diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 8d701bdeb17a..186a82a3a5a1 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -1,1952 +1,1953 @@ /* * 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 - * $Id: pmap.c,v 1.68 1995/12/10 13:36:28 phk Exp $ + * $Id: pmap.c,v 1.69 1995/12/11 04:54:58 dyson Exp $ */ /* * Derived from hp300 version by Mike Hibler, this version by William * Jolitz uses a recursive map [a pde points to the page directory] to * map the page tables using the pagetables themselves. This is done to * reduce the impact on kernel virtual memory for lots of sparse address * space, and to reduce the cost of memory to each process. * * Derived from: hp300/@(#)pmap.c 7.1 (Berkeley) 12/5/90 */ /* * Major modifications by John S. Dyson primarily to support * pageable page tables, eliminating pmap_attributes, * discontiguous memory pages, and using more efficient string * instructions. Jan 13, 1994. Further modifications on Mar 2, 1994, * general clean-up and efficiency mods. */ /* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include -static void init_pv_entries __P((int)); -extern void pmap_object_init_pt __P((pmap_t pmap, vm_offset_t addr, - vm_object_t object, vm_offset_t offset, - vm_offset_t size)); -static void pmap_remove_all __P((vm_offset_t pa)); -static void pmap_remove_entry __P((struct pmap *pmap, pv_entry_t pv, - vm_offset_t va)); - /* * Get PDEs and PTEs for user/kernel address space */ #define pmap_pde(m, v) (&((m)->pm_pdir[((vm_offset_t)(v) >> PD_SHIFT)&1023])) #define pdir_pde(m, v) (m[((vm_offset_t)(v) >> PD_SHIFT)&1023]) #define pmap_pte_pa(pte) (*(int *)(pte) & PG_FRAME) #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_U) != 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]; static struct pmap kernel_pmap_store; pmap_t kernel_pmap; 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 vm_offset_t vm_first_phys; static int nkpt; extern vm_offset_t clean_sva, clean_eva; extern int cpu_class; /* * All those kernel PT submaps that BSD is so fond of */ pt_entry_t *CMAP1; static pt_entry_t *CMAP2, *ptmmap; static pv_entry_t pv_table; caddr_t CADDR1, ptvmmap; static caddr_t CADDR2; static pt_entry_t *msgbufmap; struct msgbuf *msgbufp; static void free_pv_entry __P((pv_entry_t pv)); static pt_entry_t * get_pt_entry __P((pmap_t pmap)); static pv_entry_t get_pv_entry __P((void)); static void i386_protection_init __P((void)); +static void init_pv_entries __P((int npg)); static void pmap_alloc_pv_entry __P((void)); static void pmap_changebit __P((vm_offset_t pa, int bit, boolean_t setem)); static void pmap_enter_quick __P((pmap_t pmap, vm_offset_t va, vm_offset_t pa)); static int pmap_is_managed __P((vm_offset_t pa)); +extern void pmap_object_init_pt __P((pmap_t pmap, vm_offset_t addr, + vm_object_t object, vm_offset_t offset, + vm_offset_t size)); +static void pmap_remove_all __P((vm_offset_t pa)); +static void pmap_remove_entry __P((struct pmap *pmap, pv_entry_t pv, + vm_offset_t va)); +static vm_page_t + pmap_pte_vm_page __P((pmap_t pmap, vm_offset_t pt)); static boolean_t pmap_testbit __P((vm_offset_t pa, int bit)); /* * Routine: pmap_pte * Function: * Extract the page table entry associated * with the given map/virtual_address pair. * [ what about induced faults -wfj] */ inline pt_entry_t * __pure pmap_pte(pmap, va) register pmap_t pmap; vm_offset_t va; { if (pmap && *pmap_pde(pmap, va)) { vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; /* are we current address space or kernel? */ if ((pmap == kernel_pmap) || (frame == ((int) PTDpde & PG_FRAME))) return ((pt_entry_t *) vtopte(va)); /* otherwise, we are alternate address space */ else { if (frame != ((int) APTDpde & PG_FRAME)) { APTDpde = pmap->pm_pdir[PTDPTDI]; pmap_update(); } return ((pt_entry_t *) avtopte(va)); } } 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 pa; if (pmap && *pmap_pde(pmap, va)) { vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; /* are we current address space or kernel? */ if ((pmap == kernel_pmap) || (frame == ((int) PTDpde & PG_FRAME))) { pa = *(int *) vtopte(va); /* otherwise, we are alternate address space */ } else { if (frame != ((int) APTDpde & PG_FRAME)) { APTDpde = pmap->pm_pdir[PTDPTDI]; pmap_update(); } pa = *(int *) avtopte(va); } return ((pa & PG_FRAME) | (va & ~PG_FRAME)); } return 0; } /* * determine if a page is managed (memory vs. device) */ static inline int pmap_is_managed(pa) vm_offset_t pa; { int i; if (!pmap_initialized) return 0; for (i = 0; phys_avail[i + 1]; i += 2) { if (pa >= phys_avail[i] && pa < phys_avail[i + 1]) return 1; } return 0; } /* * find the vm_page_t of a pte (only) given va of pte and pmap */ static __inline vm_page_t pmap_pte_vm_page(pmap, pt) pmap_t pmap; vm_offset_t pt; { vm_page_t m; pt = i386_trunc_page(pt); pt = (pt - UPT_MIN_ADDRESS) / NBPG; pt = ((vm_offset_t) pmap->pm_pdir[pt]) & PG_FRAME; m = PHYS_TO_VM_PAGE(pt); return m; } /* * Wire a page table page */ __inline void pmap_use_pt(pmap, va) pmap_t pmap; vm_offset_t va; { vm_offset_t pt; if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized) return; pt = (vm_offset_t) vtopte(va); vm_page_hold(pmap_pte_vm_page(pmap, pt)); } /* * Unwire a page table page */ inline void pmap_unuse_pt(pmap, va) pmap_t pmap; vm_offset_t va; { vm_offset_t pt; vm_page_t m; if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized) return; pt = (vm_offset_t) vtopte(va); m = pmap_pte_vm_page(pmap, pt); vm_page_unhold(m); if (pmap != kernel_pmap && (m->hold_count == 0) && (m->wire_count == 0) && (va < KPT_MIN_ADDRESS)) { pmap_page_protect(VM_PAGE_TO_PHYS(m), VM_PROT_NONE); vm_page_free(m); } } /* [ macro again?, should I force kstack into user map here? -wfj ] */ void pmap_activate(pmap, pcbp) register pmap_t pmap; struct pcb *pcbp; { PMAP_ACTIVATE(pmap, pcbp); } /* * 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; avail_start = firstaddr; /* * XXX The calculation of virtual_avail is wrong. It's NKPT*NBPG 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_end = VM_MAX_KERNEL_ADDRESS; /* * Initialize protection array. */ i386_protection_init(); /* * The kernel's pmap is statically allocated so we don't have to use * pmap_create, which is unlikely to work correctly at this part of * the boot sequence. */ kernel_pmap = &kernel_pmap_store; kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + IdlePTD); kernel_pmap->pm_count = 1; 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)*NBPG); p = pte; pte += (n); va = virtual_avail; pte = pmap_pte(kernel_pmap, va); /* * CMAP1/CMAP2 are used for zeroing and copying pages. */ SYSMAP(caddr_t, CMAP1, CADDR1, 1) SYSMAP(caddr_t, CMAP2, CADDR2, 1) /* * ptmmap is used for reading arbitrary physical pages via /dev/mem. */ SYSMAP(caddr_t, ptmmap, ptvmmap, 1) /* * msgbufmap is used to map the system message buffer. */ SYSMAP(struct msgbuf *, msgbufmap, msgbufp, 1) virtual_avail = va; *(int *) CMAP1 = *(int *) CMAP2 = *(int *) PTD = 0; pmap_update(); } /* * 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; { vm_offset_t addr; vm_size_t npg, s; int i; /* * calculate the number of pv_entries needed */ vm_first_phys = phys_avail[0]; for (i = 0; phys_avail[i + 1]; i += 2); npg = (phys_avail[(i - 2) + 1] - vm_first_phys) / NBPG; /* * Allocate memory for random pmap data structures. Includes the * pv_head_table. */ s = (vm_size_t) (sizeof(struct pv_entry) * npg); s = i386_round_page(s); addr = (vm_offset_t) kmem_alloc(kernel_map, s); pv_table = (pv_entry_t) addr; /* * init the pv free list */ init_pv_entries(npg); /* * Now it is safe to enable pv_table recording. */ pmap_initialized = TRUE; } /* * Used to map a range of physical addresses into kernel * virtual address space. * * For now, VM is already on, we only need to map the * specified memory. */ vm_offset_t pmap_map(virt, start, end, prot) vm_offset_t virt; vm_offset_t start; vm_offset_t end; int prot; { while (start < end) { pmap_enter(kernel_pmap, virt, start, prot, FALSE); virt += PAGE_SIZE; start += PAGE_SIZE; } return (virt); } /* * Initialize a preallocated and zeroed pmap structure, * such as one in a vmspace structure. */ void pmap_pinit(pmap) register struct pmap *pmap; { /* * No need to allocate page table space yet but we do need a valid * page directory table. */ pmap->pm_pdir = (pd_entry_t *) kmem_alloc(kernel_map, PAGE_SIZE); /* wire in kernel global address entries */ bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * PTESIZE); /* install self-referential address mapping entry */ *(int *) (pmap->pm_pdir + PTDPTDI) = ((int) pmap_kextract((vm_offset_t) pmap->pm_pdir)) | PG_V | PG_KW; pmap->pm_count = 1; } /* * grow the number of kernel page table entries, if needed */ static vm_page_t nkpg; vm_offset_t kernel_vm_end; void pmap_growkernel(vm_offset_t addr) { struct proc *p; struct pmap *pmap; int s; 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 + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); ++nkpt; } } addr = (addr + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); while (kernel_vm_end < addr) { if (pdir_pde(PTD, kernel_vm_end)) { kernel_vm_end = (kernel_vm_end + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); continue; } ++nkpt; if (!nkpg) { nkpg = vm_page_alloc(kernel_object, 0, VM_ALLOC_SYSTEM); if (!nkpg) panic("pmap_growkernel: no memory to grow kernel"); vm_page_wire(nkpg); vm_page_remove(nkpg); pmap_zero_page(VM_PAGE_TO_PHYS(nkpg)); } pdir_pde(PTD, kernel_vm_end) = (pd_entry_t) (VM_PAGE_TO_PHYS(nkpg) | PG_V | PG_KW); nkpg = NULL; for (p = (struct proc *) allproc; p != NULL; p = p->p_next) { if (p->p_vmspace) { pmap = &p->p_vmspace->vm_pmap; *pmap_pde(pmap, kernel_vm_end) = pdir_pde(PTD, kernel_vm_end); } } *pmap_pde(kernel_pmap, kernel_vm_end) = pdir_pde(PTD, kernel_vm_end); kernel_vm_end = (kernel_vm_end + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); } splx(s); } /* * Retire the given physical map from service. * Should only be called if the map contains * no valid mappings. */ void pmap_destroy(pmap) register pmap_t pmap; { int count; if (pmap == NULL) return; count = --pmap->pm_count; if (count == 0) { pmap_release(pmap); free((caddr_t) pmap, M_VMPMAP); } } /* * 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) register struct pmap *pmap; { kmem_free(kernel_map, (vm_offset_t) pmap->pm_pdir, PAGE_SIZE); } /* * Add a reference to the specified pmap. */ void pmap_reference(pmap) pmap_t pmap; { if (pmap != NULL) { pmap->pm_count++; } } #define PV_FREELIST_MIN ((NBPG / sizeof (struct pv_entry)) / 2) /* * Data for the pv entry allocation mechanism */ static int pv_freelistcnt; static pv_entry_t pv_freelist; static vm_offset_t pvva; static int npvvapg; /* * free the pv_entry back to the free list */ inline static void free_pv_entry(pv) pv_entry_t pv; { if (!pv) return; ++pv_freelistcnt; pv->pv_next = pv_freelist; pv_freelist = 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 inline pv_entry_t get_pv_entry() { pv_entry_t tmp; /* * get more pv_entry pages if needed */ if (pv_freelistcnt < PV_FREELIST_MIN || pv_freelist == 0) { pmap_alloc_pv_entry(); } /* * get a pv_entry off of the free list */ --pv_freelistcnt; tmp = pv_freelist; pv_freelist = tmp->pv_next; return tmp; } /* * this *strange* allocation routine *statistically* eliminates the * *possibility* of a malloc failure (*FATAL*) for a pv_entry_t data structure. * also -- this code is MUCH MUCH faster than the malloc equiv... */ static void pmap_alloc_pv_entry() { /* * do we have any pre-allocated map-pages left? */ if (npvvapg) { vm_page_t m; /* * we do this to keep recursion away */ pv_freelistcnt += PV_FREELIST_MIN; /* * allocate a physical page out of the vm system */ m = vm_page_alloc(kernel_object, OFF_TO_IDX(pvva - vm_map_min(kernel_map)), VM_ALLOC_INTERRUPT); if (m) { int newentries; int i; pv_entry_t entry; newentries = (NBPG / sizeof(struct pv_entry)); /* * wire the page */ vm_page_wire(m); m->flags &= ~PG_BUSY; /* * let the kernel see it */ pmap_kenter(pvva, VM_PAGE_TO_PHYS(m)); entry = (pv_entry_t) pvva; /* * update the allocation pointers */ pvva += NBPG; --npvvapg; /* * free the entries into the free list */ for (i = 0; i < newentries; i++) { free_pv_entry(entry); entry++; } } pv_freelistcnt -= PV_FREELIST_MIN; } if (!pv_freelist) panic("get_pv_entry: cannot get a pv_entry_t"); } /* * init the pv_entry allocation system */ #define PVSPERPAGE 64 void init_pv_entries(npg) int npg; { /* * allocate enough kvm space for PVSPERPAGE entries per page (lots) * kvm space is fairly cheap, be generous!!! (the system can panic if * this is too small.) */ npvvapg = ((npg * PVSPERPAGE) * sizeof(struct pv_entry) + NBPG - 1) / NBPG; pvva = kmem_alloc_pageable(kernel_map, npvvapg * NBPG); /* * get the first batch of entries */ free_pv_entry(get_pv_entry()); } static pt_entry_t * get_pt_entry(pmap) pmap_t pmap; { vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; /* are we current address space or kernel? */ if (pmap == kernel_pmap || frame == ((int) PTDpde & PG_FRAME)) { return PTmap; } /* otherwise, we are alternate address space */ if (frame != ((int) APTDpde & PG_FRAME)) { APTDpde = pmap->pm_pdir[PTDPTDI]; pmap_update(); } return APTmap; } /* * 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 void pmap_remove_entry(pmap, pv, va) struct pmap *pmap; pv_entry_t pv; vm_offset_t va; { pv_entry_t npv; int s; s = splhigh(); if (pmap == pv->pv_pmap && va == pv->pv_va) { npv = pv->pv_next; if (npv) { *pv = *npv; free_pv_entry(npv); } else { pv->pv_pmap = NULL; } } else { for (npv = pv->pv_next; npv; npv = npv->pv_next) { if (pmap == npv->pv_pmap && va == npv->pv_va) { break; } pv = npv; } if (npv) { pv->pv_next = npv->pv_next; free_pv_entry(npv); } } splx(s); } /* * 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, sva, eva) struct pmap *pmap; register vm_offset_t sva; register vm_offset_t eva; { register pt_entry_t *ptp, *ptq; vm_offset_t pa; register pv_entry_t pv; vm_offset_t va; pt_entry_t oldpte; if (pmap == NULL) return; ptp = get_pt_entry(pmap); /* * special handling of removing one page. a very * common operation and easy to short circuit some * code. */ if ((sva + NBPG) == eva) { if (*pmap_pde(pmap, sva) == 0) return; ptq = ptp + i386_btop(sva); if (!*ptq) return; /* * Update statistics */ if (pmap_pte_w(ptq)) pmap->pm_stats.wired_count--; pmap->pm_stats.resident_count--; pa = pmap_pte_pa(ptq); oldpte = *ptq; *ptq = 0; if (pmap_is_managed(pa)) { if ((int) oldpte & PG_M) { if (sva < USRSTACK + (UPAGES * NBPG) || (sva >= KERNBASE && (sva < clean_sva || sva >= clean_eva))) { PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; } } pv = pa_to_pvh(pa); pmap_remove_entry(pmap, pv, sva); } pmap_unuse_pt(pmap, sva); pmap_update(); return; } sva = i386_btop(sva); eva = i386_btop(eva); while (sva < eva) { /* * Weed out invalid mappings. Note: we assume that the page * directory table is always allocated, and in kernel virtual. */ if (*pmap_pde(pmap, i386_ptob(sva)) == 0) { /* We can race ahead here, straight to next pde.. */ sva = ((sva + NPTEPG) & ~(NPTEPG - 1)); continue; } ptq = ptp + sva; /* * search for page table entries, use string operations that * are much faster than explicitly scanning when page tables * are not fully populated. */ if (*ptq == 0) { vm_offset_t pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1)); vm_offset_t nscan = pdnxt - sva; int found = 0; if ((nscan + sva) > eva) nscan = eva - sva; asm("xorl %%eax,%%eax;cld;repe;scasl;jz 1f;incl %%eax;1:;" : "=D"(ptq), "=a"(found) : "c"(nscan), "0"(ptq) : "cx"); if (!found) { sva = pdnxt; continue; } ptq -= 1; sva = ptq - ptp; } /* * Update statistics */ oldpte = *ptq; if (((int) oldpte) & PG_W) pmap->pm_stats.wired_count--; pmap->pm_stats.resident_count--; /* * Invalidate the PTEs. XXX: should cluster them up and * invalidate as many as possible at once. */ *ptq = 0; va = i386_ptob(sva); /* * Remove from the PV table (raise IPL since we may be called * at interrupt time). */ pa = ((int) oldpte) & PG_FRAME; if (!pmap_is_managed(pa)) { pmap_unuse_pt(pmap, va); ++sva; continue; } if ((int) oldpte & PG_M) { if (sva < USRSTACK + (UPAGES * NBPG) || (sva >= KERNBASE && (sva < clean_sva || sva >= clean_eva))) { PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; } } pv = pa_to_pvh(pa); pmap_remove_entry(pmap, pv, va); pmap_unuse_pt(pmap, va); ++sva; } pmap_update(); } /* * 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(pa) vm_offset_t pa; { register pv_entry_t pv, npv; register pt_entry_t *pte, *ptp; vm_offset_t va; struct pmap *pmap; vm_page_t m; int s; int anyvalid = 0; /* * Not one of ours */ /* * XXX this makes pmap_page_protect(NONE) illegal for non-managed * pages! */ if (!pmap_is_managed(pa)) return; pa = i386_trunc_page(pa); pv = pa_to_pvh(pa); m = PHYS_TO_VM_PAGE(pa); s = splhigh(); while (pv->pv_pmap != NULL) { pmap = pv->pv_pmap; ptp = get_pt_entry(pmap); va = pv->pv_va; pte = ptp + i386_btop(va); if (pmap_pte_w(pte)) pmap->pm_stats.wired_count--; if (*pte) { pmap->pm_stats.resident_count--; anyvalid++; /* * Update the vm_page_t clean and reference bits. */ if ((int) *pte & PG_M) { if (va < USRSTACK + (UPAGES * NBPG) || (va >= KERNBASE && (va < clean_sva || va >= clean_eva))) { PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; } } *pte = 0; pmap_unuse_pt(pmap, va); } npv = pv->pv_next; if (npv) { *pv = *npv; free_pv_entry(npv); } else { pv->pv_pmap = NULL; } } splx(s); if (anyvalid) pmap_update(); } /* * Set the physical protection on the * specified range of this map as requested. */ void pmap_protect(pmap, sva, eva, prot) register pmap_t pmap; vm_offset_t sva, eva; vm_prot_t prot; { register pt_entry_t *pte; register vm_offset_t va; int i386prot; register pt_entry_t *ptp; int evap = i386_btop(eva); int anyvalid = 0;; if (pmap == NULL) return; if ((prot & VM_PROT_READ) == VM_PROT_NONE) { pmap_remove(pmap, sva, eva); return; } if (prot & VM_PROT_WRITE) return; ptp = get_pt_entry(pmap); va = sva; while (va < eva) { int found = 0; int svap; vm_offset_t nscan; /* * Page table page is not allocated. Skip it, we don't want to * force allocation of unnecessary PTE pages just to set the * protection. */ if (!*pmap_pde(pmap, va)) { /* XXX: avoid address wrap around */ nextpde: if (va >= i386_trunc_pdr((vm_offset_t) - 1)) break; va = i386_round_pdr(va + PAGE_SIZE); continue; } pte = ptp + i386_btop(va); if (*pte == 0) { /* * scan for a non-empty pte */ svap = pte - ptp; nscan = ((svap + NPTEPG) & ~(NPTEPG - 1)) - svap; if (nscan + svap > evap) nscan = evap - svap; found = 0; if (nscan) asm("xorl %%eax,%%eax;cld;repe;scasl;jz 1f;incl %%eax;1:;" : "=D"(pte), "=a"(found) : "c"(nscan), "0"(pte) : "cx"); if (!found) goto nextpde; pte -= 1; svap = pte - ptp; va = i386_ptob(svap); } anyvalid++; i386prot = pte_prot(pmap, prot); if (va < UPT_MAX_ADDRESS) { i386prot |= PG_u; if (va >= UPT_MIN_ADDRESS) i386prot |= PG_RW; } pmap_pte_set_prot(pte, i386prot); va += PAGE_SIZE; } if (anyvalid) pmap_update(); } /* * 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, va, pa, prot, wired) register pmap_t pmap; vm_offset_t va; register vm_offset_t pa; vm_prot_t prot; boolean_t wired; { register pt_entry_t *pte; register pt_entry_t npte; vm_offset_t opa; int ptevalid = 0; if (pmap == NULL) return; va = i386_trunc_page(va); pa = i386_trunc_page(pa); if (va > VM_MAX_KERNEL_ADDRESS) panic("pmap_enter: toobig"); /* * Page Directory table entry not valid, we need a new PT page */ if (*pmap_pde(pmap, va) == 0) { printf("kernel page directory invalid pdir=%p, va=0x%lx\n", pmap->pm_pdir[PTDPTDI], va); panic("invalid kernel page directory"); } pte = pmap_pte(pmap, va); opa = pmap_pte_pa(pte); /* * Mapping has not changed, must be protection or wiring change. */ if (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 && !pmap_pte_w(pte)) pmap->pm_stats.wired_count++; else if (!wired && pmap_pte_w(pte)) pmap->pm_stats.wired_count--; goto validate; } /* * Mapping has changed, invalidate old range and fall through to * handle validating new mapping. */ if (opa) { pmap_remove(pmap, va, va + PAGE_SIZE); } /* * 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_is_managed(pa)) { register pv_entry_t pv, npv; int s; pv = pa_to_pvh(pa); s = splhigh(); /* * No entries yet, use header as the first entry */ if (pv->pv_pmap == NULL) { pv->pv_va = va; pv->pv_pmap = pmap; pv->pv_next = NULL; } /* * There is at least one other VA mapping this page. Place * this entry after the header. */ else { npv = get_pv_entry(); npv->pv_va = va; npv->pv_pmap = pmap; npv->pv_next = pv->pv_next; pv->pv_next = npv; } splx(s); } /* * Increment counters */ pmap->pm_stats.resident_count++; if (wired) pmap->pm_stats.wired_count++; validate: /* * Now validate mapping with desired protection/wiring. */ npte = (pt_entry_t) ((int) (pa | pte_prot(pmap, prot) | PG_V)); /* * When forking (copy-on-write, etc): A process will turn off write * permissions for any of its writable pages. If the data (object) is * only referred to by one process, the processes map is modified * directly as opposed to using the object manipulation routine. When * using pmap_protect, the modified bits are not kept in the vm_page_t * data structure. Therefore, when using pmap_enter in vm_fault to * bring back writability of a page, there has been no memory of the * modified or referenced bits except at the pte level. this clause * supports the carryover of the modified and used (referenced) bits. */ if (pa == opa) (int) npte |= (int) *pte & (PG_M | PG_U); if (wired) (int) npte |= PG_W; if (va < UPT_MIN_ADDRESS) (int) npte |= PG_u; else if (va < UPT_MAX_ADDRESS) (int) npte |= PG_u | PG_RW; if (*pte != npte) { if (*pte) ptevalid++; *pte = npte; } if (ptevalid) { pmap_update(); } else { pmap_use_pt(pmap, va); } } /* * 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. */ void pmap_qenter(va, m, count) vm_offset_t va; vm_page_t *m; int count; { int i; int anyvalid = 0; register pt_entry_t *pte; for (i = 0; i < count; i++) { pte = vtopte(va + i * NBPG); if (*pte) anyvalid++; *pte = (pt_entry_t) ((int) (VM_PAGE_TO_PHYS(m[i]) | PG_RW | PG_V)); } if (anyvalid) pmap_update(); } /* * this routine jerks page mappings from the * kernel -- it is meant only for temporary mappings. */ void pmap_qremove(va, count) vm_offset_t va; int count; { int i; register pt_entry_t *pte; for (i = 0; i < count; i++) { pte = vtopte(va + i * NBPG); *pte = 0; } pmap_update(); } /* * add a wired page to the kva * note that in order for the mapping to take effect -- you * should do a pmap_update after doing the pmap_kenter... */ void pmap_kenter(va, pa) vm_offset_t va; register vm_offset_t pa; { register pt_entry_t *pte; int wasvalid = 0; pte = vtopte(va); if (*pte) wasvalid++; *pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V)); if (wasvalid) pmap_update(); } /* * remove a page from the kernel pagetables */ void pmap_kremove(va) vm_offset_t va; { register pt_entry_t *pte; pte = vtopte(va); *pte = (pt_entry_t) 0; pmap_update(); } /* * 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 inline void pmap_enter_quick(pmap, va, pa) register pmap_t pmap; vm_offset_t va; register vm_offset_t pa; { register pt_entry_t *pte; register pv_entry_t pv, npv; int s; /* * 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. */ pte = vtopte(va); /* a fault on the page table might occur here */ if (*pte) { pmap_remove(pmap, va, va + PAGE_SIZE); } pv = pa_to_pvh(pa); s = splhigh(); /* * No entries yet, use header as the first entry */ if (pv->pv_pmap == NULL) { pv->pv_pmap = pmap; pv->pv_va = va; pv->pv_next = NULL; } /* * There is at least one other VA mapping this page. Place this entry * after the header. */ else { npv = get_pv_entry(); npv->pv_va = va; npv->pv_pmap = pmap; npv->pv_next = pv->pv_next; pv->pv_next = npv; } splx(s); /* * Increment counters */ pmap->pm_stats.resident_count++; /* * Now validate mapping with desired protection/wiring. */ *pte = (pt_entry_t) ((int) (pa | PG_V | PG_u)); pmap_use_pt(pmap, va); return; } #define MAX_INIT_PT (512 * 4096) /* * 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, addr, object, pindex, size) pmap_t pmap; vm_offset_t addr; vm_object_t object; vm_pindex_t pindex; vm_size_t size; { vm_offset_t tmpidx; int psize; vm_page_t p; int objpgs; if (!pmap || ((size > MAX_INIT_PT) && (object->resident_page_count > MAX_INIT_PT / PAGE_SIZE))) { return; } psize = (size >> PAGE_SHIFT); /* * if we are processing a major portion of the object, then scan the * entire thing. */ if (psize > (object->size >> 2)) { objpgs = psize; for (p = object->memq.tqh_first; ((objpgs > 0) && (p != NULL)); p = p->listq.tqe_next) { tmpidx = p->pindex; if (tmpidx < pindex) { continue; } tmpidx -= pindex; if (tmpidx >= psize) { continue; } if (((p->flags & (PG_ACTIVE | PG_INACTIVE | PG_CACHE)) != 0) && ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->bmapped == 0) && (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if (p->flags & PG_CACHE) vm_page_deactivate(p); vm_page_hold(p); p->flags |= PG_MAPPED; pmap_enter_quick(pmap, addr + (tmpidx << PAGE_SHIFT), VM_PAGE_TO_PHYS(p)); vm_page_unhold(p); } objpgs -= 1; } } else { /* * else lookup the pages one-by-one. */ for (tmpidx = 0; tmpidx < psize; tmpidx += 1) { p = vm_page_lookup(object, tmpidx + pindex); if (p && ((p->flags & (PG_ACTIVE | PG_INACTIVE | PG_CACHE)) != 0) && (p->bmapped == 0) && (p->busy == 0) && ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if (p->flags & PG_CACHE) vm_page_deactivate(p); vm_page_hold(p); p->flags |= PG_MAPPED; pmap_enter_quick(pmap, addr + (tmpidx << PAGE_SHIFT), VM_PAGE_TO_PHYS(p)); vm_page_unhold(p); } } } } /* * 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); /* * When unwiring, set the modified bit in the pte -- could have been * changed by the kernel */ if (!wired) (int) *pte |= PG_M; } /* * 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(dst_pmap, src_pmap, dst_addr, len, src_addr) pmap_t dst_pmap, src_pmap; vm_offset_t dst_addr; vm_size_t len; vm_offset_t src_addr; { } /* * Routine: pmap_kernel * Function: * Returns the physical map handle for the kernel. */ pmap_t pmap_kernel() { return (kernel_pmap); } /* * pmap_zero_page zeros the specified (machine independent) * page by mapping the page into virtual memory and using * bzero to clear its contents, one machine dependent page * at a time. */ void pmap_zero_page(phys) vm_offset_t phys; { if (*(int *) CMAP2) panic("pmap_zero_page: CMAP busy"); *(int *) CMAP2 = PG_V | PG_KW | i386_trunc_page(phys); bzero(CADDR2, NBPG); *(int *) CMAP2 = 0; pmap_update(); } /* * 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(src, dst) vm_offset_t src; vm_offset_t dst; { if (*(int *) CMAP1 || *(int *) CMAP2) panic("pmap_copy_page: CMAP busy"); *(int *) CMAP1 = PG_V | PG_KW | i386_trunc_page(src); *(int *) CMAP2 = PG_V | PG_KW | i386_trunc_page(dst); #if __GNUC__ > 1 memcpy(CADDR2, CADDR1, NBPG); #else bcopy(CADDR1, CADDR2, NBPG); #endif *(int *) CMAP1 = 0; *(int *) CMAP2 = 0; pmap_update(); } /* * 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; { } /* * this routine returns true if a physical page resides * in the given pmap. */ boolean_t pmap_page_exists(pmap, pa) pmap_t pmap; vm_offset_t pa; { register pv_entry_t pv; int s; if (!pmap_is_managed(pa)) return FALSE; pv = pa_to_pvh(pa); s = splhigh(); /* * Not found, check current mappings returning immediately if found. */ if (pv->pv_pmap != NULL) { for (; pv; pv = pv->pv_next) { if (pv->pv_pmap == pmap) { splx(s); return TRUE; } } } splx(s); return (FALSE); } /* * pmap_testbit tests bits in pte's * note that the testbit/changebit routines are inline, * and a lot of things compile-time evaluate. */ static __inline boolean_t pmap_testbit(pa, bit) register vm_offset_t pa; int bit; { register pv_entry_t pv; pt_entry_t *pte; int s; if (!pmap_is_managed(pa)) return FALSE; pv = pa_to_pvh(pa); s = splhigh(); /* * Not found, check current mappings returning immediately if found. */ if (pv->pv_pmap != NULL) { for (; pv; pv = pv->pv_next) { /* * if the bit being tested is the modified bit, then * mark UPAGES as always modified, and ptes as never * modified. */ if (bit & PG_U) { if ((pv->pv_va >= clean_sva) && (pv->pv_va < clean_eva)) { continue; } } if (bit & PG_M) { if (pv->pv_va >= USRSTACK) { if (pv->pv_va >= clean_sva && pv->pv_va < clean_eva) { continue; } if (pv->pv_va < USRSTACK + (UPAGES * NBPG)) { splx(s); return TRUE; } else if (pv->pv_va < KERNBASE) { splx(s); return FALSE; } } } if (!pv->pv_pmap) { printf("Null pmap (tb) at va: 0x%lx\n", pv->pv_va); continue; } pte = pmap_pte(pv->pv_pmap, pv->pv_va); if ((int) *pte & bit) { splx(s); return TRUE; } } } splx(s); return (FALSE); } /* * this routine is used to modify bits in ptes */ static __inline void pmap_changebit(pa, bit, setem) vm_offset_t pa; int bit; boolean_t setem; { register pv_entry_t pv; register pt_entry_t *pte, npte; vm_offset_t va; int s; if (!pmap_is_managed(pa)) return; pv = pa_to_pvh(pa); s = splhigh(); /* * Loop over all current mappings setting/clearing as appropos If * setting RO do we need to clear the VAC? */ if (pv->pv_pmap != NULL) { for (; pv; pv = pv->pv_next) { va = pv->pv_va; /* * don't write protect pager mappings */ if (!setem && (bit == PG_RW)) { if (va >= clean_sva && va < clean_eva) continue; } if (!pv->pv_pmap) { printf("Null pmap (cb) at va: 0x%lx\n", va); continue; } pte = pmap_pte(pv->pv_pmap, va); if (setem) (int) npte = (int) *pte | bit; else (int) npte = (int) *pte & ~bit; *pte = npte; } } splx(s); pmap_update(); } /* * pmap_page_protect: * * Lower the permission for all mappings to a given page. */ void pmap_page_protect(phys, prot) vm_offset_t phys; vm_prot_t prot; { if ((prot & VM_PROT_WRITE) == 0) { if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) pmap_changebit(phys, PG_RW, FALSE); else pmap_remove_all(phys); } } vm_offset_t pmap_phys_address(ppn) int ppn; { return (i386_ptob(ppn)); } /* * pmap_is_referenced: * * Return whether or not the specified physical page was referenced * by any physical maps. */ boolean_t pmap_is_referenced(vm_offset_t pa) { return pmap_testbit((pa), PG_U); } /* * pmap_is_modified: * * Return whether or not the specified physical page was modified * in any physical maps. */ boolean_t pmap_is_modified(vm_offset_t pa) { return pmap_testbit((pa), PG_M); } /* * Clear the modify bits on the specified physical page. */ void pmap_clear_modify(vm_offset_t pa) { pmap_changebit((pa), PG_M, FALSE); } /* * pmap_clear_reference: * * Clear the reference bit on the specified physical page. */ void pmap_clear_reference(vm_offset_t pa) { pmap_changebit((pa), PG_U, 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. The non-cacheable bits are set on each * mapped page. */ void * pmap_mapdev(pa, size) vm_offset_t pa; vm_size_t size; { vm_offset_t va, tmpva; pt_entry_t *pte; pa = trunc_page(pa); size = roundup(size, PAGE_SIZE); va = kmem_alloc_pageable(kernel_map, size); if (!va) panic("pmap_mapdev: Couldn't alloc kernel virtual memory"); for (tmpva = va; size > 0;) { pte = vtopte(tmpva); *pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V | PG_N)); size -= PAGE_SIZE; tmpva += PAGE_SIZE; pa += PAGE_SIZE; } pmap_update(); return ((void *) va); } #ifdef DEBUG /* print address space of pmap*/ void pads(pm) pmap_t pm; { unsigned va, i, j; pt_entry_t *ptep; if (pm == kernel_pmap) return; for (i = 0; i < 1024; i++) if (pm->pm_pdir[i]) for (j = 0; j < 1024; j++) { va = (i << PD_SHIFT) + (j << PG_SHIFT); if (pm == kernel_pmap && va < KERNBASE) continue; if (pm != kernel_pmap && va > UPT_MAX_ADDRESS) continue; ptep = pmap_pte(pm, va); if (pmap_pte_v(ptep)) printf("%x:%x ", va, *(int *) ptep); }; } void pmap_pvdump(pa) vm_offset_t pa; { register pv_entry_t pv; printf("pa %x", pa); for (pv = pa_to_pvh(pa); pv; pv = pv->pv_next) { #ifdef used_to_be printf(" -> pmap %x, va %x, flags %x", pv->pv_pmap, pv->pv_va, pv->pv_flags); #endif printf(" -> pmap %x, va %x", pv->pv_pmap, pv->pv_va); pads(pv->pv_pmap); } printf(" "); } #endif diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c index 8d701bdeb17a..186a82a3a5a1 100644 --- a/sys/i386/i386/pmap.c +++ b/sys/i386/i386/pmap.c @@ -1,1952 +1,1953 @@ /* * 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 - * $Id: pmap.c,v 1.68 1995/12/10 13:36:28 phk Exp $ + * $Id: pmap.c,v 1.69 1995/12/11 04:54:58 dyson Exp $ */ /* * Derived from hp300 version by Mike Hibler, this version by William * Jolitz uses a recursive map [a pde points to the page directory] to * map the page tables using the pagetables themselves. This is done to * reduce the impact on kernel virtual memory for lots of sparse address * space, and to reduce the cost of memory to each process. * * Derived from: hp300/@(#)pmap.c 7.1 (Berkeley) 12/5/90 */ /* * Major modifications by John S. Dyson primarily to support * pageable page tables, eliminating pmap_attributes, * discontiguous memory pages, and using more efficient string * instructions. Jan 13, 1994. Further modifications on Mar 2, 1994, * general clean-up and efficiency mods. */ /* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include -static void init_pv_entries __P((int)); -extern void pmap_object_init_pt __P((pmap_t pmap, vm_offset_t addr, - vm_object_t object, vm_offset_t offset, - vm_offset_t size)); -static void pmap_remove_all __P((vm_offset_t pa)); -static void pmap_remove_entry __P((struct pmap *pmap, pv_entry_t pv, - vm_offset_t va)); - /* * Get PDEs and PTEs for user/kernel address space */ #define pmap_pde(m, v) (&((m)->pm_pdir[((vm_offset_t)(v) >> PD_SHIFT)&1023])) #define pdir_pde(m, v) (m[((vm_offset_t)(v) >> PD_SHIFT)&1023]) #define pmap_pte_pa(pte) (*(int *)(pte) & PG_FRAME) #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_U) != 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]; static struct pmap kernel_pmap_store; pmap_t kernel_pmap; 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 vm_offset_t vm_first_phys; static int nkpt; extern vm_offset_t clean_sva, clean_eva; extern int cpu_class; /* * All those kernel PT submaps that BSD is so fond of */ pt_entry_t *CMAP1; static pt_entry_t *CMAP2, *ptmmap; static pv_entry_t pv_table; caddr_t CADDR1, ptvmmap; static caddr_t CADDR2; static pt_entry_t *msgbufmap; struct msgbuf *msgbufp; static void free_pv_entry __P((pv_entry_t pv)); static pt_entry_t * get_pt_entry __P((pmap_t pmap)); static pv_entry_t get_pv_entry __P((void)); static void i386_protection_init __P((void)); +static void init_pv_entries __P((int npg)); static void pmap_alloc_pv_entry __P((void)); static void pmap_changebit __P((vm_offset_t pa, int bit, boolean_t setem)); static void pmap_enter_quick __P((pmap_t pmap, vm_offset_t va, vm_offset_t pa)); static int pmap_is_managed __P((vm_offset_t pa)); +extern void pmap_object_init_pt __P((pmap_t pmap, vm_offset_t addr, + vm_object_t object, vm_offset_t offset, + vm_offset_t size)); +static void pmap_remove_all __P((vm_offset_t pa)); +static void pmap_remove_entry __P((struct pmap *pmap, pv_entry_t pv, + vm_offset_t va)); +static vm_page_t + pmap_pte_vm_page __P((pmap_t pmap, vm_offset_t pt)); static boolean_t pmap_testbit __P((vm_offset_t pa, int bit)); /* * Routine: pmap_pte * Function: * Extract the page table entry associated * with the given map/virtual_address pair. * [ what about induced faults -wfj] */ inline pt_entry_t * __pure pmap_pte(pmap, va) register pmap_t pmap; vm_offset_t va; { if (pmap && *pmap_pde(pmap, va)) { vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; /* are we current address space or kernel? */ if ((pmap == kernel_pmap) || (frame == ((int) PTDpde & PG_FRAME))) return ((pt_entry_t *) vtopte(va)); /* otherwise, we are alternate address space */ else { if (frame != ((int) APTDpde & PG_FRAME)) { APTDpde = pmap->pm_pdir[PTDPTDI]; pmap_update(); } return ((pt_entry_t *) avtopte(va)); } } 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 pa; if (pmap && *pmap_pde(pmap, va)) { vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; /* are we current address space or kernel? */ if ((pmap == kernel_pmap) || (frame == ((int) PTDpde & PG_FRAME))) { pa = *(int *) vtopte(va); /* otherwise, we are alternate address space */ } else { if (frame != ((int) APTDpde & PG_FRAME)) { APTDpde = pmap->pm_pdir[PTDPTDI]; pmap_update(); } pa = *(int *) avtopte(va); } return ((pa & PG_FRAME) | (va & ~PG_FRAME)); } return 0; } /* * determine if a page is managed (memory vs. device) */ static inline int pmap_is_managed(pa) vm_offset_t pa; { int i; if (!pmap_initialized) return 0; for (i = 0; phys_avail[i + 1]; i += 2) { if (pa >= phys_avail[i] && pa < phys_avail[i + 1]) return 1; } return 0; } /* * find the vm_page_t of a pte (only) given va of pte and pmap */ static __inline vm_page_t pmap_pte_vm_page(pmap, pt) pmap_t pmap; vm_offset_t pt; { vm_page_t m; pt = i386_trunc_page(pt); pt = (pt - UPT_MIN_ADDRESS) / NBPG; pt = ((vm_offset_t) pmap->pm_pdir[pt]) & PG_FRAME; m = PHYS_TO_VM_PAGE(pt); return m; } /* * Wire a page table page */ __inline void pmap_use_pt(pmap, va) pmap_t pmap; vm_offset_t va; { vm_offset_t pt; if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized) return; pt = (vm_offset_t) vtopte(va); vm_page_hold(pmap_pte_vm_page(pmap, pt)); } /* * Unwire a page table page */ inline void pmap_unuse_pt(pmap, va) pmap_t pmap; vm_offset_t va; { vm_offset_t pt; vm_page_t m; if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized) return; pt = (vm_offset_t) vtopte(va); m = pmap_pte_vm_page(pmap, pt); vm_page_unhold(m); if (pmap != kernel_pmap && (m->hold_count == 0) && (m->wire_count == 0) && (va < KPT_MIN_ADDRESS)) { pmap_page_protect(VM_PAGE_TO_PHYS(m), VM_PROT_NONE); vm_page_free(m); } } /* [ macro again?, should I force kstack into user map here? -wfj ] */ void pmap_activate(pmap, pcbp) register pmap_t pmap; struct pcb *pcbp; { PMAP_ACTIVATE(pmap, pcbp); } /* * 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; avail_start = firstaddr; /* * XXX The calculation of virtual_avail is wrong. It's NKPT*NBPG 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_end = VM_MAX_KERNEL_ADDRESS; /* * Initialize protection array. */ i386_protection_init(); /* * The kernel's pmap is statically allocated so we don't have to use * pmap_create, which is unlikely to work correctly at this part of * the boot sequence. */ kernel_pmap = &kernel_pmap_store; kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + IdlePTD); kernel_pmap->pm_count = 1; 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)*NBPG); p = pte; pte += (n); va = virtual_avail; pte = pmap_pte(kernel_pmap, va); /* * CMAP1/CMAP2 are used for zeroing and copying pages. */ SYSMAP(caddr_t, CMAP1, CADDR1, 1) SYSMAP(caddr_t, CMAP2, CADDR2, 1) /* * ptmmap is used for reading arbitrary physical pages via /dev/mem. */ SYSMAP(caddr_t, ptmmap, ptvmmap, 1) /* * msgbufmap is used to map the system message buffer. */ SYSMAP(struct msgbuf *, msgbufmap, msgbufp, 1) virtual_avail = va; *(int *) CMAP1 = *(int *) CMAP2 = *(int *) PTD = 0; pmap_update(); } /* * 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; { vm_offset_t addr; vm_size_t npg, s; int i; /* * calculate the number of pv_entries needed */ vm_first_phys = phys_avail[0]; for (i = 0; phys_avail[i + 1]; i += 2); npg = (phys_avail[(i - 2) + 1] - vm_first_phys) / NBPG; /* * Allocate memory for random pmap data structures. Includes the * pv_head_table. */ s = (vm_size_t) (sizeof(struct pv_entry) * npg); s = i386_round_page(s); addr = (vm_offset_t) kmem_alloc(kernel_map, s); pv_table = (pv_entry_t) addr; /* * init the pv free list */ init_pv_entries(npg); /* * Now it is safe to enable pv_table recording. */ pmap_initialized = TRUE; } /* * Used to map a range of physical addresses into kernel * virtual address space. * * For now, VM is already on, we only need to map the * specified memory. */ vm_offset_t pmap_map(virt, start, end, prot) vm_offset_t virt; vm_offset_t start; vm_offset_t end; int prot; { while (start < end) { pmap_enter(kernel_pmap, virt, start, prot, FALSE); virt += PAGE_SIZE; start += PAGE_SIZE; } return (virt); } /* * Initialize a preallocated and zeroed pmap structure, * such as one in a vmspace structure. */ void pmap_pinit(pmap) register struct pmap *pmap; { /* * No need to allocate page table space yet but we do need a valid * page directory table. */ pmap->pm_pdir = (pd_entry_t *) kmem_alloc(kernel_map, PAGE_SIZE); /* wire in kernel global address entries */ bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * PTESIZE); /* install self-referential address mapping entry */ *(int *) (pmap->pm_pdir + PTDPTDI) = ((int) pmap_kextract((vm_offset_t) pmap->pm_pdir)) | PG_V | PG_KW; pmap->pm_count = 1; } /* * grow the number of kernel page table entries, if needed */ static vm_page_t nkpg; vm_offset_t kernel_vm_end; void pmap_growkernel(vm_offset_t addr) { struct proc *p; struct pmap *pmap; int s; 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 + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); ++nkpt; } } addr = (addr + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); while (kernel_vm_end < addr) { if (pdir_pde(PTD, kernel_vm_end)) { kernel_vm_end = (kernel_vm_end + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); continue; } ++nkpt; if (!nkpg) { nkpg = vm_page_alloc(kernel_object, 0, VM_ALLOC_SYSTEM); if (!nkpg) panic("pmap_growkernel: no memory to grow kernel"); vm_page_wire(nkpg); vm_page_remove(nkpg); pmap_zero_page(VM_PAGE_TO_PHYS(nkpg)); } pdir_pde(PTD, kernel_vm_end) = (pd_entry_t) (VM_PAGE_TO_PHYS(nkpg) | PG_V | PG_KW); nkpg = NULL; for (p = (struct proc *) allproc; p != NULL; p = p->p_next) { if (p->p_vmspace) { pmap = &p->p_vmspace->vm_pmap; *pmap_pde(pmap, kernel_vm_end) = pdir_pde(PTD, kernel_vm_end); } } *pmap_pde(kernel_pmap, kernel_vm_end) = pdir_pde(PTD, kernel_vm_end); kernel_vm_end = (kernel_vm_end + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); } splx(s); } /* * Retire the given physical map from service. * Should only be called if the map contains * no valid mappings. */ void pmap_destroy(pmap) register pmap_t pmap; { int count; if (pmap == NULL) return; count = --pmap->pm_count; if (count == 0) { pmap_release(pmap); free((caddr_t) pmap, M_VMPMAP); } } /* * 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) register struct pmap *pmap; { kmem_free(kernel_map, (vm_offset_t) pmap->pm_pdir, PAGE_SIZE); } /* * Add a reference to the specified pmap. */ void pmap_reference(pmap) pmap_t pmap; { if (pmap != NULL) { pmap->pm_count++; } } #define PV_FREELIST_MIN ((NBPG / sizeof (struct pv_entry)) / 2) /* * Data for the pv entry allocation mechanism */ static int pv_freelistcnt; static pv_entry_t pv_freelist; static vm_offset_t pvva; static int npvvapg; /* * free the pv_entry back to the free list */ inline static void free_pv_entry(pv) pv_entry_t pv; { if (!pv) return; ++pv_freelistcnt; pv->pv_next = pv_freelist; pv_freelist = 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 inline pv_entry_t get_pv_entry() { pv_entry_t tmp; /* * get more pv_entry pages if needed */ if (pv_freelistcnt < PV_FREELIST_MIN || pv_freelist == 0) { pmap_alloc_pv_entry(); } /* * get a pv_entry off of the free list */ --pv_freelistcnt; tmp = pv_freelist; pv_freelist = tmp->pv_next; return tmp; } /* * this *strange* allocation routine *statistically* eliminates the * *possibility* of a malloc failure (*FATAL*) for a pv_entry_t data structure. * also -- this code is MUCH MUCH faster than the malloc equiv... */ static void pmap_alloc_pv_entry() { /* * do we have any pre-allocated map-pages left? */ if (npvvapg) { vm_page_t m; /* * we do this to keep recursion away */ pv_freelistcnt += PV_FREELIST_MIN; /* * allocate a physical page out of the vm system */ m = vm_page_alloc(kernel_object, OFF_TO_IDX(pvva - vm_map_min(kernel_map)), VM_ALLOC_INTERRUPT); if (m) { int newentries; int i; pv_entry_t entry; newentries = (NBPG / sizeof(struct pv_entry)); /* * wire the page */ vm_page_wire(m); m->flags &= ~PG_BUSY; /* * let the kernel see it */ pmap_kenter(pvva, VM_PAGE_TO_PHYS(m)); entry = (pv_entry_t) pvva; /* * update the allocation pointers */ pvva += NBPG; --npvvapg; /* * free the entries into the free list */ for (i = 0; i < newentries; i++) { free_pv_entry(entry); entry++; } } pv_freelistcnt -= PV_FREELIST_MIN; } if (!pv_freelist) panic("get_pv_entry: cannot get a pv_entry_t"); } /* * init the pv_entry allocation system */ #define PVSPERPAGE 64 void init_pv_entries(npg) int npg; { /* * allocate enough kvm space for PVSPERPAGE entries per page (lots) * kvm space is fairly cheap, be generous!!! (the system can panic if * this is too small.) */ npvvapg = ((npg * PVSPERPAGE) * sizeof(struct pv_entry) + NBPG - 1) / NBPG; pvva = kmem_alloc_pageable(kernel_map, npvvapg * NBPG); /* * get the first batch of entries */ free_pv_entry(get_pv_entry()); } static pt_entry_t * get_pt_entry(pmap) pmap_t pmap; { vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; /* are we current address space or kernel? */ if (pmap == kernel_pmap || frame == ((int) PTDpde & PG_FRAME)) { return PTmap; } /* otherwise, we are alternate address space */ if (frame != ((int) APTDpde & PG_FRAME)) { APTDpde = pmap->pm_pdir[PTDPTDI]; pmap_update(); } return APTmap; } /* * 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 void pmap_remove_entry(pmap, pv, va) struct pmap *pmap; pv_entry_t pv; vm_offset_t va; { pv_entry_t npv; int s; s = splhigh(); if (pmap == pv->pv_pmap && va == pv->pv_va) { npv = pv->pv_next; if (npv) { *pv = *npv; free_pv_entry(npv); } else { pv->pv_pmap = NULL; } } else { for (npv = pv->pv_next; npv; npv = npv->pv_next) { if (pmap == npv->pv_pmap && va == npv->pv_va) { break; } pv = npv; } if (npv) { pv->pv_next = npv->pv_next; free_pv_entry(npv); } } splx(s); } /* * 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, sva, eva) struct pmap *pmap; register vm_offset_t sva; register vm_offset_t eva; { register pt_entry_t *ptp, *ptq; vm_offset_t pa; register pv_entry_t pv; vm_offset_t va; pt_entry_t oldpte; if (pmap == NULL) return; ptp = get_pt_entry(pmap); /* * special handling of removing one page. a very * common operation and easy to short circuit some * code. */ if ((sva + NBPG) == eva) { if (*pmap_pde(pmap, sva) == 0) return; ptq = ptp + i386_btop(sva); if (!*ptq) return; /* * Update statistics */ if (pmap_pte_w(ptq)) pmap->pm_stats.wired_count--; pmap->pm_stats.resident_count--; pa = pmap_pte_pa(ptq); oldpte = *ptq; *ptq = 0; if (pmap_is_managed(pa)) { if ((int) oldpte & PG_M) { if (sva < USRSTACK + (UPAGES * NBPG) || (sva >= KERNBASE && (sva < clean_sva || sva >= clean_eva))) { PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; } } pv = pa_to_pvh(pa); pmap_remove_entry(pmap, pv, sva); } pmap_unuse_pt(pmap, sva); pmap_update(); return; } sva = i386_btop(sva); eva = i386_btop(eva); while (sva < eva) { /* * Weed out invalid mappings. Note: we assume that the page * directory table is always allocated, and in kernel virtual. */ if (*pmap_pde(pmap, i386_ptob(sva)) == 0) { /* We can race ahead here, straight to next pde.. */ sva = ((sva + NPTEPG) & ~(NPTEPG - 1)); continue; } ptq = ptp + sva; /* * search for page table entries, use string operations that * are much faster than explicitly scanning when page tables * are not fully populated. */ if (*ptq == 0) { vm_offset_t pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1)); vm_offset_t nscan = pdnxt - sva; int found = 0; if ((nscan + sva) > eva) nscan = eva - sva; asm("xorl %%eax,%%eax;cld;repe;scasl;jz 1f;incl %%eax;1:;" : "=D"(ptq), "=a"(found) : "c"(nscan), "0"(ptq) : "cx"); if (!found) { sva = pdnxt; continue; } ptq -= 1; sva = ptq - ptp; } /* * Update statistics */ oldpte = *ptq; if (((int) oldpte) & PG_W) pmap->pm_stats.wired_count--; pmap->pm_stats.resident_count--; /* * Invalidate the PTEs. XXX: should cluster them up and * invalidate as many as possible at once. */ *ptq = 0; va = i386_ptob(sva); /* * Remove from the PV table (raise IPL since we may be called * at interrupt time). */ pa = ((int) oldpte) & PG_FRAME; if (!pmap_is_managed(pa)) { pmap_unuse_pt(pmap, va); ++sva; continue; } if ((int) oldpte & PG_M) { if (sva < USRSTACK + (UPAGES * NBPG) || (sva >= KERNBASE && (sva < clean_sva || sva >= clean_eva))) { PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; } } pv = pa_to_pvh(pa); pmap_remove_entry(pmap, pv, va); pmap_unuse_pt(pmap, va); ++sva; } pmap_update(); } /* * 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(pa) vm_offset_t pa; { register pv_entry_t pv, npv; register pt_entry_t *pte, *ptp; vm_offset_t va; struct pmap *pmap; vm_page_t m; int s; int anyvalid = 0; /* * Not one of ours */ /* * XXX this makes pmap_page_protect(NONE) illegal for non-managed * pages! */ if (!pmap_is_managed(pa)) return; pa = i386_trunc_page(pa); pv = pa_to_pvh(pa); m = PHYS_TO_VM_PAGE(pa); s = splhigh(); while (pv->pv_pmap != NULL) { pmap = pv->pv_pmap; ptp = get_pt_entry(pmap); va = pv->pv_va; pte = ptp + i386_btop(va); if (pmap_pte_w(pte)) pmap->pm_stats.wired_count--; if (*pte) { pmap->pm_stats.resident_count--; anyvalid++; /* * Update the vm_page_t clean and reference bits. */ if ((int) *pte & PG_M) { if (va < USRSTACK + (UPAGES * NBPG) || (va >= KERNBASE && (va < clean_sva || va >= clean_eva))) { PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; } } *pte = 0; pmap_unuse_pt(pmap, va); } npv = pv->pv_next; if (npv) { *pv = *npv; free_pv_entry(npv); } else { pv->pv_pmap = NULL; } } splx(s); if (anyvalid) pmap_update(); } /* * Set the physical protection on the * specified range of this map as requested. */ void pmap_protect(pmap, sva, eva, prot) register pmap_t pmap; vm_offset_t sva, eva; vm_prot_t prot; { register pt_entry_t *pte; register vm_offset_t va; int i386prot; register pt_entry_t *ptp; int evap = i386_btop(eva); int anyvalid = 0;; if (pmap == NULL) return; if ((prot & VM_PROT_READ) == VM_PROT_NONE) { pmap_remove(pmap, sva, eva); return; } if (prot & VM_PROT_WRITE) return; ptp = get_pt_entry(pmap); va = sva; while (va < eva) { int found = 0; int svap; vm_offset_t nscan; /* * Page table page is not allocated. Skip it, we don't want to * force allocation of unnecessary PTE pages just to set the * protection. */ if (!*pmap_pde(pmap, va)) { /* XXX: avoid address wrap around */ nextpde: if (va >= i386_trunc_pdr((vm_offset_t) - 1)) break; va = i386_round_pdr(va + PAGE_SIZE); continue; } pte = ptp + i386_btop(va); if (*pte == 0) { /* * scan for a non-empty pte */ svap = pte - ptp; nscan = ((svap + NPTEPG) & ~(NPTEPG - 1)) - svap; if (nscan + svap > evap) nscan = evap - svap; found = 0; if (nscan) asm("xorl %%eax,%%eax;cld;repe;scasl;jz 1f;incl %%eax;1:;" : "=D"(pte), "=a"(found) : "c"(nscan), "0"(pte) : "cx"); if (!found) goto nextpde; pte -= 1; svap = pte - ptp; va = i386_ptob(svap); } anyvalid++; i386prot = pte_prot(pmap, prot); if (va < UPT_MAX_ADDRESS) { i386prot |= PG_u; if (va >= UPT_MIN_ADDRESS) i386prot |= PG_RW; } pmap_pte_set_prot(pte, i386prot); va += PAGE_SIZE; } if (anyvalid) pmap_update(); } /* * 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, va, pa, prot, wired) register pmap_t pmap; vm_offset_t va; register vm_offset_t pa; vm_prot_t prot; boolean_t wired; { register pt_entry_t *pte; register pt_entry_t npte; vm_offset_t opa; int ptevalid = 0; if (pmap == NULL) return; va = i386_trunc_page(va); pa = i386_trunc_page(pa); if (va > VM_MAX_KERNEL_ADDRESS) panic("pmap_enter: toobig"); /* * Page Directory table entry not valid, we need a new PT page */ if (*pmap_pde(pmap, va) == 0) { printf("kernel page directory invalid pdir=%p, va=0x%lx\n", pmap->pm_pdir[PTDPTDI], va); panic("invalid kernel page directory"); } pte = pmap_pte(pmap, va); opa = pmap_pte_pa(pte); /* * Mapping has not changed, must be protection or wiring change. */ if (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 && !pmap_pte_w(pte)) pmap->pm_stats.wired_count++; else if (!wired && pmap_pte_w(pte)) pmap->pm_stats.wired_count--; goto validate; } /* * Mapping has changed, invalidate old range and fall through to * handle validating new mapping. */ if (opa) { pmap_remove(pmap, va, va + PAGE_SIZE); } /* * 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_is_managed(pa)) { register pv_entry_t pv, npv; int s; pv = pa_to_pvh(pa); s = splhigh(); /* * No entries yet, use header as the first entry */ if (pv->pv_pmap == NULL) { pv->pv_va = va; pv->pv_pmap = pmap; pv->pv_next = NULL; } /* * There is at least one other VA mapping this page. Place * this entry after the header. */ else { npv = get_pv_entry(); npv->pv_va = va; npv->pv_pmap = pmap; npv->pv_next = pv->pv_next; pv->pv_next = npv; } splx(s); } /* * Increment counters */ pmap->pm_stats.resident_count++; if (wired) pmap->pm_stats.wired_count++; validate: /* * Now validate mapping with desired protection/wiring. */ npte = (pt_entry_t) ((int) (pa | pte_prot(pmap, prot) | PG_V)); /* * When forking (copy-on-write, etc): A process will turn off write * permissions for any of its writable pages. If the data (object) is * only referred to by one process, the processes map is modified * directly as opposed to using the object manipulation routine. When * using pmap_protect, the modified bits are not kept in the vm_page_t * data structure. Therefore, when using pmap_enter in vm_fault to * bring back writability of a page, there has been no memory of the * modified or referenced bits except at the pte level. this clause * supports the carryover of the modified and used (referenced) bits. */ if (pa == opa) (int) npte |= (int) *pte & (PG_M | PG_U); if (wired) (int) npte |= PG_W; if (va < UPT_MIN_ADDRESS) (int) npte |= PG_u; else if (va < UPT_MAX_ADDRESS) (int) npte |= PG_u | PG_RW; if (*pte != npte) { if (*pte) ptevalid++; *pte = npte; } if (ptevalid) { pmap_update(); } else { pmap_use_pt(pmap, va); } } /* * 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. */ void pmap_qenter(va, m, count) vm_offset_t va; vm_page_t *m; int count; { int i; int anyvalid = 0; register pt_entry_t *pte; for (i = 0; i < count; i++) { pte = vtopte(va + i * NBPG); if (*pte) anyvalid++; *pte = (pt_entry_t) ((int) (VM_PAGE_TO_PHYS(m[i]) | PG_RW | PG_V)); } if (anyvalid) pmap_update(); } /* * this routine jerks page mappings from the * kernel -- it is meant only for temporary mappings. */ void pmap_qremove(va, count) vm_offset_t va; int count; { int i; register pt_entry_t *pte; for (i = 0; i < count; i++) { pte = vtopte(va + i * NBPG); *pte = 0; } pmap_update(); } /* * add a wired page to the kva * note that in order for the mapping to take effect -- you * should do a pmap_update after doing the pmap_kenter... */ void pmap_kenter(va, pa) vm_offset_t va; register vm_offset_t pa; { register pt_entry_t *pte; int wasvalid = 0; pte = vtopte(va); if (*pte) wasvalid++; *pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V)); if (wasvalid) pmap_update(); } /* * remove a page from the kernel pagetables */ void pmap_kremove(va) vm_offset_t va; { register pt_entry_t *pte; pte = vtopte(va); *pte = (pt_entry_t) 0; pmap_update(); } /* * 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 inline void pmap_enter_quick(pmap, va, pa) register pmap_t pmap; vm_offset_t va; register vm_offset_t pa; { register pt_entry_t *pte; register pv_entry_t pv, npv; int s; /* * 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. */ pte = vtopte(va); /* a fault on the page table might occur here */ if (*pte) { pmap_remove(pmap, va, va + PAGE_SIZE); } pv = pa_to_pvh(pa); s = splhigh(); /* * No entries yet, use header as the first entry */ if (pv->pv_pmap == NULL) { pv->pv_pmap = pmap; pv->pv_va = va; pv->pv_next = NULL; } /* * There is at least one other VA mapping this page. Place this entry * after the header. */ else { npv = get_pv_entry(); npv->pv_va = va; npv->pv_pmap = pmap; npv->pv_next = pv->pv_next; pv->pv_next = npv; } splx(s); /* * Increment counters */ pmap->pm_stats.resident_count++; /* * Now validate mapping with desired protection/wiring. */ *pte = (pt_entry_t) ((int) (pa | PG_V | PG_u)); pmap_use_pt(pmap, va); return; } #define MAX_INIT_PT (512 * 4096) /* * 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, addr, object, pindex, size) pmap_t pmap; vm_offset_t addr; vm_object_t object; vm_pindex_t pindex; vm_size_t size; { vm_offset_t tmpidx; int psize; vm_page_t p; int objpgs; if (!pmap || ((size > MAX_INIT_PT) && (object->resident_page_count > MAX_INIT_PT / PAGE_SIZE))) { return; } psize = (size >> PAGE_SHIFT); /* * if we are processing a major portion of the object, then scan the * entire thing. */ if (psize > (object->size >> 2)) { objpgs = psize; for (p = object->memq.tqh_first; ((objpgs > 0) && (p != NULL)); p = p->listq.tqe_next) { tmpidx = p->pindex; if (tmpidx < pindex) { continue; } tmpidx -= pindex; if (tmpidx >= psize) { continue; } if (((p->flags & (PG_ACTIVE | PG_INACTIVE | PG_CACHE)) != 0) && ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->bmapped == 0) && (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if (p->flags & PG_CACHE) vm_page_deactivate(p); vm_page_hold(p); p->flags |= PG_MAPPED; pmap_enter_quick(pmap, addr + (tmpidx << PAGE_SHIFT), VM_PAGE_TO_PHYS(p)); vm_page_unhold(p); } objpgs -= 1; } } else { /* * else lookup the pages one-by-one. */ for (tmpidx = 0; tmpidx < psize; tmpidx += 1) { p = vm_page_lookup(object, tmpidx + pindex); if (p && ((p->flags & (PG_ACTIVE | PG_INACTIVE | PG_CACHE)) != 0) && (p->bmapped == 0) && (p->busy == 0) && ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { if (p->flags & PG_CACHE) vm_page_deactivate(p); vm_page_hold(p); p->flags |= PG_MAPPED; pmap_enter_quick(pmap, addr + (tmpidx << PAGE_SHIFT), VM_PAGE_TO_PHYS(p)); vm_page_unhold(p); } } } } /* * 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); /* * When unwiring, set the modified bit in the pte -- could have been * changed by the kernel */ if (!wired) (int) *pte |= PG_M; } /* * 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(dst_pmap, src_pmap, dst_addr, len, src_addr) pmap_t dst_pmap, src_pmap; vm_offset_t dst_addr; vm_size_t len; vm_offset_t src_addr; { } /* * Routine: pmap_kernel * Function: * Returns the physical map handle for the kernel. */ pmap_t pmap_kernel() { return (kernel_pmap); } /* * pmap_zero_page zeros the specified (machine independent) * page by mapping the page into virtual memory and using * bzero to clear its contents, one machine dependent page * at a time. */ void pmap_zero_page(phys) vm_offset_t phys; { if (*(int *) CMAP2) panic("pmap_zero_page: CMAP busy"); *(int *) CMAP2 = PG_V | PG_KW | i386_trunc_page(phys); bzero(CADDR2, NBPG); *(int *) CMAP2 = 0; pmap_update(); } /* * 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(src, dst) vm_offset_t src; vm_offset_t dst; { if (*(int *) CMAP1 || *(int *) CMAP2) panic("pmap_copy_page: CMAP busy"); *(int *) CMAP1 = PG_V | PG_KW | i386_trunc_page(src); *(int *) CMAP2 = PG_V | PG_KW | i386_trunc_page(dst); #if __GNUC__ > 1 memcpy(CADDR2, CADDR1, NBPG); #else bcopy(CADDR1, CADDR2, NBPG); #endif *(int *) CMAP1 = 0; *(int *) CMAP2 = 0; pmap_update(); } /* * 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; { } /* * this routine returns true if a physical page resides * in the given pmap. */ boolean_t pmap_page_exists(pmap, pa) pmap_t pmap; vm_offset_t pa; { register pv_entry_t pv; int s; if (!pmap_is_managed(pa)) return FALSE; pv = pa_to_pvh(pa); s = splhigh(); /* * Not found, check current mappings returning immediately if found. */ if (pv->pv_pmap != NULL) { for (; pv; pv = pv->pv_next) { if (pv->pv_pmap == pmap) { splx(s); return TRUE; } } } splx(s); return (FALSE); } /* * pmap_testbit tests bits in pte's * note that the testbit/changebit routines are inline, * and a lot of things compile-time evaluate. */ static __inline boolean_t pmap_testbit(pa, bit) register vm_offset_t pa; int bit; { register pv_entry_t pv; pt_entry_t *pte; int s; if (!pmap_is_managed(pa)) return FALSE; pv = pa_to_pvh(pa); s = splhigh(); /* * Not found, check current mappings returning immediately if found. */ if (pv->pv_pmap != NULL) { for (; pv; pv = pv->pv_next) { /* * if the bit being tested is the modified bit, then * mark UPAGES as always modified, and ptes as never * modified. */ if (bit & PG_U) { if ((pv->pv_va >= clean_sva) && (pv->pv_va < clean_eva)) { continue; } } if (bit & PG_M) { if (pv->pv_va >= USRSTACK) { if (pv->pv_va >= clean_sva && pv->pv_va < clean_eva) { continue; } if (pv->pv_va < USRSTACK + (UPAGES * NBPG)) { splx(s); return TRUE; } else if (pv->pv_va < KERNBASE) { splx(s); return FALSE; } } } if (!pv->pv_pmap) { printf("Null pmap (tb) at va: 0x%lx\n", pv->pv_va); continue; } pte = pmap_pte(pv->pv_pmap, pv->pv_va); if ((int) *pte & bit) { splx(s); return TRUE; } } } splx(s); return (FALSE); } /* * this routine is used to modify bits in ptes */ static __inline void pmap_changebit(pa, bit, setem) vm_offset_t pa; int bit; boolean_t setem; { register pv_entry_t pv; register pt_entry_t *pte, npte; vm_offset_t va; int s; if (!pmap_is_managed(pa)) return; pv = pa_to_pvh(pa); s = splhigh(); /* * Loop over all current mappings setting/clearing as appropos If * setting RO do we need to clear the VAC? */ if (pv->pv_pmap != NULL) { for (; pv; pv = pv->pv_next) { va = pv->pv_va; /* * don't write protect pager mappings */ if (!setem && (bit == PG_RW)) { if (va >= clean_sva && va < clean_eva) continue; } if (!pv->pv_pmap) { printf("Null pmap (cb) at va: 0x%lx\n", va); continue; } pte = pmap_pte(pv->pv_pmap, va); if (setem) (int) npte = (int) *pte | bit; else (int) npte = (int) *pte & ~bit; *pte = npte; } } splx(s); pmap_update(); } /* * pmap_page_protect: * * Lower the permission for all mappings to a given page. */ void pmap_page_protect(phys, prot) vm_offset_t phys; vm_prot_t prot; { if ((prot & VM_PROT_WRITE) == 0) { if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) pmap_changebit(phys, PG_RW, FALSE); else pmap_remove_all(phys); } } vm_offset_t pmap_phys_address(ppn) int ppn; { return (i386_ptob(ppn)); } /* * pmap_is_referenced: * * Return whether or not the specified physical page was referenced * by any physical maps. */ boolean_t pmap_is_referenced(vm_offset_t pa) { return pmap_testbit((pa), PG_U); } /* * pmap_is_modified: * * Return whether or not the specified physical page was modified * in any physical maps. */ boolean_t pmap_is_modified(vm_offset_t pa) { return pmap_testbit((pa), PG_M); } /* * Clear the modify bits on the specified physical page. */ void pmap_clear_modify(vm_offset_t pa) { pmap_changebit((pa), PG_M, FALSE); } /* * pmap_clear_reference: * * Clear the reference bit on the specified physical page. */ void pmap_clear_reference(vm_offset_t pa) { pmap_changebit((pa), PG_U, 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. The non-cacheable bits are set on each * mapped page. */ void * pmap_mapdev(pa, size) vm_offset_t pa; vm_size_t size; { vm_offset_t va, tmpva; pt_entry_t *pte; pa = trunc_page(pa); size = roundup(size, PAGE_SIZE); va = kmem_alloc_pageable(kernel_map, size); if (!va) panic("pmap_mapdev: Couldn't alloc kernel virtual memory"); for (tmpva = va; size > 0;) { pte = vtopte(tmpva); *pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V | PG_N)); size -= PAGE_SIZE; tmpva += PAGE_SIZE; pa += PAGE_SIZE; } pmap_update(); return ((void *) va); } #ifdef DEBUG /* print address space of pmap*/ void pads(pm) pmap_t pm; { unsigned va, i, j; pt_entry_t *ptep; if (pm == kernel_pmap) return; for (i = 0; i < 1024; i++) if (pm->pm_pdir[i]) for (j = 0; j < 1024; j++) { va = (i << PD_SHIFT) + (j << PG_SHIFT); if (pm == kernel_pmap && va < KERNBASE) continue; if (pm != kernel_pmap && va > UPT_MAX_ADDRESS) continue; ptep = pmap_pte(pm, va); if (pmap_pte_v(ptep)) printf("%x:%x ", va, *(int *) ptep); }; } void pmap_pvdump(pa) vm_offset_t pa; { register pv_entry_t pv; printf("pa %x", pa); for (pv = pa_to_pvh(pa); pv; pv = pv->pv_next) { #ifdef used_to_be printf(" -> pmap %x, va %x, flags %x", pv->pv_pmap, pv->pv_va, pv->pv_flags); #endif printf(" -> pmap %x, va %x", pv->pv_pmap, pv->pv_va); pads(pv->pv_pmap); } printf(" "); } #endif