. However, invalidations * of virtual-to-physical mappings must be done as * requested. * * In order to cope with hardware architectures which * make virtual-to-physical map invalidates expensive, * this module may delay invalidate or reduced protection * operations until such time as they are actually * necessary. This module is given full information as * to which processors are currently using which maps, * and to when physical maps must be made correct. */ #include "opt_pmap.h" #include "opt_msgbuf.h" #include "opt_kstack_pages.h" #include #include #include #include #include #include #include #include #include #include #include #include #ifdef SMP #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(SMP) || defined(APIC_IO) #include #include #include #include #endif /* SMP || APIC_IO */ #define PMAP_KEEP_PDIRS #ifndef PMAP_SHPGPERPROC #define PMAP_SHPGPERPROC 200 #endif #if defined(DIAGNOSTIC) #define PMAP_DIAGNOSTIC #endif #define MINPV 2048 #if !defined(PMAP_DIAGNOSTIC) #define PMAP_INLINE __inline #else #define PMAP_INLINE #endif /* * Get PDEs and PTEs for user/kernel address space */ #define pmap_pde(m, v) (&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT])) #define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT]) #define pmap_pde_v(pte) ((*(int *)pte & PG_V) != 0) #define pmap_pte_w(pte) ((*(int *)pte & PG_W) != 0) #define pmap_pte_m(pte) ((*(int *)pte & PG_M) != 0) #define pmap_pte_u(pte) ((*(int *)pte & PG_A) != 0) #define pmap_pte_v(pte) ((*(int *)pte & PG_V) != 0) #define pmap_pte_set_w(pte, v) ((v)?(*(int *)pte |= PG_W):(*(int *)pte &= ~PG_W)) #define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v))) /* * Given a map and a machine independent protection code, * convert to a vax protection code. */ #define pte_prot(m, p) (protection_codes[p]) static int protection_codes[8]; struct pmap kernel_pmap_store; LIST_HEAD(pmaplist, pmap); struct pmaplist allpmaps; vm_offset_t avail_start; /* PA of first available physical page */ vm_offset_t avail_end; /* PA of last available physical page */ vm_offset_t virtual_avail; /* VA of first avail page (after kernel bss) */ vm_offset_t virtual_end; /* VA of last avail page (end of kernel AS) */ static boolean_t pmap_initialized = FALSE; /* Has pmap_init completed? */ static int pgeflag; /* PG_G or-in */ static int pseflag; /* PG_PS or-in */ static vm_object_t kptobj; static int nkpt; vm_offset_t kernel_vm_end; extern u_int32_t KERNend; /* * Data for the pv entry allocation mechanism */ static uma_zone_t pvzone; static struct vm_object pvzone_obj; static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0; static int pmap_pagedaemon_waken = 0; /* * All those kernel PT submaps that BSD is so fond of */ pt_entry_t *CMAP1 = 0; static pt_entry_t *CMAP2, *CMAP3, *ptmmap; caddr_t CADDR1 = 0, ptvmmap = 0; static caddr_t CADDR2, CADDR3; static pt_entry_t *msgbufmap; struct msgbuf *msgbufp = 0; /* * Crashdump maps. */ static pt_entry_t *pt_crashdumpmap; static caddr_t crashdumpmap; #ifdef SMP extern pt_entry_t *SMPpt; #endif static pt_entry_t *PMAP1 = 0; static pt_entry_t *PADDR1 = 0; static PMAP_INLINE void free_pv_entry(pv_entry_t pv); static pt_entry_t *get_ptbase(pmap_t pmap); static pv_entry_t get_pv_entry(void); static void i386_protection_init(void); static __inline void pmap_changebit(vm_page_t m, int bit, boolean_t setem); static void pmap_remove_all(vm_page_t m); static vm_page_t pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_page_t mpte); static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t sva); static void pmap_remove_page(struct pmap *pmap, vm_offset_t va); static int pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va); static boolean_t pmap_testbit(vm_page_t m, int bit); static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m); static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va); static int pmap_release_free_page(pmap_t pmap, vm_page_t p); static vm_page_t _pmap_allocpte(pmap_t pmap, unsigned ptepindex); static pt_entry_t *pmap_pte_quick(pmap_t pmap, vm_offset_t va); static vm_page_t pmap_page_lookup(vm_object_t object, vm_pindex_t pindex); static int pmap_unuse_pt(pmap_t, vm_offset_t, vm_page_t); static vm_offset_t pmap_kmem_choose(vm_offset_t addr); static void *pmap_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait); static pd_entry_t pdir4mb; /* * Routine: pmap_pte * Function: * Extract the page table entry associated * with the given map/virtual_address pair. */ PMAP_INLINE pt_entry_t * pmap_pte(pmap, va) register pmap_t pmap; vm_offset_t va; { pd_entry_t *pdeaddr; if (pmap) { pdeaddr = pmap_pde(pmap, va); if (*pdeaddr & PG_PS) return pdeaddr; if (*pdeaddr) { return get_ptbase(pmap) + i386_btop(va); } } return (0); } /* * Move the kernel virtual free pointer to the next * 4MB. This is used to help improve performance * by using a large (4MB) page for much of the kernel * (.text, .data, .bss) */ static vm_offset_t pmap_kmem_choose(vm_offset_t addr) { vm_offset_t newaddr = addr; #ifndef DISABLE_PSE if (cpu_feature & CPUID_PSE) newaddr = (addr + (NBPDR - 1)) & ~(NBPDR - 1); #endif return newaddr; } /* * Bootstrap the system enough to run with virtual memory. * * On the i386 this is called after mapping has already been enabled * and just syncs the pmap module with what has already been done. * [We can't call it easily with mapping off since the kernel is not * mapped with PA == VA, hence we would have to relocate every address * from the linked base (virtual) address "KERNBASE" to the actual * (physical) address starting relative to 0] */ void pmap_bootstrap(firstaddr, loadaddr) vm_offset_t firstaddr; vm_offset_t loadaddr; { vm_offset_t va; pt_entry_t *pte; int i; avail_start = firstaddr; /* * XXX The calculation of virtual_avail is wrong. It's NKPT*PAGE_SIZE too * large. It should instead be correctly calculated in locore.s and * not based on 'first' (which is a physical address, not a virtual * address, for the start of unused physical memory). The kernel * page tables are NOT double mapped and thus should not be included * in this calculation. */ virtual_avail = (vm_offset_t) KERNBASE + firstaddr; virtual_avail = pmap_kmem_choose(virtual_avail); virtual_end = VM_MAX_KERNEL_ADDRESS; /* * Initialize protection array. */ i386_protection_init(); /* * Initialize the kernel pmap (which is statically allocated). */ kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + (u_int)IdlePTD); kernel_pmap->pm_active = -1; /* don't allow deactivation */ TAILQ_INIT(&kernel_pmap->pm_pvlist); LIST_INIT(&allpmaps); LIST_INSERT_HEAD(&allpmaps, kernel_pmap, pm_list); nkpt = NKPT; /* * Reserve some special page table entries/VA space for temporary * mapping of pages. */ #define SYSMAP(c, p, v, n) \ v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n); va = virtual_avail; pte = (pt_entry_t *) pmap_pte(kernel_pmap, va); /* * CMAP1/CMAP2 are used for zeroing and copying pages. * CMAP3 is used for the idle process page zeroing. */ SYSMAP(caddr_t, CMAP1, CADDR1, 1) SYSMAP(caddr_t, CMAP2, CADDR2, 1) SYSMAP(caddr_t, CMAP3, CADDR3, 1) /* * Crashdump maps. */ SYSMAP(caddr_t, pt_crashdumpmap, crashdumpmap, MAXDUMPPGS); /* * ptvmmap is used for reading arbitrary physical pages via /dev/mem. * XXX ptmmap is not used. */ SYSMAP(caddr_t, ptmmap, ptvmmap, 1) /* * msgbufp is used to map the system message buffer. * XXX msgbufmap is not used. */ SYSMAP(struct msgbuf *, msgbufmap, msgbufp, atop(round_page(MSGBUF_SIZE))) /* * ptemap is used for pmap_pte_quick */ SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1); virtual_avail = va; *CMAP1 = *CMAP2 = 0; for (i = 0; i < NKPT; i++) PTD[i] = 0; pgeflag = 0; #ifndef DISABLE_PG_G if (cpu_feature & CPUID_PGE) pgeflag = PG_G; #endif /* * Initialize the 4MB page size flag */ pseflag = 0; /* * The 4MB page version of the initial * kernel page mapping. */ pdir4mb = 0; #ifndef DISABLE_PSE if (cpu_feature & CPUID_PSE) { pd_entry_t ptditmp; /* * Note that we have enabled PSE mode */ pseflag = PG_PS; ptditmp = *(PTmap + i386_btop(KERNBASE)); ptditmp &= ~(NBPDR - 1); ptditmp |= PG_V | PG_RW | PG_PS | PG_U | pgeflag; pdir4mb = ptditmp; } #endif #ifndef SMP /* * Turn on PGE/PSE. SMP does this later on since the * 4K page tables are required for AP boot (for now). * XXX fixme. */ pmap_set_opt(); #endif #ifdef SMP if (cpu_apic_address == 0) panic("pmap_bootstrap: no local apic! (non-SMP hardware?)"); /* local apic is mapped on last page */ SMPpt[NPTEPG - 1] = (pt_entry_t)(PG_V | PG_RW | PG_N | pgeflag | (cpu_apic_address & PG_FRAME)); #endif invltlb(); } /* * Enable 4MB page mode for MP startup. Turn on PG_G support. * BSP will run this after all the AP's have started up. */ void pmap_set_opt(void) { pt_entry_t *pte; vm_offset_t va, endva; if (pgeflag && (cpu_feature & CPUID_PGE)) { load_cr4(rcr4() | CR4_PGE); invltlb(); /* Insurance */ } #ifndef DISABLE_PSE if (pseflag && (cpu_feature & CPUID_PSE)) { load_cr4(rcr4() | CR4_PSE); invltlb(); /* Insurance */ } #endif if (PCPU_GET(cpuid) == 0) { #ifndef DISABLE_PSE if (pdir4mb) { kernel_pmap->pm_pdir[KPTDI] = PTD[KPTDI] = pdir4mb; invltlb(); /* Insurance */ } #endif if (pgeflag) { /* Turn on PG_G for text, data, bss pages. */ va = (vm_offset_t)btext; #ifndef DISABLE_PSE if (pseflag && (cpu_feature & CPUID_PSE)) { if (va < KERNBASE + (1 << PDRSHIFT)) va = KERNBASE + (1 << PDRSHIFT); } #endif endva = KERNBASE + KERNend; while (va < endva) { pte = vtopte(va); if (*pte) *pte |= pgeflag; va += PAGE_SIZE; } invltlb(); /* Insurance */ } /* * We do not need to broadcast the invltlb here, because * each AP does it the moment it is released from the boot * lock. See ap_init(). */ } } void * pmap_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait) { *flags = UMA_SLAB_PRIV; return (void *)kmem_alloc(kernel_map, bytes); } /* * Initialize the pmap module. * Called by vm_init, to initialize any structures that the pmap * system needs to map virtual memory. * pmap_init has been enhanced to support in a fairly consistant * way, discontiguous physical memory. */ void pmap_init(phys_start, phys_end) vm_offset_t phys_start, phys_end; { int i; int initial_pvs; /* * object for kernel page table pages */ kptobj = vm_object_allocate(OBJT_DEFAULT, NKPDE); /* * Allocate memory for random pmap data structures. Includes the * pv_head_table. */ for(i = 0; i < vm_page_array_size; i++) { vm_page_t m; m = &vm_page_array[i]; TAILQ_INIT(&m->md.pv_list); m->md.pv_list_count = 0; } /* * init the pv free list */ initial_pvs = vm_page_array_size; if (initial_pvs < MINPV) initial_pvs = MINPV; pvzone = uma_zcreate("PV ENTRY", sizeof (struct pv_entry), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM); uma_zone_set_allocf(pvzone, pmap_allocf); uma_prealloc(pvzone, initial_pvs); /* * Now it is safe to enable pv_table recording. */ pmap_initialized = TRUE; } /* * Initialize the address space (zone) for the pv_entries. Set a * high water mark so that the system can recover from excessive * numbers of pv entries. */ void pmap_init2() { int shpgperproc = PMAP_SHPGPERPROC; TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc); pv_entry_max = shpgperproc * maxproc + vm_page_array_size; TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max); pv_entry_high_water = 9 * (pv_entry_max / 10); uma_zone_set_obj(pvzone, &pvzone_obj, pv_entry_max); } /*************************************************** * Low level helper routines..... ***************************************************/ #if defined(PMAP_DIAGNOSTIC) /* * This code checks for non-writeable/modified pages. * This should be an invalid condition. */ static int pmap_nw_modified(pt_entry_t ptea) { int pte; pte = (int) ptea; if ((pte & (PG_M|PG_RW)) == PG_M) return 1; else return 0; } #endif /* * this routine defines the region(s) of memory that should * not be tested for the modified bit. */ static PMAP_INLINE int pmap_track_modified(vm_offset_t va) { if ((va < kmi.clean_sva) || (va >= kmi.clean_eva)) return 1; else return 0; } #ifdef I386_CPU /* * i386 only has "invalidate everything" and no SMP to worry about. */ PMAP_INLINE void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } PMAP_INLINE void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } PMAP_INLINE void pmap_invalidate_all(pmap_t pmap) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } #else /* !I386_CPU */ #ifdef SMP /* * For SMP, these functions have to use the IPI mechanism for coherence. */ void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { u_int cpumask; u_int other_cpus; critical_enter(); /* * We need to disable interrupt preemption but MUST NOT have * interrupts disabled here. * XXX we may need to hold schedlock to get a coherent pm_active */ if (pmap->pm_active == -1 || pmap->pm_active == all_cpus) { invlpg(va); smp_invlpg(va); } else { cpumask = PCPU_GET(cpumask); other_cpus = PCPU_GET(other_cpus); if (pmap->pm_active & cpumask) invlpg(va); if (pmap->pm_active & other_cpus) smp_masked_invlpg(pmap->pm_active & other_cpus, va); } critical_exit(); } void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { u_int cpumask; u_int other_cpus; vm_offset_t addr; critical_enter(); /* * We need to disable interrupt preemption but MUST NOT have * interrupts disabled here. * XXX we may need to hold schedlock to get a coherent pm_active */ if (pmap->pm_active == -1 || pmap->pm_active == all_cpus) { for (addr = sva; addr < eva; addr += PAGE_SIZE) invlpg(addr); smp_invlpg_range(sva, eva); } else { cpumask = PCPU_GET(cpumask); other_cpus = PCPU_GET(other_cpus); if (pmap->pm_active & cpumask) for (addr = sva; addr < eva; addr += PAGE_SIZE) invlpg(addr); if (pmap->pm_active & other_cpus) smp_masked_invlpg_range(pmap->pm_active & other_cpus, sva, eva); } critical_exit(); } void pmap_invalidate_all(pmap_t pmap) { u_int cpumask; u_int other_cpus; critical_enter(); /* * We need to disable interrupt preemption but MUST NOT have * interrupts disabled here. * XXX we may need to hold schedlock to get a coherent pm_active */ if (pmap->pm_active == -1 || pmap->pm_active == all_cpus) { invltlb(); smp_invltlb(); } else { cpumask = PCPU_GET(cpumask); other_cpus = PCPU_GET(other_cpus); if (pmap->pm_active & cpumask) invltlb(); if (pmap->pm_active & other_cpus) smp_masked_invltlb(pmap->pm_active & other_cpus); } critical_exit(); } #else /* !SMP */ /* * Normal, non-SMP, 486+ invalidation functions. * We inline these within pmap.c for speed. */ PMAP_INLINE void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { if (pmap == kernel_pmap || pmap->pm_active) invlpg(va); } PMAP_INLINE void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { vm_offset_t addr; if (pmap == kernel_pmap || pmap->pm_active) for (addr = sva; addr < eva; addr += PAGE_SIZE) invlpg(addr); } PMAP_INLINE void pmap_invalidate_all(pmap_t pmap) { if (pmap == kernel_pmap || pmap->pm_active) invltlb(); } #endif /* !SMP */ #endif /* !I386_CPU */ /* * Return an address which is the base of the Virtual mapping of * all the PTEs for the given pmap. Note this doesn't say that * all the PTEs will be present or that the pages there are valid. * The PTEs are made available by the recursive mapping trick. * It will map in the alternate PTE space if needed. */ static pt_entry_t * get_ptbase(pmap) pmap_t pmap; { pd_entry_t frame; /* are we current address space or kernel? */ if (pmap == kernel_pmap) return PTmap; frame = pmap->pm_pdir[PTDPTDI] & PG_FRAME; if (frame == (PTDpde & PG_FRAME)) return PTmap; /* otherwise, we are alternate address space */ if (frame != (APTDpde & PG_FRAME)) { APTDpde = (pd_entry_t) (frame | PG_RW | PG_V); pmap_invalidate_all(kernel_pmap); /* XXX Bandaid */ } return APTmap; } /* * Super fast pmap_pte routine best used when scanning * the pv lists. This eliminates many coarse-grained * invltlb calls. Note that many of the pv list * scans are across different pmaps. It is very wasteful * to do an entire invltlb for checking a single mapping. */ static pt_entry_t * pmap_pte_quick(pmap, va) register pmap_t pmap; vm_offset_t va; { pd_entry_t pde, newpf; pde = pmap->pm_pdir[va >> PDRSHIFT]; if (pde != 0) { pd_entry_t frame = pmap->pm_pdir[PTDPTDI] & PG_FRAME; unsigned index = i386_btop(va); /* are we current address space or kernel? */ if (pmap == kernel_pmap || frame == (PTDpde & PG_FRAME)) return PTmap + index; newpf = pde & PG_FRAME; if (((*PMAP1) & PG_FRAME) != newpf) { *PMAP1 = newpf | PG_RW | PG_V; pmap_invalidate_page(kernel_pmap, (vm_offset_t)PADDR1); } return PADDR1 + (index & (NPTEPG - 1)); } return (0); } /* * Routine: pmap_extract * Function: * Extract the physical page address associated * with the given map/virtual_address pair. */ vm_offset_t pmap_extract(pmap, va) register pmap_t pmap; vm_offset_t va; { vm_offset_t rtval; /* XXX FIXME */ vm_offset_t pdirindex; if (pmap == 0) return 0; pdirindex = va >> PDRSHIFT; rtval = pmap->pm_pdir[pdirindex]; if (rtval != 0) { pt_entry_t *pte; if ((rtval & PG_PS) != 0) { rtval &= ~(NBPDR - 1); rtval |= va & (NBPDR - 1); return rtval; } pte = get_ptbase(pmap) + i386_btop(va); rtval = ((*pte & PG_FRAME) | (va & PAGE_MASK)); return rtval; } return 0; } /*************************************************** * Low level mapping routines..... ***************************************************/ /* * Add a wired page to the kva. * Note: not SMP coherent. */ PMAP_INLINE void pmap_kenter(vm_offset_t va, vm_offset_t pa) { pt_entry_t *pte; pte = vtopte(va); *pte = pa | PG_RW | PG_V | pgeflag; } /* * Remove a page from the kernel pagetables. * Note: not SMP coherent. */ PMAP_INLINE void pmap_kremove(vm_offset_t va) { pt_entry_t *pte; pte = vtopte(va); *pte = 0; } /* * Used to map a range of physical addresses into kernel * virtual address space. * * The value passed in '*virt' is a suggested virtual address for * the mapping. Architectures which can support a direct-mapped * physical to virtual region can return the appropriate address * within that region, leaving '*virt' unchanged. Other * architectures should map the pages starting at '*virt' and * update '*virt' with the first usable address after the mapped * region. */ vm_offset_t pmap_map(vm_offset_t *virt, vm_offset_t start, vm_offset_t end, int prot) { vm_offset_t va, sva; va = sva = *virt; while (start < end) { pmap_kenter(va, start); va += PAGE_SIZE; start += PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); *virt = va; return (sva); } /* * Add a list of wired pages to the kva * this routine is only used for temporary * kernel mappings that do not need to have * page modification or references recorded. * Note that old mappings are simply written * over. The page *must* be wired. * Note: SMP coherent. Uses a ranged shootdown IPI. */ void pmap_qenter(vm_offset_t sva, vm_page_t *m, int count) { vm_offset_t va; va = sva; while (count-- > 0) { pmap_kenter(va, VM_PAGE_TO_PHYS(*m)); va += PAGE_SIZE; m++; } pmap_invalidate_range(kernel_pmap, sva, va); } /* * This routine tears out page mappings from the * kernel -- it is meant only for temporary mappings. * Note: SMP coherent. Uses a ranged shootdown IPI. */ void pmap_qremove(vm_offset_t sva, int count) { vm_offset_t va; va = sva; while (count-- > 0) { pmap_kremove(va); va += PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); } static vm_page_t pmap_page_lookup(vm_object_t object, vm_pindex_t pindex) { vm_page_t m; retry: m = vm_page_lookup(object, pindex); if (m && vm_page_sleep_busy(m, FALSE, "pplookp")) goto retry; return m; } /* * Create the kernel stack (including pcb for i386) for a new thread. * This routine directly affects the fork perf for a process and * create performance for a thread. */ void pmap_new_thread(struct thread *td) { int i; vm_page_t ma[KSTACK_PAGES]; vm_object_t ksobj; vm_page_t m; vm_offset_t ks; /* * allocate object for the kstack */ ksobj = vm_object_allocate(OBJT_DEFAULT, KSTACK_PAGES); td->td_kstack_obj = ksobj; /* get a kernel virtual address for the kstack for this thread */ #ifdef KSTACK_GUARD ks = kmem_alloc_nofault(kernel_map, (KSTACK_PAGES + 1) * PAGE_SIZE); if (ks == 0) panic("pmap_new_thread: kstack allocation failed"); if (*vtopte(ks) != 0) pmap_qremove(ks, 1); ks += PAGE_SIZE; td->td_kstack = ks; #else /* get a kernel virtual address for the kstack for this thread */ ks = kmem_alloc_nofault(kernel_map, KSTACK_PAGES * PAGE_SIZE); if (ks == 0) panic("pmap_new_thread: kstack allocation failed"); td->td_kstack = ks; #endif /* * For the length of the stack, link in a real page of ram for each * page of stack. */ for (i = 0; i < KSTACK_PAGES; i++) { /* * Get a kernel stack page */ m = vm_page_grab(ksobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); ma[i] = m; /* * Wire the page */ m->wire_count++; cnt.v_wire_count++; vm_page_wakeup(m); vm_page_flag_clear(m, PG_ZERO); vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE); m->valid = VM_PAGE_BITS_ALL; } pmap_qenter(ks, ma, KSTACK_PAGES); } /* * Dispose the kernel stack for a thread that has exited. * This routine directly impacts the exit perf of a process and thread. */ void pmap_dispose_thread(td) struct thread *td; { int i; vm_object_t ksobj; vm_offset_t ks; vm_page_t m; ksobj = td->td_kstack_obj; ks = td->td_kstack; pmap_qremove(ks, KSTACK_PAGES); for (i = 0; i < KSTACK_PAGES; i++) { m = vm_page_lookup(ksobj, i); if (m == NULL) panic("pmap_dispose_thread: kstack already missing?"); vm_page_lock_queues(); vm_page_busy(m); vm_page_unwire(m, 0); vm_page_free(m); vm_page_unlock_queues(); } /* * Free the space that this stack was mapped to in the kernel * address map. */ #ifdef KSTACK_GUARD kmem_free(kernel_map, ks - PAGE_SIZE, (KSTACK_PAGES + 1) * PAGE_SIZE); #else kmem_free(kernel_map, ks, KSTACK_PAGES * PAGE_SIZE); #endif vm_object_deallocate(ksobj); } /* * Allow the Kernel stack for a thread to be prejudicially paged out. */ void pmap_swapout_thread(td) struct thread *td; { int i; vm_object_t ksobj; vm_offset_t ks; vm_page_t m; ksobj = td->td_kstack_obj; ks = td->td_kstack; pmap_qremove(ks, KSTACK_PAGES); for (i = 0; i < KSTACK_PAGES; i++) { m = vm_page_lookup(ksobj, i); if (m == NULL) panic("pmap_swapout_thread: kstack already missing?"); vm_page_lock_queues(); vm_page_dirty(m); vm_page_unwire(m, 0); vm_page_unlock_queues(); } } /* * Bring the kernel stack for a specified thread back in. */ void pmap_swapin_thread(td) struct thread *td; { int i, rv; vm_page_t ma[KSTACK_PAGES]; vm_object_t ksobj; vm_offset_t ks; vm_page_t m; ksobj = td->td_kstack_obj; ks = td->td_kstack; for (i = 0; i < KSTACK_PAGES; i++) { m = vm_page_grab(ksobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); if (m->valid != VM_PAGE_BITS_ALL) { rv = vm_pager_get_pages(ksobj, &m, 1, 0); if (rv != VM_PAGER_OK) panic("pmap_swapin_thread: cannot get kstack for proc: %d\n", td->td_proc->p_pid); m = vm_page_lookup(ksobj, i); m->valid = VM_PAGE_BITS_ALL; } ma[i] = m; vm_page_lock_queues(); vm_page_wire(m); vm_page_wakeup(m); vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE); vm_page_unlock_queues(); } pmap_qenter(ks, ma, KSTACK_PAGES); } /*************************************************** * Page table page management routines..... ***************************************************/ /* * This routine unholds page table pages, and if the hold count * drops to zero, then it decrements the wire count. */ static int _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m) { while (vm_page_sleep_busy(m, FALSE, "pmuwpt")) ; if (m->hold_count == 0) { vm_offset_t pteva; /* * unmap the page table page */ pmap->pm_pdir[m->pindex] = 0; --pmap->pm_stats.resident_count; if ((pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde & PG_FRAME)) { /* * Do a invltlb to make the invalidated mapping * take effect immediately. */ pteva = VM_MAXUSER_ADDRESS + i386_ptob(m->pindex); pmap_invalidate_page(pmap, pteva); } if (pmap->pm_ptphint == m) pmap->pm_ptphint = NULL; /* * If the page is finally unwired, simply free it. */ --m->wire_count; if (m->wire_count == 0) { vm_page_flash(m); vm_page_busy(m); vm_page_free_zero(m); --cnt.v_wire_count; } return 1; } return 0; } static PMAP_INLINE int pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m) { vm_page_unhold(m); if (m->hold_count == 0) return _pmap_unwire_pte_hold(pmap, m); else return 0; } /* * After removing a page table entry, this routine is used to * conditionally free the page, and manage the hold/wire counts. */ static int pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t mpte) { unsigned ptepindex; if (va >= VM_MAXUSER_ADDRESS) return 0; if (mpte == NULL) { ptepindex = (va >> PDRSHIFT); if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == ptepindex)) { mpte = pmap->pm_ptphint; } else { mpte = pmap_page_lookup(pmap->pm_pteobj, ptepindex); pmap->pm_ptphint = mpte; } } return pmap_unwire_pte_hold(pmap, mpte); } void pmap_pinit0(pmap) struct pmap *pmap; { pmap->pm_pdir = (pd_entry_t *)kmem_alloc_pageable(kernel_map, PAGE_SIZE); pmap_kenter((vm_offset_t)pmap->pm_pdir, (vm_offset_t)IdlePTD); #ifndef I386_CPU invlpg((vm_offset_t)pmap->pm_pdir); #else invltlb(); #endif pmap->pm_ptphint = NULL; pmap->pm_active = 0; TAILQ_INIT(&pmap->pm_pvlist); bzero(&pmap->pm_stats, sizeof pmap->pm_stats); LIST_INSERT_HEAD(&allpmaps, pmap, pm_list); } /* * Initialize a preallocated and zeroed pmap structure, * such as one in a vmspace structure. */ void pmap_pinit(pmap) register struct pmap *pmap; { vm_page_t ptdpg; /* * No need to allocate page table space yet but we do need a valid * page directory table. */ if (pmap->pm_pdir == NULL) pmap->pm_pdir = (pd_entry_t *)kmem_alloc_pageable(kernel_map, PAGE_SIZE); /* * allocate object for the ptes */ if (pmap->pm_pteobj == NULL) pmap->pm_pteobj = vm_object_allocate(OBJT_DEFAULT, PTDPTDI + 1); /* * allocate the page directory page */ ptdpg = vm_page_grab(pmap->pm_pteobj, PTDPTDI, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); ptdpg->wire_count = 1; ++cnt.v_wire_count; vm_page_flag_clear(ptdpg, PG_MAPPED | PG_BUSY); /* not usually mapped*/ ptdpg->valid = VM_PAGE_BITS_ALL; pmap_qenter((vm_offset_t) pmap->pm_pdir, &ptdpg, 1); if ((ptdpg->flags & PG_ZERO) == 0) bzero(pmap->pm_pdir, PAGE_SIZE); LIST_INSERT_HEAD(&allpmaps, pmap, pm_list); /* Wire in kernel global address entries. */ /* XXX copies current process, does not fill in MPPTDI */ bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * PTESIZE); #ifdef SMP pmap->pm_pdir[MPPTDI] = PTD[MPPTDI]; #endif /* install self-referential address mapping entry */ pmap->pm_pdir[PTDPTDI] = VM_PAGE_TO_PHYS(ptdpg) | PG_V | PG_RW | PG_A | PG_M; pmap->pm_active = 0; pmap->pm_ptphint = NULL; TAILQ_INIT(&pmap->pm_pvlist); bzero(&pmap->pm_stats, sizeof pmap->pm_stats); } /* * Wire in kernel global address entries. To avoid a race condition * between pmap initialization and pmap_growkernel, this procedure * should be called after the vmspace is attached to the process * but before this pmap is activated. */ void pmap_pinit2(pmap) struct pmap *pmap; { /* XXX: Remove this stub when no longer called */ } static int pmap_release_free_page(pmap_t pmap, vm_page_t p) { pd_entry_t *pde = pmap->pm_pdir; /* * This code optimizes the case of freeing non-busy * page-table pages. Those pages are zero now, and * might as well be placed directly into the zero queue. */ if (vm_page_sleep_busy(p, FALSE, "pmaprl")) return 0; vm_page_busy(p); /* * Remove the page table page from the processes address space. */ pde[p->pindex] = 0; pmap->pm_stats.resident_count--; if (p->hold_count) { panic("pmap_release: freeing held page table page"); } /* * Page directory pages need to have the kernel * stuff cleared, so they can go into the zero queue also. */ if (p->pindex == PTDPTDI) { bzero(pde + KPTDI, nkpt * PTESIZE); #ifdef SMP pde[MPPTDI] = 0; #endif pde[APTDPTDI] = 0; pmap_kremove((vm_offset_t) pmap->pm_pdir); } if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == p->pindex)) pmap->pm_ptphint = NULL; p->wire_count--; cnt.v_wire_count--; vm_page_free_zero(p); return 1; } /* * this routine is called if the page table page is not * mapped correctly. */ static vm_page_t _pmap_allocpte(pmap, ptepindex) pmap_t pmap; unsigned ptepindex; { vm_offset_t pteva, ptepa; /* XXXPA */ vm_page_t m; /* * Find or fabricate a new pagetable page */ m = vm_page_grab(pmap->pm_pteobj, ptepindex, VM_ALLOC_ZERO | VM_ALLOC_RETRY); KASSERT(m->queue == PQ_NONE, ("_pmap_allocpte: %p->queue != PQ_NONE", m)); if (m->wire_count == 0) cnt.v_wire_count++; m->wire_count++; /* * Increment the hold count for the page table page * (denoting a new mapping.) */ m->hold_count++; /* * Map the pagetable page into the process address space, if * it isn't already there. */ pmap->pm_stats.resident_count++; ptepa = VM_PAGE_TO_PHYS(m); pmap->pm_pdir[ptepindex] = (pd_entry_t) (ptepa | PG_U | PG_RW | PG_V | PG_A | PG_M); /* * Set the page table hint */ pmap->pm_ptphint = m; /* * Try to use the new mapping, but if we cannot, then * do it with the routine that maps the page explicitly. */ if ((m->flags & PG_ZERO) == 0) { if ((pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde & PG_FRAME)) { pteva = VM_MAXUSER_ADDRESS + i386_ptob(ptepindex); bzero((caddr_t) pteva, PAGE_SIZE); } else { pmap_zero_page(m); } } m->valid = VM_PAGE_BITS_ALL; vm_page_flag_clear(m, PG_ZERO); vm_page_flag_set(m, PG_MAPPED); vm_page_wakeup(m); return m; } static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va) { unsigned ptepindex; pd_entry_t ptepa; vm_page_t m; /* * Calculate pagetable page index */ ptepindex = va >> PDRSHIFT; /* * Get the page directory entry */ ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex]; /* * This supports switching from a 4MB page to a * normal 4K page. */ if (ptepa & PG_PS) { pmap->pm_pdir[ptepindex] = 0; ptepa = 0; pmap_invalidate_all(kernel_pmap); } /* * If the page table page is mapped, we just increment the * hold count, and activate it. */ if (ptepa) { /* * In order to get the page table page, try the * hint first. */ if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == ptepindex)) { m = pmap->pm_ptphint; } else { m = pmap_page_lookup(pmap->pm_pteobj, ptepindex); pmap->pm_ptphint = m; } m->hold_count++; return m; } /* * Here if the pte page isn't mapped, or if it has been deallocated. */ return _pmap_allocpte(pmap, ptepindex); } /*************************************************** * Pmap allocation/deallocation routines. ***************************************************/ /* * Release any resources held by the given physical map. * Called when a pmap initialized by pmap_pinit is being released. * Should only be called if the map contains no valid mappings. */ void pmap_release(pmap_t pmap) { vm_page_t p,n,ptdpg; vm_object_t object = pmap->pm_pteobj; int curgeneration; #if defined(DIAGNOSTIC) if (object->ref_count != 1) panic("pmap_release: pteobj reference count != 1"); #endif ptdpg = NULL; LIST_REMOVE(pmap, pm_list); retry: curgeneration = object->generation; for (p = TAILQ_FIRST(&object->memq); p != NULL; p = n) { n = TAILQ_NEXT(p, listq); if (p->pindex == PTDPTDI) { ptdpg = p; continue; } while (1) { if (!pmap_release_free_page(pmap, p) && (object->generation != curgeneration)) goto retry; } } if (ptdpg && !pmap_release_free_page(pmap, ptdpg)) goto retry; } static int kvm_size(SYSCTL_HANDLER_ARGS) { unsigned long ksize = VM_MAX_KERNEL_ADDRESS - KERNBASE; return sysctl_handle_long(oidp, &ksize, 0, req); } SYSCTL_PROC(_vm, OID_AUTO, kvm_size, CTLTYPE_LONG|CTLFLAG_RD, 0, 0, kvm_size, "IU", "Size of KVM"); static int kvm_free(SYSCTL_HANDLER_ARGS) { unsigned long kfree = VM_MAX_KERNEL_ADDRESS - kernel_vm_end; return sysctl_handle_long(oidp, &kfree, 0, req); } SYSCTL_PROC(_vm, OID_AUTO, kvm_free, CTLTYPE_LONG|CTLFLAG_RD, 0, 0, kvm_free, "IU", "Amount of KVM free"); /* * grow the number of kernel page table entries, if needed */ void pmap_growkernel(vm_offset_t addr) { struct pmap *pmap; int s; vm_offset_t ptppaddr; vm_page_t nkpg; pd_entry_t newpdir; s = splhigh(); if (kernel_vm_end == 0) { kernel_vm_end = KERNBASE; nkpt = 0; while (pdir_pde(PTD, kernel_vm_end)) { kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); nkpt++; } } addr = (addr + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); while (kernel_vm_end < addr) { if (pdir_pde(PTD, kernel_vm_end)) { kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); continue; } /* * This index is bogus, but out of the way */ - nkpg = vm_page_alloc(kptobj, nkpt, VM_ALLOC_SYSTEM); + nkpg = vm_page_alloc(kptobj, nkpt, + VM_ALLOC_SYSTEM | VM_ALLOC_WIRED); if (!nkpg) panic("pmap_growkernel: no memory to grow kernel"); nkpt++; - vm_page_lock_queues(); - vm_page_wire(nkpg); - vm_page_unlock_queues(); pmap_zero_page(nkpg); ptppaddr = VM_PAGE_TO_PHYS(nkpg); newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M); pdir_pde(PTD, kernel_vm_end) = newpdir; LIST_FOREACH(pmap, &allpmaps, pm_list) { *pmap_pde(pmap, kernel_vm_end) = newpdir; } kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); } splx(s); } /*************************************************** * page management routines. ***************************************************/ /* * free the pv_entry back to the free list */ static PMAP_INLINE void free_pv_entry(pv_entry_t pv) { pv_entry_count--; uma_zfree(pvzone, pv); } /* * get a new pv_entry, allocating a block from the system * when needed. * the memory allocation is performed bypassing the malloc code * because of the possibility of allocations at interrupt time. */ static pv_entry_t get_pv_entry(void) { pv_entry_count++; if (pv_entry_high_water && (pv_entry_count > pv_entry_high_water) && (pmap_pagedaemon_waken == 0)) { pmap_pagedaemon_waken = 1; wakeup (&vm_pages_needed); } return uma_zalloc(pvzone, M_NOWAIT); } /* * This routine is very drastic, but can save the system * in a pinch. */ void pmap_collect() { int i; vm_page_t m; static int warningdone = 0; if (pmap_pagedaemon_waken == 0) return; if (warningdone < 5) { printf("pmap_collect: collecting pv entries -- suggest increasing PMAP_SHPGPERPROC\n"); warningdone++; } for(i = 0; i < vm_page_array_size; i++) { m = &vm_page_array[i]; if (m->wire_count || m->hold_count || m->busy || (m->flags & (PG_BUSY | PG_UNMANAGED))) continue; pmap_remove_all(m); } pmap_pagedaemon_waken = 0; } /* * If it is the first entry on the list, it is actually * in the header and we must copy the following entry up * to the header. Otherwise we must search the list for * the entry. In either case we free the now unused entry. */ static int pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va) { pv_entry_t pv; int rtval; int s; s = splvm(); if (m->md.pv_list_count < pmap->pm_stats.resident_count) { TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { if (pmap == pv->pv_pmap && va == pv->pv_va) break; } } else { TAILQ_FOREACH(pv, &pmap->pm_pvlist, pv_plist) { if (va == pv->pv_va) break; } } rtval = 0; if (pv) { rtval = pmap_unuse_pt(pmap, va, pv->pv_ptem); TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); m->md.pv_list_count--; if (TAILQ_FIRST(&m->md.pv_list) == NULL) vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist); free_pv_entry(pv); } splx(s); return rtval; } /* * Create a pv entry for page at pa for * (pmap, va). */ static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m) { int s; pv_entry_t pv; s = splvm(); pv = get_pv_entry(); pv->pv_va = va; pv->pv_pmap = pmap; pv->pv_ptem = mpte; TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list); m->md.pv_list_count++; splx(s); } /* * pmap_remove_pte: do the things to unmap a page in a process */ static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va) { pt_entry_t oldpte; vm_page_t m; oldpte = atomic_readandclear_int(ptq); if (oldpte & PG_W) pmap->pm_stats.wired_count -= 1; /* * Machines that don't support invlpg, also don't support * PG_G. */ if (oldpte & PG_G) pmap_invalidate_page(kernel_pmap, va); pmap->pm_stats.resident_count -= 1; if (oldpte & PG_MANAGED) { m = PHYS_TO_VM_PAGE(oldpte); if (oldpte & PG_M) { #if defined(PMAP_DIAGNOSTIC) if (pmap_nw_modified((pt_entry_t) oldpte)) { printf( "pmap_remove: modified page not writable: va: 0x%x, pte: 0x%x\n", va, oldpte); } #endif if (pmap_track_modified(va)) vm_page_dirty(m); } if (oldpte & PG_A) vm_page_flag_set(m, PG_REFERENCED); return pmap_remove_entry(pmap, m, va); } else { return pmap_unuse_pt(pmap, va, NULL); } return 0; } /* * Remove a single page from a process address space */ static void pmap_remove_page(pmap_t pmap, vm_offset_t va) { register pt_entry_t *ptq; /* * if there is no pte for this address, just skip it!!! */ if (*pmap_pde(pmap, va) == 0) { return; } /* * get a local va for mappings for this pmap. */ ptq = get_ptbase(pmap) + i386_btop(va); if (*ptq) { (void) pmap_remove_pte(pmap, ptq, va); pmap_invalidate_page(pmap, va); } return; } /* * Remove the given range of addresses from the specified map. * * It is assumed that the start and end are properly * rounded to the page size. */ void pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { register pt_entry_t *ptbase; vm_offset_t pdnxt; pd_entry_t ptpaddr; vm_offset_t sindex, eindex; int anyvalid; if (pmap == NULL) return; if (pmap->pm_stats.resident_count == 0) return; /* * special handling of removing one page. a very * common operation and easy to short circuit some * code. */ if ((sva + PAGE_SIZE == eva) && ((pmap->pm_pdir[(sva >> PDRSHIFT)] & PG_PS) == 0)) { pmap_remove_page(pmap, sva); return; } anyvalid = 0; /* * Get a local virtual address for the mappings that are being * worked with. */ ptbase = get_ptbase(pmap); sindex = i386_btop(sva); eindex = i386_btop(eva); for (; sindex < eindex; sindex = pdnxt) { unsigned pdirindex; /* * Calculate index for next page table. */ pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1)); if (pmap->pm_stats.resident_count == 0) break; pdirindex = sindex / NPDEPG; ptpaddr = pmap->pm_pdir[pdirindex]; if ((ptpaddr & PG_PS) != 0) { pmap->pm_pdir[pdirindex] = 0; pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE; anyvalid++; continue; } /* * Weed out invalid mappings. Note: we assume that the page * directory table is always allocated, and in kernel virtual. */ if (ptpaddr == 0) continue; /* * Limit our scan to either the end of the va represented * by the current page table page, or to the end of the * range being removed. */ if (pdnxt > eindex) { pdnxt = eindex; } for (; sindex != pdnxt; sindex++) { vm_offset_t va; if (ptbase[sindex] == 0) { continue; } va = i386_ptob(sindex); anyvalid++; if (pmap_remove_pte(pmap, ptbase + sindex, va)) break; } } if (anyvalid) pmap_invalidate_all(pmap); } /* * Routine: pmap_remove_all * Function: * Removes this physical page from * all physical maps in which it resides. * Reflects back modify bits to the pager. * * Notes: * Original versions of this routine were very * inefficient because they iteratively called * pmap_remove (slow...) */ static void pmap_remove_all(vm_page_t m) { register pv_entry_t pv; pt_entry_t *pte, tpte; int s; #if defined(PMAP_DIAGNOSTIC) /* * XXX this makes pmap_page_protect(NONE) illegal for non-managed * pages! */ if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) { panic("pmap_page_protect: illegal for unmanaged page, va: 0x%x", VM_PAGE_TO_PHYS(m)); } #endif s = splvm(); while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) { pv->pv_pmap->pm_stats.resident_count--; pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); tpte = atomic_readandclear_int(pte); if (tpte & PG_W) pv->pv_pmap->pm_stats.wired_count--; if (tpte & PG_A) vm_page_flag_set(m, PG_REFERENCED); /* * Update the vm_page_t clean and reference bits. */ if (tpte & PG_M) { #if defined(PMAP_DIAGNOSTIC) if (pmap_nw_modified((pt_entry_t) tpte)) { printf( "pmap_remove_all: modified page not writable: va: 0x%x, pte: 0x%x\n", pv->pv_va, tpte); } #endif if (pmap_track_modified(pv->pv_va)) vm_page_dirty(m); } pmap_invalidate_page(pv->pv_pmap, pv->pv_va); TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist); TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); m->md.pv_list_count--; pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem); free_pv_entry(pv); } vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); splx(s); } /* * Set the physical protection on the * specified range of this map as requested. */ void pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot) { register pt_entry_t *ptbase; vm_offset_t pdnxt; pd_entry_t ptpaddr; vm_offset_t sindex, eindex; int anychanged; if (pmap == NULL) return; if ((prot & VM_PROT_READ) == VM_PROT_NONE) { pmap_remove(pmap, sva, eva); return; } if (prot & VM_PROT_WRITE) return; anychanged = 0; ptbase = get_ptbase(pmap); sindex = i386_btop(sva); eindex = i386_btop(eva); for (; sindex < eindex; sindex = pdnxt) { unsigned pdirindex; pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1)); pdirindex = sindex / NPDEPG; ptpaddr = pmap->pm_pdir[pdirindex]; if ((ptpaddr & PG_PS) != 0) { pmap->pm_pdir[pdirindex] &= ~(PG_M|PG_RW); pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE; anychanged++; continue; } /* * Weed out invalid mappings. Note: we assume that the page * directory table is always allocated, and in kernel virtual. */ if (ptpaddr == 0) continue; if (pdnxt > eindex) { pdnxt = eindex; } for (; sindex != pdnxt; sindex++) { pt_entry_t pbits; vm_page_t m; pbits = ptbase[sindex]; if (pbits & PG_MANAGED) { m = NULL; if (pbits & PG_A) { m = PHYS_TO_VM_PAGE(pbits); vm_page_flag_set(m, PG_REFERENCED); pbits &= ~PG_A; } if (pbits & PG_M) { if (pmap_track_modified(i386_ptob(sindex))) { if (m == NULL) m = PHYS_TO_VM_PAGE(pbits); vm_page_dirty(m); pbits &= ~PG_M; } } } pbits &= ~PG_RW; if (pbits != ptbase[sindex]) { ptbase[sindex] = pbits; anychanged = 1; } } } if (anychanged) pmap_invalidate_all(pmap); } /* * Insert the given physical page (p) at * the specified virtual address (v) in the * target physical map with the protection requested. * * If specified, the page will be wired down, meaning * that the related pte can not be reclaimed. * * NB: This is the only routine which MAY NOT lazy-evaluate * or lose information. That is, this routine must actually * insert this page into the given map NOW. */ void pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, boolean_t wired) { vm_offset_t pa; register pt_entry_t *pte; vm_offset_t opa; pt_entry_t origpte, newpte; vm_page_t mpte; if (pmap == NULL) return; va &= PG_FRAME; #ifdef PMAP_DIAGNOSTIC if (va > VM_MAX_KERNEL_ADDRESS) panic("pmap_enter: toobig"); if ((va >= UPT_MIN_ADDRESS) && (va < UPT_MAX_ADDRESS)) panic("pmap_enter: invalid to pmap_enter page table pages (va: 0x%x)", va); #endif mpte = NULL; /* * In the case that a page table page is not * resident, we are creating it here. */ if (va < VM_MAXUSER_ADDRESS) { mpte = pmap_allocpte(pmap, va); } #if 0 && defined(PMAP_DIAGNOSTIC) else { pd_entry_t *pdeaddr = pmap_pde(pmap, va); origpte = *pdeaddr; if ((origpte & PG_V) == 0) { panic("pmap_enter: invalid kernel page table page, pdir=%p, pde=%p, va=%p\n", pmap->pm_pdir[PTDPTDI], origpte, va); } } #endif pte = pmap_pte(pmap, va); /* * Page Directory table entry not valid, we need a new PT page */ if (pte == NULL) { panic("pmap_enter: invalid page directory, pdir=%p, va=0x%x\n", (void *)pmap->pm_pdir[PTDPTDI], va); } pa = VM_PAGE_TO_PHYS(m) & PG_FRAME; origpte = *(vm_offset_t *)pte; opa = origpte & PG_FRAME; if (origpte & PG_PS) panic("pmap_enter: attempted pmap_enter on 4MB page"); /* * Mapping has not changed, must be protection or wiring change. */ if (origpte && (opa == pa)) { /* * Wiring change, just update stats. We don't worry about * wiring PT pages as they remain resident as long as there * are valid mappings in them. Hence, if a user page is wired, * the PT page will be also. */ if (wired && ((origpte & PG_W) == 0)) pmap->pm_stats.wired_count++; else if (!wired && (origpte & PG_W)) pmap->pm_stats.wired_count--; #if defined(PMAP_DIAGNOSTIC) if (pmap_nw_modified((pt_entry_t) origpte)) { printf( "pmap_enter: modified page not writable: va: 0x%x, pte: 0x%x\n", va, origpte); } #endif /* * Remove extra pte reference */ if (mpte) mpte->hold_count--; if ((prot & VM_PROT_WRITE) && (origpte & PG_V)) { if ((origpte & PG_RW) == 0) { *pte |= PG_RW; pmap_invalidate_page(pmap, va); } return; } /* * We might be turning off write access to the page, * so we go ahead and sense modify status. */ if (origpte & PG_MANAGED) { if ((origpte & PG_M) && pmap_track_modified(va)) { vm_page_t om; om = PHYS_TO_VM_PAGE(opa); vm_page_dirty(om); } pa |= PG_MANAGED; } goto validate; } /* * Mapping has changed, invalidate old range and fall through to * handle validating new mapping. */ if (opa) { int err; err = pmap_remove_pte(pmap, pte, va); if (err) panic("pmap_enter: pte vanished, va: 0x%x", va); } /* * Enter on the PV list if part of our managed memory. Note that we * raise IPL while manipulating pv_table since pmap_enter can be * called at interrupt time. */ if (pmap_initialized && (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) { pmap_insert_entry(pmap, va, mpte, m); pa |= PG_MANAGED; } /* * Increment counters */ pmap->pm_stats.resident_count++; if (wired) pmap->pm_stats.wired_count++; validate: /* * Now validate mapping with desired protection/wiring. */ newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | PG_V); if (wired) newpte |= PG_W; if (va < VM_MAXUSER_ADDRESS) newpte |= PG_U; if (pmap == kernel_pmap) newpte |= pgeflag; /* * if the mapping or permission bits are different, we need * to update the pte. */ if ((origpte & ~(PG_M|PG_A)) != newpte) { *pte = newpte | PG_A; /*if (origpte)*/ { pmap_invalidate_page(pmap, va); } } } /* * this code makes some *MAJOR* assumptions: * 1. Current pmap & pmap exists. * 2. Not wired. * 3. Read access. * 4. No page table pages. * 5. Tlbflush is deferred to calling procedure. * 6. Page IS managed. * but is *MUCH* faster than pmap_enter... */ static vm_page_t pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_page_t mpte) { pt_entry_t *pte; vm_offset_t pa; /* * In the case that a page table page is not * resident, we are creating it here. */ if (va < VM_MAXUSER_ADDRESS) { unsigned ptepindex; pd_entry_t ptepa; /* * Calculate pagetable page index */ ptepindex = va >> PDRSHIFT; if (mpte && (mpte->pindex == ptepindex)) { mpte->hold_count++; } else { retry: /* * Get the page directory entry */ ptepa = pmap->pm_pdir[ptepindex]; /* * If the page table page is mapped, we just increment * the hold count, and activate it. */ if (ptepa) { if (ptepa & PG_PS) panic("pmap_enter_quick: unexpected mapping into 4MB page"); if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == ptepindex)) { mpte = pmap->pm_ptphint; } else { mpte = pmap_page_lookup(pmap->pm_pteobj, ptepindex); pmap->pm_ptphint = mpte; } if (mpte == NULL) goto retry; mpte->hold_count++; } else { mpte = _pmap_allocpte(pmap, ptepindex); } } } else { mpte = NULL; } /* * This call to vtopte makes the assumption that we are * entering the page into the current pmap. In order to support * quick entry into any pmap, one would likely use pmap_pte_quick. * But that isn't as quick as vtopte. */ pte = vtopte(va); if (*pte) { if (mpte) pmap_unwire_pte_hold(pmap, mpte); return 0; } /* * Enter on the PV list if part of our managed memory. Note that we * raise IPL while manipulating pv_table since pmap_enter can be * called at interrupt time. */ if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) pmap_insert_entry(pmap, va, mpte, m); /* * Increment counters */ pmap->pm_stats.resident_count++; pa = VM_PAGE_TO_PHYS(m); /* * Now validate mapping with RO protection */ if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) *pte = pa | PG_V | PG_U; else *pte = pa | PG_V | PG_U | PG_MANAGED; return mpte; } /* * Make a temporary mapping for a physical address. This is only intended * to be used for panic dumps. */ void * pmap_kenter_temporary(vm_offset_t pa, int i) { vm_offset_t va; va = (vm_offset_t)crashdumpmap + (i * PAGE_SIZE); pmap_kenter(va, pa); #ifndef I386_CPU invlpg(va); #else invltlb(); #endif return ((void *)crashdumpmap); } #define MAX_INIT_PT (96) /* * pmap_object_init_pt preloads the ptes for a given object * into the specified pmap. This eliminates the blast of soft * faults on process startup and immediately after an mmap. */ void pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_object_t object, vm_pindex_t pindex, vm_size_t size, int limit) { vm_offset_t tmpidx; int psize; vm_page_t p, mpte; int objpgs; if (pmap == NULL || object == NULL) return; /* * This code maps large physical mmap regions into the * processor address space. Note that some shortcuts * are taken, but the code works. */ if (pseflag && (object->type == OBJT_DEVICE) && ((addr & (NBPDR - 1)) == 0) && ((size & (NBPDR - 1)) == 0)) { int i; vm_page_t m[1]; unsigned int ptepindex; int npdes; pd_entry_t ptepa; if (pmap->pm_pdir[ptepindex = (addr >> PDRSHIFT)]) return; retry: p = vm_page_lookup(object, pindex); if (p && vm_page_sleep_busy(p, FALSE, "init4p")) goto retry; if (p == NULL) { p = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL); if (p == NULL) return; m[0] = p; if (vm_pager_get_pages(object, m, 1, 0) != VM_PAGER_OK) { vm_page_free(p); return; } p = vm_page_lookup(object, pindex); vm_page_wakeup(p); } ptepa = VM_PAGE_TO_PHYS(p); if (ptepa & (NBPDR - 1)) { return; } p->valid = VM_PAGE_BITS_ALL; pmap->pm_stats.resident_count += size >> PAGE_SHIFT; npdes = size >> PDRSHIFT; for(i = 0; i < npdes; i++) { pmap->pm_pdir[ptepindex] = ptepa | PG_U | PG_RW | PG_V | PG_PS; ptepa += NBPDR; ptepindex += 1; } vm_page_flag_set(p, PG_MAPPED); pmap_invalidate_all(kernel_pmap); return; } psize = i386_btop(size); if ((object->type != OBJT_VNODE) || ((limit & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) && (object->resident_page_count > MAX_INIT_PT))) { return; } if (psize + pindex > object->size) { if (object->size < pindex) return; psize = object->size - pindex; } mpte = NULL; /* * if we are processing a major portion of the object, then scan the * entire thing. */ if (psize > (object->resident_page_count >> 2)) { objpgs = psize; for (p = TAILQ_FIRST(&object->memq); ((objpgs > 0) && (p != NULL)); p = TAILQ_NEXT(p, listq)) { if (p->pindex < pindex || p->pindex - pindex >= psize) { continue; } tmpidx = p->pindex - pindex; /* * don't allow an madvise to blow away our really * free pages allocating pv entries. */ if ((limit & MAP_PREFAULT_MADVISE) && cnt.v_free_count < cnt.v_free_reserved) { break; } if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if ((p->queue - p->pc) == PQ_CACHE) vm_page_deactivate(p); vm_page_busy(p); mpte = pmap_enter_quick(pmap, addr + i386_ptob(tmpidx), p, mpte); vm_page_flag_set(p, PG_MAPPED); vm_page_wakeup(p); } objpgs -= 1; } } else { /* * else lookup the pages one-by-one. */ for (tmpidx = 0; tmpidx < psize; tmpidx += 1) { /* * don't allow an madvise to blow away our really * free pages allocating pv entries. */ if ((limit & MAP_PREFAULT_MADVISE) && cnt.v_free_count < cnt.v_free_reserved) { break; } p = vm_page_lookup(object, tmpidx + pindex); if (p && ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if ((p->queue - p->pc) == PQ_CACHE) vm_page_deactivate(p); vm_page_busy(p); mpte = pmap_enter_quick(pmap, addr + i386_ptob(tmpidx), p, mpte); vm_page_flag_set(p, PG_MAPPED); vm_page_wakeup(p); } } } return; } /* * pmap_prefault provides a quick way of clustering * pagefaults into a processes address space. It is a "cousin" * of pmap_object_init_pt, except it runs at page fault time instead * of mmap time. */ #define PFBAK 4 #define PFFOR 4 #define PAGEORDER_SIZE (PFBAK+PFFOR) static int pmap_prefault_pageorder[] = { -PAGE_SIZE, PAGE_SIZE, -2 * PAGE_SIZE, 2 * PAGE_SIZE, -3 * PAGE_SIZE, 3 * PAGE_SIZE -4 * PAGE_SIZE, 4 * PAGE_SIZE }; void pmap_prefault(pmap, addra, entry) pmap_t pmap; vm_offset_t addra; vm_map_entry_t entry; { int i; vm_offset_t starta; vm_offset_t addr; vm_pindex_t pindex; vm_page_t m, mpte; vm_object_t object; if (!curthread || (pmap != vmspace_pmap(curthread->td_proc->p_vmspace))) return; object = entry->object.vm_object; starta = addra - PFBAK * PAGE_SIZE; if (starta < entry->start) { starta = entry->start; } else if (starta > addra) { starta = 0; } mpte = NULL; for (i = 0; i < PAGEORDER_SIZE; i++) { vm_object_t lobject; pt_entry_t *pte; addr = addra + pmap_prefault_pageorder[i]; if (addr > addra + (PFFOR * PAGE_SIZE)) addr = 0; if (addr < starta || addr >= entry->end) continue; if ((*pmap_pde(pmap, addr)) == NULL) continue; pte = vtopte(addr); if (*pte) continue; pindex = ((addr - entry->start) + entry->offset) >> PAGE_SHIFT; lobject = object; for (m = vm_page_lookup(lobject, pindex); (!m && (lobject->type == OBJT_DEFAULT) && (lobject->backing_object)); lobject = lobject->backing_object) { if (lobject->backing_object_offset & PAGE_MASK) break; pindex += (lobject->backing_object_offset >> PAGE_SHIFT); m = vm_page_lookup(lobject->backing_object, pindex); } /* * give-up when a page is not in memory */ if (m == NULL) break; if (((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (m->busy == 0) && (m->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if ((m->queue - m->pc) == PQ_CACHE) { vm_page_deactivate(m); } vm_page_busy(m); mpte = pmap_enter_quick(pmap, addr, m, mpte); vm_page_flag_set(m, PG_MAPPED); vm_page_wakeup(m); } } } /* * Routine: pmap_change_wiring * Function: Change the wiring attribute for a map/virtual-address * pair. * In/out conditions: * The mapping must already exist in the pmap. */ void pmap_change_wiring(pmap, va, wired) register pmap_t pmap; vm_offset_t va; boolean_t wired; { register pt_entry_t *pte; if (pmap == NULL) return; pte = pmap_pte(pmap, va); if (wired && !pmap_pte_w(pte)) pmap->pm_stats.wired_count++; else if (!wired && pmap_pte_w(pte)) pmap->pm_stats.wired_count--; /* * Wiring is not a hardware characteristic so there is no need to * invalidate TLB. */ pmap_pte_set_w(pte, wired); } /* * Copy the range specified by src_addr/len * from the source map to the range dst_addr/len * in the destination map. * * This routine is only advisory and need not do anything. */ void pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len, vm_offset_t src_addr) { vm_offset_t addr; vm_offset_t end_addr = src_addr + len; vm_offset_t pdnxt; pd_entry_t src_frame, dst_frame; vm_page_t m; if (dst_addr != src_addr) return; src_frame = src_pmap->pm_pdir[PTDPTDI] & PG_FRAME; if (src_frame != (PTDpde & PG_FRAME)) return; dst_frame = dst_pmap->pm_pdir[PTDPTDI] & PG_FRAME; for (addr = src_addr; addr < end_addr; addr = pdnxt) { pt_entry_t *src_pte, *dst_pte; vm_page_t dstmpte, srcmpte; pd_entry_t srcptepaddr; unsigned ptepindex; if (addr >= UPT_MIN_ADDRESS) panic("pmap_copy: invalid to pmap_copy page tables\n"); /* * Don't let optional prefaulting of pages make us go * way below the low water mark of free pages or way * above high water mark of used pv entries. */ if (cnt.v_free_count < cnt.v_free_reserved || pv_entry_count > pv_entry_high_water) break; pdnxt = ((addr + PAGE_SIZE*NPTEPG) & ~(PAGE_SIZE*NPTEPG - 1)); ptepindex = addr >> PDRSHIFT; srcptepaddr = src_pmap->pm_pdir[ptepindex]; if (srcptepaddr == 0) continue; if (srcptepaddr & PG_PS) { if (dst_pmap->pm_pdir[ptepindex] == 0) { dst_pmap->pm_pdir[ptepindex] = srcptepaddr; dst_pmap->pm_stats.resident_count += NBPDR / PAGE_SIZE; } continue; } srcmpte = vm_page_lookup(src_pmap->pm_pteobj, ptepindex); if ((srcmpte == NULL) || (srcmpte->hold_count == 0) || (srcmpte->flags & PG_BUSY)) continue; if (pdnxt > end_addr) pdnxt = end_addr; /* * Have to recheck this before every avtopte() call below * in case we have blocked and something else used APTDpde. */ if (dst_frame != (APTDpde & PG_FRAME)) { APTDpde = dst_frame | PG_RW | PG_V; pmap_invalidate_all(kernel_pmap); /* XXX Bandaid */ } src_pte = vtopte(addr); dst_pte = avtopte(addr); while (addr < pdnxt) { pt_entry_t ptetemp; ptetemp = *src_pte; /* * we only virtual copy managed pages */ if ((ptetemp & PG_MANAGED) != 0) { /* * We have to check after allocpte for the * pte still being around... allocpte can * block. */ dstmpte = pmap_allocpte(dst_pmap, addr); if ((*dst_pte == 0) && (ptetemp = *src_pte)) { /* * Clear the modified and * accessed (referenced) bits * during the copy. */ m = PHYS_TO_VM_PAGE(ptetemp); *dst_pte = ptetemp & ~(PG_M | PG_A); dst_pmap->pm_stats.resident_count++; pmap_insert_entry(dst_pmap, addr, dstmpte, m); } else { pmap_unwire_pte_hold(dst_pmap, dstmpte); } if (dstmpte->hold_count >= srcmpte->hold_count) break; } addr += PAGE_SIZE; src_pte++; dst_pte++; } } } #ifdef SMP /* * pmap_zpi_switchin*() * * These functions allow us to avoid doing IPIs alltogether in certain * temporary page-mapping situations (page zeroing). Instead to deal * with being preempted and moved onto a different cpu we invalidate * the page when the scheduler switches us in. This does not occur * very often so we remain relatively optimal with very little effort. */ static void pmap_zpi_switchin12(void) { invlpg((u_int)CADDR1); invlpg((u_int)CADDR2); } static void pmap_zpi_switchin2(void) { invlpg((u_int)CADDR2); } static void pmap_zpi_switchin3(void) { invlpg((u_int)CADDR3); } #endif /* * pmap_zero_page zeros the specified hardware page by mapping * the page into KVM and using bzero to clear its contents. */ void pmap_zero_page(vm_page_t m) { vm_offset_t phys; phys = VM_PAGE_TO_PHYS(m); if (*CMAP2) panic("pmap_zero_page: CMAP2 busy"); *CMAP2 = PG_V | PG_RW | phys | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin2; #endif invlpg((u_int)CADDR2); #endif #if defined(I686_CPU) if (cpu_class == CPUCLASS_686) i686_pagezero(CADDR2); else #endif bzero(CADDR2, PAGE_SIZE); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP2 = 0; } /* * pmap_zero_page_area zeros the specified hardware page by mapping * the page into KVM and using bzero to clear its contents. * * off and size may not cover an area beyond a single hardware page. */ void pmap_zero_page_area(vm_page_t m, int off, int size) { vm_offset_t phys; phys = VM_PAGE_TO_PHYS(m); if (*CMAP2) panic("pmap_zero_page: CMAP2 busy"); *CMAP2 = PG_V | PG_RW | phys | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin2; #endif invlpg((u_int)CADDR2); #endif #if defined(I686_CPU) if (cpu_class == CPUCLASS_686 && off == 0 && size == PAGE_SIZE) i686_pagezero(CADDR2); else #endif bzero((char *)CADDR2 + off, size); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP2 = 0; } /* * pmap_zero_page_idle zeros the specified hardware page by mapping * the page into KVM and using bzero to clear its contents. This * is intended to be called from the vm_pagezero process only and * outside of Giant. */ void pmap_zero_page_idle(vm_page_t m) { vm_offset_t phys; phys = VM_PAGE_TO_PHYS(m); if (*CMAP3) panic("pmap_zero_page: CMAP3 busy"); *CMAP3 = PG_V | PG_RW | phys | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin3; #endif invlpg((u_int)CADDR3); #endif #if defined(I686_CPU) if (cpu_class == CPUCLASS_686) i686_pagezero(CADDR3); else #endif bzero(CADDR3, PAGE_SIZE); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP3 = 0; } /* * pmap_copy_page copies the specified (machine independent) * page by mapping the page into virtual memory and using * bcopy to copy the page, one machine dependent page at a * time. */ void pmap_copy_page(vm_page_t src, vm_page_t dst) { if (*CMAP1) panic("pmap_copy_page: CMAP1 busy"); if (*CMAP2) panic("pmap_copy_page: CMAP2 busy"); *CMAP1 = PG_V | VM_PAGE_TO_PHYS(src) | PG_A; *CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(dst) | PG_A | PG_M; #ifdef I386_CPU invltlb(); #else #ifdef SMP curthread->td_switchin = pmap_zpi_switchin12; #endif invlpg((u_int)CADDR1); invlpg((u_int)CADDR2); #endif bcopy(CADDR1, CADDR2, PAGE_SIZE); #ifdef SMP curthread->td_switchin = NULL; #endif *CMAP1 = 0; *CMAP2 = 0; } /* * Routine: pmap_pageable * Function: * Make the specified pages (by pmap, offset) * pageable (or not) as requested. * * A page which is not pageable may not take * a fault; therefore, its page table entry * must remain valid for the duration. * * This routine is merely advisory; pmap_enter * will specify that these pages are to be wired * down (or not) as appropriate. */ void pmap_pageable(pmap, sva, eva, pageable) pmap_t pmap; vm_offset_t sva, eva; boolean_t pageable; { } /* * Returns true if the pmap's pv is one of the first * 16 pvs linked to from this page. This count may * be changed upwards or downwards in the future; it * is only necessary that true be returned for a small * subset of pmaps for proper page aging. */ boolean_t pmap_page_exists_quick(pmap, m) pmap_t pmap; vm_page_t m; { pv_entry_t pv; int loops = 0; int s; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return FALSE; s = splvm(); TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { if (pv->pv_pmap == pmap) { splx(s); return TRUE; } loops++; if (loops >= 16) break; } splx(s); return (FALSE); } #define PMAP_REMOVE_PAGES_CURPROC_ONLY /* * Remove all pages from specified address space * this aids process exit speeds. Also, this code * is special cased for current process only, but * can have the more generic (and slightly slower) * mode enabled. This is much faster than pmap_remove * in the case of running down an entire address space. */ void pmap_remove_pages(pmap, sva, eva) pmap_t pmap; vm_offset_t sva, eva; { pt_entry_t *pte, tpte; vm_page_t m; pv_entry_t pv, npv; int s; #ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY if (!curthread || (pmap != vmspace_pmap(curthread->td_proc->p_vmspace))) { printf("warning: pmap_remove_pages called with non-current pmap\n"); return; } #endif s = splvm(); for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) { if (pv->pv_va >= eva || pv->pv_va < sva) { npv = TAILQ_NEXT(pv, pv_plist); continue; } #ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY pte = vtopte(pv->pv_va); #else pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); #endif tpte = *pte; if (tpte == 0) { printf("TPTE at %p IS ZERO @ VA %08x\n", pte, pv->pv_va); panic("bad pte"); } /* * We cannot remove wired pages from a process' mapping at this time */ if (tpte & PG_W) { npv = TAILQ_NEXT(pv, pv_plist); continue; } m = PHYS_TO_VM_PAGE(tpte); KASSERT(m->phys_addr == (tpte & PG_FRAME), ("vm_page_t %p phys_addr mismatch %08x %08x", m, m->phys_addr, tpte)); KASSERT(m < &vm_page_array[vm_page_array_size], ("pmap_remove_pages: bad tpte %x", tpte)); pv->pv_pmap->pm_stats.resident_count--; *pte = 0; /* * Update the vm_page_t clean and reference bits. */ if (tpte & PG_M) { vm_page_dirty(m); } npv = TAILQ_NEXT(pv, pv_plist); TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist); m->md.pv_list_count--; TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); if (TAILQ_FIRST(&m->md.pv_list) == NULL) { vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); } pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem); free_pv_entry(pv); } splx(s); pmap_invalidate_all(pmap); } /* * pmap_testbit tests bits in pte's * note that the testbit/changebit routines are inline, * and a lot of things compile-time evaluate. */ static boolean_t pmap_testbit(m, bit) vm_page_t m; int bit; { pv_entry_t pv; pt_entry_t *pte; int s; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return FALSE; if (TAILQ_FIRST(&m->md.pv_list) == NULL) return FALSE; s = splvm(); TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { /* * if the bit being tested is the modified bit, then * mark clean_map and ptes as never * modified. */ if (bit & (PG_A|PG_M)) { if (!pmap_track_modified(pv->pv_va)) continue; } #if defined(PMAP_DIAGNOSTIC) if (!pv->pv_pmap) { printf("Null pmap (tb) at va: 0x%x\n", pv->pv_va); continue; } #endif pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); if (*pte & bit) { splx(s); return TRUE; } } splx(s); return (FALSE); } /* * this routine is used to modify bits in ptes */ static __inline void pmap_changebit(vm_page_t m, int bit, boolean_t setem) { register pv_entry_t pv; register pt_entry_t *pte; int s; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return; s = splvm(); /* * Loop over all current mappings setting/clearing as appropos If * setting RO do we need to clear the VAC? */ TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { /* * don't write protect pager mappings */ if (!setem && (bit == PG_RW)) { if (!pmap_track_modified(pv->pv_va)) continue; } #if defined(PMAP_DIAGNOSTIC) if (!pv->pv_pmap) { printf("Null pmap (cb) at va: 0x%x\n", pv->pv_va); continue; } #endif pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); if (setem) { *pte |= bit; pmap_invalidate_page(pv->pv_pmap, pv->pv_va); } else { pt_entry_t pbits = *pte; if (pbits & bit) { if (bit == PG_RW) { if (pbits & PG_M) { vm_page_dirty(m); } *pte = pbits & ~(PG_M|PG_RW); } else { *pte = pbits & ~bit; } pmap_invalidate_page(pv->pv_pmap, pv->pv_va); } } } splx(s); } /* * pmap_page_protect: * * Lower the permission for all mappings to a given page. */ void pmap_page_protect(vm_page_t m, vm_prot_t prot) { if ((prot & VM_PROT_WRITE) == 0) { if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) { pmap_changebit(m, PG_RW, FALSE); } else { pmap_remove_all(m); } } } vm_offset_t pmap_phys_address(ppn) int ppn; { return (i386_ptob(ppn)); } /* * pmap_ts_referenced: * * Return a count of reference bits for a page, clearing those bits. * It is not necessary for every reference bit to be cleared, but it * is necessary that 0 only be returned when there are truly no * reference bits set. * * XXX: The exact number of bits to check and clear is a matter that * should be tested and standardized at some point in the future for * optimal aging of shared pages. */ int pmap_ts_referenced(vm_page_t m) { register pv_entry_t pv, pvf, pvn; pt_entry_t *pte; int s; int rtval = 0; if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) return (rtval); s = splvm(); if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) { pvf = pv; do { pvn = TAILQ_NEXT(pv, pv_list); TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list); if (!pmap_track_modified(pv->pv_va)) continue; pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va); if (pte && (*pte & PG_A)) { *pte &= ~PG_A; pmap_invalidate_page(pv->pv_pmap, pv->pv_va); rtval++; if (rtval > 4) { break; } } } while ((pv = pvn) != NULL && pv != pvf); } splx(s); return (rtval); } /* * pmap_is_modified: * * Return whether or not the specified physical page was modified * in any physical maps. */ boolean_t pmap_is_modified(vm_page_t m) { return pmap_testbit(m, PG_M); } /* * Clear the modify bits on the specified physical page. */ void pmap_clear_modify(vm_page_t m) { pmap_changebit(m, PG_M, FALSE); } /* * pmap_clear_reference: * * Clear the reference bit on the specified physical page. */ void pmap_clear_reference(vm_page_t m) { pmap_changebit(m, PG_A, FALSE); } /* * Miscellaneous support routines follow */ static void i386_protection_init() { register int *kp, prot; kp = protection_codes; for (prot = 0; prot < 8; prot++) { switch (prot) { case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_NONE: /* * Read access is also 0. There isn't any execute bit, * so just make it readable. */ case VM_PROT_READ | VM_PROT_NONE | VM_PROT_NONE: case VM_PROT_READ | VM_PROT_NONE | VM_PROT_EXECUTE: case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_EXECUTE: *kp++ = 0; break; case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_NONE: case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_EXECUTE: case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_NONE: case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE: *kp++ = PG_RW; break; } } } /* * Map a set of physical memory pages into the kernel virtual * address space. Return a pointer to where it is mapped. This * routine is intended to be used for mapping device memory, * NOT real memory. */ void * pmap_mapdev(pa, size) vm_offset_t pa; vm_size_t size; { vm_offset_t va, tmpva, offset; pt_entry_t *pte; offset = pa & PAGE_MASK; size = roundup(offset + size, PAGE_SIZE); GIANT_REQUIRED; va = kmem_alloc_pageable(kernel_map, size); if (!va) panic("pmap_mapdev: Couldn't alloc kernel virtual memory"); pa = pa & PG_FRAME; for (tmpva = va; size > 0; ) { pte = vtopte(tmpva); *pte = pa | PG_RW | PG_V | pgeflag; size -= PAGE_SIZE; tmpva += PAGE_SIZE; pa += PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, va, tmpva); return ((void *)(va + offset)); } void pmap_unmapdev(va, size) vm_offset_t va; vm_size_t size; { vm_offset_t base, offset, tmpva; pt_entry_t *pte; base = va & PG_FRAME; offset = va & PAGE_MASK; size = roundup(offset + size, PAGE_SIZE); for (tmpva = base; tmpva < (base + size); tmpva += PAGE_SIZE) { pte = vtopte(tmpva); *pte = 0; } pmap_invalidate_range(kernel_pmap, va, tmpva); kmem_free(kernel_map, base, size); } /* * perform the pmap work for mincore */ int pmap_mincore(pmap, addr) pmap_t pmap; vm_offset_t addr; { pt_entry_t *ptep, pte; vm_page_t m; int val = 0; ptep = pmap_pte(pmap, addr); if (ptep == 0) { return 0; } if ((pte = *ptep) != 0) { vm_offset_t pa; val = MINCORE_INCORE; if ((pte & PG_MANAGED) == 0) return val; pa = pte & PG_FRAME; m = PHYS_TO_VM_PAGE(pa); /* * Modified by us */ if (pte & PG_M) val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER; /* * Modified by someone */ else if (m->dirty || pmap_is_modified(m)) val |= MINCORE_MODIFIED_OTHER; /* * Referenced by us */ if (pte & PG_A) val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER; /* * Referenced by someone */ else if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) { val |= MINCORE_REFERENCED_OTHER; vm_page_flag_set(m, PG_REFERENCED); } } return val; } void pmap_activate(struct thread *td) { struct proc *p = td->td_proc; pmap_t pmap; u_int32_t cr3; pmap = vmspace_pmap(td->td_proc->p_vmspace); #if defined(SMP) pmap->pm_active |= PCPU_GET(cpumask); #else pmap->pm_active |= 1; #endif #if defined(SWTCH_OPTIM_STATS) tlb_flush_count++; #endif cr3 = vtophys(pmap->pm_pdir); /* XXXKSE this is wrong. * pmap_activate is for the current thread on the current cpu */ if (p->p_flag & P_KSES) { /* Make sure all other cr3 entries are updated. */ /* what if they are running? XXXKSE (maybe abort them) */ FOREACH_THREAD_IN_PROC(p, td) { td->td_pcb->pcb_cr3 = cr3; } } else { td->td_pcb->pcb_cr3 = cr3; } load_cr3(cr3); } vm_offset_t pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size) { if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) { return addr; } addr = (addr + (NBPDR - 1)) & ~(NBPDR - 1); return addr; } #if defined(PMAP_DEBUG) pmap_pid_dump(int pid) { pmap_t pmap; struct proc *p; int npte = 0; int index; sx_slock(&allproc_lock); LIST_FOREACH(p, &allproc, p_list) { if (p->p_pid != pid) continue; if (p->p_vmspace) { int i,j; index = 0; pmap = vmspace_pmap(p->p_vmspace); for (i = 0; i < NPDEPG; i++) { pd_entry_t *pde; pt_entry_t *pte; vm_offset_t base = i << PDRSHIFT; pde = &pmap->pm_pdir[i]; if (pde && pmap_pde_v(pde)) { for (j = 0; j < NPTEPG; j++) { vm_offset_t va = base + (j << PAGE_SHIFT); if (va >= (vm_offset_t) VM_MIN_KERNEL_ADDRESS) { if (index) { index = 0; printf("\n"); } sx_sunlock(&allproc_lock); return npte; } pte = pmap_pte_quick(pmap, va); if (pte && pmap_pte_v(pte)) { pt_entry_t pa; vm_page_t m; pa = *pte; m = PHYS_TO_VM_PAGE(pa); printf("va: 0x%x, pt: 0x%x, h: %d, w: %d, f: 0x%x", va, pa, m->hold_count, m->wire_count, m->flags); npte++; index++; if (index >= 2) { index = 0; printf("\n"); } else { printf(" "); } } } } } } } sx_sunlock(&allproc_lock); return npte; } #endif #if defined(DEBUG) static void pads(pmap_t pm); void pmap_pvdump(vm_offset_t pa); /* print address space of pmap*/ static void pads(pm) pmap_t pm; { int i, j; vm_offset_t va; pt_entry_t *ptep; if (pm == kernel_pmap) return; for (i = 0; i < NPDEPG; i++) if (pm->pm_pdir[i]) for (j = 0; j < NPTEPG; j++) { va = (i << PDRSHIFT) + (j << PAGE_SHIFT); if (pm == kernel_pmap && va < KERNBASE) continue; if (pm != kernel_pmap && va > UPT_MAX_ADDRESS) continue; ptep = pmap_pte_quick(pm, va); if (pmap_pte_v(ptep)) printf("%x:%x ", va, *ptep); }; } void pmap_pvdump(pa) vm_offset_t pa; { pv_entry_t pv; vm_page_t m; printf("pa %x", pa); m = PHYS_TO_VM_PAGE(pa); TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { printf(" -> pmap %p, va %x", (void *)pv->pv_pmap, pv->pv_va); pads(pv->pv_pmap); } printf(" "); } #endif Index: head/sys/kern/vfs_bio.c =================================================================== --- head/sys/kern/vfs_bio.c (revision 100377) +++ head/sys/kern/vfs_bio.c (revision 100378) @@ -1,3445 +1,3444 @@ /* * Copyright (c) 1994,1997 John S. Dyson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice immediately at the beginning of the file, without modification, * this list of conditions, and the following disclaimer. * 2. Absolutely no warranty of function or purpose is made by the author * John S. Dyson. * * $FreeBSD$ */ /* * this file contains a new buffer I/O scheme implementing a coherent * VM object and buffer cache scheme. Pains have been taken to make * sure that the performance degradation associated with schemes such * as this is not realized. * * Author: John S. Dyson * Significant help during the development and debugging phases * had been provided by David Greenman, also of the FreeBSD core team. * * see man buf(9) for more info. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_BIOBUF, "BIO buffer", "BIO buffer"); struct bio_ops bioops; /* I/O operation notification */ struct buf_ops buf_ops_bio = { "buf_ops_bio", bwrite }; /* * XXX buf is global because kern_shutdown.c and ffs_checkoverlap has * carnal knowledge of buffers. This knowledge should be moved to vfs_bio.c. */ struct buf *buf; /* buffer header pool */ struct mtx buftimelock; /* Interlock on setting prio and timo */ static void vm_hold_free_pages(struct buf * bp, vm_offset_t from, vm_offset_t to); static void vm_hold_load_pages(struct buf * bp, vm_offset_t from, vm_offset_t to); static void vfs_page_set_valid(struct buf *bp, vm_ooffset_t off, int pageno, vm_page_t m); static void vfs_clean_pages(struct buf * bp); static void vfs_setdirty(struct buf *bp); static void vfs_vmio_release(struct buf *bp); static void vfs_backgroundwritedone(struct buf *bp); static int flushbufqueues(void); static void buf_daemon(void); int vmiodirenable = TRUE; SYSCTL_INT(_vfs, OID_AUTO, vmiodirenable, CTLFLAG_RW, &vmiodirenable, 0, "Use the VM system for directory writes"); int runningbufspace; SYSCTL_INT(_vfs, OID_AUTO, runningbufspace, CTLFLAG_RD, &runningbufspace, 0, "Amount of presently outstanding async buffer io"); static int bufspace; SYSCTL_INT(_vfs, OID_AUTO, bufspace, CTLFLAG_RD, &bufspace, 0, "KVA memory used for bufs"); static int maxbufspace; SYSCTL_INT(_vfs, OID_AUTO, maxbufspace, CTLFLAG_RD, &maxbufspace, 0, "Maximum allowed value of bufspace (including buf_daemon)"); static int bufmallocspace; SYSCTL_INT(_vfs, OID_AUTO, bufmallocspace, CTLFLAG_RD, &bufmallocspace, 0, "Amount of malloced memory for buffers"); static int maxbufmallocspace; SYSCTL_INT(_vfs, OID_AUTO, maxmallocbufspace, CTLFLAG_RW, &maxbufmallocspace, 0, "Maximum amount of malloced memory for buffers"); static int lobufspace; SYSCTL_INT(_vfs, OID_AUTO, lobufspace, CTLFLAG_RD, &lobufspace, 0, "Minimum amount of buffers we want to have"); static int hibufspace; SYSCTL_INT(_vfs, OID_AUTO, hibufspace, CTLFLAG_RD, &hibufspace, 0, "Maximum allowed value of bufspace (excluding buf_daemon)"); static int bufreusecnt; SYSCTL_INT(_vfs, OID_AUTO, bufreusecnt, CTLFLAG_RW, &bufreusecnt, 0, "Number of times we have reused a buffer"); static int buffreekvacnt; SYSCTL_INT(_vfs, OID_AUTO, buffreekvacnt, CTLFLAG_RW, &buffreekvacnt, 0, "Number of times we have freed the KVA space from some buffer"); static int bufdefragcnt; SYSCTL_INT(_vfs, OID_AUTO, bufdefragcnt, CTLFLAG_RW, &bufdefragcnt, 0, "Number of times we have had to repeat buffer allocation to defragment"); static int lorunningspace; SYSCTL_INT(_vfs, OID_AUTO, lorunningspace, CTLFLAG_RW, &lorunningspace, 0, "Minimum preferred space used for in-progress I/O"); static int hirunningspace; SYSCTL_INT(_vfs, OID_AUTO, hirunningspace, CTLFLAG_RW, &hirunningspace, 0, "Maximum amount of space to use for in-progress I/O"); static int numdirtybuffers; SYSCTL_INT(_vfs, OID_AUTO, numdirtybuffers, CTLFLAG_RD, &numdirtybuffers, 0, "Number of buffers that are dirty (has unwritten changes) at the moment"); static int lodirtybuffers; SYSCTL_INT(_vfs, OID_AUTO, lodirtybuffers, CTLFLAG_RW, &lodirtybuffers, 0, "How many buffers we want to have free before bufdaemon can sleep"); static int hidirtybuffers; SYSCTL_INT(_vfs, OID_AUTO, hidirtybuffers, CTLFLAG_RW, &hidirtybuffers, 0, "When the number of dirty buffers is considered severe"); static int numfreebuffers; SYSCTL_INT(_vfs, OID_AUTO, numfreebuffers, CTLFLAG_RD, &numfreebuffers, 0, "Number of free buffers"); static int lofreebuffers; SYSCTL_INT(_vfs, OID_AUTO, lofreebuffers, CTLFLAG_RW, &lofreebuffers, 0, "XXX Unused"); static int hifreebuffers; SYSCTL_INT(_vfs, OID_AUTO, hifreebuffers, CTLFLAG_RW, &hifreebuffers, 0, "XXX Complicatedly unused"); static int getnewbufcalls; SYSCTL_INT(_vfs, OID_AUTO, getnewbufcalls, CTLFLAG_RW, &getnewbufcalls, 0, "Number of calls to getnewbuf"); static int getnewbufrestarts; SYSCTL_INT(_vfs, OID_AUTO, getnewbufrestarts, CTLFLAG_RW, &getnewbufrestarts, 0, "Number of times getnewbuf has had to restart a buffer aquisition"); static int dobkgrdwrite = 1; SYSCTL_INT(_debug, OID_AUTO, dobkgrdwrite, CTLFLAG_RW, &dobkgrdwrite, 0, "Do background writes (honoring the BX_BKGRDWRITE flag)?"); /* * Wakeup point for bufdaemon, as well as indicator of whether it is already * active. Set to 1 when the bufdaemon is already "on" the queue, 0 when it * is idling. */ static int bd_request; /* * bogus page -- for I/O to/from partially complete buffers * this is a temporary solution to the problem, but it is not * really that bad. it would be better to split the buffer * for input in the case of buffers partially already in memory, * but the code is intricate enough already. */ vm_page_t bogus_page; /* * Offset for bogus_page. * XXX bogus_offset should be local to bufinit */ static vm_offset_t bogus_offset; /* * Synchronization (sleep/wakeup) variable for active buffer space requests. * Set when wait starts, cleared prior to wakeup(). * Used in runningbufwakeup() and waitrunningbufspace(). */ static int runningbufreq; /* * Synchronization (sleep/wakeup) variable for buffer requests. * Can contain the VFS_BIO_NEED flags defined below; setting/clearing is done * by and/or. * Used in numdirtywakeup(), bufspacewakeup(), bufcountwakeup(), bwillwrite(), * getnewbuf(), and getblk(). */ static int needsbuffer; #ifdef USE_BUFHASH /* * Mask for index into the buffer hash table, which needs to be power of 2 in * size. Set in kern_vfs_bio_buffer_alloc. */ static int bufhashmask; /* * Hash table for all buffers, with a linked list hanging from each table * entry. Set in kern_vfs_bio_buffer_alloc, initialized in buf_init. */ static LIST_HEAD(bufhashhdr, buf) *bufhashtbl; /* * Somewhere to store buffers when they are not in another list, to always * have them in a list (and thus being able to use the same set of operations * on them.) */ static struct bufhashhdr invalhash; #endif /* * Definitions for the buffer free lists. */ #define BUFFER_QUEUES 6 /* number of free buffer queues */ #define QUEUE_NONE 0 /* on no queue */ #define QUEUE_LOCKED 1 /* locked buffers */ #define QUEUE_CLEAN 2 /* non-B_DELWRI buffers */ #define QUEUE_DIRTY 3 /* B_DELWRI buffers */ #define QUEUE_EMPTYKVA 4 /* empty buffer headers w/KVA assignment */ #define QUEUE_EMPTY 5 /* empty buffer headers */ /* Queues for free buffers with various properties */ static TAILQ_HEAD(bqueues, buf) bufqueues[BUFFER_QUEUES] = { { 0 } }; /* * Single global constant for BUF_WMESG, to avoid getting multiple references. * buf_wmesg is referred from macros. */ const char *buf_wmesg = BUF_WMESG; #define VFS_BIO_NEED_ANY 0x01 /* any freeable buffer */ #define VFS_BIO_NEED_DIRTYFLUSH 0x02 /* waiting for dirty buffer flush */ #define VFS_BIO_NEED_FREE 0x04 /* wait for free bufs, hi hysteresis */ #define VFS_BIO_NEED_BUFSPACE 0x08 /* wait for buf space, lo hysteresis */ #ifdef USE_BUFHASH /* * Buffer hash table code. Note that the logical block scans linearly, which * gives us some L1 cache locality. */ static __inline struct bufhashhdr * bufhash(struct vnode *vnp, daddr_t bn) { return(&bufhashtbl[(((uintptr_t)(vnp) >> 7) + (int)bn) & bufhashmask]); } #endif /* * numdirtywakeup: * * If someone is blocked due to there being too many dirty buffers, * and numdirtybuffers is now reasonable, wake them up. */ static __inline void numdirtywakeup(int level) { if (numdirtybuffers <= level) { if (needsbuffer & VFS_BIO_NEED_DIRTYFLUSH) { needsbuffer &= ~VFS_BIO_NEED_DIRTYFLUSH; wakeup(&needsbuffer); } } } /* * bufspacewakeup: * * Called when buffer space is potentially available for recovery. * getnewbuf() will block on this flag when it is unable to free * sufficient buffer space. Buffer space becomes recoverable when * bp's get placed back in the queues. */ static __inline void bufspacewakeup(void) { /* * If someone is waiting for BUF space, wake them up. Even * though we haven't freed the kva space yet, the waiting * process will be able to now. */ if (needsbuffer & VFS_BIO_NEED_BUFSPACE) { needsbuffer &= ~VFS_BIO_NEED_BUFSPACE; wakeup(&needsbuffer); } } /* * runningbufwakeup() - in-progress I/O accounting. * */ static __inline void runningbufwakeup(struct buf *bp) { if (bp->b_runningbufspace) { runningbufspace -= bp->b_runningbufspace; bp->b_runningbufspace = 0; if (runningbufreq && runningbufspace <= lorunningspace) { runningbufreq = 0; wakeup(&runningbufreq); } } } /* * bufcountwakeup: * * Called when a buffer has been added to one of the free queues to * account for the buffer and to wakeup anyone waiting for free buffers. * This typically occurs when large amounts of metadata are being handled * by the buffer cache ( else buffer space runs out first, usually ). */ static __inline void bufcountwakeup(void) { ++numfreebuffers; if (needsbuffer) { needsbuffer &= ~VFS_BIO_NEED_ANY; if (numfreebuffers >= hifreebuffers) needsbuffer &= ~VFS_BIO_NEED_FREE; wakeup(&needsbuffer); } } /* * waitrunningbufspace() * * runningbufspace is a measure of the amount of I/O currently * running. This routine is used in async-write situations to * prevent creating huge backups of pending writes to a device. * Only asynchronous writes are governed by this function. * * Reads will adjust runningbufspace, but will not block based on it. * The read load has a side effect of reducing the allowed write load. * * This does NOT turn an async write into a sync write. It waits * for earlier writes to complete and generally returns before the * caller's write has reached the device. */ static __inline void waitrunningbufspace(void) { /* * XXX race against wakeup interrupt, currently * protected by Giant. FIXME! */ while (runningbufspace > hirunningspace) { ++runningbufreq; tsleep(&runningbufreq, PVM, "wdrain", 0); } } /* * vfs_buf_test_cache: * * Called when a buffer is extended. This function clears the B_CACHE * bit if the newly extended portion of the buffer does not contain * valid data. */ static __inline__ void vfs_buf_test_cache(struct buf *bp, vm_ooffset_t foff, vm_offset_t off, vm_offset_t size, vm_page_t m) { GIANT_REQUIRED; if (bp->b_flags & B_CACHE) { int base = (foff + off) & PAGE_MASK; if (vm_page_is_valid(m, base, size) == 0) bp->b_flags &= ~B_CACHE; } } /* Wake up the buffer deamon if necessary */ static __inline__ void bd_wakeup(int dirtybuflevel) { if (bd_request == 0 && numdirtybuffers >= dirtybuflevel) { bd_request = 1; wakeup(&bd_request); } } /* * bd_speedup - speedup the buffer cache flushing code */ static __inline__ void bd_speedup(void) { bd_wakeup(1); } /* * Calculating buffer cache scaling values and reserve space for buffer * headers. This is called during low level kernel initialization and * may be called more then once. We CANNOT write to the memory area * being reserved at this time. */ caddr_t kern_vfs_bio_buffer_alloc(caddr_t v, int physmem_est) { /* * physmem_est is in pages. Convert it to kilobytes (assumes * PAGE_SIZE is >= 1K) */ physmem_est = physmem_est * (PAGE_SIZE / 1024); /* * The nominal buffer size (and minimum KVA allocation) is BKVASIZE. * For the first 64MB of ram nominally allocate sufficient buffers to * cover 1/4 of our ram. Beyond the first 64MB allocate additional * buffers to cover 1/20 of our ram over 64MB. When auto-sizing * the buffer cache we limit the eventual kva reservation to * maxbcache bytes. * * factor represents the 1/4 x ram conversion. */ if (nbuf == 0) { int factor = 4 * BKVASIZE / 1024; nbuf = 50; if (physmem_est > 4096) nbuf += min((physmem_est - 4096) / factor, 65536 / factor); if (physmem_est > 65536) nbuf += (physmem_est - 65536) * 2 / (factor * 5); if (maxbcache && nbuf > maxbcache / BKVASIZE) nbuf = maxbcache / BKVASIZE; } #if 0 /* * Do not allow the buffer_map to be more then 1/2 the size of the * kernel_map. */ if (nbuf > (kernel_map->max_offset - kernel_map->min_offset) / (BKVASIZE * 2)) { nbuf = (kernel_map->max_offset - kernel_map->min_offset) / (BKVASIZE * 2); printf("Warning: nbufs capped at %d\n", nbuf); } #endif /* * swbufs are used as temporary holders for I/O, such as paging I/O. * We have no less then 16 and no more then 256. */ nswbuf = max(min(nbuf/4, 256), 16); /* * Reserve space for the buffer cache buffers */ swbuf = (void *)v; v = (caddr_t)(swbuf + nswbuf); buf = (void *)v; v = (caddr_t)(buf + nbuf); #ifdef USE_BUFHASH /* * Calculate the hash table size and reserve space */ for (bufhashmask = 8; bufhashmask < nbuf / 4; bufhashmask <<= 1) ; bufhashtbl = (void *)v; v = (caddr_t)(bufhashtbl + bufhashmask); --bufhashmask; #endif return(v); } /* Initialize the buffer subsystem. Called before use of any buffers. */ void bufinit(void) { struct buf *bp; int i; GIANT_REQUIRED; #ifdef USE_BUFHASH LIST_INIT(&invalhash); #endif mtx_init(&buftimelock, "buftime lock", NULL, MTX_DEF); #ifdef USE_BUFHASH for (i = 0; i <= bufhashmask; i++) LIST_INIT(&bufhashtbl[i]); #endif /* next, make a null set of free lists */ for (i = 0; i < BUFFER_QUEUES; i++) TAILQ_INIT(&bufqueues[i]); /* finally, initialize each buffer header and stick on empty q */ for (i = 0; i < nbuf; i++) { bp = &buf[i]; bzero(bp, sizeof *bp); bp->b_flags = B_INVAL; /* we're just an empty header */ bp->b_dev = NODEV; bp->b_rcred = NOCRED; bp->b_wcred = NOCRED; bp->b_qindex = QUEUE_EMPTY; bp->b_xflags = 0; LIST_INIT(&bp->b_dep); BUF_LOCKINIT(bp); TAILQ_INSERT_TAIL(&bufqueues[QUEUE_EMPTY], bp, b_freelist); #ifdef USE_BUFHASH LIST_INSERT_HEAD(&invalhash, bp, b_hash); #endif } /* * maxbufspace is the absolute maximum amount of buffer space we are * allowed to reserve in KVM and in real terms. The absolute maximum * is nominally used by buf_daemon. hibufspace is the nominal maximum * used by most other processes. The differential is required to * ensure that buf_daemon is able to run when other processes might * be blocked waiting for buffer space. * * maxbufspace is based on BKVASIZE. Allocating buffers larger then * this may result in KVM fragmentation which is not handled optimally * by the system. */ maxbufspace = nbuf * BKVASIZE; hibufspace = imax(3 * maxbufspace / 4, maxbufspace - MAXBSIZE * 10); lobufspace = hibufspace - MAXBSIZE; lorunningspace = 512 * 1024; hirunningspace = 1024 * 1024; /* * Limit the amount of malloc memory since it is wired permanently into * the kernel space. Even though this is accounted for in the buffer * allocation, we don't want the malloced region to grow uncontrolled. * The malloc scheme improves memory utilization significantly on average * (small) directories. */ maxbufmallocspace = hibufspace / 20; /* * Reduce the chance of a deadlock occuring by limiting the number * of delayed-write dirty buffers we allow to stack up. */ hidirtybuffers = nbuf / 4 + 20; numdirtybuffers = 0; /* * To support extreme low-memory systems, make sure hidirtybuffers cannot * eat up all available buffer space. This occurs when our minimum cannot * be met. We try to size hidirtybuffers to 3/4 our buffer space assuming * BKVASIZE'd (8K) buffers. */ while (hidirtybuffers * BKVASIZE > 3 * hibufspace / 4) { hidirtybuffers >>= 1; } lodirtybuffers = hidirtybuffers / 2; /* * Try to keep the number of free buffers in the specified range, * and give special processes (e.g. like buf_daemon) access to an * emergency reserve. */ lofreebuffers = nbuf / 18 + 5; hifreebuffers = 2 * lofreebuffers; numfreebuffers = nbuf; /* * Maximum number of async ops initiated per buf_daemon loop. This is * somewhat of a hack at the moment, we really need to limit ourselves * based on the number of bytes of I/O in-transit that were initiated * from buf_daemon. */ bogus_offset = kmem_alloc_pageable(kernel_map, PAGE_SIZE); bogus_page = vm_page_alloc(kernel_object, ((bogus_offset - VM_MIN_KERNEL_ADDRESS) >> PAGE_SHIFT), VM_ALLOC_NORMAL); cnt.v_wire_count++; } /* * bfreekva() - free the kva allocation for a buffer. * * Must be called at splbio() or higher as this is the only locking for * buffer_map. * * Since this call frees up buffer space, we call bufspacewakeup(). */ static void bfreekva(struct buf * bp) { GIANT_REQUIRED; if (bp->b_kvasize) { ++buffreekvacnt; bufspace -= bp->b_kvasize; vm_map_delete(buffer_map, (vm_offset_t) bp->b_kvabase, (vm_offset_t) bp->b_kvabase + bp->b_kvasize ); bp->b_kvasize = 0; bufspacewakeup(); } } /* * bremfree: * * Remove the buffer from the appropriate free list. */ void bremfree(struct buf * bp) { int s = splbio(); int old_qindex = bp->b_qindex; GIANT_REQUIRED; if (bp->b_qindex != QUEUE_NONE) { KASSERT(BUF_REFCNT(bp) == 1, ("bremfree: bp %p not locked",bp)); TAILQ_REMOVE(&bufqueues[bp->b_qindex], bp, b_freelist); bp->b_qindex = QUEUE_NONE; } else { if (BUF_REFCNT(bp) <= 1) panic("bremfree: removing a buffer not on a queue"); } /* * Fixup numfreebuffers count. If the buffer is invalid or not * delayed-write, and it was on the EMPTY, LRU, or AGE queues, * the buffer was free and we must decrement numfreebuffers. */ if ((bp->b_flags & B_INVAL) || (bp->b_flags & B_DELWRI) == 0) { switch(old_qindex) { case QUEUE_DIRTY: case QUEUE_CLEAN: case QUEUE_EMPTY: case QUEUE_EMPTYKVA: --numfreebuffers; break; default: break; } } splx(s); } /* * Get a buffer with the specified data. Look in the cache first. We * must clear BIO_ERROR and B_INVAL prior to initiating I/O. If B_CACHE * is set, the buffer is valid and we do not have to do anything ( see * getblk() ). This is really just a special case of breadn(). */ int bread(struct vnode * vp, daddr_t blkno, int size, struct ucred * cred, struct buf ** bpp) { return (breadn(vp, blkno, size, 0, 0, 0, cred, bpp)); } /* * Operates like bread, but also starts asynchronous I/O on * read-ahead blocks. We must clear BIO_ERROR and B_INVAL prior * to initiating I/O . If B_CACHE is set, the buffer is valid * and we do not have to do anything. */ int breadn(struct vnode * vp, daddr_t blkno, int size, daddr_t * rablkno, int *rabsize, int cnt, struct ucred * cred, struct buf ** bpp) { struct buf *bp, *rabp; int i; int rv = 0, readwait = 0; *bpp = bp = getblk(vp, blkno, size, 0, 0); /* if not found in cache, do some I/O */ if ((bp->b_flags & B_CACHE) == 0) { if (curthread != PCPU_GET(idlethread)) curthread->td_proc->p_stats->p_ru.ru_inblock++; bp->b_iocmd = BIO_READ; bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; if (bp->b_rcred == NOCRED && cred != NOCRED) bp->b_rcred = crhold(cred); vfs_busy_pages(bp, 0); VOP_STRATEGY(vp, bp); ++readwait; } for (i = 0; i < cnt; i++, rablkno++, rabsize++) { if (inmem(vp, *rablkno)) continue; rabp = getblk(vp, *rablkno, *rabsize, 0, 0); if ((rabp->b_flags & B_CACHE) == 0) { if (curthread != PCPU_GET(idlethread)) curthread->td_proc->p_stats->p_ru.ru_inblock++; rabp->b_flags |= B_ASYNC; rabp->b_flags &= ~B_INVAL; rabp->b_ioflags &= ~BIO_ERROR; rabp->b_iocmd = BIO_READ; if (rabp->b_rcred == NOCRED && cred != NOCRED) rabp->b_rcred = crhold(cred); vfs_busy_pages(rabp, 0); BUF_KERNPROC(rabp); VOP_STRATEGY(vp, rabp); } else { brelse(rabp); } } if (readwait) { rv = bufwait(bp); } return (rv); } /* * Write, release buffer on completion. (Done by iodone * if async). Do not bother writing anything if the buffer * is invalid. * * Note that we set B_CACHE here, indicating that buffer is * fully valid and thus cacheable. This is true even of NFS * now so we set it generally. This could be set either here * or in biodone() since the I/O is synchronous. We put it * here. */ int bwrite(struct buf * bp) { int oldflags, s; struct buf *newbp; if (bp->b_flags & B_INVAL) { brelse(bp); return (0); } oldflags = bp->b_flags; if (BUF_REFCNT(bp) == 0) panic("bwrite: buffer is not busy???"); s = splbio(); /* * If a background write is already in progress, delay * writing this block if it is asynchronous. Otherwise * wait for the background write to complete. */ if (bp->b_xflags & BX_BKGRDINPROG) { if (bp->b_flags & B_ASYNC) { splx(s); bdwrite(bp); return (0); } bp->b_xflags |= BX_BKGRDWAIT; tsleep(&bp->b_xflags, PRIBIO, "bwrbg", 0); if (bp->b_xflags & BX_BKGRDINPROG) panic("bwrite: still writing"); } /* Mark the buffer clean */ bundirty(bp); /* * If this buffer is marked for background writing and we * do not have to wait for it, make a copy and write the * copy so as to leave this buffer ready for further use. * * This optimization eats a lot of memory. If we have a page * or buffer shortfall we can't do it. */ if (dobkgrdwrite && (bp->b_xflags & BX_BKGRDWRITE) && (bp->b_flags & B_ASYNC) && !vm_page_count_severe() && !buf_dirty_count_severe()) { if (bp->b_iodone != NULL) { printf("bp->b_iodone = %p\n", bp->b_iodone); panic("bwrite: need chained iodone"); } /* get a new block */ newbp = geteblk(bp->b_bufsize); /* * set it to be identical to the old block. We have to * set b_lblkno and BKGRDMARKER before calling bgetvp() * to avoid confusing the splay tree and gbincore(). */ memcpy(newbp->b_data, bp->b_data, bp->b_bufsize); newbp->b_lblkno = bp->b_lblkno; newbp->b_xflags |= BX_BKGRDMARKER; bgetvp(bp->b_vp, newbp); newbp->b_blkno = bp->b_blkno; newbp->b_offset = bp->b_offset; newbp->b_iodone = vfs_backgroundwritedone; newbp->b_flags |= B_ASYNC; newbp->b_flags &= ~B_INVAL; /* move over the dependencies */ if (LIST_FIRST(&bp->b_dep) != NULL) buf_movedeps(bp, newbp); /* * Initiate write on the copy, release the original to * the B_LOCKED queue so that it cannot go away until * the background write completes. If not locked it could go * away and then be reconstituted while it was being written. * If the reconstituted buffer were written, we could end up * with two background copies being written at the same time. */ bp->b_xflags |= BX_BKGRDINPROG; bp->b_flags |= B_LOCKED; bqrelse(bp); bp = newbp; } bp->b_flags &= ~B_DONE; bp->b_ioflags &= ~BIO_ERROR; bp->b_flags |= B_WRITEINPROG | B_CACHE; bp->b_iocmd = BIO_WRITE; bp->b_vp->v_numoutput++; vfs_busy_pages(bp, 1); /* * Normal bwrites pipeline writes */ bp->b_runningbufspace = bp->b_bufsize; runningbufspace += bp->b_runningbufspace; if (curthread != PCPU_GET(idlethread)) curthread->td_proc->p_stats->p_ru.ru_oublock++; splx(s); if (oldflags & B_ASYNC) BUF_KERNPROC(bp); BUF_STRATEGY(bp); if ((oldflags & B_ASYNC) == 0) { int rtval = bufwait(bp); brelse(bp); return (rtval); } else if ((oldflags & B_NOWDRAIN) == 0) { /* * don't allow the async write to saturate the I/O * system. Deadlocks can occur only if a device strategy * routine (like in MD) turns around and issues another * high-level write, in which case B_NOWDRAIN is expected * to be set. Otherwise we will not deadlock here because * we are blocking waiting for I/O that is already in-progress * to complete. */ waitrunningbufspace(); } return (0); } /* * Complete a background write started from bwrite. */ static void vfs_backgroundwritedone(bp) struct buf *bp; { struct buf *origbp; /* * Find the original buffer that we are writing. */ if ((origbp = gbincore(bp->b_vp, bp->b_lblkno)) == NULL) panic("backgroundwritedone: lost buffer"); /* * Process dependencies then return any unfinished ones. */ if (LIST_FIRST(&bp->b_dep) != NULL) buf_complete(bp); if (LIST_FIRST(&bp->b_dep) != NULL) buf_movedeps(bp, origbp); /* * Clear the BX_BKGRDINPROG flag in the original buffer * and awaken it if it is waiting for the write to complete. * If BX_BKGRDINPROG is not set in the original buffer it must * have been released and re-instantiated - which is not legal. */ KASSERT((origbp->b_xflags & BX_BKGRDINPROG), ("backgroundwritedone: lost buffer2")); origbp->b_xflags &= ~BX_BKGRDINPROG; if (origbp->b_xflags & BX_BKGRDWAIT) { origbp->b_xflags &= ~BX_BKGRDWAIT; wakeup(&origbp->b_xflags); } /* * Clear the B_LOCKED flag and remove it from the locked * queue if it currently resides there. */ origbp->b_flags &= ~B_LOCKED; if (BUF_LOCK(origbp, LK_EXCLUSIVE | LK_NOWAIT) == 0) { bremfree(origbp); bqrelse(origbp); } /* * This buffer is marked B_NOCACHE, so when it is released * by biodone, it will be tossed. We mark it with BIO_READ * to avoid biodone doing a second vwakeup. */ bp->b_flags |= B_NOCACHE; bp->b_iocmd = BIO_READ; bp->b_flags &= ~(B_CACHE | B_DONE); bp->b_iodone = 0; bufdone(bp); } /* * Delayed write. (Buffer is marked dirty). Do not bother writing * anything if the buffer is marked invalid. * * Note that since the buffer must be completely valid, we can safely * set B_CACHE. In fact, we have to set B_CACHE here rather then in * biodone() in order to prevent getblk from writing the buffer * out synchronously. */ void bdwrite(struct buf * bp) { GIANT_REQUIRED; if (BUF_REFCNT(bp) == 0) panic("bdwrite: buffer is not busy"); if (bp->b_flags & B_INVAL) { brelse(bp); return; } bdirty(bp); /* * Set B_CACHE, indicating that the buffer is fully valid. This is * true even of NFS now. */ bp->b_flags |= B_CACHE; /* * This bmap keeps the system from needing to do the bmap later, * perhaps when the system is attempting to do a sync. Since it * is likely that the indirect block -- or whatever other datastructure * that the filesystem needs is still in memory now, it is a good * thing to do this. Note also, that if the pageout daemon is * requesting a sync -- there might not be enough memory to do * the bmap then... So, this is important to do. */ if (bp->b_lblkno == bp->b_blkno) { VOP_BMAP(bp->b_vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL, NULL); } /* * Set the *dirty* buffer range based upon the VM system dirty pages. */ vfs_setdirty(bp); /* * We need to do this here to satisfy the vnode_pager and the * pageout daemon, so that it thinks that the pages have been * "cleaned". Note that since the pages are in a delayed write * buffer -- the VFS layer "will" see that the pages get written * out on the next sync, or perhaps the cluster will be completed. */ vfs_clean_pages(bp); bqrelse(bp); /* * Wakeup the buffer flushing daemon if we have a lot of dirty * buffers (midpoint between our recovery point and our stall * point). */ bd_wakeup((lodirtybuffers + hidirtybuffers) / 2); /* * note: we cannot initiate I/O from a bdwrite even if we wanted to, * due to the softdep code. */ } /* * bdirty: * * Turn buffer into delayed write request. We must clear BIO_READ and * B_RELBUF, and we must set B_DELWRI. We reassign the buffer to * itself to properly update it in the dirty/clean lists. We mark it * B_DONE to ensure that any asynchronization of the buffer properly * clears B_DONE ( else a panic will occur later ). * * bdirty() is kinda like bdwrite() - we have to clear B_INVAL which * might have been set pre-getblk(). Unlike bwrite/bdwrite, bdirty() * should only be called if the buffer is known-good. * * Since the buffer is not on a queue, we do not update the numfreebuffers * count. * * Must be called at splbio(). * The buffer must be on QUEUE_NONE. */ void bdirty(bp) struct buf *bp; { KASSERT(bp->b_qindex == QUEUE_NONE, ("bdirty: buffer %p still on queue %d", bp, bp->b_qindex)); bp->b_flags &= ~(B_RELBUF); bp->b_iocmd = BIO_WRITE; if ((bp->b_flags & B_DELWRI) == 0) { bp->b_flags |= B_DONE | B_DELWRI; reassignbuf(bp, bp->b_vp); ++numdirtybuffers; bd_wakeup((lodirtybuffers + hidirtybuffers) / 2); } } /* * bundirty: * * Clear B_DELWRI for buffer. * * Since the buffer is not on a queue, we do not update the numfreebuffers * count. * * Must be called at splbio(). * The buffer must be on QUEUE_NONE. */ void bundirty(bp) struct buf *bp; { KASSERT(bp->b_qindex == QUEUE_NONE, ("bundirty: buffer %p still on queue %d", bp, bp->b_qindex)); if (bp->b_flags & B_DELWRI) { bp->b_flags &= ~B_DELWRI; reassignbuf(bp, bp->b_vp); --numdirtybuffers; numdirtywakeup(lodirtybuffers); } /* * Since it is now being written, we can clear its deferred write flag. */ bp->b_flags &= ~B_DEFERRED; } /* * bawrite: * * Asynchronous write. Start output on a buffer, but do not wait for * it to complete. The buffer is released when the output completes. * * bwrite() ( or the VOP routine anyway ) is responsible for handling * B_INVAL buffers. Not us. */ void bawrite(struct buf * bp) { bp->b_flags |= B_ASYNC; (void) BUF_WRITE(bp); } /* * bwillwrite: * * Called prior to the locking of any vnodes when we are expecting to * write. We do not want to starve the buffer cache with too many * dirty buffers so we block here. By blocking prior to the locking * of any vnodes we attempt to avoid the situation where a locked vnode * prevents the various system daemons from flushing related buffers. */ void bwillwrite(void) { if (numdirtybuffers >= hidirtybuffers) { int s; mtx_lock(&Giant); s = splbio(); while (numdirtybuffers >= hidirtybuffers) { bd_wakeup(1); needsbuffer |= VFS_BIO_NEED_DIRTYFLUSH; tsleep(&needsbuffer, (PRIBIO + 4), "flswai", 0); } splx(s); mtx_unlock(&Giant); } } /* * Return true if we have too many dirty buffers. */ int buf_dirty_count_severe(void) { return(numdirtybuffers >= hidirtybuffers); } /* * brelse: * * Release a busy buffer and, if requested, free its resources. The * buffer will be stashed in the appropriate bufqueue[] allowing it * to be accessed later as a cache entity or reused for other purposes. */ void brelse(struct buf * bp) { int s; GIANT_REQUIRED; KASSERT(!(bp->b_flags & (B_CLUSTER|B_PAGING)), ("brelse: inappropriate B_PAGING or B_CLUSTER bp %p", bp)); s = splbio(); if (bp->b_flags & B_LOCKED) bp->b_ioflags &= ~BIO_ERROR; if (bp->b_iocmd == BIO_WRITE && (bp->b_ioflags & BIO_ERROR) && !(bp->b_flags & B_INVAL)) { /* * Failed write, redirty. Must clear BIO_ERROR to prevent * pages from being scrapped. If B_INVAL is set then * this case is not run and the next case is run to * destroy the buffer. B_INVAL can occur if the buffer * is outside the range supported by the underlying device. */ bp->b_ioflags &= ~BIO_ERROR; bdirty(bp); } else if ((bp->b_flags & (B_NOCACHE | B_INVAL)) || (bp->b_ioflags & BIO_ERROR) || bp->b_iocmd == BIO_DELETE || (bp->b_bufsize <= 0)) { /* * Either a failed I/O or we were asked to free or not * cache the buffer. */ bp->b_flags |= B_INVAL; if (LIST_FIRST(&bp->b_dep) != NULL) buf_deallocate(bp); if (bp->b_flags & B_DELWRI) { --numdirtybuffers; numdirtywakeup(lodirtybuffers); } bp->b_flags &= ~(B_DELWRI | B_CACHE); if ((bp->b_flags & B_VMIO) == 0) { if (bp->b_bufsize) allocbuf(bp, 0); if (bp->b_vp) brelvp(bp); } } /* * We must clear B_RELBUF if B_DELWRI is set. If vfs_vmio_release() * is called with B_DELWRI set, the underlying pages may wind up * getting freed causing a previous write (bdwrite()) to get 'lost' * because pages associated with a B_DELWRI bp are marked clean. * * We still allow the B_INVAL case to call vfs_vmio_release(), even * if B_DELWRI is set. * * If B_DELWRI is not set we may have to set B_RELBUF if we are low * on pages to return pages to the VM page queues. */ if (bp->b_flags & B_DELWRI) bp->b_flags &= ~B_RELBUF; else if (vm_page_count_severe() && !(bp->b_xflags & BX_BKGRDINPROG)) bp->b_flags |= B_RELBUF; /* * VMIO buffer rundown. It is not very necessary to keep a VMIO buffer * constituted, not even NFS buffers now. Two flags effect this. If * B_INVAL, the struct buf is invalidated but the VM object is kept * around ( i.e. so it is trivial to reconstitute the buffer later ). * * If BIO_ERROR or B_NOCACHE is set, pages in the VM object will be * invalidated. BIO_ERROR cannot be set for a failed write unless the * buffer is also B_INVAL because it hits the re-dirtying code above. * * Normally we can do this whether a buffer is B_DELWRI or not. If * the buffer is an NFS buffer, it is tracking piecemeal writes or * the commit state and we cannot afford to lose the buffer. If the * buffer has a background write in progress, we need to keep it * around to prevent it from being reconstituted and starting a second * background write. */ if ((bp->b_flags & B_VMIO) && !(bp->b_vp->v_tag == VT_NFS && !vn_isdisk(bp->b_vp, NULL) && (bp->b_flags & B_DELWRI)) ) { int i, j, resid; vm_page_t m; off_t foff; vm_pindex_t poff; vm_object_t obj; struct vnode *vp; vp = bp->b_vp; obj = bp->b_object; /* * Get the base offset and length of the buffer. Note that * in the VMIO case if the buffer block size is not * page-aligned then b_data pointer may not be page-aligned. * But our b_pages[] array *IS* page aligned. * * block sizes less then DEV_BSIZE (usually 512) are not * supported due to the page granularity bits (m->valid, * m->dirty, etc...). * * See man buf(9) for more information */ resid = bp->b_bufsize; foff = bp->b_offset; for (i = 0; i < bp->b_npages; i++) { int had_bogus = 0; m = bp->b_pages[i]; vm_page_flag_clear(m, PG_ZERO); /* * If we hit a bogus page, fixup *all* the bogus pages * now. */ if (m == bogus_page) { poff = OFF_TO_IDX(bp->b_offset); had_bogus = 1; for (j = i; j < bp->b_npages; j++) { vm_page_t mtmp; mtmp = bp->b_pages[j]; if (mtmp == bogus_page) { mtmp = vm_page_lookup(obj, poff + j); if (!mtmp) { panic("brelse: page missing\n"); } bp->b_pages[j] = mtmp; } } if ((bp->b_flags & B_INVAL) == 0) { pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } m = bp->b_pages[i]; } if ((bp->b_flags & B_NOCACHE) || (bp->b_ioflags & BIO_ERROR)) { int poffset = foff & PAGE_MASK; int presid = resid > (PAGE_SIZE - poffset) ? (PAGE_SIZE - poffset) : resid; KASSERT(presid >= 0, ("brelse: extra page")); vm_page_set_invalid(m, poffset, presid); if (had_bogus) printf("avoided corruption bug in bogus_page/brelse code\n"); } resid -= PAGE_SIZE - (foff & PAGE_MASK); foff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; } if (bp->b_flags & (B_INVAL | B_RELBUF)) vfs_vmio_release(bp); } else if (bp->b_flags & B_VMIO) { if (bp->b_flags & (B_INVAL | B_RELBUF)) { vfs_vmio_release(bp); } } if (bp->b_qindex != QUEUE_NONE) panic("brelse: free buffer onto another queue???"); if (BUF_REFCNT(bp) > 1) { /* do not release to free list */ BUF_UNLOCK(bp); splx(s); return; } /* enqueue */ /* buffers with no memory */ if (bp->b_bufsize == 0) { bp->b_flags |= B_INVAL; bp->b_xflags &= ~(BX_BKGRDWRITE | BX_ALTDATA); if (bp->b_xflags & BX_BKGRDINPROG) panic("losing buffer 1"); if (bp->b_kvasize) { bp->b_qindex = QUEUE_EMPTYKVA; } else { bp->b_qindex = QUEUE_EMPTY; } TAILQ_INSERT_HEAD(&bufqueues[bp->b_qindex], bp, b_freelist); #ifdef USE_BUFHASH LIST_REMOVE(bp, b_hash); LIST_INSERT_HEAD(&invalhash, bp, b_hash); #endif bp->b_dev = NODEV; /* buffers with junk contents */ } else if (bp->b_flags & (B_INVAL | B_NOCACHE | B_RELBUF) || (bp->b_ioflags & BIO_ERROR)) { bp->b_flags |= B_INVAL; bp->b_xflags &= ~(BX_BKGRDWRITE | BX_ALTDATA); if (bp->b_xflags & BX_BKGRDINPROG) panic("losing buffer 2"); bp->b_qindex = QUEUE_CLEAN; TAILQ_INSERT_HEAD(&bufqueues[QUEUE_CLEAN], bp, b_freelist); #ifdef USE_BUFHASH LIST_REMOVE(bp, b_hash); LIST_INSERT_HEAD(&invalhash, bp, b_hash); #endif bp->b_dev = NODEV; /* buffers that are locked */ } else if (bp->b_flags & B_LOCKED) { bp->b_qindex = QUEUE_LOCKED; TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LOCKED], bp, b_freelist); /* remaining buffers */ } else { if (bp->b_flags & B_DELWRI) bp->b_qindex = QUEUE_DIRTY; else bp->b_qindex = QUEUE_CLEAN; if (bp->b_flags & B_AGE) TAILQ_INSERT_HEAD(&bufqueues[bp->b_qindex], bp, b_freelist); else TAILQ_INSERT_TAIL(&bufqueues[bp->b_qindex], bp, b_freelist); } /* * If B_INVAL and B_DELWRI is set, clear B_DELWRI. We have already * placed the buffer on the correct queue. We must also disassociate * the device and vnode for a B_INVAL buffer so gbincore() doesn't * find it. */ if (bp->b_flags & B_INVAL) { if (bp->b_flags & B_DELWRI) bundirty(bp); if (bp->b_vp) brelvp(bp); } /* * Fixup numfreebuffers count. The bp is on an appropriate queue * unless locked. We then bump numfreebuffers if it is not B_DELWRI. * We've already handled the B_INVAL case ( B_DELWRI will be clear * if B_INVAL is set ). */ if ((bp->b_flags & B_LOCKED) == 0 && !(bp->b_flags & B_DELWRI)) bufcountwakeup(); /* * Something we can maybe free or reuse */ if (bp->b_bufsize || bp->b_kvasize) bufspacewakeup(); /* unlock */ BUF_UNLOCK(bp); bp->b_flags &= ~(B_ASYNC | B_NOCACHE | B_AGE | B_RELBUF | B_DIRECT | B_NOWDRAIN); if ((bp->b_flags & B_DELWRI) == 0 && (bp->b_xflags & BX_VNDIRTY)) panic("brelse: not dirty"); splx(s); } /* * Release a buffer back to the appropriate queue but do not try to free * it. The buffer is expected to be used again soon. * * bqrelse() is used by bdwrite() to requeue a delayed write, and used by * biodone() to requeue an async I/O on completion. It is also used when * known good buffers need to be requeued but we think we may need the data * again soon. * * XXX we should be able to leave the B_RELBUF hint set on completion. */ void bqrelse(struct buf * bp) { int s; s = splbio(); KASSERT(!(bp->b_flags & (B_CLUSTER|B_PAGING)), ("bqrelse: inappropriate B_PAGING or B_CLUSTER bp %p", bp)); if (bp->b_qindex != QUEUE_NONE) panic("bqrelse: free buffer onto another queue???"); if (BUF_REFCNT(bp) > 1) { /* do not release to free list */ BUF_UNLOCK(bp); splx(s); return; } if (bp->b_flags & B_LOCKED) { bp->b_ioflags &= ~BIO_ERROR; bp->b_qindex = QUEUE_LOCKED; TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LOCKED], bp, b_freelist); /* buffers with stale but valid contents */ } else if (bp->b_flags & B_DELWRI) { bp->b_qindex = QUEUE_DIRTY; TAILQ_INSERT_TAIL(&bufqueues[QUEUE_DIRTY], bp, b_freelist); } else if (vm_page_count_severe()) { /* * We are too low on memory, we have to try to free the * buffer (most importantly: the wired pages making up its * backing store) *now*. */ splx(s); brelse(bp); return; } else { bp->b_qindex = QUEUE_CLEAN; TAILQ_INSERT_TAIL(&bufqueues[QUEUE_CLEAN], bp, b_freelist); } if ((bp->b_flags & B_LOCKED) == 0 && ((bp->b_flags & B_INVAL) || !(bp->b_flags & B_DELWRI))) { bufcountwakeup(); } /* * Something we can maybe free or reuse. */ if (bp->b_bufsize && !(bp->b_flags & B_DELWRI)) bufspacewakeup(); /* unlock */ BUF_UNLOCK(bp); bp->b_flags &= ~(B_ASYNC | B_NOCACHE | B_AGE | B_RELBUF); if ((bp->b_flags & B_DELWRI) == 0 && (bp->b_xflags & BX_VNDIRTY)) panic("bqrelse: not dirty"); splx(s); } /* Give pages used by the bp back to the VM system (where possible) */ static void vfs_vmio_release(bp) struct buf *bp; { int i; vm_page_t m; GIANT_REQUIRED; vm_page_lock_queues(); for (i = 0; i < bp->b_npages; i++) { m = bp->b_pages[i]; bp->b_pages[i] = NULL; /* * In order to keep page LRU ordering consistent, put * everything on the inactive queue. */ vm_page_unwire(m, 0); /* * We don't mess with busy pages, it is * the responsibility of the process that * busied the pages to deal with them. */ if ((m->flags & PG_BUSY) || (m->busy != 0)) continue; if (m->wire_count == 0) { vm_page_flag_clear(m, PG_ZERO); /* * Might as well free the page if we can and it has * no valid data. We also free the page if the * buffer was used for direct I/O */ if ((bp->b_flags & B_ASYNC) == 0 && !m->valid && m->hold_count == 0) { vm_page_busy(m); vm_page_protect(m, VM_PROT_NONE); vm_page_free(m); } else if (bp->b_flags & B_DIRECT) { vm_page_try_to_free(m); } else if (vm_page_count_severe()) { vm_page_try_to_cache(m); } } } vm_page_unlock_queues(); pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages); if (bp->b_bufsize) { bufspacewakeup(); bp->b_bufsize = 0; } bp->b_npages = 0; bp->b_flags &= ~B_VMIO; if (bp->b_vp) brelvp(bp); } #ifdef USE_BUFHASH /* * XXX MOVED TO VFS_SUBR.C * * Check to see if a block is currently memory resident. */ struct buf * gbincore(struct vnode * vp, daddr_t blkno) { struct buf *bp; struct bufhashhdr *bh; bh = bufhash(vp, blkno); /* Search hash chain */ LIST_FOREACH(bp, bh, b_hash) { /* hit */ if (bp->b_vp == vp && bp->b_lblkno == blkno && (bp->b_flags & B_INVAL) == 0) { break; } } return (bp); } #endif /* * vfs_bio_awrite: * * Implement clustered async writes for clearing out B_DELWRI buffers. * This is much better then the old way of writing only one buffer at * a time. Note that we may not be presented with the buffers in the * correct order, so we search for the cluster in both directions. */ int vfs_bio_awrite(struct buf * bp) { int i; int j; daddr_t lblkno = bp->b_lblkno; struct vnode *vp = bp->b_vp; int s; int ncl; struct buf *bpa; int nwritten; int size; int maxcl; s = splbio(); /* * right now we support clustered writing only to regular files. If * we find a clusterable block we could be in the middle of a cluster * rather then at the beginning. */ if ((vp->v_type == VREG) && (vp->v_mount != 0) && /* Only on nodes that have the size info */ (bp->b_flags & (B_CLUSTEROK | B_INVAL)) == B_CLUSTEROK) { size = vp->v_mount->mnt_stat.f_iosize; maxcl = MAXPHYS / size; for (i = 1; i < maxcl; i++) { if ((bpa = gbincore(vp, lblkno + i)) && BUF_REFCNT(bpa) == 0 && ((bpa->b_flags & (B_DELWRI | B_CLUSTEROK | B_INVAL)) == (B_DELWRI | B_CLUSTEROK)) && (bpa->b_bufsize == size)) { if ((bpa->b_blkno == bpa->b_lblkno) || (bpa->b_blkno != bp->b_blkno + ((i * size) >> DEV_BSHIFT))) break; } else { break; } } for (j = 1; i + j <= maxcl && j <= lblkno; j++) { if ((bpa = gbincore(vp, lblkno - j)) && BUF_REFCNT(bpa) == 0 && ((bpa->b_flags & (B_DELWRI | B_CLUSTEROK | B_INVAL)) == (B_DELWRI | B_CLUSTEROK)) && (bpa->b_bufsize == size)) { if ((bpa->b_blkno == bpa->b_lblkno) || (bpa->b_blkno != bp->b_blkno - ((j * size) >> DEV_BSHIFT))) break; } else { break; } } --j; ncl = i + j; /* * this is a possible cluster write */ if (ncl != 1) { nwritten = cluster_wbuild(vp, size, lblkno - j, ncl); splx(s); return nwritten; } } BUF_LOCK(bp, LK_EXCLUSIVE); bremfree(bp); bp->b_flags |= B_ASYNC; splx(s); /* * default (old) behavior, writing out only one block * * XXX returns b_bufsize instead of b_bcount for nwritten? */ nwritten = bp->b_bufsize; (void) BUF_WRITE(bp); return nwritten; } /* * getnewbuf: * * Find and initialize a new buffer header, freeing up existing buffers * in the bufqueues as necessary. The new buffer is returned locked. * * Important: B_INVAL is not set. If the caller wishes to throw the * buffer away, the caller must set B_INVAL prior to calling brelse(). * * We block if: * We have insufficient buffer headers * We have insufficient buffer space * buffer_map is too fragmented ( space reservation fails ) * If we have to flush dirty buffers ( but we try to avoid this ) * * To avoid VFS layer recursion we do not flush dirty buffers ourselves. * Instead we ask the buf daemon to do it for us. We attempt to * avoid piecemeal wakeups of the pageout daemon. */ static struct buf * getnewbuf(int slpflag, int slptimeo, int size, int maxsize) { struct buf *bp; struct buf *nbp; int defrag = 0; int nqindex; static int flushingbufs; GIANT_REQUIRED; /* * We can't afford to block since we might be holding a vnode lock, * which may prevent system daemons from running. We deal with * low-memory situations by proactively returning memory and running * async I/O rather then sync I/O. */ ++getnewbufcalls; --getnewbufrestarts; restart: ++getnewbufrestarts; /* * Setup for scan. If we do not have enough free buffers, * we setup a degenerate case that immediately fails. Note * that if we are specially marked process, we are allowed to * dip into our reserves. * * The scanning sequence is nominally: EMPTY->EMPTYKVA->CLEAN * * We start with EMPTYKVA. If the list is empty we backup to EMPTY. * However, there are a number of cases (defragging, reusing, ...) * where we cannot backup. */ nqindex = QUEUE_EMPTYKVA; nbp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTYKVA]); if (nbp == NULL) { /* * If no EMPTYKVA buffers and we are either * defragging or reusing, locate a CLEAN buffer * to free or reuse. If bufspace useage is low * skip this step so we can allocate a new buffer. */ if (defrag || bufspace >= lobufspace) { nqindex = QUEUE_CLEAN; nbp = TAILQ_FIRST(&bufqueues[QUEUE_CLEAN]); } /* * If we could not find or were not allowed to reuse a * CLEAN buffer, check to see if it is ok to use an EMPTY * buffer. We can only use an EMPTY buffer if allocating * its KVA would not otherwise run us out of buffer space. */ if (nbp == NULL && defrag == 0 && bufspace + maxsize < hibufspace) { nqindex = QUEUE_EMPTY; nbp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTY]); } } /* * Run scan, possibly freeing data and/or kva mappings on the fly * depending. */ while ((bp = nbp) != NULL) { int qindex = nqindex; /* * Calculate next bp ( we can only use it if we do not block * or do other fancy things ). */ if ((nbp = TAILQ_NEXT(bp, b_freelist)) == NULL) { switch(qindex) { case QUEUE_EMPTY: nqindex = QUEUE_EMPTYKVA; if ((nbp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTYKVA]))) break; /* fall through */ case QUEUE_EMPTYKVA: nqindex = QUEUE_CLEAN; if ((nbp = TAILQ_FIRST(&bufqueues[QUEUE_CLEAN]))) break; /* fall through */ case QUEUE_CLEAN: /* * nbp is NULL. */ break; } } /* * Sanity Checks */ KASSERT(bp->b_qindex == qindex, ("getnewbuf: inconsistant queue %d bp %p", qindex, bp)); /* * Note: we no longer distinguish between VMIO and non-VMIO * buffers. */ KASSERT((bp->b_flags & B_DELWRI) == 0, ("delwri buffer %p found in queue %d", bp, qindex)); /* * If we are defragging then we need a buffer with * b_kvasize != 0. XXX this situation should no longer * occur, if defrag is non-zero the buffer's b_kvasize * should also be non-zero at this point. XXX */ if (defrag && bp->b_kvasize == 0) { printf("Warning: defrag empty buffer %p\n", bp); continue; } /* * Start freeing the bp. This is somewhat involved. nbp * remains valid only for QUEUE_EMPTY[KVA] bp's. */ if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT) != 0) panic("getnewbuf: locked buf"); bremfree(bp); if (qindex == QUEUE_CLEAN) { if (bp->b_flags & B_VMIO) { bp->b_flags &= ~B_ASYNC; vfs_vmio_release(bp); } if (bp->b_vp) brelvp(bp); } /* * NOTE: nbp is now entirely invalid. We can only restart * the scan from this point on. * * Get the rest of the buffer freed up. b_kva* is still * valid after this operation. */ if (bp->b_rcred != NOCRED) { crfree(bp->b_rcred); bp->b_rcred = NOCRED; } if (bp->b_wcred != NOCRED) { crfree(bp->b_wcred); bp->b_wcred = NOCRED; } if (LIST_FIRST(&bp->b_dep) != NULL) buf_deallocate(bp); if (bp->b_xflags & BX_BKGRDINPROG) panic("losing buffer 3"); #ifdef USE_BUFHASH LIST_REMOVE(bp, b_hash); LIST_INSERT_HEAD(&invalhash, bp, b_hash); #endif if (bp->b_bufsize) allocbuf(bp, 0); bp->b_flags = 0; bp->b_ioflags = 0; bp->b_xflags = 0; bp->b_dev = NODEV; bp->b_vp = NULL; bp->b_blkno = bp->b_lblkno = 0; bp->b_offset = NOOFFSET; bp->b_iodone = 0; bp->b_error = 0; bp->b_resid = 0; bp->b_bcount = 0; bp->b_npages = 0; bp->b_dirtyoff = bp->b_dirtyend = 0; bp->b_magic = B_MAGIC_BIO; bp->b_op = &buf_ops_bio; bp->b_object = NULL; LIST_INIT(&bp->b_dep); /* * If we are defragging then free the buffer. */ if (defrag) { bp->b_flags |= B_INVAL; bfreekva(bp); brelse(bp); defrag = 0; goto restart; } /* * If we are overcomitted then recover the buffer and its * KVM space. This occurs in rare situations when multiple * processes are blocked in getnewbuf() or allocbuf(). */ if (bufspace >= hibufspace) flushingbufs = 1; if (flushingbufs && bp->b_kvasize != 0) { bp->b_flags |= B_INVAL; bfreekva(bp); brelse(bp); goto restart; } if (bufspace < lobufspace) flushingbufs = 0; break; } /* * If we exhausted our list, sleep as appropriate. We may have to * wakeup various daemons and write out some dirty buffers. * * Generally we are sleeping due to insufficient buffer space. */ if (bp == NULL) { int flags; char *waitmsg; if (defrag) { flags = VFS_BIO_NEED_BUFSPACE; waitmsg = "nbufkv"; } else if (bufspace >= hibufspace) { waitmsg = "nbufbs"; flags = VFS_BIO_NEED_BUFSPACE; } else { waitmsg = "newbuf"; flags = VFS_BIO_NEED_ANY; } bd_speedup(); /* heeeelp */ needsbuffer |= flags; while (needsbuffer & flags) { if (tsleep(&needsbuffer, (PRIBIO + 4) | slpflag, waitmsg, slptimeo)) return (NULL); } } else { /* * We finally have a valid bp. We aren't quite out of the * woods, we still have to reserve kva space. In order * to keep fragmentation sane we only allocate kva in * BKVASIZE chunks. */ maxsize = (maxsize + BKVAMASK) & ~BKVAMASK; if (maxsize != bp->b_kvasize) { vm_offset_t addr = 0; bfreekva(bp); if (vm_map_findspace(buffer_map, vm_map_min(buffer_map), maxsize, &addr)) { /* * Uh oh. Buffer map is to fragmented. We * must defragment the map. */ ++bufdefragcnt; defrag = 1; bp->b_flags |= B_INVAL; brelse(bp); goto restart; } if (addr) { vm_map_insert(buffer_map, NULL, 0, addr, addr + maxsize, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); bp->b_kvabase = (caddr_t) addr; bp->b_kvasize = maxsize; bufspace += bp->b_kvasize; ++bufreusecnt; } } bp->b_data = bp->b_kvabase; } return(bp); } /* * buf_daemon: * * buffer flushing daemon. Buffers are normally flushed by the * update daemon but if it cannot keep up this process starts to * take the load in an attempt to prevent getnewbuf() from blocking. */ static struct proc *bufdaemonproc; static struct kproc_desc buf_kp = { "bufdaemon", buf_daemon, &bufdaemonproc }; SYSINIT(bufdaemon, SI_SUB_KTHREAD_BUF, SI_ORDER_FIRST, kproc_start, &buf_kp) static void buf_daemon() { int s; mtx_lock(&Giant); /* * This process needs to be suspended prior to shutdown sync. */ EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, bufdaemonproc, SHUTDOWN_PRI_LAST); /* * This process is allowed to take the buffer cache to the limit */ s = splbio(); for (;;) { kthread_suspend_check(bufdaemonproc); bd_request = 0; /* * Do the flush. Limit the amount of in-transit I/O we * allow to build up, otherwise we would completely saturate * the I/O system. Wakeup any waiting processes before we * normally would so they can run in parallel with our drain. */ while (numdirtybuffers > lodirtybuffers) { if (flushbufqueues() == 0) break; waitrunningbufspace(); numdirtywakeup((lodirtybuffers + hidirtybuffers) / 2); } /* * Only clear bd_request if we have reached our low water * mark. The buf_daemon normally waits 1 second and * then incrementally flushes any dirty buffers that have * built up, within reason. * * If we were unable to hit our low water mark and couldn't * find any flushable buffers, we sleep half a second. * Otherwise we loop immediately. */ if (numdirtybuffers <= lodirtybuffers) { /* * We reached our low water mark, reset the * request and sleep until we are needed again. * The sleep is just so the suspend code works. */ bd_request = 0; tsleep(&bd_request, PVM, "psleep", hz); } else { /* * We couldn't find any flushable dirty buffers but * still have too many dirty buffers, we * have to sleep and try again. (rare) */ tsleep(&bd_request, PVM, "qsleep", hz / 2); } } } /* * flushbufqueues: * * Try to flush a buffer in the dirty queue. We must be careful to * free up B_INVAL buffers instead of write them, which NFS is * particularly sensitive to. */ static int flushbufqueues(void) { struct buf *bp; int r = 0; bp = TAILQ_FIRST(&bufqueues[QUEUE_DIRTY]); while (bp) { KASSERT((bp->b_flags & B_DELWRI), ("unexpected clean buffer %p", bp)); if ((bp->b_flags & B_DELWRI) != 0 && (bp->b_xflags & BX_BKGRDINPROG) == 0) { if (bp->b_flags & B_INVAL) { if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT) != 0) panic("flushbufqueues: locked buf"); bremfree(bp); brelse(bp); ++r; break; } if (LIST_FIRST(&bp->b_dep) != NULL && (bp->b_flags & B_DEFERRED) == 0 && buf_countdeps(bp, 0)) { TAILQ_REMOVE(&bufqueues[QUEUE_DIRTY], bp, b_freelist); TAILQ_INSERT_TAIL(&bufqueues[QUEUE_DIRTY], bp, b_freelist); bp->b_flags |= B_DEFERRED; bp = TAILQ_FIRST(&bufqueues[QUEUE_DIRTY]); continue; } vfs_bio_awrite(bp); ++r; break; } bp = TAILQ_NEXT(bp, b_freelist); } return (r); } /* * Check to see if a block is currently memory resident. */ struct buf * incore(struct vnode * vp, daddr_t blkno) { struct buf *bp; int s = splbio(); bp = gbincore(vp, blkno); splx(s); return (bp); } /* * Returns true if no I/O is needed to access the * associated VM object. This is like incore except * it also hunts around in the VM system for the data. */ int inmem(struct vnode * vp, daddr_t blkno) { vm_object_t obj; vm_offset_t toff, tinc, size; vm_page_t m; vm_ooffset_t off; GIANT_REQUIRED; if (incore(vp, blkno)) return 1; if (vp->v_mount == NULL) return 0; if (VOP_GETVOBJECT(vp, &obj) != 0 || (vp->v_flag & VOBJBUF) == 0) return 0; size = PAGE_SIZE; if (size > vp->v_mount->mnt_stat.f_iosize) size = vp->v_mount->mnt_stat.f_iosize; off = (vm_ooffset_t)blkno * (vm_ooffset_t)vp->v_mount->mnt_stat.f_iosize; for (toff = 0; toff < vp->v_mount->mnt_stat.f_iosize; toff += tinc) { m = vm_page_lookup(obj, OFF_TO_IDX(off + toff)); if (!m) goto notinmem; tinc = size; if (tinc > PAGE_SIZE - ((toff + off) & PAGE_MASK)) tinc = PAGE_SIZE - ((toff + off) & PAGE_MASK); if (vm_page_is_valid(m, (vm_offset_t) ((toff + off) & PAGE_MASK), tinc) == 0) goto notinmem; } return 1; notinmem: return (0); } /* * vfs_setdirty: * * Sets the dirty range for a buffer based on the status of the dirty * bits in the pages comprising the buffer. * * The range is limited to the size of the buffer. * * This routine is primarily used by NFS, but is generalized for the * B_VMIO case. */ static void vfs_setdirty(struct buf *bp) { int i; vm_object_t object; GIANT_REQUIRED; /* * Degenerate case - empty buffer */ if (bp->b_bufsize == 0) return; /* * We qualify the scan for modified pages on whether the * object has been flushed yet. The OBJ_WRITEABLE flag * is not cleared simply by protecting pages off. */ if ((bp->b_flags & B_VMIO) == 0) return; object = bp->b_pages[0]->object; if ((object->flags & OBJ_WRITEABLE) && !(object->flags & OBJ_MIGHTBEDIRTY)) printf("Warning: object %p writeable but not mightbedirty\n", object); if (!(object->flags & OBJ_WRITEABLE) && (object->flags & OBJ_MIGHTBEDIRTY)) printf("Warning: object %p mightbedirty but not writeable\n", object); if (object->flags & (OBJ_MIGHTBEDIRTY|OBJ_CLEANING)) { vm_offset_t boffset; vm_offset_t eoffset; /* * test the pages to see if they have been modified directly * by users through the VM system. */ for (i = 0; i < bp->b_npages; i++) { vm_page_flag_clear(bp->b_pages[i], PG_ZERO); vm_page_test_dirty(bp->b_pages[i]); } /* * Calculate the encompassing dirty range, boffset and eoffset, * (eoffset - boffset) bytes. */ for (i = 0; i < bp->b_npages; i++) { if (bp->b_pages[i]->dirty) break; } boffset = (i << PAGE_SHIFT) - (bp->b_offset & PAGE_MASK); for (i = bp->b_npages - 1; i >= 0; --i) { if (bp->b_pages[i]->dirty) { break; } } eoffset = ((i + 1) << PAGE_SHIFT) - (bp->b_offset & PAGE_MASK); /* * Fit it to the buffer. */ if (eoffset > bp->b_bcount) eoffset = bp->b_bcount; /* * If we have a good dirty range, merge with the existing * dirty range. */ if (boffset < eoffset) { if (bp->b_dirtyoff > boffset) bp->b_dirtyoff = boffset; if (bp->b_dirtyend < eoffset) bp->b_dirtyend = eoffset; } } } /* * getblk: * * Get a block given a specified block and offset into a file/device. * The buffers B_DONE bit will be cleared on return, making it almost * ready for an I/O initiation. B_INVAL may or may not be set on * return. The caller should clear B_INVAL prior to initiating a * READ. * * For a non-VMIO buffer, B_CACHE is set to the opposite of B_INVAL for * an existing buffer. * * For a VMIO buffer, B_CACHE is modified according to the backing VM. * If getblk()ing a previously 0-sized invalid buffer, B_CACHE is set * and then cleared based on the backing VM. If the previous buffer is * non-0-sized but invalid, B_CACHE will be cleared. * * If getblk() must create a new buffer, the new buffer is returned with * both B_INVAL and B_CACHE clear unless it is a VMIO buffer, in which * case it is returned with B_INVAL clear and B_CACHE set based on the * backing VM. * * getblk() also forces a BUF_WRITE() for any B_DELWRI buffer whos * B_CACHE bit is clear. * * What this means, basically, is that the caller should use B_CACHE to * determine whether the buffer is fully valid or not and should clear * B_INVAL prior to issuing a read. If the caller intends to validate * the buffer by loading its data area with something, the caller needs * to clear B_INVAL. If the caller does this without issuing an I/O, * the caller should set B_CACHE ( as an optimization ), else the caller * should issue the I/O and biodone() will set B_CACHE if the I/O was * a write attempt or if it was a successfull read. If the caller * intends to issue a READ, the caller must clear B_INVAL and BIO_ERROR * prior to issuing the READ. biodone() will *not* clear B_INVAL. */ struct buf * getblk(struct vnode * vp, daddr_t blkno, int size, int slpflag, int slptimeo) { struct buf *bp; int s; #ifdef USE_BUFHASH struct bufhashhdr *bh; #endif if (size > MAXBSIZE) panic("getblk: size(%d) > MAXBSIZE(%d)\n", size, MAXBSIZE); s = splbio(); loop: /* * Block if we are low on buffers. Certain processes are allowed * to completely exhaust the buffer cache. * * If this check ever becomes a bottleneck it may be better to * move it into the else, when gbincore() fails. At the moment * it isn't a problem. * * XXX remove if 0 sections (clean this up after its proven) */ if (numfreebuffers == 0) { if (curthread == PCPU_GET(idlethread)) return NULL; needsbuffer |= VFS_BIO_NEED_ANY; } if ((bp = gbincore(vp, blkno))) { /* * Buffer is in-core. If the buffer is not busy, it must * be on a queue. */ if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { if (BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL, "getblk", slpflag, slptimeo) == ENOLCK) goto loop; splx(s); return (struct buf *) NULL; } /* * The buffer is locked. B_CACHE is cleared if the buffer is * invalid. Otherwise, for a non-VMIO buffer, B_CACHE is set * and for a VMIO buffer B_CACHE is adjusted according to the * backing VM cache. */ if (bp->b_flags & B_INVAL) bp->b_flags &= ~B_CACHE; else if ((bp->b_flags & (B_VMIO | B_INVAL)) == 0) bp->b_flags |= B_CACHE; bremfree(bp); /* * check for size inconsistancies for non-VMIO case. */ if (bp->b_bcount != size) { if ((bp->b_flags & B_VMIO) == 0 || (size > bp->b_kvasize)) { if (bp->b_flags & B_DELWRI) { bp->b_flags |= B_NOCACHE; BUF_WRITE(bp); } else { if ((bp->b_flags & B_VMIO) && (LIST_FIRST(&bp->b_dep) == NULL)) { bp->b_flags |= B_RELBUF; brelse(bp); } else { bp->b_flags |= B_NOCACHE; BUF_WRITE(bp); } } goto loop; } } /* * If the size is inconsistant in the VMIO case, we can resize * the buffer. This might lead to B_CACHE getting set or * cleared. If the size has not changed, B_CACHE remains * unchanged from its previous state. */ if (bp->b_bcount != size) allocbuf(bp, size); KASSERT(bp->b_offset != NOOFFSET, ("getblk: no buffer offset")); /* * A buffer with B_DELWRI set and B_CACHE clear must * be committed before we can return the buffer in * order to prevent the caller from issuing a read * ( due to B_CACHE not being set ) and overwriting * it. * * Most callers, including NFS and FFS, need this to * operate properly either because they assume they * can issue a read if B_CACHE is not set, or because * ( for example ) an uncached B_DELWRI might loop due * to softupdates re-dirtying the buffer. In the latter * case, B_CACHE is set after the first write completes, * preventing further loops. * NOTE! b*write() sets B_CACHE. If we cleared B_CACHE * above while extending the buffer, we cannot allow the * buffer to remain with B_CACHE set after the write * completes or it will represent a corrupt state. To * deal with this we set B_NOCACHE to scrap the buffer * after the write. * * We might be able to do something fancy, like setting * B_CACHE in bwrite() except if B_DELWRI is already set, * so the below call doesn't set B_CACHE, but that gets real * confusing. This is much easier. */ if ((bp->b_flags & (B_CACHE|B_DELWRI)) == B_DELWRI) { bp->b_flags |= B_NOCACHE; BUF_WRITE(bp); goto loop; } splx(s); bp->b_flags &= ~B_DONE; } else { /* * Buffer is not in-core, create new buffer. The buffer * returned by getnewbuf() is locked. Note that the returned * buffer is also considered valid (not marked B_INVAL). */ int bsize, maxsize, vmio; off_t offset; if (vn_isdisk(vp, NULL)) bsize = DEV_BSIZE; else if (vp->v_mountedhere) bsize = vp->v_mountedhere->mnt_stat.f_iosize; else if (vp->v_mount) bsize = vp->v_mount->mnt_stat.f_iosize; else bsize = size; offset = blkno * bsize; vmio = (VOP_GETVOBJECT(vp, NULL) == 0) && (vp->v_flag & VOBJBUF); maxsize = vmio ? size + (offset & PAGE_MASK) : size; maxsize = imax(maxsize, bsize); if ((bp = getnewbuf(slpflag, slptimeo, size, maxsize)) == NULL) { if (slpflag || slptimeo) { splx(s); return NULL; } goto loop; } /* * This code is used to make sure that a buffer is not * created while the getnewbuf routine is blocked. * This can be a problem whether the vnode is locked or not. * If the buffer is created out from under us, we have to * throw away the one we just created. There is now window * race because we are safely running at splbio() from the * point of the duplicate buffer creation through to here, * and we've locked the buffer. * * Note: this must occur before we associate the buffer * with the vp especially considering limitations in * the splay tree implementation when dealing with duplicate * lblkno's. */ if (gbincore(vp, blkno)) { bp->b_flags |= B_INVAL; brelse(bp); goto loop; } /* * Insert the buffer into the hash, so that it can * be found by incore. */ bp->b_blkno = bp->b_lblkno = blkno; bp->b_offset = offset; bgetvp(vp, bp); #ifdef USE_BUFHASH LIST_REMOVE(bp, b_hash); bh = bufhash(vp, blkno); LIST_INSERT_HEAD(bh, bp, b_hash); #endif /* * set B_VMIO bit. allocbuf() the buffer bigger. Since the * buffer size starts out as 0, B_CACHE will be set by * allocbuf() for the VMIO case prior to it testing the * backing store for validity. */ if (vmio) { bp->b_flags |= B_VMIO; #if defined(VFS_BIO_DEBUG) if (vp->v_type != VREG) printf("getblk: vmioing file type %d???\n", vp->v_type); #endif VOP_GETVOBJECT(vp, &bp->b_object); } else { bp->b_flags &= ~B_VMIO; bp->b_object = NULL; } allocbuf(bp, size); splx(s); bp->b_flags &= ~B_DONE; } KASSERT(BUF_REFCNT(bp) == 1, ("getblk: bp %p not locked",bp)); return (bp); } /* * Get an empty, disassociated buffer of given size. The buffer is initially * set to B_INVAL. */ struct buf * geteblk(int size) { struct buf *bp; int s; int maxsize; maxsize = (size + BKVAMASK) & ~BKVAMASK; s = splbio(); while ((bp = getnewbuf(0, 0, size, maxsize)) == 0); splx(s); allocbuf(bp, size); bp->b_flags |= B_INVAL; /* b_dep cleared by getnewbuf() */ KASSERT(BUF_REFCNT(bp) == 1, ("geteblk: bp %p not locked",bp)); return (bp); } /* * This code constitutes the buffer memory from either anonymous system * memory (in the case of non-VMIO operations) or from an associated * VM object (in the case of VMIO operations). This code is able to * resize a buffer up or down. * * Note that this code is tricky, and has many complications to resolve * deadlock or inconsistant data situations. Tread lightly!!! * There are B_CACHE and B_DELWRI interactions that must be dealt with by * the caller. Calling this code willy nilly can result in the loss of data. * * allocbuf() only adjusts B_CACHE for VMIO buffers. getblk() deals with * B_CACHE for the non-VMIO case. */ int allocbuf(struct buf *bp, int size) { int newbsize, mbsize; int i; GIANT_REQUIRED; if (BUF_REFCNT(bp) == 0) panic("allocbuf: buffer not busy"); if (bp->b_kvasize < size) panic("allocbuf: buffer too small"); if ((bp->b_flags & B_VMIO) == 0) { caddr_t origbuf; int origbufsize; /* * Just get anonymous memory from the kernel. Don't * mess with B_CACHE. */ mbsize = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); if (bp->b_flags & B_MALLOC) newbsize = mbsize; else newbsize = round_page(size); if (newbsize < bp->b_bufsize) { /* * malloced buffers are not shrunk */ if (bp->b_flags & B_MALLOC) { if (newbsize) { bp->b_bcount = size; } else { free(bp->b_data, M_BIOBUF); if (bp->b_bufsize) { bufmallocspace -= bp->b_bufsize; bufspacewakeup(); bp->b_bufsize = 0; } bp->b_data = bp->b_kvabase; bp->b_bcount = 0; bp->b_flags &= ~B_MALLOC; } return 1; } vm_hold_free_pages( bp, (vm_offset_t) bp->b_data + newbsize, (vm_offset_t) bp->b_data + bp->b_bufsize); } else if (newbsize > bp->b_bufsize) { /* * We only use malloced memory on the first allocation. * and revert to page-allocated memory when the buffer * grows. */ if ( (bufmallocspace < maxbufmallocspace) && (bp->b_bufsize == 0) && (mbsize <= PAGE_SIZE/2)) { bp->b_data = malloc(mbsize, M_BIOBUF, M_WAITOK); bp->b_bufsize = mbsize; bp->b_bcount = size; bp->b_flags |= B_MALLOC; bufmallocspace += mbsize; return 1; } origbuf = NULL; origbufsize = 0; /* * If the buffer is growing on its other-than-first allocation, * then we revert to the page-allocation scheme. */ if (bp->b_flags & B_MALLOC) { origbuf = bp->b_data; origbufsize = bp->b_bufsize; bp->b_data = bp->b_kvabase; if (bp->b_bufsize) { bufmallocspace -= bp->b_bufsize; bufspacewakeup(); bp->b_bufsize = 0; } bp->b_flags &= ~B_MALLOC; newbsize = round_page(newbsize); } vm_hold_load_pages( bp, (vm_offset_t) bp->b_data + bp->b_bufsize, (vm_offset_t) bp->b_data + newbsize); if (origbuf) { bcopy(origbuf, bp->b_data, origbufsize); free(origbuf, M_BIOBUF); } } } else { vm_page_t m; int desiredpages; newbsize = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); desiredpages = (size == 0) ? 0 : num_pages((bp->b_offset & PAGE_MASK) + newbsize); if (bp->b_flags & B_MALLOC) panic("allocbuf: VMIO buffer can't be malloced"); /* * Set B_CACHE initially if buffer is 0 length or will become * 0-length. */ if (size == 0 || bp->b_bufsize == 0) bp->b_flags |= B_CACHE; if (newbsize < bp->b_bufsize) { /* * DEV_BSIZE aligned new buffer size is less then the * DEV_BSIZE aligned existing buffer size. Figure out * if we have to remove any pages. */ if (desiredpages < bp->b_npages) { for (i = desiredpages; i < bp->b_npages; i++) { /* * the page is not freed here -- it * is the responsibility of * vnode_pager_setsize */ m = bp->b_pages[i]; KASSERT(m != bogus_page, ("allocbuf: bogus page found")); while (vm_page_sleep_busy(m, TRUE, "biodep")) ; bp->b_pages[i] = NULL; vm_page_lock_queues(); vm_page_unwire(m, 0); vm_page_unlock_queues(); } pmap_qremove((vm_offset_t) trunc_page((vm_offset_t)bp->b_data) + (desiredpages << PAGE_SHIFT), (bp->b_npages - desiredpages)); bp->b_npages = desiredpages; } } else if (size > bp->b_bcount) { /* * We are growing the buffer, possibly in a * byte-granular fashion. */ struct vnode *vp; vm_object_t obj; vm_offset_t toff; vm_offset_t tinc; /* * Step 1, bring in the VM pages from the object, * allocating them if necessary. We must clear * B_CACHE if these pages are not valid for the * range covered by the buffer. */ vp = bp->b_vp; obj = bp->b_object; while (bp->b_npages < desiredpages) { vm_page_t m; vm_pindex_t pi; pi = OFF_TO_IDX(bp->b_offset) + bp->b_npages; if ((m = vm_page_lookup(obj, pi)) == NULL) { /* * note: must allocate system pages * since blocking here could intefere * with paging I/O, no matter which * process we are. */ - m = vm_page_alloc(obj, pi, VM_ALLOC_SYSTEM); + m = vm_page_alloc(obj, pi, + VM_ALLOC_SYSTEM | VM_ALLOC_WIRED); if (m == NULL) { VM_WAIT; vm_pageout_deficit += desiredpages - bp->b_npages; } else { vm_page_lock_queues(); - vm_page_wire(m); vm_page_wakeup(m); vm_page_unlock_queues(); bp->b_flags &= ~B_CACHE; bp->b_pages[bp->b_npages] = m; ++bp->b_npages; } continue; } /* * We found a page. If we have to sleep on it, * retry because it might have gotten freed out * from under us. * * We can only test PG_BUSY here. Blocking on * m->busy might lead to a deadlock: * * vm_fault->getpages->cluster_read->allocbuf * */ if (vm_page_sleep_busy(m, FALSE, "pgtblk")) continue; /* * We have a good page. Should we wakeup the * page daemon? */ if ((curproc != pageproc) && ((m->queue - m->pc) == PQ_CACHE) && ((cnt.v_free_count + cnt.v_cache_count) < (cnt.v_free_min + cnt.v_cache_min))) { pagedaemon_wakeup(); } vm_page_lock_queues(); vm_page_flag_clear(m, PG_ZERO); vm_page_wire(m); vm_page_unlock_queues(); bp->b_pages[bp->b_npages] = m; ++bp->b_npages; } /* * Step 2. We've loaded the pages into the buffer, * we have to figure out if we can still have B_CACHE * set. Note that B_CACHE is set according to the * byte-granular range ( bcount and size ), new the * aligned range ( newbsize ). * * The VM test is against m->valid, which is DEV_BSIZE * aligned. Needless to say, the validity of the data * needs to also be DEV_BSIZE aligned. Note that this * fails with NFS if the server or some other client * extends the file's EOF. If our buffer is resized, * B_CACHE may remain set! XXX */ toff = bp->b_bcount; tinc = PAGE_SIZE - ((bp->b_offset + toff) & PAGE_MASK); while ((bp->b_flags & B_CACHE) && toff < size) { vm_pindex_t pi; if (tinc > (size - toff)) tinc = size - toff; pi = ((bp->b_offset & PAGE_MASK) + toff) >> PAGE_SHIFT; vfs_buf_test_cache( bp, bp->b_offset, toff, tinc, bp->b_pages[pi] ); toff += tinc; tinc = PAGE_SIZE; } /* * Step 3, fixup the KVM pmap. Remember that * bp->b_data is relative to bp->b_offset, but * bp->b_offset may be offset into the first page. */ bp->b_data = (caddr_t) trunc_page((vm_offset_t)bp->b_data); pmap_qenter( (vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages ); bp->b_data = (caddr_t)((vm_offset_t)bp->b_data | (vm_offset_t)(bp->b_offset & PAGE_MASK)); } } if (newbsize < bp->b_bufsize) bufspacewakeup(); bp->b_bufsize = newbsize; /* actual buffer allocation */ bp->b_bcount = size; /* requested buffer size */ return 1; } /* * bufwait: * * Wait for buffer I/O completion, returning error status. The buffer * is left locked and B_DONE on return. B_EINTR is converted into a EINTR * error and cleared. */ int bufwait(register struct buf * bp) { int s; s = splbio(); while ((bp->b_flags & B_DONE) == 0) { if (bp->b_iocmd == BIO_READ) tsleep(bp, PRIBIO, "biord", 0); else tsleep(bp, PRIBIO, "biowr", 0); } splx(s); if (bp->b_flags & B_EINTR) { bp->b_flags &= ~B_EINTR; return (EINTR); } if (bp->b_ioflags & BIO_ERROR) { return (bp->b_error ? bp->b_error : EIO); } else { return (0); } } /* * Call back function from struct bio back up to struct buf. * The corresponding initialization lives in sys/conf.h:DEV_STRATEGY(). */ void bufdonebio(struct bio *bp) { bufdone(bp->bio_caller2); } /* * bufdone: * * Finish I/O on a buffer, optionally calling a completion function. * This is usually called from an interrupt so process blocking is * not allowed. * * biodone is also responsible for setting B_CACHE in a B_VMIO bp. * In a non-VMIO bp, B_CACHE will be set on the next getblk() * assuming B_INVAL is clear. * * For the VMIO case, we set B_CACHE if the op was a read and no * read error occured, or if the op was a write. B_CACHE is never * set if the buffer is invalid or otherwise uncacheable. * * biodone does not mess with B_INVAL, allowing the I/O routine or the * initiator to leave B_INVAL set to brelse the buffer out of existance * in the biodone routine. */ void bufdone(struct buf *bp) { int s; void (*biodone)(struct buf *); GIANT_REQUIRED; s = splbio(); KASSERT(BUF_REFCNT(bp) > 0, ("biodone: bp %p not busy %d", bp, BUF_REFCNT(bp))); KASSERT(!(bp->b_flags & B_DONE), ("biodone: bp %p already done", bp)); bp->b_flags |= B_DONE; runningbufwakeup(bp); if (bp->b_iocmd == BIO_DELETE) { brelse(bp); splx(s); return; } if (bp->b_iocmd == BIO_WRITE) { vwakeup(bp); } /* call optional completion function if requested */ if (bp->b_iodone != NULL) { biodone = bp->b_iodone; bp->b_iodone = NULL; (*biodone) (bp); splx(s); return; } if (LIST_FIRST(&bp->b_dep) != NULL) buf_complete(bp); if (bp->b_flags & B_VMIO) { int i; vm_ooffset_t foff; vm_page_t m; vm_object_t obj; int iosize; struct vnode *vp = bp->b_vp; obj = bp->b_object; #if defined(VFS_BIO_DEBUG) if (vp->v_usecount == 0) { panic("biodone: zero vnode ref count"); } if ((vp->v_flag & VOBJBUF) == 0) { panic("biodone: vnode is not setup for merged cache"); } #endif foff = bp->b_offset; KASSERT(bp->b_offset != NOOFFSET, ("biodone: no buffer offset")); #if defined(VFS_BIO_DEBUG) if (obj->paging_in_progress < bp->b_npages) { printf("biodone: paging in progress(%d) < bp->b_npages(%d)\n", obj->paging_in_progress, bp->b_npages); } #endif /* * Set B_CACHE if the op was a normal read and no error * occured. B_CACHE is set for writes in the b*write() * routines. */ iosize = bp->b_bcount - bp->b_resid; if (bp->b_iocmd == BIO_READ && !(bp->b_flags & (B_INVAL|B_NOCACHE)) && !(bp->b_ioflags & BIO_ERROR)) { bp->b_flags |= B_CACHE; } for (i = 0; i < bp->b_npages; i++) { int bogusflag = 0; int resid; resid = ((foff + PAGE_SIZE) & ~(off_t)PAGE_MASK) - foff; if (resid > iosize) resid = iosize; /* * cleanup bogus pages, restoring the originals */ m = bp->b_pages[i]; if (m == bogus_page) { bogusflag = 1; m = vm_page_lookup(obj, OFF_TO_IDX(foff)); if (m == NULL) panic("biodone: page disappeared!"); bp->b_pages[i] = m; pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } #if defined(VFS_BIO_DEBUG) if (OFF_TO_IDX(foff) != m->pindex) { printf( "biodone: foff(%jd)/m->pindex(%ju) mismatch\n", (intmax_t)foff, (uintmax_t)m->pindex); } #endif /* * In the write case, the valid and clean bits are * already changed correctly ( see bdwrite() ), so we * only need to do this here in the read case. */ if ((bp->b_iocmd == BIO_READ) && !bogusflag && resid > 0) { vfs_page_set_valid(bp, foff, i, m); } vm_page_flag_clear(m, PG_ZERO); /* * when debugging new filesystems or buffer I/O methods, this * is the most common error that pops up. if you see this, you * have not set the page busy flag correctly!!! */ if (m->busy == 0) { printf("biodone: page busy < 0, " "pindex: %d, foff: 0x(%x,%x), " "resid: %d, index: %d\n", (int) m->pindex, (int)(foff >> 32), (int) foff & 0xffffffff, resid, i); if (!vn_isdisk(vp, NULL)) printf(" iosize: %ld, lblkno: %jd, flags: 0x%lx, npages: %d\n", bp->b_vp->v_mount->mnt_stat.f_iosize, (intmax_t) bp->b_lblkno, bp->b_flags, bp->b_npages); else printf(" VDEV, lblkno: %jd, flags: 0x%lx, npages: %d\n", (intmax_t) bp->b_lblkno, bp->b_flags, bp->b_npages); printf(" valid: 0x%x, dirty: 0x%x, wired: %d\n", m->valid, m->dirty, m->wire_count); panic("biodone: page busy < 0\n"); } vm_page_io_finish(m); vm_object_pip_subtract(obj, 1); foff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; iosize -= resid; } if (obj) vm_object_pip_wakeupn(obj, 0); } /* * For asynchronous completions, release the buffer now. The brelse * will do a wakeup there if necessary - so no need to do a wakeup * here in the async case. The sync case always needs to do a wakeup. */ if (bp->b_flags & B_ASYNC) { if ((bp->b_flags & (B_NOCACHE | B_INVAL | B_RELBUF)) || (bp->b_ioflags & BIO_ERROR)) brelse(bp); else bqrelse(bp); } else { wakeup(bp); } splx(s); } /* * This routine is called in lieu of iodone in the case of * incomplete I/O. This keeps the busy status for pages * consistant. */ void vfs_unbusy_pages(struct buf * bp) { int i; GIANT_REQUIRED; runningbufwakeup(bp); if (bp->b_flags & B_VMIO) { vm_object_t obj; obj = bp->b_object; for (i = 0; i < bp->b_npages; i++) { vm_page_t m = bp->b_pages[i]; if (m == bogus_page) { m = vm_page_lookup(obj, OFF_TO_IDX(bp->b_offset) + i); if (!m) { panic("vfs_unbusy_pages: page missing\n"); } bp->b_pages[i] = m; pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } vm_object_pip_subtract(obj, 1); vm_page_flag_clear(m, PG_ZERO); vm_page_io_finish(m); } vm_object_pip_wakeupn(obj, 0); } } /* * vfs_page_set_valid: * * Set the valid bits in a page based on the supplied offset. The * range is restricted to the buffer's size. * * This routine is typically called after a read completes. */ static void vfs_page_set_valid(struct buf *bp, vm_ooffset_t off, int pageno, vm_page_t m) { vm_ooffset_t soff, eoff; GIANT_REQUIRED; /* * Start and end offsets in buffer. eoff - soff may not cross a * page boundry or cross the end of the buffer. The end of the * buffer, in this case, is our file EOF, not the allocation size * of the buffer. */ soff = off; eoff = (off + PAGE_SIZE) & ~(off_t)PAGE_MASK; if (eoff > bp->b_offset + bp->b_bcount) eoff = bp->b_offset + bp->b_bcount; /* * Set valid range. This is typically the entire buffer and thus the * entire page. */ if (eoff > soff) { vm_page_set_validclean( m, (vm_offset_t) (soff & PAGE_MASK), (vm_offset_t) (eoff - soff) ); } } /* * This routine is called before a device strategy routine. * It is used to tell the VM system that paging I/O is in * progress, and treat the pages associated with the buffer * almost as being PG_BUSY. Also the object paging_in_progress * flag is handled to make sure that the object doesn't become * inconsistant. * * Since I/O has not been initiated yet, certain buffer flags * such as BIO_ERROR or B_INVAL may be in an inconsistant state * and should be ignored. */ void vfs_busy_pages(struct buf * bp, int clear_modify) { int i, bogus; GIANT_REQUIRED; if (bp->b_flags & B_VMIO) { vm_object_t obj; vm_ooffset_t foff; obj = bp->b_object; foff = bp->b_offset; KASSERT(bp->b_offset != NOOFFSET, ("vfs_busy_pages: no buffer offset")); vfs_setdirty(bp); retry: for (i = 0; i < bp->b_npages; i++) { vm_page_t m = bp->b_pages[i]; if (vm_page_sleep_busy(m, FALSE, "vbpage")) goto retry; } bogus = 0; for (i = 0; i < bp->b_npages; i++) { vm_page_t m = bp->b_pages[i]; vm_page_flag_clear(m, PG_ZERO); if ((bp->b_flags & B_CLUSTER) == 0) { vm_object_pip_add(obj, 1); vm_page_io_start(m); } /* * When readying a buffer for a read ( i.e * clear_modify == 0 ), it is important to do * bogus_page replacement for valid pages in * partially instantiated buffers. Partially * instantiated buffers can, in turn, occur when * reconstituting a buffer from its VM backing store * base. We only have to do this if B_CACHE is * clear ( which causes the I/O to occur in the * first place ). The replacement prevents the read * I/O from overwriting potentially dirty VM-backed * pages. XXX bogus page replacement is, uh, bogus. * It may not work properly with small-block devices. * We need to find a better way. */ vm_page_protect(m, VM_PROT_NONE); if (clear_modify) vfs_page_set_valid(bp, foff, i, m); else if (m->valid == VM_PAGE_BITS_ALL && (bp->b_flags & B_CACHE) == 0) { bp->b_pages[i] = bogus_page; bogus++; } foff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; } if (bogus) pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } } /* * Tell the VM system that the pages associated with this buffer * are clean. This is used for delayed writes where the data is * going to go to disk eventually without additional VM intevention. * * Note that while we only really need to clean through to b_bcount, we * just go ahead and clean through to b_bufsize. */ static void vfs_clean_pages(struct buf * bp) { int i; GIANT_REQUIRED; if (bp->b_flags & B_VMIO) { vm_ooffset_t foff; foff = bp->b_offset; KASSERT(bp->b_offset != NOOFFSET, ("vfs_clean_pages: no buffer offset")); for (i = 0; i < bp->b_npages; i++) { vm_page_t m = bp->b_pages[i]; vm_ooffset_t noff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; vm_ooffset_t eoff = noff; if (eoff > bp->b_offset + bp->b_bufsize) eoff = bp->b_offset + bp->b_bufsize; vfs_page_set_valid(bp, foff, i, m); /* vm_page_clear_dirty(m, foff & PAGE_MASK, eoff - foff); */ foff = noff; } } } /* * vfs_bio_set_validclean: * * Set the range within the buffer to valid and clean. The range is * relative to the beginning of the buffer, b_offset. Note that b_offset * itself may be offset from the beginning of the first page. * */ void vfs_bio_set_validclean(struct buf *bp, int base, int size) { if (bp->b_flags & B_VMIO) { int i; int n; /* * Fixup base to be relative to beginning of first page. * Set initial n to be the maximum number of bytes in the * first page that can be validated. */ base += (bp->b_offset & PAGE_MASK); n = PAGE_SIZE - (base & PAGE_MASK); for (i = base / PAGE_SIZE; size > 0 && i < bp->b_npages; ++i) { vm_page_t m = bp->b_pages[i]; if (n > size) n = size; vm_page_set_validclean(m, base & PAGE_MASK, n); base += n; size -= n; n = PAGE_SIZE; } } } /* * vfs_bio_clrbuf: * * clear a buffer. This routine essentially fakes an I/O, so we need * to clear BIO_ERROR and B_INVAL. * * Note that while we only theoretically need to clear through b_bcount, * we go ahead and clear through b_bufsize. */ void vfs_bio_clrbuf(struct buf *bp) { int i, mask = 0; caddr_t sa, ea; GIANT_REQUIRED; if ((bp->b_flags & (B_VMIO | B_MALLOC)) == B_VMIO) { bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; if( (bp->b_npages == 1) && (bp->b_bufsize < PAGE_SIZE) && (bp->b_offset & PAGE_MASK) == 0) { mask = (1 << (bp->b_bufsize / DEV_BSIZE)) - 1; if ((bp->b_pages[0]->valid & mask) == mask) { bp->b_resid = 0; return; } if (((bp->b_pages[0]->flags & PG_ZERO) == 0) && ((bp->b_pages[0]->valid & mask) == 0)) { bzero(bp->b_data, bp->b_bufsize); bp->b_pages[0]->valid |= mask; bp->b_resid = 0; return; } } ea = sa = bp->b_data; for(i=0;ib_npages;i++,sa=ea) { int j = ((vm_offset_t)sa & PAGE_MASK) / DEV_BSIZE; ea = (caddr_t)trunc_page((vm_offset_t)sa + PAGE_SIZE); ea = (caddr_t)(vm_offset_t)ulmin( (u_long)(vm_offset_t)ea, (u_long)(vm_offset_t)bp->b_data + bp->b_bufsize); mask = ((1 << ((ea - sa) / DEV_BSIZE)) - 1) << j; if ((bp->b_pages[i]->valid & mask) == mask) continue; if ((bp->b_pages[i]->valid & mask) == 0) { if ((bp->b_pages[i]->flags & PG_ZERO) == 0) { bzero(sa, ea - sa); } } else { for (; sa < ea; sa += DEV_BSIZE, j++) { if (((bp->b_pages[i]->flags & PG_ZERO) == 0) && (bp->b_pages[i]->valid & (1<b_pages[i]->valid |= mask; vm_page_flag_clear(bp->b_pages[i], PG_ZERO); } bp->b_resid = 0; } else { clrbuf(bp); } } /* * vm_hold_load_pages and vm_hold_free_pages get pages into * a buffers address space. The pages are anonymous and are * not associated with a file object. */ static void vm_hold_load_pages(struct buf * bp, vm_offset_t from, vm_offset_t to) { vm_offset_t pg; vm_page_t p; int index; GIANT_REQUIRED; to = round_page(to); from = round_page(from); index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT; for (pg = from; pg < to; pg += PAGE_SIZE, index++) { tryagain: /* * note: must allocate system pages since blocking here * could intefere with paging I/O, no matter which * process we are. */ p = vm_page_alloc(kernel_object, ((pg - VM_MIN_KERNEL_ADDRESS) >> PAGE_SHIFT), - VM_ALLOC_SYSTEM); + VM_ALLOC_SYSTEM | VM_ALLOC_WIRED); if (!p) { vm_pageout_deficit += (to - from) >> PAGE_SHIFT; VM_WAIT; goto tryagain; } vm_page_lock_queues(); - vm_page_wire(p); p->valid = VM_PAGE_BITS_ALL; vm_page_flag_clear(p, PG_ZERO); vm_page_unlock_queues(); pmap_qenter(pg, &p, 1); bp->b_pages[index] = p; vm_page_wakeup(p); } bp->b_npages = index; } /* Return pages associated with this buf to the vm system */ void vm_hold_free_pages(struct buf * bp, vm_offset_t from, vm_offset_t to) { vm_offset_t pg; vm_page_t p; int index, newnpages; GIANT_REQUIRED; from = round_page(from); to = round_page(to); newnpages = index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT; for (pg = from; pg < to; pg += PAGE_SIZE, index++) { p = bp->b_pages[index]; if (p && (index < bp->b_npages)) { if (p->busy) { printf( "vm_hold_free_pages: blkno: %jd, lblkno: %jd\n", (intmax_t)bp->b_blkno, (intmax_t)bp->b_lblkno); } bp->b_pages[index] = NULL; pmap_qremove(pg, 1); vm_page_lock_queues(); vm_page_busy(p); vm_page_unwire(p, 0); vm_page_free(p); vm_page_unlock_queues(); } } bp->b_npages = newnpages; } #include "opt_ddb.h" #ifdef DDB #include /* DDB command to show buffer data */ DB_SHOW_COMMAND(buffer, db_show_buffer) { /* get args */ struct buf *bp = (struct buf *)addr; if (!have_addr) { db_printf("usage: show buffer \n"); return; } db_printf("b_flags = 0x%b\n", (u_int)bp->b_flags, PRINT_BUF_FLAGS); db_printf( "b_error = %d, b_bufsize = %ld, b_bcount = %ld, b_resid = %ld\n" "b_dev = (%d,%d), b_data = %p, b_blkno = %jd, b_pblkno = %jd\n", bp->b_error, bp->b_bufsize, bp->b_bcount, bp->b_resid, major(bp->b_dev), minor(bp->b_dev), bp->b_data, (intmax_t)bp->b_blkno, (intmax_t)bp->b_pblkno); if (bp->b_npages) { int i; db_printf("b_npages = %d, pages(OBJ, IDX, PA): ", bp->b_npages); for (i = 0; i < bp->b_npages; i++) { vm_page_t m; m = bp->b_pages[i]; db_printf("(%p, 0x%lx, 0x%lx)", (void *)m->object, (u_long)m->pindex, (u_long)VM_PAGE_TO_PHYS(m)); if ((i + 1) < bp->b_npages) db_printf(","); } db_printf("\n"); } } #endif /* DDB */