diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c index 3fa3a4b62711..176762b9bfff 100644 --- a/sys/arm64/arm64/pmap.c +++ b/sys/arm64/arm64/pmap.c @@ -1,7337 +1,7351 @@ /*- * 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. * Copyright (c) 2003 Peter Wemm * All rights reserved. * Copyright (c) 2005-2010 Alan L. Cox * All rights reserved. * Copyright (c) 2014 Andrew Turner * All rights reserved. * Copyright (c) 2014-2016 The FreeBSD Foundation * 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. * * This software was developed by Andrew Turner under sponsorship from * the FreeBSD Foundation. * * 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 */ /*- * Copyright (c) 2003 Networks Associates Technology, Inc. * All rights reserved. * * This software was developed for the FreeBSD Project by Jake Burkholder, * Safeport Network Services, and Network Associates Laboratories, the * Security Research Division of Network Associates, Inc. under * DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA * CHATS research program. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. */ #include __FBSDID("$FreeBSD$"); /* * Manages physical address maps. * * 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_vm.h" #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 #include #include #include #include #include #include #include #include #include #include #include #include #include #define PMAP_ASSERT_STAGE1(pmap) MPASS((pmap)->pm_stage == PM_STAGE1) #define PMAP_ASSERT_STAGE2(pmap) MPASS((pmap)->pm_stage == PM_STAGE2) #define NL0PG (PAGE_SIZE/(sizeof (pd_entry_t))) #define NL1PG (PAGE_SIZE/(sizeof (pd_entry_t))) #define NL2PG (PAGE_SIZE/(sizeof (pd_entry_t))) #define NL3PG (PAGE_SIZE/(sizeof (pt_entry_t))) #define NUL0E L0_ENTRIES #define NUL1E (NUL0E * NL1PG) #define NUL2E (NUL1E * NL2PG) #if !defined(DIAGNOSTIC) #ifdef __GNUC_GNU_INLINE__ #define PMAP_INLINE __attribute__((__gnu_inline__)) inline #else #define PMAP_INLINE extern inline #endif #else #define PMAP_INLINE #endif #ifdef PV_STATS #define PV_STAT(x) do { x ; } while (0) #else #define PV_STAT(x) do { } while (0) #endif #define pmap_l0_pindex(v) (NUL2E + NUL1E + ((v) >> L0_SHIFT)) #define pmap_l1_pindex(v) (NUL2E + ((v) >> L1_SHIFT)) #define pmap_l2_pindex(v) ((v) >> L2_SHIFT) static struct md_page * pa_to_pvh(vm_paddr_t pa) { struct vm_phys_seg *seg; int segind; for (segind = 0; segind < vm_phys_nsegs; segind++) { seg = &vm_phys_segs[segind]; if (pa >= seg->start && pa < seg->end) return ((struct md_page *)seg->md_first + pmap_l2_pindex(pa) - pmap_l2_pindex(seg->start)); } panic("pa 0x%jx not within vm_phys_segs", (uintmax_t)pa); } static struct md_page * page_to_pvh(vm_page_t m) { struct vm_phys_seg *seg; seg = &vm_phys_segs[m->segind]; return ((struct md_page *)seg->md_first + pmap_l2_pindex(VM_PAGE_TO_PHYS(m)) - pmap_l2_pindex(seg->start)); } #define NPV_LIST_LOCKS MAXCPU #define PHYS_TO_PV_LIST_LOCK(pa) \ (&pv_list_locks[pa_index(pa) % NPV_LIST_LOCKS]) #define CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, pa) do { \ struct rwlock **_lockp = (lockp); \ struct rwlock *_new_lock; \ \ _new_lock = PHYS_TO_PV_LIST_LOCK(pa); \ if (_new_lock != *_lockp) { \ if (*_lockp != NULL) \ rw_wunlock(*_lockp); \ *_lockp = _new_lock; \ rw_wlock(*_lockp); \ } \ } while (0) #define CHANGE_PV_LIST_LOCK_TO_VM_PAGE(lockp, m) \ CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, VM_PAGE_TO_PHYS(m)) #define RELEASE_PV_LIST_LOCK(lockp) do { \ struct rwlock **_lockp = (lockp); \ \ if (*_lockp != NULL) { \ rw_wunlock(*_lockp); \ *_lockp = NULL; \ } \ } while (0) #define VM_PAGE_TO_PV_LIST_LOCK(m) \ PHYS_TO_PV_LIST_LOCK(VM_PAGE_TO_PHYS(m)) /* * The presence of this flag indicates that the mapping is writeable. * If the ATTR_S1_AP_RO bit is also set, then the mapping is clean, otherwise * it is dirty. This flag may only be set on managed mappings. * * The DBM bit is reserved on ARMv8.0 but it seems we can safely treat it * as a software managed bit. */ #define ATTR_SW_DBM ATTR_DBM struct pmap kernel_pmap_store; /* Used for mapping ACPI memory before VM is initialized */ #define PMAP_PREINIT_MAPPING_COUNT 32 #define PMAP_PREINIT_MAPPING_SIZE (PMAP_PREINIT_MAPPING_COUNT * L2_SIZE) static vm_offset_t preinit_map_va; /* Start VA of pre-init mapping space */ static int vm_initialized = 0; /* No need to use pre-init maps when set */ /* * Reserve a few L2 blocks starting from 'preinit_map_va' pointer. * Always map entire L2 block for simplicity. * VA of L2 block = preinit_map_va + i * L2_SIZE */ static struct pmap_preinit_mapping { vm_paddr_t pa; vm_offset_t va; vm_size_t size; } pmap_preinit_mapping[PMAP_PREINIT_MAPPING_COUNT]; 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) */ vm_offset_t kernel_vm_end = 0; /* * Data for the pv entry allocation mechanism. */ static TAILQ_HEAD(pch, pv_chunk) pv_chunks = TAILQ_HEAD_INITIALIZER(pv_chunks); static struct mtx pv_chunks_mutex; static struct rwlock pv_list_locks[NPV_LIST_LOCKS]; static struct md_page *pv_table; static struct md_page pv_dummy; vm_paddr_t dmap_phys_base; /* The start of the dmap region */ vm_paddr_t dmap_phys_max; /* The limit of the dmap region */ vm_offset_t dmap_max_addr; /* The virtual address limit of the dmap */ /* This code assumes all L1 DMAP entries will be used */ CTASSERT((DMAP_MIN_ADDRESS & ~L0_OFFSET) == DMAP_MIN_ADDRESS); CTASSERT((DMAP_MAX_ADDRESS & ~L0_OFFSET) == DMAP_MAX_ADDRESS); #define DMAP_TABLES ((DMAP_MAX_ADDRESS - DMAP_MIN_ADDRESS) >> L0_SHIFT) extern pt_entry_t pagetable_dmap[]; #define PHYSMAP_SIZE (2 * (VM_PHYSSEG_MAX - 1)) static vm_paddr_t physmap[PHYSMAP_SIZE]; static u_int physmap_idx; static SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "VM/pmap parameters"); /* * This ASID allocator uses a bit vector ("asid_set") to remember which ASIDs * that it has currently allocated to a pmap, a cursor ("asid_next") to * optimize its search for a free ASID in the bit vector, and an epoch number * ("asid_epoch") to indicate when it has reclaimed all previously allocated * ASIDs that are not currently active on a processor. * * The current epoch number is always in the range [0, INT_MAX). Negative * numbers and INT_MAX are reserved for special cases that are described * below. */ struct asid_set { int asid_bits; bitstr_t *asid_set; int asid_set_size; int asid_next; int asid_epoch; struct mtx asid_set_mutex; }; static struct asid_set asids; static struct asid_set vmids; static SYSCTL_NODE(_vm_pmap, OID_AUTO, asid, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "ASID allocator"); SYSCTL_INT(_vm_pmap_asid, OID_AUTO, bits, CTLFLAG_RD, &asids.asid_bits, 0, "The number of bits in an ASID"); SYSCTL_INT(_vm_pmap_asid, OID_AUTO, next, CTLFLAG_RD, &asids.asid_next, 0, "The last allocated ASID plus one"); SYSCTL_INT(_vm_pmap_asid, OID_AUTO, epoch, CTLFLAG_RD, &asids.asid_epoch, 0, "The current epoch number"); static SYSCTL_NODE(_vm_pmap, OID_AUTO, vmid, CTLFLAG_RD, 0, "VMID allocator"); SYSCTL_INT(_vm_pmap_vmid, OID_AUTO, bits, CTLFLAG_RD, &vmids.asid_bits, 0, "The number of bits in an VMID"); SYSCTL_INT(_vm_pmap_vmid, OID_AUTO, next, CTLFLAG_RD, &vmids.asid_next, 0, "The last allocated VMID plus one"); SYSCTL_INT(_vm_pmap_vmid, OID_AUTO, epoch, CTLFLAG_RD, &vmids.asid_epoch, 0, "The current epoch number"); void (*pmap_clean_stage2_tlbi)(void); void (*pmap_invalidate_vpipt_icache)(void); /* * A pmap's cookie encodes an ASID and epoch number. Cookies for reserved * ASIDs have a negative epoch number, specifically, INT_MIN. Cookies for * dynamically allocated ASIDs have a non-negative epoch number. * * An invalid ASID is represented by -1. * * There are two special-case cookie values: (1) COOKIE_FROM(-1, INT_MIN), * which indicates that an ASID should never be allocated to the pmap, and * (2) COOKIE_FROM(-1, INT_MAX), which indicates that an ASID should be * allocated when the pmap is next activated. */ #define COOKIE_FROM(asid, epoch) ((long)((u_int)(asid) | \ ((u_long)(epoch) << 32))) #define COOKIE_TO_ASID(cookie) ((int)(cookie)) #define COOKIE_TO_EPOCH(cookie) ((int)((u_long)(cookie) >> 32)) static int superpages_enabled = 1; SYSCTL_INT(_vm_pmap, OID_AUTO, superpages_enabled, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &superpages_enabled, 0, "Are large page mappings enabled?"); /* * Internal flags for pmap_enter()'s helper functions. */ #define PMAP_ENTER_NORECLAIM 0x1000000 /* Don't reclaim PV entries. */ #define PMAP_ENTER_NOREPLACE 0x2000000 /* Don't replace mappings. */ static void free_pv_chunk(struct pv_chunk *pc); static void free_pv_entry(pmap_t pmap, pv_entry_t pv); static pv_entry_t get_pv_entry(pmap_t pmap, struct rwlock **lockp); static vm_page_t reclaim_pv_chunk(pmap_t locked_pmap, struct rwlock **lockp); static void pmap_pvh_free(struct md_page *pvh, pmap_t pmap, vm_offset_t va); static pv_entry_t pmap_pvh_remove(struct md_page *pvh, pmap_t pmap, vm_offset_t va); static void pmap_abort_ptp(pmap_t pmap, vm_offset_t va, vm_page_t mpte); static bool pmap_activate_int(pmap_t pmap); static void pmap_alloc_asid(pmap_t pmap); static int pmap_change_props_locked(vm_offset_t va, vm_size_t size, vm_prot_t prot, int mode); static pt_entry_t *pmap_demote_l1(pmap_t pmap, pt_entry_t *l1, vm_offset_t va); static pt_entry_t *pmap_demote_l2_locked(pmap_t pmap, pt_entry_t *l2, vm_offset_t va, struct rwlock **lockp); static pt_entry_t *pmap_demote_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t va); static vm_page_t pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, vm_page_t mpte, struct rwlock **lockp); static int pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2, u_int flags, vm_page_t m, struct rwlock **lockp); static int pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva, pd_entry_t l1e, struct spglist *free, struct rwlock **lockp); static int pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_t sva, pd_entry_t l2e, struct spglist *free, struct rwlock **lockp); static void pmap_reset_asid_set(pmap_t pmap); static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va, vm_page_t m, struct rwlock **lockp); static vm_page_t _pmap_alloc_l3(pmap_t pmap, vm_pindex_t ptepindex, struct rwlock **lockp); static void _pmap_unwire_l3(pmap_t pmap, vm_offset_t va, vm_page_t m, struct spglist *free); static int pmap_unuse_pt(pmap_t, vm_offset_t, pd_entry_t, struct spglist *); static __inline vm_page_t pmap_remove_pt_page(pmap_t pmap, vm_offset_t va); /* * These load the old table data and store the new value. * They need to be atomic as the System MMU may write to the table at * the same time as the CPU. */ #define pmap_clear(table) atomic_store_64(table, 0) #define pmap_clear_bits(table, bits) atomic_clear_64(table, bits) #define pmap_load(table) (*table) #define pmap_load_clear(table) atomic_swap_64(table, 0) #define pmap_load_store(table, entry) atomic_swap_64(table, entry) #define pmap_set_bits(table, bits) atomic_set_64(table, bits) #define pmap_store(table, entry) atomic_store_64(table, entry) /********************/ /* Inline functions */ /********************/ static __inline void pagecopy(void *s, void *d) { memcpy(d, s, PAGE_SIZE); } static __inline pd_entry_t * pmap_l0(pmap_t pmap, vm_offset_t va) { return (&pmap->pm_l0[pmap_l0_index(va)]); } static __inline pd_entry_t * pmap_l0_to_l1(pd_entry_t *l0, vm_offset_t va) { pd_entry_t *l1; l1 = (pd_entry_t *)PHYS_TO_DMAP(pmap_load(l0) & ~ATTR_MASK); return (&l1[pmap_l1_index(va)]); } static __inline pd_entry_t * pmap_l1(pmap_t pmap, vm_offset_t va) { pd_entry_t *l0; l0 = pmap_l0(pmap, va); if ((pmap_load(l0) & ATTR_DESCR_MASK) != L0_TABLE) return (NULL); return (pmap_l0_to_l1(l0, va)); } static __inline pd_entry_t * pmap_l1_to_l2(pd_entry_t *l1p, vm_offset_t va) { pd_entry_t l1, *l2p; l1 = pmap_load(l1p); KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); /* * The valid bit may be clear if pmap_update_entry() is concurrently * modifying the entry, so for KVA only the entry type may be checked. */ KASSERT(ADDR_IS_KERNEL(va) || (l1 & ATTR_DESCR_VALID) != 0, ("%s: L1 entry %#lx for %#lx is invalid", __func__, l1, va)); KASSERT((l1 & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_TABLE, ("%s: L1 entry %#lx for %#lx is a leaf", __func__, l1, va)); l2p = (pd_entry_t *)PHYS_TO_DMAP(l1 & ~ATTR_MASK); return (&l2p[pmap_l2_index(va)]); } static __inline pd_entry_t * pmap_l2(pmap_t pmap, vm_offset_t va) { pd_entry_t *l1; l1 = pmap_l1(pmap, va); if ((pmap_load(l1) & ATTR_DESCR_MASK) != L1_TABLE) return (NULL); return (pmap_l1_to_l2(l1, va)); } static __inline pt_entry_t * pmap_l2_to_l3(pd_entry_t *l2p, vm_offset_t va) { pd_entry_t l2; pt_entry_t *l3p; l2 = pmap_load(l2p); KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); /* * The valid bit may be clear if pmap_update_entry() is concurrently * modifying the entry, so for KVA only the entry type may be checked. */ KASSERT(ADDR_IS_KERNEL(va) || (l2 & ATTR_DESCR_VALID) != 0, ("%s: L2 entry %#lx for %#lx is invalid", __func__, l2, va)); KASSERT((l2 & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_TABLE, ("%s: L2 entry %#lx for %#lx is a leaf", __func__, l2, va)); l3p = (pt_entry_t *)PHYS_TO_DMAP(l2 & ~ATTR_MASK); return (&l3p[pmap_l3_index(va)]); } /* * Returns the lowest valid pde for a given virtual address. * The next level may or may not point to a valid page or block. */ static __inline pd_entry_t * pmap_pde(pmap_t pmap, vm_offset_t va, int *level) { pd_entry_t *l0, *l1, *l2, desc; l0 = pmap_l0(pmap, va); desc = pmap_load(l0) & ATTR_DESCR_MASK; if (desc != L0_TABLE) { *level = -1; return (NULL); } l1 = pmap_l0_to_l1(l0, va); desc = pmap_load(l1) & ATTR_DESCR_MASK; if (desc != L1_TABLE) { *level = 0; return (l0); } l2 = pmap_l1_to_l2(l1, va); desc = pmap_load(l2) & ATTR_DESCR_MASK; if (desc != L2_TABLE) { *level = 1; return (l1); } *level = 2; return (l2); } /* * Returns the lowest valid pte block or table entry for a given virtual * address. If there are no valid entries return NULL and set the level to * the first invalid level. */ static __inline pt_entry_t * pmap_pte(pmap_t pmap, vm_offset_t va, int *level) { pd_entry_t *l1, *l2, desc; pt_entry_t *l3; l1 = pmap_l1(pmap, va); if (l1 == NULL) { *level = 0; return (NULL); } desc = pmap_load(l1) & ATTR_DESCR_MASK; if (desc == L1_BLOCK) { *level = 1; return (l1); } if (desc != L1_TABLE) { *level = 1; return (NULL); } l2 = pmap_l1_to_l2(l1, va); desc = pmap_load(l2) & ATTR_DESCR_MASK; if (desc == L2_BLOCK) { *level = 2; return (l2); } if (desc != L2_TABLE) { *level = 2; return (NULL); } *level = 3; l3 = pmap_l2_to_l3(l2, va); if ((pmap_load(l3) & ATTR_DESCR_MASK) != L3_PAGE) return (NULL); return (l3); } bool pmap_ps_enabled(pmap_t pmap __unused) { return (superpages_enabled != 0); } bool pmap_get_tables(pmap_t pmap, vm_offset_t va, pd_entry_t **l0, pd_entry_t **l1, pd_entry_t **l2, pt_entry_t **l3) { pd_entry_t *l0p, *l1p, *l2p; if (pmap->pm_l0 == NULL) return (false); l0p = pmap_l0(pmap, va); *l0 = l0p; if ((pmap_load(l0p) & ATTR_DESCR_MASK) != L0_TABLE) return (false); l1p = pmap_l0_to_l1(l0p, va); *l1 = l1p; if ((pmap_load(l1p) & ATTR_DESCR_MASK) == L1_BLOCK) { *l2 = NULL; *l3 = NULL; return (true); } if ((pmap_load(l1p) & ATTR_DESCR_MASK) != L1_TABLE) return (false); l2p = pmap_l1_to_l2(l1p, va); *l2 = l2p; if ((pmap_load(l2p) & ATTR_DESCR_MASK) == L2_BLOCK) { *l3 = NULL; return (true); } if ((pmap_load(l2p) & ATTR_DESCR_MASK) != L2_TABLE) return (false); *l3 = pmap_l2_to_l3(l2p, va); return (true); } static __inline int pmap_l3_valid(pt_entry_t l3) { return ((l3 & ATTR_DESCR_MASK) == L3_PAGE); } CTASSERT(L1_BLOCK == L2_BLOCK); static pt_entry_t pmap_pte_memattr(pmap_t pmap, vm_memattr_t memattr) { pt_entry_t val; if (pmap->pm_stage == PM_STAGE1) { val = ATTR_S1_IDX(memattr); if (memattr == VM_MEMATTR_DEVICE) val |= ATTR_S1_XN; return (val); } val = 0; switch (memattr) { case VM_MEMATTR_DEVICE: return (ATTR_S2_MEMATTR(ATTR_S2_MEMATTR_DEVICE_nGnRnE) | ATTR_S2_XN(ATTR_S2_XN_ALL)); case VM_MEMATTR_UNCACHEABLE: return (ATTR_S2_MEMATTR(ATTR_S2_MEMATTR_NC)); case VM_MEMATTR_WRITE_BACK: return (ATTR_S2_MEMATTR(ATTR_S2_MEMATTR_WB)); case VM_MEMATTR_WRITE_THROUGH: return (ATTR_S2_MEMATTR(ATTR_S2_MEMATTR_WT)); default: panic("%s: invalid memory attribute %x", __func__, memattr); } } static pt_entry_t pmap_pte_prot(pmap_t pmap, vm_prot_t prot) { pt_entry_t val; val = 0; if (pmap->pm_stage == PM_STAGE1) { if ((prot & VM_PROT_EXECUTE) == 0) val |= ATTR_S1_XN; if ((prot & VM_PROT_WRITE) == 0) val |= ATTR_S1_AP(ATTR_S1_AP_RO); } else { if ((prot & VM_PROT_WRITE) != 0) val |= ATTR_S2_S2AP(ATTR_S2_S2AP_WRITE); if ((prot & VM_PROT_READ) != 0) val |= ATTR_S2_S2AP(ATTR_S2_S2AP_READ); if ((prot & VM_PROT_EXECUTE) == 0) val |= ATTR_S2_XN(ATTR_S2_XN_ALL); } return (val); } /* * Checks if the PTE is dirty. */ static inline int pmap_pte_dirty(pmap_t pmap, pt_entry_t pte) { KASSERT((pte & ATTR_SW_MANAGED) != 0, ("pte %#lx is unmanaged", pte)); if (pmap->pm_stage == PM_STAGE1) { KASSERT((pte & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) != 0, ("pte %#lx is writeable and missing ATTR_SW_DBM", pte)); return ((pte & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) == (ATTR_S1_AP(ATTR_S1_AP_RW) | ATTR_SW_DBM)); } return ((pte & ATTR_S2_S2AP(ATTR_S2_S2AP_WRITE)) == ATTR_S2_S2AP(ATTR_S2_S2AP_WRITE)); } static __inline void pmap_resident_count_inc(pmap_t pmap, int count) { PMAP_LOCK_ASSERT(pmap, MA_OWNED); pmap->pm_stats.resident_count += count; } static __inline void pmap_resident_count_dec(pmap_t pmap, int count) { PMAP_LOCK_ASSERT(pmap, MA_OWNED); KASSERT(pmap->pm_stats.resident_count >= count, ("pmap %p resident count underflow %ld %d", pmap, pmap->pm_stats.resident_count, count)); pmap->pm_stats.resident_count -= count; } static vm_paddr_t pmap_early_vtophys(vm_offset_t l1pt, vm_offset_t va) { vm_paddr_t pa_page; pa_page = arm64_address_translate_s1e1r(va) & PAR_PA_MASK; return (pa_page | (va & PAR_LOW_MASK)); } static vm_offset_t pmap_bootstrap_dmap(vm_offset_t kern_l1, vm_paddr_t min_pa, vm_offset_t freemempos) { pt_entry_t *l2; vm_offset_t va; vm_paddr_t l2_pa, pa; u_int l1_slot, l2_slot, prev_l1_slot; int i; dmap_phys_base = min_pa & ~L1_OFFSET; dmap_phys_max = 0; dmap_max_addr = 0; l2 = NULL; prev_l1_slot = -1; #define DMAP_TABLES ((DMAP_MAX_ADDRESS - DMAP_MIN_ADDRESS) >> L0_SHIFT) memset(pagetable_dmap, 0, PAGE_SIZE * DMAP_TABLES); for (i = 0; i < (physmap_idx * 2); i += 2) { pa = physmap[i] & ~L2_OFFSET; va = pa - dmap_phys_base + DMAP_MIN_ADDRESS; /* Create L2 mappings at the start of the region */ if ((pa & L1_OFFSET) != 0) { l1_slot = ((va - DMAP_MIN_ADDRESS) >> L1_SHIFT); if (l1_slot != prev_l1_slot) { prev_l1_slot = l1_slot; l2 = (pt_entry_t *)freemempos; l2_pa = pmap_early_vtophys(kern_l1, (vm_offset_t)l2); freemempos += PAGE_SIZE; pmap_store(&pagetable_dmap[l1_slot], (l2_pa & ~Ln_TABLE_MASK) | TATTR_PXN_TABLE | L1_TABLE); memset(l2, 0, PAGE_SIZE); } KASSERT(l2 != NULL, ("pmap_bootstrap_dmap: NULL l2 map")); for (; va < DMAP_MAX_ADDRESS && pa < physmap[i + 1]; pa += L2_SIZE, va += L2_SIZE) { /* * We are on a boundary, stop to * create a level 1 block */ if ((pa & L1_OFFSET) == 0) break; l2_slot = pmap_l2_index(va); KASSERT(l2_slot != 0, ("...")); pmap_store(&l2[l2_slot], (pa & ~L2_OFFSET) | ATTR_DEFAULT | ATTR_S1_XN | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK) | L2_BLOCK); } KASSERT(va == (pa - dmap_phys_base + DMAP_MIN_ADDRESS), ("...")); } for (; va < DMAP_MAX_ADDRESS && pa < physmap[i + 1] && (physmap[i + 1] - pa) >= L1_SIZE; pa += L1_SIZE, va += L1_SIZE) { l1_slot = ((va - DMAP_MIN_ADDRESS) >> L1_SHIFT); pmap_store(&pagetable_dmap[l1_slot], (pa & ~L1_OFFSET) | ATTR_DEFAULT | ATTR_S1_XN | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK) | L1_BLOCK); } /* Create L2 mappings at the end of the region */ if (pa < physmap[i + 1]) { l1_slot = ((va - DMAP_MIN_ADDRESS) >> L1_SHIFT); if (l1_slot != prev_l1_slot) { prev_l1_slot = l1_slot; l2 = (pt_entry_t *)freemempos; l2_pa = pmap_early_vtophys(kern_l1, (vm_offset_t)l2); freemempos += PAGE_SIZE; pmap_store(&pagetable_dmap[l1_slot], (l2_pa & ~Ln_TABLE_MASK) | L1_TABLE); memset(l2, 0, PAGE_SIZE); } KASSERT(l2 != NULL, ("pmap_bootstrap_dmap: NULL l2 map")); for (; va < DMAP_MAX_ADDRESS && pa < physmap[i + 1]; pa += L2_SIZE, va += L2_SIZE) { l2_slot = pmap_l2_index(va); pmap_store(&l2[l2_slot], (pa & ~L2_OFFSET) | ATTR_DEFAULT | ATTR_S1_XN | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK) | L2_BLOCK); } } if (pa > dmap_phys_max) { dmap_phys_max = pa; dmap_max_addr = va; } } cpu_tlb_flushID(); return (freemempos); } static vm_offset_t pmap_bootstrap_l2(vm_offset_t l1pt, vm_offset_t va, vm_offset_t l2_start) { vm_offset_t l2pt; vm_paddr_t pa; pd_entry_t *l1; u_int l1_slot; KASSERT((va & L1_OFFSET) == 0, ("Invalid virtual address")); l1 = (pd_entry_t *)l1pt; l1_slot = pmap_l1_index(va); l2pt = l2_start; for (; va < VM_MAX_KERNEL_ADDRESS; l1_slot++, va += L1_SIZE) { KASSERT(l1_slot < Ln_ENTRIES, ("Invalid L1 index")); pa = pmap_early_vtophys(l1pt, l2pt); pmap_store(&l1[l1_slot], (pa & ~Ln_TABLE_MASK) | L1_TABLE); l2pt += PAGE_SIZE; } /* Clean the L2 page table */ memset((void *)l2_start, 0, l2pt - l2_start); return l2pt; } static vm_offset_t pmap_bootstrap_l3(vm_offset_t l1pt, vm_offset_t va, vm_offset_t l3_start) { vm_offset_t l3pt; vm_paddr_t pa; pd_entry_t *l2; u_int l2_slot; KASSERT((va & L2_OFFSET) == 0, ("Invalid virtual address")); l2 = pmap_l2(kernel_pmap, va); l2 = (pd_entry_t *)rounddown2((uintptr_t)l2, PAGE_SIZE); l2_slot = pmap_l2_index(va); l3pt = l3_start; for (; va < VM_MAX_KERNEL_ADDRESS; l2_slot++, va += L2_SIZE) { KASSERT(l2_slot < Ln_ENTRIES, ("Invalid L2 index")); pa = pmap_early_vtophys(l1pt, l3pt); pmap_store(&l2[l2_slot], (pa & ~Ln_TABLE_MASK) | ATTR_S1_UXN | L2_TABLE); l3pt += PAGE_SIZE; } /* Clean the L2 page table */ memset((void *)l3_start, 0, l3pt - l3_start); return l3pt; } /* * Bootstrap the system enough to run with virtual memory. */ void pmap_bootstrap(vm_offset_t l0pt, vm_offset_t l1pt, vm_paddr_t kernstart, vm_size_t kernlen) { vm_offset_t freemempos; vm_offset_t dpcpu, msgbufpv; vm_paddr_t start_pa, pa, min_pa; uint64_t kern_delta; int i; /* Verify that the ASID is set through TTBR0. */ KASSERT((READ_SPECIALREG(tcr_el1) & TCR_A1) == 0, ("pmap_bootstrap: TCR_EL1.A1 != 0")); kern_delta = KERNBASE - kernstart; printf("pmap_bootstrap %lx %lx %lx\n", l1pt, kernstart, kernlen); printf("%lx\n", l1pt); printf("%lx\n", (KERNBASE >> L1_SHIFT) & Ln_ADDR_MASK); /* Set this early so we can use the pagetable walking functions */ kernel_pmap_store.pm_l0 = (pd_entry_t *)l0pt; PMAP_LOCK_INIT(kernel_pmap); kernel_pmap->pm_l0_paddr = l0pt - kern_delta; kernel_pmap->pm_cookie = COOKIE_FROM(-1, INT_MIN); kernel_pmap->pm_stage = PM_STAGE1; kernel_pmap->pm_levels = 4; kernel_pmap->pm_ttbr = kernel_pmap->pm_l0_paddr; kernel_pmap->pm_asid_set = &asids; /* Assume the address we were loaded to is a valid physical address */ min_pa = KERNBASE - kern_delta; physmap_idx = physmem_avail(physmap, nitems(physmap)); physmap_idx /= 2; /* * Find the minimum physical address. physmap is sorted, * but may contain empty ranges. */ for (i = 0; i < physmap_idx * 2; i += 2) { if (physmap[i] == physmap[i + 1]) continue; if (physmap[i] <= min_pa) min_pa = physmap[i]; } freemempos = KERNBASE + kernlen; freemempos = roundup2(freemempos, PAGE_SIZE); /* Create a direct map region early so we can use it for pa -> va */ freemempos = pmap_bootstrap_dmap(l1pt, min_pa, freemempos); start_pa = pa = KERNBASE - kern_delta; /* * Create the l2 tables up to VM_MAX_KERNEL_ADDRESS. We assume that the * loader allocated the first and only l2 page table page used to map * the kernel, preloaded files and module metadata. */ freemempos = pmap_bootstrap_l2(l1pt, KERNBASE + L1_SIZE, freemempos); /* And the l3 tables for the early devmap */ freemempos = pmap_bootstrap_l3(l1pt, VM_MAX_KERNEL_ADDRESS - (PMAP_MAPDEV_EARLY_SIZE), freemempos); cpu_tlb_flushID(); #define alloc_pages(var, np) \ (var) = freemempos; \ freemempos += (np * PAGE_SIZE); \ memset((char *)(var), 0, ((np) * PAGE_SIZE)); /* Allocate dynamic per-cpu area. */ alloc_pages(dpcpu, DPCPU_SIZE / PAGE_SIZE); dpcpu_init((void *)dpcpu, 0); /* Allocate memory for the msgbuf, e.g. for /sbin/dmesg */ alloc_pages(msgbufpv, round_page(msgbufsize) / PAGE_SIZE); msgbufp = (void *)msgbufpv; /* Reserve some VA space for early BIOS/ACPI mapping */ preinit_map_va = roundup2(freemempos, L2_SIZE); virtual_avail = preinit_map_va + PMAP_PREINIT_MAPPING_SIZE; virtual_avail = roundup2(virtual_avail, L1_SIZE); virtual_end = VM_MAX_KERNEL_ADDRESS - (PMAP_MAPDEV_EARLY_SIZE); kernel_vm_end = virtual_avail; pa = pmap_early_vtophys(l1pt, freemempos); physmem_exclude_region(start_pa, pa - start_pa, EXFLAG_NOALLOC); cpu_tlb_flushID(); } /* * Initialize a vm_page's machine-dependent fields. */ void pmap_page_init(vm_page_t m) { TAILQ_INIT(&m->md.pv_list); m->md.pv_memattr = VM_MEMATTR_WRITE_BACK; } static void pmap_init_asids(struct asid_set *set, int bits) { int i; set->asid_bits = bits; /* * We may be too early in the overall initialization process to use * bit_alloc(). */ set->asid_set_size = 1 << set->asid_bits; set->asid_set = (bitstr_t *)kmem_malloc(bitstr_size(set->asid_set_size), M_WAITOK | M_ZERO); for (i = 0; i < ASID_FIRST_AVAILABLE; i++) bit_set(set->asid_set, i); set->asid_next = ASID_FIRST_AVAILABLE; mtx_init(&set->asid_set_mutex, "asid set", NULL, MTX_SPIN); } /* * Initialize the pmap module. * Called by vm_init, to initialize any structures that the pmap * system needs to map virtual memory. */ void pmap_init(void) { struct vm_phys_seg *seg, *next_seg; struct md_page *pvh; vm_size_t s; uint64_t mmfr1; int i, pv_npg, vmid_bits; /* * Are large page mappings enabled? */ TUNABLE_INT_FETCH("vm.pmap.superpages_enabled", &superpages_enabled); if (superpages_enabled) { KASSERT(MAXPAGESIZES > 1 && pagesizes[1] == 0, ("pmap_init: can't assign to pagesizes[1]")); pagesizes[1] = L2_SIZE; KASSERT(MAXPAGESIZES > 2 && pagesizes[2] == 0, ("pmap_init: can't assign to pagesizes[2]")); pagesizes[2] = L1_SIZE; } /* * Initialize the ASID allocator. */ pmap_init_asids(&asids, (READ_SPECIALREG(tcr_el1) & TCR_ASID_16) != 0 ? 16 : 8); if (has_hyp()) { mmfr1 = READ_SPECIALREG(id_aa64mmfr1_el1); vmid_bits = 8; if (ID_AA64MMFR1_VMIDBits_VAL(mmfr1) == ID_AA64MMFR1_VMIDBits_16) vmid_bits = 16; pmap_init_asids(&vmids, vmid_bits); } /* * Initialize the pv chunk list mutex. */ mtx_init(&pv_chunks_mutex, "pmap pv chunk list", NULL, MTX_DEF); /* * Initialize the pool of pv list locks. */ for (i = 0; i < NPV_LIST_LOCKS; i++) rw_init(&pv_list_locks[i], "pmap pv list"); /* * Calculate the size of the pv head table for superpages. */ pv_npg = 0; for (i = 0; i < vm_phys_nsegs; i++) { seg = &vm_phys_segs[i]; pv_npg += pmap_l2_pindex(roundup2(seg->end, L2_SIZE)) - pmap_l2_pindex(seg->start); } /* * Allocate memory for the pv head table for superpages. */ s = (vm_size_t)(pv_npg * sizeof(struct md_page)); s = round_page(s); pv_table = (struct md_page *)kmem_malloc(s, M_WAITOK | M_ZERO); for (i = 0; i < pv_npg; i++) TAILQ_INIT(&pv_table[i].pv_list); TAILQ_INIT(&pv_dummy.pv_list); /* * Set pointers from vm_phys_segs to pv_table. */ for (i = 0, pvh = pv_table; i < vm_phys_nsegs; i++) { seg = &vm_phys_segs[i]; seg->md_first = pvh; pvh += pmap_l2_pindex(roundup2(seg->end, L2_SIZE)) - pmap_l2_pindex(seg->start); /* * If there is a following segment, and the final * superpage of this segment and the initial superpage * of the next segment are the same then adjust the * pv_table entry for that next segment down by one so * that the pv_table entries will be shared. */ if (i + 1 < vm_phys_nsegs) { next_seg = &vm_phys_segs[i + 1]; if (pmap_l2_pindex(roundup2(seg->end, L2_SIZE)) - 1 == pmap_l2_pindex(next_seg->start)) { pvh--; } } } vm_initialized = 1; } static SYSCTL_NODE(_vm_pmap, OID_AUTO, l2, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "2MB page mapping counters"); static u_long pmap_l2_demotions; SYSCTL_ULONG(_vm_pmap_l2, OID_AUTO, demotions, CTLFLAG_RD, &pmap_l2_demotions, 0, "2MB page demotions"); static u_long pmap_l2_mappings; SYSCTL_ULONG(_vm_pmap_l2, OID_AUTO, mappings, CTLFLAG_RD, &pmap_l2_mappings, 0, "2MB page mappings"); static u_long pmap_l2_p_failures; SYSCTL_ULONG(_vm_pmap_l2, OID_AUTO, p_failures, CTLFLAG_RD, &pmap_l2_p_failures, 0, "2MB page promotion failures"); static u_long pmap_l2_promotions; SYSCTL_ULONG(_vm_pmap_l2, OID_AUTO, promotions, CTLFLAG_RD, &pmap_l2_promotions, 0, "2MB page promotions"); /* * Invalidate a single TLB entry. */ static __inline void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { uint64_t r; PMAP_ASSERT_STAGE1(pmap); dsb(ishst); if (pmap == kernel_pmap) { r = atop(va); __asm __volatile("tlbi vaae1is, %0" : : "r" (r)); } else { r = ASID_TO_OPERAND(COOKIE_TO_ASID(pmap->pm_cookie)) | atop(va); __asm __volatile("tlbi vae1is, %0" : : "r" (r)); } dsb(ish); isb(); } static __inline void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { uint64_t end, r, start; PMAP_ASSERT_STAGE1(pmap); dsb(ishst); if (pmap == kernel_pmap) { start = atop(sva); end = atop(eva); for (r = start; r < end; r++) __asm __volatile("tlbi vaae1is, %0" : : "r" (r)); } else { start = end = ASID_TO_OPERAND(COOKIE_TO_ASID(pmap->pm_cookie)); start |= atop(sva); end |= atop(eva); for (r = start; r < end; r++) __asm __volatile("tlbi vae1is, %0" : : "r" (r)); } dsb(ish); isb(); } static __inline void pmap_invalidate_all(pmap_t pmap) { uint64_t r; PMAP_ASSERT_STAGE1(pmap); dsb(ishst); if (pmap == kernel_pmap) { __asm __volatile("tlbi vmalle1is"); } else { r = ASID_TO_OPERAND(COOKIE_TO_ASID(pmap->pm_cookie)); __asm __volatile("tlbi aside1is, %0" : : "r" (r)); } dsb(ish); isb(); } /* * Routine: pmap_extract * Function: * Extract the physical page address associated * with the given map/virtual_address pair. */ vm_paddr_t pmap_extract(pmap_t pmap, vm_offset_t va) { pt_entry_t *pte, tpte; vm_paddr_t pa; int lvl; pa = 0; PMAP_LOCK(pmap); /* * Find the block or page map for this virtual address. pmap_pte * will return either a valid block/page entry, or NULL. */ pte = pmap_pte(pmap, va, &lvl); if (pte != NULL) { tpte = pmap_load(pte); pa = tpte & ~ATTR_MASK; switch(lvl) { case 1: KASSERT((tpte & ATTR_DESCR_MASK) == L1_BLOCK, ("pmap_extract: Invalid L1 pte found: %lx", tpte & ATTR_DESCR_MASK)); pa |= (va & L1_OFFSET); break; case 2: KASSERT((tpte & ATTR_DESCR_MASK) == L2_BLOCK, ("pmap_extract: Invalid L2 pte found: %lx", tpte & ATTR_DESCR_MASK)); pa |= (va & L2_OFFSET); break; case 3: KASSERT((tpte & ATTR_DESCR_MASK) == L3_PAGE, ("pmap_extract: Invalid L3 pte found: %lx", tpte & ATTR_DESCR_MASK)); pa |= (va & L3_OFFSET); break; } } PMAP_UNLOCK(pmap); return (pa); } /* * Routine: pmap_extract_and_hold * Function: * Atomically extract and hold the physical page * with the given pmap and virtual address pair * if that mapping permits the given protection. */ vm_page_t pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot) { pt_entry_t *pte, tpte; vm_offset_t off; vm_page_t m; int lvl; bool use; m = NULL; PMAP_LOCK(pmap); pte = pmap_pte(pmap, va, &lvl); if (pte != NULL) { tpte = pmap_load(pte); KASSERT(lvl > 0 && lvl <= 3, ("pmap_extract_and_hold: Invalid level %d", lvl)); CTASSERT(L1_BLOCK == L2_BLOCK); KASSERT((lvl == 3 && (tpte & ATTR_DESCR_MASK) == L3_PAGE) || (lvl < 3 && (tpte & ATTR_DESCR_MASK) == L1_BLOCK), ("pmap_extract_and_hold: Invalid pte at L%d: %lx", lvl, tpte & ATTR_DESCR_MASK)); use = false; if ((prot & VM_PROT_WRITE) == 0) use = true; else if (pmap->pm_stage == PM_STAGE1 && (tpte & ATTR_S1_AP_RW_BIT) == ATTR_S1_AP(ATTR_S1_AP_RW)) use = true; else if (pmap->pm_stage == PM_STAGE2 && ((tpte & ATTR_S2_S2AP(ATTR_S2_S2AP_WRITE)) == ATTR_S2_S2AP(ATTR_S2_S2AP_WRITE))) use = true; if (use) { switch (lvl) { case 1: off = va & L1_OFFSET; break; case 2: off = va & L2_OFFSET; break; case 3: default: off = 0; } m = PHYS_TO_VM_PAGE((tpte & ~ATTR_MASK) | off); if (m != NULL && !vm_page_wire_mapped(m)) m = NULL; } } PMAP_UNLOCK(pmap); return (m); } /* * Walks the page tables to translate a kernel virtual address to a * physical address. Returns true if the kva is valid and stores the * physical address in pa if it is not NULL. */ bool pmap_klookup(vm_offset_t va, vm_paddr_t *pa) { pt_entry_t *pte, tpte; register_t intr; uint64_t par; /* * Disable interrupts so we don't get interrupted between asking * for address translation, and getting the result back. */ intr = intr_disable(); par = arm64_address_translate_s1e1r(va); intr_restore(intr); if (PAR_SUCCESS(par)) { if (pa != NULL) *pa = (par & PAR_PA_MASK) | (va & PAR_LOW_MASK); return (true); } /* * Fall back to walking the page table. The address translation * instruction may fail when the page is in a break-before-make * sequence. As we only clear the valid bit in said sequence we * can walk the page table to find the physical address. */ pte = pmap_l1(kernel_pmap, va); if (pte == NULL) return (false); /* * A concurrent pmap_update_entry() will clear the entry's valid bit * but leave the rest of the entry unchanged. Therefore, we treat a * non-zero entry as being valid, and we ignore the valid bit when * determining whether the entry maps a block, page, or table. */ tpte = pmap_load(pte); if (tpte == 0) return (false); if ((tpte & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_BLOCK) { if (pa != NULL) *pa = (tpte & ~ATTR_MASK) | (va & L1_OFFSET); return (true); } pte = pmap_l1_to_l2(&tpte, va); tpte = pmap_load(pte); if (tpte == 0) return (false); if ((tpte & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_BLOCK) { if (pa != NULL) *pa = (tpte & ~ATTR_MASK) | (va & L2_OFFSET); return (true); } pte = pmap_l2_to_l3(&tpte, va); tpte = pmap_load(pte); if (tpte == 0) return (false); if (pa != NULL) *pa = (tpte & ~ATTR_MASK) | (va & L3_OFFSET); return (true); } vm_paddr_t pmap_kextract(vm_offset_t va) { vm_paddr_t pa; if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS) return (DMAP_TO_PHYS(va)); if (pmap_klookup(va, &pa) == false) return (0); return (pa); } /*************************************************** * Low level mapping routines..... ***************************************************/ void pmap_kenter(vm_offset_t sva, vm_size_t size, vm_paddr_t pa, int mode) { pd_entry_t *pde; pt_entry_t *pte, attr; vm_offset_t va; int lvl; KASSERT((pa & L3_OFFSET) == 0, ("pmap_kenter: Invalid physical address")); KASSERT((sva & L3_OFFSET) == 0, ("pmap_kenter: Invalid virtual address")); KASSERT((size & PAGE_MASK) == 0, ("pmap_kenter: Mapping is not page-sized")); attr = ATTR_DEFAULT | ATTR_S1_AP(ATTR_S1_AP_RW) | ATTR_S1_XN | ATTR_S1_IDX(mode) | L3_PAGE; va = sva; while (size != 0) { pde = pmap_pde(kernel_pmap, va, &lvl); KASSERT(pde != NULL, ("pmap_kenter: Invalid page entry, va: 0x%lx", va)); KASSERT(lvl == 2, ("pmap_kenter: Invalid level %d", lvl)); pte = pmap_l2_to_l3(pde, va); pmap_load_store(pte, (pa & ~L3_OFFSET) | attr); va += PAGE_SIZE; pa += PAGE_SIZE; size -= PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); } void pmap_kenter_device(vm_offset_t sva, vm_size_t size, vm_paddr_t pa) { pmap_kenter(sva, size, pa, VM_MEMATTR_DEVICE); } /* * Remove a page from the kernel pagetables. */ PMAP_INLINE void pmap_kremove(vm_offset_t va) { pt_entry_t *pte; int lvl; pte = pmap_pte(kernel_pmap, va, &lvl); KASSERT(pte != NULL, ("pmap_kremove: Invalid address")); KASSERT(lvl == 3, ("pmap_kremove: Invalid pte level %d", lvl)); pmap_clear(pte); pmap_invalidate_page(kernel_pmap, va); } void pmap_kremove_device(vm_offset_t sva, vm_size_t size) { pt_entry_t *pte; vm_offset_t va; int lvl; KASSERT((sva & L3_OFFSET) == 0, ("pmap_kremove_device: Invalid virtual address")); KASSERT((size & PAGE_MASK) == 0, ("pmap_kremove_device: Mapping is not page-sized")); va = sva; while (size != 0) { pte = pmap_pte(kernel_pmap, va, &lvl); KASSERT(pte != NULL, ("Invalid page table, va: 0x%lx", va)); KASSERT(lvl == 3, ("Invalid device pagetable level: %d != 3", lvl)); pmap_clear(pte); va += PAGE_SIZE; size -= PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); } /* * 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_paddr_t start, vm_paddr_t end, int prot) { return PHYS_TO_DMAP(start); } /* * 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 *ma, int count) { pd_entry_t *pde; pt_entry_t *pte, pa; vm_offset_t va; vm_page_t m; int i, lvl; va = sva; for (i = 0; i < count; i++) { pde = pmap_pde(kernel_pmap, va, &lvl); KASSERT(pde != NULL, ("pmap_qenter: Invalid page entry, va: 0x%lx", va)); KASSERT(lvl == 2, ("pmap_qenter: Invalid level %d", lvl)); m = ma[i]; pa = VM_PAGE_TO_PHYS(m) | ATTR_DEFAULT | ATTR_S1_AP(ATTR_S1_AP_RW) | ATTR_S1_XN | ATTR_S1_IDX(m->md.pv_memattr) | L3_PAGE; pte = pmap_l2_to_l3(pde, va); pmap_load_store(pte, pa); va += L3_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); } /* * This routine tears out page mappings from the * kernel -- it is meant only for temporary mappings. */ void pmap_qremove(vm_offset_t sva, int count) { pt_entry_t *pte; vm_offset_t va; int lvl; KASSERT(ADDR_IS_CANONICAL(sva), ("%s: Address not in canonical form: %lx", __func__, sva)); KASSERT(ADDR_IS_KERNEL(sva), ("usermode va %lx", sva)); va = sva; while (count-- > 0) { pte = pmap_pte(kernel_pmap, va, &lvl); KASSERT(lvl == 3, ("Invalid device pagetable level: %d != 3", lvl)); if (pte != NULL) { pmap_clear(pte); } va += PAGE_SIZE; } pmap_invalidate_range(kernel_pmap, sva, va); } /*************************************************** * Page table page management routines..... ***************************************************/ /* * Schedule the specified unused page table page to be freed. Specifically, * add the page to the specified list of pages that will be released to the * physical memory manager after the TLB has been updated. */ static __inline void pmap_add_delayed_free_list(vm_page_t m, struct spglist *free, boolean_t set_PG_ZERO) { if (set_PG_ZERO) m->flags |= PG_ZERO; else m->flags &= ~PG_ZERO; SLIST_INSERT_HEAD(free, m, plinks.s.ss); } /* * Decrements a page table page's reference count, which is used to record the * number of valid page table entries within the page. If the reference count * drops to zero, then the page table page is unmapped. Returns TRUE if the * page table page was unmapped and FALSE otherwise. */ static inline boolean_t pmap_unwire_l3(pmap_t pmap, vm_offset_t va, vm_page_t m, struct spglist *free) { --m->ref_count; if (m->ref_count == 0) { _pmap_unwire_l3(pmap, va, m, free); return (TRUE); } else return (FALSE); } static void _pmap_unwire_l3(pmap_t pmap, vm_offset_t va, vm_page_t m, struct spglist *free) { PMAP_LOCK_ASSERT(pmap, MA_OWNED); /* * unmap the page table page */ if (m->pindex >= (NUL2E + NUL1E)) { /* l1 page */ pd_entry_t *l0; l0 = pmap_l0(pmap, va); pmap_clear(l0); } else if (m->pindex >= NUL2E) { /* l2 page */ pd_entry_t *l1; l1 = pmap_l1(pmap, va); pmap_clear(l1); } else { /* l3 page */ pd_entry_t *l2; l2 = pmap_l2(pmap, va); pmap_clear(l2); } pmap_resident_count_dec(pmap, 1); if (m->pindex < NUL2E) { /* We just released an l3, unhold the matching l2 */ pd_entry_t *l1, tl1; vm_page_t l2pg; l1 = pmap_l1(pmap, va); tl1 = pmap_load(l1); l2pg = PHYS_TO_VM_PAGE(tl1 & ~ATTR_MASK); pmap_unwire_l3(pmap, va, l2pg, free); } else if (m->pindex < (NUL2E + NUL1E)) { /* We just released an l2, unhold the matching l1 */ pd_entry_t *l0, tl0; vm_page_t l1pg; l0 = pmap_l0(pmap, va); tl0 = pmap_load(l0); l1pg = PHYS_TO_VM_PAGE(tl0 & ~ATTR_MASK); pmap_unwire_l3(pmap, va, l1pg, free); } pmap_invalidate_page(pmap, va); /* * Put page on a list so that it is released after * *ALL* TLB shootdown is done */ pmap_add_delayed_free_list(m, free, TRUE); } /* * After removing a page table entry, this routine is used to * conditionally free the page, and manage the reference count. */ static int pmap_unuse_pt(pmap_t pmap, vm_offset_t va, pd_entry_t ptepde, struct spglist *free) { vm_page_t mpte; KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); if (ADDR_IS_KERNEL(va)) return (0); KASSERT(ptepde != 0, ("pmap_unuse_pt: ptepde != 0")); mpte = PHYS_TO_VM_PAGE(ptepde & ~ATTR_MASK); return (pmap_unwire_l3(pmap, va, mpte, free)); } /* * Release a page table page reference after a failed attempt to create a * mapping. */ static void pmap_abort_ptp(pmap_t pmap, vm_offset_t va, vm_page_t mpte) { struct spglist free; SLIST_INIT(&free); if (pmap_unwire_l3(pmap, va, mpte, &free)) { /* * Although "va" was never mapped, the TLB could nonetheless * have intermediate entries that refer to the freed page * table pages. Invalidate those entries. * * XXX redundant invalidation (See _pmap_unwire_l3().) */ pmap_invalidate_page(pmap, va); vm_page_free_pages_toq(&free, true); } } void pmap_pinit0(pmap_t pmap) { PMAP_LOCK_INIT(pmap); bzero(&pmap->pm_stats, sizeof(pmap->pm_stats)); pmap->pm_l0_paddr = READ_SPECIALREG(ttbr0_el1); pmap->pm_l0 = (pd_entry_t *)PHYS_TO_DMAP(pmap->pm_l0_paddr); pmap->pm_root.rt_root = 0; pmap->pm_cookie = COOKIE_FROM(ASID_RESERVED_FOR_PID_0, INT_MIN); pmap->pm_stage = PM_STAGE1; pmap->pm_levels = 4; pmap->pm_ttbr = pmap->pm_l0_paddr; pmap->pm_asid_set = &asids; PCPU_SET(curpmap, pmap); } int pmap_pinit_stage(pmap_t pmap, enum pmap_stage stage, int levels) { vm_page_t m; /* * allocate the l0 page */ while ((m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO)) == NULL) vm_wait(NULL); pmap->pm_l0_paddr = VM_PAGE_TO_PHYS(m); pmap->pm_l0 = (pd_entry_t *)PHYS_TO_DMAP(pmap->pm_l0_paddr); if ((m->flags & PG_ZERO) == 0) pagezero(pmap->pm_l0); pmap->pm_root.rt_root = 0; bzero(&pmap->pm_stats, sizeof(pmap->pm_stats)); pmap->pm_cookie = COOKIE_FROM(-1, INT_MAX); MPASS(levels == 3 || levels == 4); pmap->pm_levels = levels; pmap->pm_stage = stage; switch (stage) { case PM_STAGE1: pmap->pm_asid_set = &asids; break; case PM_STAGE2: pmap->pm_asid_set = &vmids; break; default: panic("%s: Invalid pmap type %d", __func__, stage); break; } /* XXX Temporarily disable deferred ASID allocation. */ pmap_alloc_asid(pmap); /* * Allocate the level 1 entry to use as the root. This will increase * the refcount on the level 1 page so it won't be removed until * pmap_release() is called. */ if (pmap->pm_levels == 3) { PMAP_LOCK(pmap); m = _pmap_alloc_l3(pmap, NUL2E + NUL1E, NULL); PMAP_UNLOCK(pmap); } pmap->pm_ttbr = VM_PAGE_TO_PHYS(m); return (1); } int pmap_pinit(pmap_t pmap) { return (pmap_pinit_stage(pmap, PM_STAGE1, 4)); } /* * This routine is called if the desired page table page does not exist. * * If page table page allocation fails, this routine may sleep before * returning NULL. It sleeps only if a lock pointer was given. * * Note: If a page allocation fails at page table level two or three, * one or two pages may be held during the wait, only to be released * afterwards. This conservative approach is easily argued to avoid * race conditions. */ static vm_page_t _pmap_alloc_l3(pmap_t pmap, vm_pindex_t ptepindex, struct rwlock **lockp) { vm_page_t m, l1pg, l2pg; PMAP_LOCK_ASSERT(pmap, MA_OWNED); /* * Allocate a page table page. */ if ((m = vm_page_alloc(NULL, ptepindex, VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO)) == NULL) { if (lockp != NULL) { RELEASE_PV_LIST_LOCK(lockp); PMAP_UNLOCK(pmap); vm_wait(NULL); PMAP_LOCK(pmap); } /* * Indicate the need to retry. While waiting, the page table * page may have been allocated. */ return (NULL); } if ((m->flags & PG_ZERO) == 0) pmap_zero_page(m); /* * Because of AArch64's weak memory consistency model, we must have a * barrier here to ensure that the stores for zeroing "m", whether by * pmap_zero_page() or an earlier function, are visible before adding * "m" to the page table. Otherwise, a page table walk by another * processor's MMU could see the mapping to "m" and a stale, non-zero * PTE within "m". */ dmb(ishst); /* * Map the pagetable page into the process address space, if * it isn't already there. */ if (ptepindex >= (NUL2E + NUL1E)) { pd_entry_t *l0p, l0e; vm_pindex_t l0index; l0index = ptepindex - (NUL2E + NUL1E); l0p = &pmap->pm_l0[l0index]; KASSERT((pmap_load(l0p) & ATTR_DESCR_VALID) == 0, ("%s: L0 entry %#lx is valid", __func__, pmap_load(l0p))); l0e = VM_PAGE_TO_PHYS(m) | L0_TABLE; /* * Mark all kernel memory as not accessible from userspace * and userspace memory as not executable from the kernel. * This has been done for the bootstrap L0 entries in * locore.S. */ if (pmap == kernel_pmap) l0e |= TATTR_UXN_TABLE | TATTR_AP_TABLE_NO_EL0; else l0e |= TATTR_PXN_TABLE; pmap_store(l0p, l0e); } else if (ptepindex >= NUL2E) { vm_pindex_t l0index, l1index; pd_entry_t *l0, *l1; pd_entry_t tl0; l1index = ptepindex - NUL2E; l0index = l1index >> L0_ENTRIES_SHIFT; l0 = &pmap->pm_l0[l0index]; tl0 = pmap_load(l0); if (tl0 == 0) { /* recurse for allocating page dir */ if (_pmap_alloc_l3(pmap, NUL2E + NUL1E + l0index, lockp) == NULL) { vm_page_unwire_noq(m); vm_page_free_zero(m); return (NULL); } } else { l1pg = PHYS_TO_VM_PAGE(tl0 & ~ATTR_MASK); l1pg->ref_count++; } l1 = (pd_entry_t *)PHYS_TO_DMAP(pmap_load(l0) & ~ATTR_MASK); l1 = &l1[ptepindex & Ln_ADDR_MASK]; KASSERT((pmap_load(l1) & ATTR_DESCR_VALID) == 0, ("%s: L1 entry %#lx is valid", __func__, pmap_load(l1))); pmap_store(l1, VM_PAGE_TO_PHYS(m) | L1_TABLE); } else { vm_pindex_t l0index, l1index; pd_entry_t *l0, *l1, *l2; pd_entry_t tl0, tl1; l1index = ptepindex >> Ln_ENTRIES_SHIFT; l0index = l1index >> L0_ENTRIES_SHIFT; l0 = &pmap->pm_l0[l0index]; tl0 = pmap_load(l0); if (tl0 == 0) { /* recurse for allocating page dir */ if (_pmap_alloc_l3(pmap, NUL2E + l1index, lockp) == NULL) { vm_page_unwire_noq(m); vm_page_free_zero(m); return (NULL); } tl0 = pmap_load(l0); l1 = (pd_entry_t *)PHYS_TO_DMAP(tl0 & ~ATTR_MASK); l1 = &l1[l1index & Ln_ADDR_MASK]; } else { l1 = (pd_entry_t *)PHYS_TO_DMAP(tl0 & ~ATTR_MASK); l1 = &l1[l1index & Ln_ADDR_MASK]; tl1 = pmap_load(l1); if (tl1 == 0) { /* recurse for allocating page dir */ if (_pmap_alloc_l3(pmap, NUL2E + l1index, lockp) == NULL) { vm_page_unwire_noq(m); vm_page_free_zero(m); return (NULL); } } else { l2pg = PHYS_TO_VM_PAGE(tl1 & ~ATTR_MASK); l2pg->ref_count++; } } l2 = (pd_entry_t *)PHYS_TO_DMAP(pmap_load(l1) & ~ATTR_MASK); l2 = &l2[ptepindex & Ln_ADDR_MASK]; KASSERT((pmap_load(l2) & ATTR_DESCR_VALID) == 0, ("%s: L2 entry %#lx is valid", __func__, pmap_load(l2))); pmap_store(l2, VM_PAGE_TO_PHYS(m) | L2_TABLE); } pmap_resident_count_inc(pmap, 1); return (m); } static pd_entry_t * pmap_alloc_l2(pmap_t pmap, vm_offset_t va, vm_page_t *l2pgp, struct rwlock **lockp) { pd_entry_t *l1, *l2; vm_page_t l2pg; vm_pindex_t l2pindex; KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); retry: l1 = pmap_l1(pmap, va); if (l1 != NULL && (pmap_load(l1) & ATTR_DESCR_MASK) == L1_TABLE) { l2 = pmap_l1_to_l2(l1, va); if (!ADDR_IS_KERNEL(va)) { /* Add a reference to the L2 page. */ l2pg = PHYS_TO_VM_PAGE(pmap_load(l1) & ~ATTR_MASK); l2pg->ref_count++; } else l2pg = NULL; } else if (!ADDR_IS_KERNEL(va)) { /* Allocate a L2 page. */ l2pindex = pmap_l2_pindex(va) >> Ln_ENTRIES_SHIFT; l2pg = _pmap_alloc_l3(pmap, NUL2E + l2pindex, lockp); if (l2pg == NULL) { if (lockp != NULL) goto retry; else return (NULL); } l2 = (pd_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(l2pg)); l2 = &l2[pmap_l2_index(va)]; } else panic("pmap_alloc_l2: missing page table page for va %#lx", va); *l2pgp = l2pg; return (l2); } static vm_page_t pmap_alloc_l3(pmap_t pmap, vm_offset_t va, struct rwlock **lockp) { vm_pindex_t ptepindex; pd_entry_t *pde, tpde; #ifdef INVARIANTS pt_entry_t *pte; #endif vm_page_t m; int lvl; /* * Calculate pagetable page index */ ptepindex = pmap_l2_pindex(va); retry: /* * Get the page directory entry */ pde = pmap_pde(pmap, va, &lvl); /* * If the page table page is mapped, we just increment the hold count, * and activate it. If we get a level 2 pde it will point to a level 3 * table. */ switch (lvl) { case -1: break; case 0: #ifdef INVARIANTS pte = pmap_l0_to_l1(pde, va); KASSERT(pmap_load(pte) == 0, ("pmap_alloc_l3: TODO: l0 superpages")); #endif break; case 1: #ifdef INVARIANTS pte = pmap_l1_to_l2(pde, va); KASSERT(pmap_load(pte) == 0, ("pmap_alloc_l3: TODO: l1 superpages")); #endif break; case 2: tpde = pmap_load(pde); if (tpde != 0) { m = PHYS_TO_VM_PAGE(tpde & ~ATTR_MASK); m->ref_count++; return (m); } break; default: panic("pmap_alloc_l3: Invalid level %d", lvl); } /* * Here if the pte page isn't mapped, or if it has been deallocated. */ m = _pmap_alloc_l3(pmap, ptepindex, lockp); if (m == NULL && lockp != NULL) goto retry; return (m); } /*************************************************** * 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) { boolean_t rv; struct spglist free; struct asid_set *set; vm_page_t m; int asid; if (pmap->pm_levels != 4) { PMAP_ASSERT_STAGE2(pmap); KASSERT(pmap->pm_stats.resident_count == 1, ("pmap_release: pmap resident count %ld != 0", pmap->pm_stats.resident_count)); KASSERT((pmap->pm_l0[0] & ATTR_DESCR_VALID) == ATTR_DESCR_VALID, ("pmap_release: Invalid l0 entry: %lx", pmap->pm_l0[0])); SLIST_INIT(&free); m = PHYS_TO_VM_PAGE(pmap->pm_ttbr); PMAP_LOCK(pmap); rv = pmap_unwire_l3(pmap, 0, m, &free); PMAP_UNLOCK(pmap); MPASS(rv == TRUE); vm_page_free_pages_toq(&free, true); } KASSERT(pmap->pm_stats.resident_count == 0, ("pmap_release: pmap resident count %ld != 0", pmap->pm_stats.resident_count)); KASSERT(vm_radix_is_empty(&pmap->pm_root), ("pmap_release: pmap has reserved page table page(s)")); set = pmap->pm_asid_set; KASSERT(set != NULL, ("%s: NULL asid set", __func__)); /* * Allow the ASID to be reused. In stage 2 VMIDs we don't invalidate * the entries when removing them so rely on a later tlb invalidation. * this will happen when updating the VMID generation. Because of this * we don't reuse VMIDs within a generation. */ if (pmap->pm_stage == PM_STAGE1) { mtx_lock_spin(&set->asid_set_mutex); if (COOKIE_TO_EPOCH(pmap->pm_cookie) == set->asid_epoch) { asid = COOKIE_TO_ASID(pmap->pm_cookie); KASSERT(asid >= ASID_FIRST_AVAILABLE && asid < set->asid_set_size, ("pmap_release: pmap cookie has out-of-range asid")); bit_clear(set->asid_set, asid); } mtx_unlock_spin(&set->asid_set_mutex); } m = PHYS_TO_VM_PAGE(pmap->pm_l0_paddr); vm_page_unwire_noq(m); vm_page_free_zero(m); } static int kvm_size(SYSCTL_HANDLER_ARGS) { unsigned long ksize = VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS; return sysctl_handle_long(oidp, &ksize, 0, req); } SYSCTL_PROC(_vm, OID_AUTO, kvm_size, CTLTYPE_LONG | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0, kvm_size, "LU", "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 | CTLFLAG_MPSAFE, 0, 0, kvm_free, "LU", "Amount of KVM free"); /* * grow the number of kernel page table entries, if needed */ void pmap_growkernel(vm_offset_t addr) { vm_paddr_t paddr; vm_page_t nkpg; pd_entry_t *l0, *l1, *l2; mtx_assert(&kernel_map->system_mtx, MA_OWNED); addr = roundup2(addr, L2_SIZE); if (addr - 1 >= vm_map_max(kernel_map)) addr = vm_map_max(kernel_map); while (kernel_vm_end < addr) { l0 = pmap_l0(kernel_pmap, kernel_vm_end); KASSERT(pmap_load(l0) != 0, ("pmap_growkernel: No level 0 kernel entry")); l1 = pmap_l0_to_l1(l0, kernel_vm_end); if (pmap_load(l1) == 0) { /* We need a new PDP entry */ nkpg = vm_page_alloc(NULL, kernel_vm_end >> L1_SHIFT, VM_ALLOC_INTERRUPT | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO); if (nkpg == NULL) panic("pmap_growkernel: no memory to grow kernel"); if ((nkpg->flags & PG_ZERO) == 0) pmap_zero_page(nkpg); /* See the dmb() in _pmap_alloc_l3(). */ dmb(ishst); paddr = VM_PAGE_TO_PHYS(nkpg); pmap_store(l1, paddr | L1_TABLE); continue; /* try again */ } l2 = pmap_l1_to_l2(l1, kernel_vm_end); if (pmap_load(l2) != 0) { kernel_vm_end = (kernel_vm_end + L2_SIZE) & ~L2_OFFSET; if (kernel_vm_end - 1 >= vm_map_max(kernel_map)) { kernel_vm_end = vm_map_max(kernel_map); break; } continue; } nkpg = vm_page_alloc(NULL, kernel_vm_end >> L2_SHIFT, VM_ALLOC_INTERRUPT | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO); if (nkpg == NULL) panic("pmap_growkernel: no memory to grow kernel"); if ((nkpg->flags & PG_ZERO) == 0) pmap_zero_page(nkpg); /* See the dmb() in _pmap_alloc_l3(). */ dmb(ishst); paddr = VM_PAGE_TO_PHYS(nkpg); pmap_store(l2, paddr | L2_TABLE); kernel_vm_end = (kernel_vm_end + L2_SIZE) & ~L2_OFFSET; if (kernel_vm_end - 1 >= vm_map_max(kernel_map)) { kernel_vm_end = vm_map_max(kernel_map); break; } } } /*************************************************** * page management routines. ***************************************************/ CTASSERT(sizeof(struct pv_chunk) == PAGE_SIZE); CTASSERT(_NPCM == 3); CTASSERT(_NPCPV == 168); static __inline struct pv_chunk * pv_to_chunk(pv_entry_t pv) { return ((struct pv_chunk *)((uintptr_t)pv & ~(uintptr_t)PAGE_MASK)); } #define PV_PMAP(pv) (pv_to_chunk(pv)->pc_pmap) #define PC_FREE0 0xfffffffffffffffful #define PC_FREE1 0xfffffffffffffffful #define PC_FREE2 0x000000fffffffffful static const uint64_t pc_freemask[_NPCM] = { PC_FREE0, PC_FREE1, PC_FREE2 }; #ifdef PV_STATS static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail; SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_count, CTLFLAG_RD, &pc_chunk_count, 0, "Current number of pv entry chunks"); SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_allocs, CTLFLAG_RD, &pc_chunk_allocs, 0, "Current number of pv entry chunks allocated"); SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_frees, CTLFLAG_RD, &pc_chunk_frees, 0, "Current number of pv entry chunks frees"); SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_tryfail, CTLFLAG_RD, &pc_chunk_tryfail, 0, "Number of times tried to get a chunk page but failed."); static long pv_entry_frees, pv_entry_allocs, pv_entry_count; static int pv_entry_spare; SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_frees, CTLFLAG_RD, &pv_entry_frees, 0, "Current number of pv entry frees"); SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_allocs, CTLFLAG_RD, &pv_entry_allocs, 0, "Current number of pv entry allocs"); SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_count, CTLFLAG_RD, &pv_entry_count, 0, "Current number of pv entries"); SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_spare, CTLFLAG_RD, &pv_entry_spare, 0, "Current number of spare pv entries"); #endif /* * We are in a serious low memory condition. Resort to * drastic measures to free some pages so we can allocate * another pv entry chunk. * * Returns NULL if PV entries were reclaimed from the specified pmap. * * We do not, however, unmap 2mpages because subsequent accesses will * allocate per-page pv entries until repromotion occurs, thereby * exacerbating the shortage of free pv entries. */ static vm_page_t reclaim_pv_chunk(pmap_t locked_pmap, struct rwlock **lockp) { struct pv_chunk *pc, *pc_marker, *pc_marker_end; struct pv_chunk_header pc_marker_b, pc_marker_end_b; struct md_page *pvh; pd_entry_t *pde; pmap_t next_pmap, pmap; pt_entry_t *pte, tpte; pv_entry_t pv; vm_offset_t va; vm_page_t m, m_pc; struct spglist free; uint64_t inuse; int bit, field, freed, lvl; static int active_reclaims = 0; PMAP_LOCK_ASSERT(locked_pmap, MA_OWNED); KASSERT(lockp != NULL, ("reclaim_pv_chunk: lockp is NULL")); pmap = NULL; m_pc = NULL; SLIST_INIT(&free); bzero(&pc_marker_b, sizeof(pc_marker_b)); bzero(&pc_marker_end_b, sizeof(pc_marker_end_b)); pc_marker = (struct pv_chunk *)&pc_marker_b; pc_marker_end = (struct pv_chunk *)&pc_marker_end_b; mtx_lock(&pv_chunks_mutex); active_reclaims++; TAILQ_INSERT_HEAD(&pv_chunks, pc_marker, pc_lru); TAILQ_INSERT_TAIL(&pv_chunks, pc_marker_end, pc_lru); while ((pc = TAILQ_NEXT(pc_marker, pc_lru)) != pc_marker_end && SLIST_EMPTY(&free)) { next_pmap = pc->pc_pmap; if (next_pmap == NULL) { /* * The next chunk is a marker. However, it is * not our marker, so active_reclaims must be * > 1. Consequently, the next_chunk code * will not rotate the pv_chunks list. */ goto next_chunk; } mtx_unlock(&pv_chunks_mutex); /* * A pv_chunk can only be removed from the pc_lru list * when both pv_chunks_mutex is owned and the * corresponding pmap is locked. */ if (pmap != next_pmap) { if (pmap != NULL && pmap != locked_pmap) PMAP_UNLOCK(pmap); pmap = next_pmap; /* Avoid deadlock and lock recursion. */ if (pmap > locked_pmap) { RELEASE_PV_LIST_LOCK(lockp); PMAP_LOCK(pmap); mtx_lock(&pv_chunks_mutex); continue; } else if (pmap != locked_pmap) { if (PMAP_TRYLOCK(pmap)) { mtx_lock(&pv_chunks_mutex); continue; } else { pmap = NULL; /* pmap is not locked */ mtx_lock(&pv_chunks_mutex); pc = TAILQ_NEXT(pc_marker, pc_lru); if (pc == NULL || pc->pc_pmap != next_pmap) continue; goto next_chunk; } } } /* * Destroy every non-wired, 4 KB page mapping in the chunk. */ freed = 0; for (field = 0; field < _NPCM; field++) { for (inuse = ~pc->pc_map[field] & pc_freemask[field]; inuse != 0; inuse &= ~(1UL << bit)) { bit = ffsl(inuse) - 1; pv = &pc->pc_pventry[field * 64 + bit]; va = pv->pv_va; pde = pmap_pde(pmap, va, &lvl); if (lvl != 2) continue; pte = pmap_l2_to_l3(pde, va); tpte = pmap_load(pte); if ((tpte & ATTR_SW_WIRED) != 0) continue; tpte = pmap_load_clear(pte); m = PHYS_TO_VM_PAGE(tpte & ~ATTR_MASK); if (pmap_pte_dirty(pmap, tpte)) vm_page_dirty(m); if ((tpte & ATTR_AF) != 0) { pmap_invalidate_page(pmap, va); vm_page_aflag_set(m, PGA_REFERENCED); } CHANGE_PV_LIST_LOCK_TO_VM_PAGE(lockp, m); TAILQ_REMOVE(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; if (TAILQ_EMPTY(&m->md.pv_list) && (m->flags & PG_FICTITIOUS) == 0) { pvh = page_to_pvh(m); if (TAILQ_EMPTY(&pvh->pv_list)) { vm_page_aflag_clear(m, PGA_WRITEABLE); } } pc->pc_map[field] |= 1UL << bit; pmap_unuse_pt(pmap, va, pmap_load(pde), &free); freed++; } } if (freed == 0) { mtx_lock(&pv_chunks_mutex); goto next_chunk; } /* Every freed mapping is for a 4 KB page. */ pmap_resident_count_dec(pmap, freed); PV_STAT(atomic_add_long(&pv_entry_frees, freed)); PV_STAT(atomic_add_int(&pv_entry_spare, freed)); PV_STAT(atomic_subtract_long(&pv_entry_count, freed)); TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); if (pc->pc_map[0] == PC_FREE0 && pc->pc_map[1] == PC_FREE1 && pc->pc_map[2] == PC_FREE2) { PV_STAT(atomic_subtract_int(&pv_entry_spare, _NPCPV)); PV_STAT(atomic_subtract_int(&pc_chunk_count, 1)); PV_STAT(atomic_add_int(&pc_chunk_frees, 1)); /* Entire chunk is free; return it. */ m_pc = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t)pc)); dump_drop_page(m_pc->phys_addr); mtx_lock(&pv_chunks_mutex); TAILQ_REMOVE(&pv_chunks, pc, pc_lru); break; } TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list); mtx_lock(&pv_chunks_mutex); /* One freed pv entry in locked_pmap is sufficient. */ if (pmap == locked_pmap) break; next_chunk: TAILQ_REMOVE(&pv_chunks, pc_marker, pc_lru); TAILQ_INSERT_AFTER(&pv_chunks, pc, pc_marker, pc_lru); if (active_reclaims == 1 && pmap != NULL) { /* * Rotate the pv chunks list so that we do not * scan the same pv chunks that could not be * freed (because they contained a wired * and/or superpage mapping) on every * invocation of reclaim_pv_chunk(). */ while ((pc = TAILQ_FIRST(&pv_chunks)) != pc_marker) { MPASS(pc->pc_pmap != NULL); TAILQ_REMOVE(&pv_chunks, pc, pc_lru); TAILQ_INSERT_TAIL(&pv_chunks, pc, pc_lru); } } } TAILQ_REMOVE(&pv_chunks, pc_marker, pc_lru); TAILQ_REMOVE(&pv_chunks, pc_marker_end, pc_lru); active_reclaims--; mtx_unlock(&pv_chunks_mutex); if (pmap != NULL && pmap != locked_pmap) PMAP_UNLOCK(pmap); if (m_pc == NULL && !SLIST_EMPTY(&free)) { m_pc = SLIST_FIRST(&free); SLIST_REMOVE_HEAD(&free, plinks.s.ss); /* Recycle a freed page table page. */ m_pc->ref_count = 1; } vm_page_free_pages_toq(&free, true); return (m_pc); } /* * free the pv_entry back to the free list */ static void free_pv_entry(pmap_t pmap, pv_entry_t pv) { struct pv_chunk *pc; int idx, field, bit; PMAP_LOCK_ASSERT(pmap, MA_OWNED); PV_STAT(atomic_add_long(&pv_entry_frees, 1)); PV_STAT(atomic_add_int(&pv_entry_spare, 1)); PV_STAT(atomic_subtract_long(&pv_entry_count, 1)); pc = pv_to_chunk(pv); idx = pv - &pc->pc_pventry[0]; field = idx / 64; bit = idx % 64; pc->pc_map[field] |= 1ul << bit; if (pc->pc_map[0] != PC_FREE0 || pc->pc_map[1] != PC_FREE1 || pc->pc_map[2] != PC_FREE2) { /* 98% of the time, pc is already at the head of the list. */ if (__predict_false(pc != TAILQ_FIRST(&pmap->pm_pvchunk))) { TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list); } return; } TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); free_pv_chunk(pc); } static void free_pv_chunk(struct pv_chunk *pc) { vm_page_t m; mtx_lock(&pv_chunks_mutex); TAILQ_REMOVE(&pv_chunks, pc, pc_lru); mtx_unlock(&pv_chunks_mutex); PV_STAT(atomic_subtract_int(&pv_entry_spare, _NPCPV)); PV_STAT(atomic_subtract_int(&pc_chunk_count, 1)); PV_STAT(atomic_add_int(&pc_chunk_frees, 1)); /* entire chunk is free, return it */ m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t)pc)); dump_drop_page(m->phys_addr); vm_page_unwire_noq(m); vm_page_free(m); } /* * Returns a new PV entry, allocating a new PV chunk from the system when * needed. If this PV chunk allocation fails and a PV list lock pointer was * given, a PV chunk is reclaimed from an arbitrary pmap. Otherwise, NULL is * returned. * * The given PV list lock may be released. */ static pv_entry_t get_pv_entry(pmap_t pmap, struct rwlock **lockp) { int bit, field; pv_entry_t pv; struct pv_chunk *pc; vm_page_t m; PMAP_LOCK_ASSERT(pmap, MA_OWNED); PV_STAT(atomic_add_long(&pv_entry_allocs, 1)); retry: pc = TAILQ_FIRST(&pmap->pm_pvchunk); if (pc != NULL) { for (field = 0; field < _NPCM; field++) { if (pc->pc_map[field]) { bit = ffsl(pc->pc_map[field]) - 1; break; } } if (field < _NPCM) { pv = &pc->pc_pventry[field * 64 + bit]; pc->pc_map[field] &= ~(1ul << bit); /* If this was the last item, move it to tail */ if (pc->pc_map[0] == 0 && pc->pc_map[1] == 0 && pc->pc_map[2] == 0) { TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list); } PV_STAT(atomic_add_long(&pv_entry_count, 1)); PV_STAT(atomic_subtract_int(&pv_entry_spare, 1)); return (pv); } } /* No free items, allocate another chunk */ m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED); if (m == NULL) { if (lockp == NULL) { PV_STAT(pc_chunk_tryfail++); return (NULL); } m = reclaim_pv_chunk(pmap, lockp); if (m == NULL) goto retry; } PV_STAT(atomic_add_int(&pc_chunk_count, 1)); PV_STAT(atomic_add_int(&pc_chunk_allocs, 1)); dump_add_page(m->phys_addr); pc = (void *)PHYS_TO_DMAP(m->phys_addr); pc->pc_pmap = pmap; pc->pc_map[0] = PC_FREE0 & ~1ul; /* preallocated bit 0 */ pc->pc_map[1] = PC_FREE1; pc->pc_map[2] = PC_FREE2; mtx_lock(&pv_chunks_mutex); TAILQ_INSERT_TAIL(&pv_chunks, pc, pc_lru); mtx_unlock(&pv_chunks_mutex); pv = &pc->pc_pventry[0]; TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list); PV_STAT(atomic_add_long(&pv_entry_count, 1)); PV_STAT(atomic_add_int(&pv_entry_spare, _NPCPV - 1)); return (pv); } /* * Ensure that the number of spare PV entries in the specified pmap meets or * exceeds the given count, "needed". * * The given PV list lock may be released. */ static void reserve_pv_entries(pmap_t pmap, int needed, struct rwlock **lockp) { struct pch new_tail; struct pv_chunk *pc; vm_page_t m; int avail, free; bool reclaimed; PMAP_LOCK_ASSERT(pmap, MA_OWNED); KASSERT(lockp != NULL, ("reserve_pv_entries: lockp is NULL")); /* * Newly allocated PV chunks must be stored in a private list until * the required number of PV chunks have been allocated. Otherwise, * reclaim_pv_chunk() could recycle one of these chunks. In * contrast, these chunks must be added to the pmap upon allocation. */ TAILQ_INIT(&new_tail); retry: avail = 0; TAILQ_FOREACH(pc, &pmap->pm_pvchunk, pc_list) { bit_count((bitstr_t *)pc->pc_map, 0, sizeof(pc->pc_map) * NBBY, &free); if (free == 0) break; avail += free; if (avail >= needed) break; } for (reclaimed = false; avail < needed; avail += _NPCPV) { m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED); if (m == NULL) { m = reclaim_pv_chunk(pmap, lockp); if (m == NULL) goto retry; reclaimed = true; } PV_STAT(atomic_add_int(&pc_chunk_count, 1)); PV_STAT(atomic_add_int(&pc_chunk_allocs, 1)); dump_add_page(m->phys_addr); pc = (void *)PHYS_TO_DMAP(m->phys_addr); pc->pc_pmap = pmap; pc->pc_map[0] = PC_FREE0; pc->pc_map[1] = PC_FREE1; pc->pc_map[2] = PC_FREE2; TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list); TAILQ_INSERT_TAIL(&new_tail, pc, pc_lru); PV_STAT(atomic_add_int(&pv_entry_spare, _NPCPV)); /* * The reclaim might have freed a chunk from the current pmap. * If that chunk contained available entries, we need to * re-count the number of available entries. */ if (reclaimed) goto retry; } if (!TAILQ_EMPTY(&new_tail)) { mtx_lock(&pv_chunks_mutex); TAILQ_CONCAT(&pv_chunks, &new_tail, pc_lru); mtx_unlock(&pv_chunks_mutex); } } /* * First find and then remove the pv entry for the specified pmap and virtual * address from the specified pv list. Returns the pv entry if found and NULL * otherwise. This operation can be performed on pv lists for either 4KB or * 2MB page mappings. */ static __inline pv_entry_t pmap_pvh_remove(struct md_page *pvh, pmap_t pmap, vm_offset_t va) { pv_entry_t pv; TAILQ_FOREACH(pv, &pvh->pv_list, pv_next) { if (pmap == PV_PMAP(pv) && va == pv->pv_va) { TAILQ_REMOVE(&pvh->pv_list, pv, pv_next); pvh->pv_gen++; break; } } return (pv); } /* * After demotion from a 2MB page mapping to 512 4KB page mappings, * destroy the pv entry for the 2MB page mapping and reinstantiate the pv * entries for each of the 4KB page mappings. */ static void pmap_pv_demote_l2(pmap_t pmap, vm_offset_t va, vm_paddr_t pa, struct rwlock **lockp) { struct md_page *pvh; struct pv_chunk *pc; pv_entry_t pv; vm_offset_t va_last; vm_page_t m; int bit, field; PMAP_LOCK_ASSERT(pmap, MA_OWNED); KASSERT((va & L2_OFFSET) == 0, ("pmap_pv_demote_l2: va is not 2mpage aligned")); KASSERT((pa & L2_OFFSET) == 0, ("pmap_pv_demote_l2: pa is not 2mpage aligned")); CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, pa); /* * Transfer the 2mpage's pv entry for this mapping to the first * page's pv list. Once this transfer begins, the pv list lock * must not be released until the last pv entry is reinstantiated. */ pvh = pa_to_pvh(pa); pv = pmap_pvh_remove(pvh, pmap, va); KASSERT(pv != NULL, ("pmap_pv_demote_l2: pv not found")); m = PHYS_TO_VM_PAGE(pa); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; /* Instantiate the remaining Ln_ENTRIES - 1 pv entries. */ PV_STAT(atomic_add_long(&pv_entry_allocs, Ln_ENTRIES - 1)); va_last = va + L2_SIZE - PAGE_SIZE; for (;;) { pc = TAILQ_FIRST(&pmap->pm_pvchunk); KASSERT(pc->pc_map[0] != 0 || pc->pc_map[1] != 0 || pc->pc_map[2] != 0, ("pmap_pv_demote_l2: missing spare")); for (field = 0; field < _NPCM; field++) { while (pc->pc_map[field]) { bit = ffsl(pc->pc_map[field]) - 1; pc->pc_map[field] &= ~(1ul << bit); pv = &pc->pc_pventry[field * 64 + bit]; va += PAGE_SIZE; pv->pv_va = va; m++; KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_pv_demote_l2: page %p is not managed", m)); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; if (va == va_last) goto out; } } TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list); } out: if (pc->pc_map[0] == 0 && pc->pc_map[1] == 0 && pc->pc_map[2] == 0) { TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list); } PV_STAT(atomic_add_long(&pv_entry_count, Ln_ENTRIES - 1)); PV_STAT(atomic_subtract_int(&pv_entry_spare, Ln_ENTRIES - 1)); } /* * First find and then destroy the pv entry for the specified pmap and virtual * address. This operation can be performed on pv lists for either 4KB or 2MB * page mappings. */ static void pmap_pvh_free(struct md_page *pvh, pmap_t pmap, vm_offset_t va) { pv_entry_t pv; pv = pmap_pvh_remove(pvh, pmap, va); KASSERT(pv != NULL, ("pmap_pvh_free: pv not found")); free_pv_entry(pmap, pv); } /* * Conditionally create the PV entry for a 4KB page mapping if the required * memory can be allocated without resorting to reclamation. */ static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va, vm_page_t m, struct rwlock **lockp) { pv_entry_t pv; PMAP_LOCK_ASSERT(pmap, MA_OWNED); /* Pass NULL instead of the lock pointer to disable reclamation. */ if ((pv = get_pv_entry(pmap, NULL)) != NULL) { pv->pv_va = va; CHANGE_PV_LIST_LOCK_TO_VM_PAGE(lockp, m); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; return (TRUE); } else return (FALSE); } /* * Create the PV entry for a 2MB page mapping. Always returns true unless the * flag PMAP_ENTER_NORECLAIM is specified. If that flag is specified, returns * false if the PV entry cannot be allocated without resorting to reclamation. */ static bool pmap_pv_insert_l2(pmap_t pmap, vm_offset_t va, pd_entry_t l2e, u_int flags, struct rwlock **lockp) { struct md_page *pvh; pv_entry_t pv; vm_paddr_t pa; PMAP_LOCK_ASSERT(pmap, MA_OWNED); /* Pass NULL instead of the lock pointer to disable reclamation. */ if ((pv = get_pv_entry(pmap, (flags & PMAP_ENTER_NORECLAIM) != 0 ? NULL : lockp)) == NULL) return (false); pv->pv_va = va; pa = l2e & ~ATTR_MASK; CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, pa); pvh = pa_to_pvh(pa); TAILQ_INSERT_TAIL(&pvh->pv_list, pv, pv_next); pvh->pv_gen++; return (true); } static void pmap_remove_kernel_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t va) { pt_entry_t newl2, oldl2; vm_page_t ml3; vm_paddr_t ml3pa; KASSERT(!VIRT_IN_DMAP(va), ("removing direct mapping of %#lx", va)); KASSERT(pmap == kernel_pmap, ("pmap %p is not kernel_pmap", pmap)); PMAP_LOCK_ASSERT(pmap, MA_OWNED); ml3 = pmap_remove_pt_page(pmap, va); if (ml3 == NULL) panic("pmap_remove_kernel_l2: Missing pt page"); ml3pa = VM_PAGE_TO_PHYS(ml3); newl2 = ml3pa | L2_TABLE; /* * If this page table page was unmapped by a promotion, then it * contains valid mappings. Zero it to invalidate those mappings. */ if (ml3->valid != 0) pagezero((void *)PHYS_TO_DMAP(ml3pa)); /* * Demote the mapping. The caller must have already invalidated the * mapping (i.e., the "break" in break-before-make). */ oldl2 = pmap_load_store(l2, newl2); KASSERT(oldl2 == 0, ("%s: found existing mapping at %p: %#lx", __func__, l2, oldl2)); } /* * pmap_remove_l2: Do the things to unmap a level 2 superpage. */ static int pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva, pd_entry_t l1e, struct spglist *free, struct rwlock **lockp) { struct md_page *pvh; pt_entry_t old_l2; vm_page_t m, ml3, mt; PMAP_LOCK_ASSERT(pmap, MA_OWNED); KASSERT((sva & L2_OFFSET) == 0, ("pmap_remove_l2: sva is not aligned")); old_l2 = pmap_load_clear(l2); KASSERT((old_l2 & ATTR_DESCR_MASK) == L2_BLOCK, ("pmap_remove_l2: L2e %lx is not a block mapping", old_l2)); /* * Since a promotion must break the 4KB page mappings before making * the 2MB page mapping, a pmap_invalidate_page() suffices. */ pmap_invalidate_page(pmap, sva); if (old_l2 & ATTR_SW_WIRED) pmap->pm_stats.wired_count -= L2_SIZE / PAGE_SIZE; pmap_resident_count_dec(pmap, L2_SIZE / PAGE_SIZE); if (old_l2 & ATTR_SW_MANAGED) { m = PHYS_TO_VM_PAGE(old_l2 & ~ATTR_MASK); pvh = page_to_pvh(m); CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, old_l2 & ~ATTR_MASK); pmap_pvh_free(pvh, pmap, sva); for (mt = m; mt < &m[L2_SIZE / PAGE_SIZE]; mt++) { if (pmap_pte_dirty(pmap, old_l2)) vm_page_dirty(mt); if (old_l2 & ATTR_AF) vm_page_aflag_set(mt, PGA_REFERENCED); if (TAILQ_EMPTY(&mt->md.pv_list) && TAILQ_EMPTY(&pvh->pv_list)) vm_page_aflag_clear(mt, PGA_WRITEABLE); } } if (pmap == kernel_pmap) { pmap_remove_kernel_l2(pmap, l2, sva); } else { ml3 = pmap_remove_pt_page(pmap, sva); if (ml3 != NULL) { KASSERT(ml3->valid == VM_PAGE_BITS_ALL, ("pmap_remove_l2: l3 page not promoted")); pmap_resident_count_dec(pmap, 1); KASSERT(ml3->ref_count == NL3PG, ("pmap_remove_l2: l3 page ref count error")); ml3->ref_count = 0; pmap_add_delayed_free_list(ml3, free, FALSE); } } return (pmap_unuse_pt(pmap, sva, l1e, free)); } /* * pmap_remove_l3: do the things to unmap a page in a process */ static int pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_t va, pd_entry_t l2e, struct spglist *free, struct rwlock **lockp) { struct md_page *pvh; pt_entry_t old_l3; vm_page_t m; PMAP_LOCK_ASSERT(pmap, MA_OWNED); old_l3 = pmap_load_clear(l3); pmap_invalidate_page(pmap, va); if (old_l3 & ATTR_SW_WIRED) pmap->pm_stats.wired_count -= 1; pmap_resident_count_dec(pmap, 1); if (old_l3 & ATTR_SW_MANAGED) { m = PHYS_TO_VM_PAGE(old_l3 & ~ATTR_MASK); if (pmap_pte_dirty(pmap, old_l3)) vm_page_dirty(m); if (old_l3 & ATTR_AF) vm_page_aflag_set(m, PGA_REFERENCED); CHANGE_PV_LIST_LOCK_TO_VM_PAGE(lockp, m); pmap_pvh_free(&m->md, pmap, va); if (TAILQ_EMPTY(&m->md.pv_list) && (m->flags & PG_FICTITIOUS) == 0) { pvh = page_to_pvh(m); if (TAILQ_EMPTY(&pvh->pv_list)) vm_page_aflag_clear(m, PGA_WRITEABLE); } } return (pmap_unuse_pt(pmap, va, l2e, free)); } /* * Remove the specified range of addresses from the L3 page table that is * identified by the given L2 entry. */ static void pmap_remove_l3_range(pmap_t pmap, pd_entry_t l2e, vm_offset_t sva, vm_offset_t eva, struct spglist *free, struct rwlock **lockp) { struct md_page *pvh; struct rwlock *new_lock; pt_entry_t *l3, old_l3; vm_offset_t va; vm_page_t l3pg, m; KASSERT(ADDR_IS_CANONICAL(sva), ("%s: Start address not in canonical form: %lx", __func__, sva)); KASSERT(ADDR_IS_CANONICAL(eva) || eva == VM_MAX_USER_ADDRESS, ("%s: End address not in canonical form: %lx", __func__, eva)); PMAP_LOCK_ASSERT(pmap, MA_OWNED); KASSERT(rounddown2(sva, L2_SIZE) + L2_SIZE == roundup2(eva, L2_SIZE), ("pmap_remove_l3_range: range crosses an L3 page table boundary")); l3pg = !ADDR_IS_KERNEL(sva) ? PHYS_TO_VM_PAGE(l2e & ~ATTR_MASK) : NULL; va = eva; for (l3 = pmap_l2_to_l3(&l2e, sva); sva != eva; l3++, sva += L3_SIZE) { if (!pmap_l3_valid(pmap_load(l3))) { if (va != eva) { pmap_invalidate_range(pmap, va, sva); va = eva; } continue; } old_l3 = pmap_load_clear(l3); if ((old_l3 & ATTR_SW_WIRED) != 0) pmap->pm_stats.wired_count--; pmap_resident_count_dec(pmap, 1); if ((old_l3 & ATTR_SW_MANAGED) != 0) { m = PHYS_TO_VM_PAGE(old_l3 & ~ATTR_MASK); if (pmap_pte_dirty(pmap, old_l3)) vm_page_dirty(m); if ((old_l3 & ATTR_AF) != 0) vm_page_aflag_set(m, PGA_REFERENCED); new_lock = PHYS_TO_PV_LIST_LOCK(VM_PAGE_TO_PHYS(m)); if (new_lock != *lockp) { if (*lockp != NULL) { /* * Pending TLB invalidations must be * performed before the PV list lock is * released. Otherwise, a concurrent * pmap_remove_all() on a physical page * could return while a stale TLB entry * still provides access to that page. */ if (va != eva) { pmap_invalidate_range(pmap, va, sva); va = eva; } rw_wunlock(*lockp); } *lockp = new_lock; rw_wlock(*lockp); } pmap_pvh_free(&m->md, pmap, sva); if (TAILQ_EMPTY(&m->md.pv_list) && (m->flags & PG_FICTITIOUS) == 0) { pvh = page_to_pvh(m); if (TAILQ_EMPTY(&pvh->pv_list)) vm_page_aflag_clear(m, PGA_WRITEABLE); } } if (va == eva) va = sva; if (l3pg != NULL && pmap_unwire_l3(pmap, sva, l3pg, free)) { sva += L3_SIZE; break; } } if (va != eva) pmap_invalidate_range(pmap, va, sva); } /* * 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) { struct rwlock *lock; vm_offset_t va_next; pd_entry_t *l0, *l1, *l2; pt_entry_t l3_paddr; struct spglist free; /* * Perform an unsynchronized read. This is, however, safe. */ if (pmap->pm_stats.resident_count == 0) return; SLIST_INIT(&free); PMAP_LOCK(pmap); lock = NULL; for (; sva < eva; sva = va_next) { if (pmap->pm_stats.resident_count == 0) break; l0 = pmap_l0(pmap, sva); if (pmap_load(l0) == 0) { va_next = (sva + L0_SIZE) & ~L0_OFFSET; if (va_next < sva) va_next = eva; continue; } va_next = (sva + L1_SIZE) & ~L1_OFFSET; if (va_next < sva) va_next = eva; l1 = pmap_l0_to_l1(l0, sva); if (pmap_load(l1) == 0) continue; if ((pmap_load(l1) & ATTR_DESCR_MASK) == L1_BLOCK) { KASSERT(va_next <= eva, ("partial update of non-transparent 1G page " "l1 %#lx sva %#lx eva %#lx va_next %#lx", pmap_load(l1), sva, eva, va_next)); MPASS(pmap != kernel_pmap); MPASS((pmap_load(l1) & ATTR_SW_MANAGED) == 0); pmap_clear(l1); pmap_invalidate_page(pmap, sva); pmap_resident_count_dec(pmap, L1_SIZE / PAGE_SIZE); pmap_unuse_pt(pmap, sva, pmap_load(l0), &free); continue; } /* * Calculate index for next page table. */ va_next = (sva + L2_SIZE) & ~L2_OFFSET; if (va_next < sva) va_next = eva; l2 = pmap_l1_to_l2(l1, sva); if (l2 == NULL) continue; l3_paddr = pmap_load(l2); if ((l3_paddr & ATTR_DESCR_MASK) == L2_BLOCK) { if (sva + L2_SIZE == va_next && eva >= va_next) { pmap_remove_l2(pmap, l2, sva, pmap_load(l1), &free, &lock); continue; } else if (pmap_demote_l2_locked(pmap, l2, sva, &lock) == NULL) continue; l3_paddr = pmap_load(l2); } /* * Weed out invalid mappings. */ if ((l3_paddr & ATTR_DESCR_MASK) != L2_TABLE) 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 (va_next > eva) va_next = eva; pmap_remove_l3_range(pmap, l3_paddr, sva, va_next, &free, &lock); } if (lock != NULL) rw_wunlock(lock); PMAP_UNLOCK(pmap); vm_page_free_pages_toq(&free, true); } /* * 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...) */ void pmap_remove_all(vm_page_t m) { struct md_page *pvh; pv_entry_t pv; pmap_t pmap; struct rwlock *lock; pd_entry_t *pde, tpde; pt_entry_t *pte, tpte; vm_offset_t va; struct spglist free; int lvl, pvh_gen, md_gen; KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_remove_all: page %p is not managed", m)); SLIST_INIT(&free); lock = VM_PAGE_TO_PV_LIST_LOCK(m); pvh = (m->flags & PG_FICTITIOUS) != 0 ? &pv_dummy : page_to_pvh(m); rw_wlock(lock); retry: while ((pv = TAILQ_FIRST(&pvh->pv_list)) != NULL) { pmap = PV_PMAP(pv); if (!PMAP_TRYLOCK(pmap)) { pvh_gen = pvh->pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen) { PMAP_UNLOCK(pmap); goto retry; } } va = pv->pv_va; pte = pmap_pte(pmap, va, &lvl); KASSERT(pte != NULL, ("pmap_remove_all: no page table entry found")); KASSERT(lvl == 2, ("pmap_remove_all: invalid pte level %d", lvl)); pmap_demote_l2_locked(pmap, pte, va, &lock); PMAP_UNLOCK(pmap); } while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) { pmap = PV_PMAP(pv); PMAP_ASSERT_STAGE1(pmap); if (!PMAP_TRYLOCK(pmap)) { pvh_gen = pvh->pv_gen; md_gen = m->md.pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen || md_gen != m->md.pv_gen) { PMAP_UNLOCK(pmap); goto retry; } } pmap_resident_count_dec(pmap, 1); pde = pmap_pde(pmap, pv->pv_va, &lvl); KASSERT(pde != NULL, ("pmap_remove_all: no page directory entry found")); KASSERT(lvl == 2, ("pmap_remove_all: invalid pde level %d", lvl)); tpde = pmap_load(pde); pte = pmap_l2_to_l3(pde, pv->pv_va); tpte = pmap_load_clear(pte); if (tpte & ATTR_SW_WIRED) pmap->pm_stats.wired_count--; if ((tpte & ATTR_AF) != 0) { pmap_invalidate_page(pmap, pv->pv_va); vm_page_aflag_set(m, PGA_REFERENCED); } /* * Update the vm_page_t clean and reference bits. */ if (pmap_pte_dirty(pmap, tpte)) vm_page_dirty(m); pmap_unuse_pt(pmap, pv->pv_va, tpde, &free); TAILQ_REMOVE(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; free_pv_entry(pmap, pv); PMAP_UNLOCK(pmap); } vm_page_aflag_clear(m, PGA_WRITEABLE); rw_wunlock(lock); vm_page_free_pages_toq(&free, true); } /* * pmap_protect_l2: do the things to protect a 2MB page in a pmap */ static void pmap_protect_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva, pt_entry_t mask, pt_entry_t nbits) { pd_entry_t old_l2; vm_page_t m, mt; PMAP_LOCK_ASSERT(pmap, MA_OWNED); PMAP_ASSERT_STAGE1(pmap); KASSERT((sva & L2_OFFSET) == 0, ("pmap_protect_l2: sva is not 2mpage aligned")); old_l2 = pmap_load(l2); KASSERT((old_l2 & ATTR_DESCR_MASK) == L2_BLOCK, ("pmap_protect_l2: L2e %lx is not a block mapping", old_l2)); /* * Return if the L2 entry already has the desired access restrictions * in place. */ if ((old_l2 & mask) == nbits) return; while (!atomic_fcmpset_64(l2, &old_l2, (old_l2 & ~mask) | nbits)) cpu_spinwait(); /* * When a dirty read/write superpage mapping is write protected, * update the dirty field of each of the superpage's constituent 4KB * pages. */ if ((old_l2 & ATTR_SW_MANAGED) != 0 && (nbits & ATTR_S1_AP(ATTR_S1_AP_RO)) != 0 && pmap_pte_dirty(pmap, old_l2)) { m = PHYS_TO_VM_PAGE(old_l2 & ~ATTR_MASK); for (mt = m; mt < &m[L2_SIZE / PAGE_SIZE]; mt++) vm_page_dirty(mt); } /* * Since a promotion must break the 4KB page mappings before making * the 2MB page mapping, a pmap_invalidate_page() suffices. */ pmap_invalidate_page(pmap, sva); } /* * 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) { vm_offset_t va, va_next; pd_entry_t *l0, *l1, *l2; pt_entry_t *l3p, l3, mask, nbits; PMAP_ASSERT_STAGE1(pmap); KASSERT((prot & ~VM_PROT_ALL) == 0, ("invalid prot %x", prot)); if (prot == VM_PROT_NONE) { pmap_remove(pmap, sva, eva); return; } mask = nbits = 0; if ((prot & VM_PROT_WRITE) == 0) { mask |= ATTR_S1_AP_RW_BIT | ATTR_SW_DBM; nbits |= ATTR_S1_AP(ATTR_S1_AP_RO); } if ((prot & VM_PROT_EXECUTE) == 0) { mask |= ATTR_S1_XN; nbits |= ATTR_S1_XN; } if (mask == 0) return; PMAP_LOCK(pmap); for (; sva < eva; sva = va_next) { l0 = pmap_l0(pmap, sva); if (pmap_load(l0) == 0) { va_next = (sva + L0_SIZE) & ~L0_OFFSET; if (va_next < sva) va_next = eva; continue; } va_next = (sva + L1_SIZE) & ~L1_OFFSET; if (va_next < sva) va_next = eva; l1 = pmap_l0_to_l1(l0, sva); if (pmap_load(l1) == 0) continue; if ((pmap_load(l1) & ATTR_DESCR_MASK) == L1_BLOCK) { KASSERT(va_next <= eva, ("partial update of non-transparent 1G page " "l1 %#lx sva %#lx eva %#lx va_next %#lx", pmap_load(l1), sva, eva, va_next)); MPASS((pmap_load(l1) & ATTR_SW_MANAGED) == 0); if ((pmap_load(l1) & mask) != nbits) { pmap_store(l1, (pmap_load(l1) & ~mask) | nbits); pmap_invalidate_page(pmap, sva); } continue; } va_next = (sva + L2_SIZE) & ~L2_OFFSET; if (va_next < sva) va_next = eva; l2 = pmap_l1_to_l2(l1, sva); if (pmap_load(l2) == 0) continue; if ((pmap_load(l2) & ATTR_DESCR_MASK) == L2_BLOCK) { if (sva + L2_SIZE == va_next && eva >= va_next) { pmap_protect_l2(pmap, l2, sva, mask, nbits); continue; } else if (pmap_demote_l2(pmap, l2, sva) == NULL) continue; } KASSERT((pmap_load(l2) & ATTR_DESCR_MASK) == L2_TABLE, ("pmap_protect: Invalid L2 entry after demotion")); if (va_next > eva) va_next = eva; va = va_next; for (l3p = pmap_l2_to_l3(l2, sva); sva != va_next; l3p++, sva += L3_SIZE) { l3 = pmap_load(l3p); /* * Go to the next L3 entry if the current one is * invalid or already has the desired access * restrictions in place. (The latter case occurs * frequently. For example, in a "buildworld" * workload, almost 1 out of 4 L3 entries already * have the desired restrictions.) */ if (!pmap_l3_valid(l3) || (l3 & mask) == nbits) { if (va != va_next) { pmap_invalidate_range(pmap, va, sva); va = va_next; } continue; } while (!atomic_fcmpset_64(l3p, &l3, (l3 & ~mask) | nbits)) cpu_spinwait(); /* * When a dirty read/write mapping is write protected, * update the page's dirty field. */ if ((l3 & ATTR_SW_MANAGED) != 0 && (nbits & ATTR_S1_AP(ATTR_S1_AP_RO)) != 0 && pmap_pte_dirty(pmap, l3)) vm_page_dirty(PHYS_TO_VM_PAGE(l3 & ~ATTR_MASK)); if (va == va_next) va = sva; } if (va != va_next) pmap_invalidate_range(pmap, va, sva); } PMAP_UNLOCK(pmap); } /* * Inserts the specified page table page into the specified pmap's collection * of idle page table pages. Each of a pmap's page table pages is responsible * for mapping a distinct range of virtual addresses. The pmap's collection is * ordered by this virtual address range. * * If "promoted" is false, then the page table page "mpte" must be zero filled. */ static __inline int pmap_insert_pt_page(pmap_t pmap, vm_page_t mpte, bool promoted) { PMAP_LOCK_ASSERT(pmap, MA_OWNED); mpte->valid = promoted ? VM_PAGE_BITS_ALL : 0; return (vm_radix_insert(&pmap->pm_root, mpte)); } /* * Removes the page table page mapping the specified virtual address from the * specified pmap's collection of idle page table pages, and returns it. * Otherwise, returns NULL if there is no page table page corresponding to the * specified virtual address. */ static __inline vm_page_t pmap_remove_pt_page(pmap_t pmap, vm_offset_t va) { PMAP_LOCK_ASSERT(pmap, MA_OWNED); return (vm_radix_remove(&pmap->pm_root, pmap_l2_pindex(va))); } /* * Performs a break-before-make update of a pmap entry. This is needed when * either promoting or demoting pages to ensure the TLB doesn't get into an * inconsistent state. */ static void pmap_update_entry(pmap_t pmap, pd_entry_t *pte, pd_entry_t newpte, vm_offset_t va, vm_size_t size) { register_t intr; PMAP_LOCK_ASSERT(pmap, MA_OWNED); /* * Ensure we don't get switched out with the page table in an * inconsistent state. We also need to ensure no interrupts fire * as they may make use of an address we are about to invalidate. */ intr = intr_disable(); /* * Clear the old mapping's valid bit, but leave the rest of the entry * unchanged, so that a lockless, concurrent pmap_kextract() can still * lookup the physical address. */ pmap_clear_bits(pte, ATTR_DESCR_VALID); pmap_invalidate_range(pmap, va, va + size); /* Create the new mapping */ pmap_store(pte, newpte); dsb(ishst); intr_restore(intr); } #if VM_NRESERVLEVEL > 0 /* * After promotion from 512 4KB page mappings to a single 2MB page mapping, * replace the many pv entries for the 4KB page mappings by a single pv entry * for the 2MB page mapping. */ static void pmap_pv_promote_l2(pmap_t pmap, vm_offset_t va, vm_paddr_t pa, struct rwlock **lockp) { struct md_page *pvh; pv_entry_t pv; vm_offset_t va_last; vm_page_t m; KASSERT((pa & L2_OFFSET) == 0, ("pmap_pv_promote_l2: pa is not 2mpage aligned")); CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, pa); /* * Transfer the first page's pv entry for this mapping to the 2mpage's * pv list. Aside from avoiding the cost of a call to get_pv_entry(), * a transfer avoids the possibility that get_pv_entry() calls * reclaim_pv_chunk() and that reclaim_pv_chunk() removes one of the * mappings that is being promoted. */ m = PHYS_TO_VM_PAGE(pa); va = va & ~L2_OFFSET; pv = pmap_pvh_remove(&m->md, pmap, va); KASSERT(pv != NULL, ("pmap_pv_promote_l2: pv not found")); pvh = page_to_pvh(m); TAILQ_INSERT_TAIL(&pvh->pv_list, pv, pv_next); pvh->pv_gen++; /* Free the remaining NPTEPG - 1 pv entries. */ va_last = va + L2_SIZE - PAGE_SIZE; do { m++; va += PAGE_SIZE; pmap_pvh_free(&m->md, pmap, va); } while (va < va_last); } /* * Tries to promote the 512, contiguous 4KB page mappings that are within a * single level 2 table entry to a single 2MB page mapping. For promotion * to occur, two conditions must be met: (1) the 4KB page mappings must map * aligned, contiguous physical memory and (2) the 4KB page mappings must have * identical characteristics. */ static void pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, struct rwlock **lockp) { pt_entry_t *firstl3, *l3, newl2, oldl3, pa; vm_page_t mpte; vm_offset_t sva; PMAP_LOCK_ASSERT(pmap, MA_OWNED); PMAP_ASSERT_STAGE1(pmap); sva = va & ~L2_OFFSET; firstl3 = pmap_l2_to_l3(l2, sva); newl2 = pmap_load(firstl3); if (((newl2 & (~ATTR_MASK | ATTR_AF)) & L2_OFFSET) != ATTR_AF) { atomic_add_long(&pmap_l2_p_failures, 1); CTR2(KTR_PMAP, "pmap_promote_l2: failure for va %#lx" " in pmap %p", va, pmap); return; } setl2: if ((newl2 & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) == (ATTR_S1_AP(ATTR_S1_AP_RO) | ATTR_SW_DBM)) { /* * When the mapping is clean, i.e., ATTR_S1_AP_RO is set, * ATTR_SW_DBM can be cleared without a TLB invalidation. */ if (!atomic_fcmpset_64(firstl3, &newl2, newl2 & ~ATTR_SW_DBM)) goto setl2; newl2 &= ~ATTR_SW_DBM; } pa = newl2 + L2_SIZE - PAGE_SIZE; for (l3 = firstl3 + NL3PG - 1; l3 > firstl3; l3--) { oldl3 = pmap_load(l3); setl3: if ((oldl3 & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) == (ATTR_S1_AP(ATTR_S1_AP_RO) | ATTR_SW_DBM)) { /* * When the mapping is clean, i.e., ATTR_S1_AP_RO is * set, ATTR_SW_DBM can be cleared without a TLB * invalidation. */ if (!atomic_fcmpset_64(l3, &oldl3, oldl3 & ~ATTR_SW_DBM)) goto setl3; oldl3 &= ~ATTR_SW_DBM; } if (oldl3 != pa) { atomic_add_long(&pmap_l2_p_failures, 1); CTR2(KTR_PMAP, "pmap_promote_l2: failure for va %#lx" " in pmap %p", va, pmap); return; } pa -= PAGE_SIZE; } /* * Save the page table page in its current state until the L2 * mapping the superpage is demoted by pmap_demote_l2() or * destroyed by pmap_remove_l3(). */ mpte = PHYS_TO_VM_PAGE(pmap_load(l2) & ~ATTR_MASK); KASSERT(mpte >= vm_page_array && mpte < &vm_page_array[vm_page_array_size], ("pmap_promote_l2: page table page is out of range")); KASSERT(mpte->pindex == pmap_l2_pindex(va), ("pmap_promote_l2: page table page's pindex is wrong")); if (pmap_insert_pt_page(pmap, mpte, true)) { atomic_add_long(&pmap_l2_p_failures, 1); CTR2(KTR_PMAP, "pmap_promote_l2: failure for va %#lx in pmap %p", va, pmap); return; } if ((newl2 & ATTR_SW_MANAGED) != 0) pmap_pv_promote_l2(pmap, va, newl2 & ~ATTR_MASK, lockp); newl2 &= ~ATTR_DESCR_MASK; newl2 |= L2_BLOCK; pmap_update_entry(pmap, l2, newl2, sva, L2_SIZE); atomic_add_long(&pmap_l2_promotions, 1); CTR2(KTR_PMAP, "pmap_promote_l2: success for va %#lx in pmap %p", va, pmap); } #endif /* VM_NRESERVLEVEL > 0 */ static int pmap_enter_largepage(pmap_t pmap, vm_offset_t va, pt_entry_t newpte, int flags, int psind) { pd_entry_t *l0p, *l1p, *l2p, origpte; vm_page_t mp; PMAP_LOCK_ASSERT(pmap, MA_OWNED); KASSERT(psind > 0 && psind < MAXPAGESIZES, ("psind %d unexpected", psind)); KASSERT(((newpte & ~ATTR_MASK) & (pagesizes[psind] - 1)) == 0, ("unaligned phys address %#lx newpte %#lx psind %d", (newpte & ~ATTR_MASK), newpte, psind)); restart: if (psind == 2) { l0p = pmap_l0(pmap, va); if ((pmap_load(l0p) & ATTR_DESCR_VALID) == 0) { mp = _pmap_alloc_l3(pmap, pmap_l0_pindex(va), NULL); if (mp == NULL) { if ((flags & PMAP_ENTER_NOSLEEP) != 0) return (KERN_RESOURCE_SHORTAGE); PMAP_UNLOCK(pmap); vm_wait(NULL); PMAP_LOCK(pmap); goto restart; } l1p = pmap_l0_to_l1(l0p, va); KASSERT(l1p != NULL, ("va %#lx lost l1 entry", va)); origpte = pmap_load(l1p); } else { l1p = pmap_l0_to_l1(l0p, va); KASSERT(l1p != NULL, ("va %#lx lost l1 entry", va)); origpte = pmap_load(l1p); if ((origpte & ATTR_DESCR_VALID) == 0) { mp = PHYS_TO_VM_PAGE(pmap_load(l0p) & ~ATTR_MASK); mp->ref_count++; } } KASSERT((origpte & ATTR_DESCR_VALID) == 0 || ((origpte & ATTR_DESCR_MASK) == L1_BLOCK && (origpte & ~ATTR_MASK) == (newpte & ~ATTR_MASK)), ("va %#lx changing 1G phys page l1 %#lx newpte %#lx", va, origpte, newpte)); pmap_store(l1p, newpte); } else /* (psind == 1) */ { l2p = pmap_l2(pmap, va); if (l2p == NULL) { mp = _pmap_alloc_l3(pmap, pmap_l1_pindex(va), NULL); if (mp == NULL) { if ((flags & PMAP_ENTER_NOSLEEP) != 0) return (KERN_RESOURCE_SHORTAGE); PMAP_UNLOCK(pmap); vm_wait(NULL); PMAP_LOCK(pmap); goto restart; } l2p = (pd_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(mp)); l2p = &l2p[pmap_l2_index(va)]; origpte = pmap_load(l2p); } else { l1p = pmap_l1(pmap, va); origpte = pmap_load(l2p); if ((origpte & ATTR_DESCR_VALID) == 0) { mp = PHYS_TO_VM_PAGE(pmap_load(l1p) & ~ATTR_MASK); mp->ref_count++; } } KASSERT((origpte & ATTR_DESCR_VALID) == 0 || ((origpte & ATTR_DESCR_MASK) == L2_BLOCK && (origpte & ~ATTR_MASK) == (newpte & ~ATTR_MASK)), ("va %#lx changing 2M phys page l2 %#lx newpte %#lx", va, origpte, newpte)); pmap_store(l2p, newpte); } dsb(ishst); if ((origpte & ATTR_DESCR_VALID) == 0) pmap_resident_count_inc(pmap, pagesizes[psind] / PAGE_SIZE); if ((newpte & ATTR_SW_WIRED) != 0 && (origpte & ATTR_SW_WIRED) == 0) pmap->pm_stats.wired_count += pagesizes[psind] / PAGE_SIZE; else if ((newpte & ATTR_SW_WIRED) == 0 && (origpte & ATTR_SW_WIRED) != 0) pmap->pm_stats.wired_count -= pagesizes[psind] / PAGE_SIZE; return (KERN_SUCCESS); } /* * Add a single SMMU entry. This function does not sleep. */ int pmap_senter(pmap_t pmap, vm_offset_t va, vm_paddr_t pa, vm_prot_t prot, u_int flags) { pd_entry_t *pde; pt_entry_t new_l3, orig_l3; pt_entry_t *l3; vm_page_t mpte; int lvl; int rv; PMAP_ASSERT_STAGE1(pmap); KASSERT(va < VM_MAXUSER_ADDRESS, ("wrong address space")); va = trunc_page(va); new_l3 = (pt_entry_t)(pa | ATTR_DEFAULT | ATTR_S1_IDX(VM_MEMATTR_DEVICE) | L3_PAGE); if ((prot & VM_PROT_WRITE) == 0) new_l3 |= ATTR_S1_AP(ATTR_S1_AP_RO); new_l3 |= ATTR_S1_XN; /* Execute never. */ new_l3 |= ATTR_S1_AP(ATTR_S1_AP_USER); new_l3 |= ATTR_S1_nG; /* Non global. */ CTR2(KTR_PMAP, "pmap_senter: %.16lx -> %.16lx", va, pa); PMAP_LOCK(pmap); /* * In the case that a page table page is not * resident, we are creating it here. */ retry: pde = pmap_pde(pmap, va, &lvl); if (pde != NULL && lvl == 2) { l3 = pmap_l2_to_l3(pde, va); } else { mpte = _pmap_alloc_l3(pmap, pmap_l2_pindex(va), NULL); if (mpte == NULL) { CTR0(KTR_PMAP, "pmap_enter: mpte == NULL"); rv = KERN_RESOURCE_SHORTAGE; goto out; } goto retry; } orig_l3 = pmap_load(l3); KASSERT(!pmap_l3_valid(orig_l3), ("l3 is valid")); /* New mapping */ pmap_store(l3, new_l3); pmap_resident_count_inc(pmap, 1); dsb(ishst); rv = KERN_SUCCESS; out: PMAP_UNLOCK(pmap); return (rv); } /* * Remove a single SMMU entry. */ int pmap_sremove(pmap_t pmap, vm_offset_t va) { pt_entry_t *pte; int lvl; int rc; PMAP_LOCK(pmap); pte = pmap_pte(pmap, va, &lvl); KASSERT(lvl == 3, ("Invalid SMMU pagetable level: %d != 3", lvl)); if (pte != NULL) { pmap_resident_count_dec(pmap, 1); pmap_clear(pte); rc = KERN_SUCCESS; } else rc = KERN_FAILURE; PMAP_UNLOCK(pmap); return (rc); } /* * Remove all the allocated L1, L2 pages from SMMU pmap. * All the L3 entires must be cleared in advance, otherwise * this function panics. */ void pmap_sremove_pages(pmap_t pmap) { pd_entry_t l0e, *l1, l1e, *l2, l2e; pt_entry_t *l3, l3e; vm_page_t m, m0, m1; vm_offset_t sva; vm_paddr_t pa; vm_paddr_t pa0; vm_paddr_t pa1; int i, j, k, l; PMAP_LOCK(pmap); for (sva = VM_MINUSER_ADDRESS, i = pmap_l0_index(sva); (i < Ln_ENTRIES && sva < VM_MAXUSER_ADDRESS); i++) { l0e = pmap->pm_l0[i]; if ((l0e & ATTR_DESCR_VALID) == 0) { sva += L0_SIZE; continue; } pa0 = l0e & ~ATTR_MASK; m0 = PHYS_TO_VM_PAGE(pa0); l1 = (pd_entry_t *)PHYS_TO_DMAP(pa0); for (j = pmap_l1_index(sva); j < Ln_ENTRIES; j++) { l1e = l1[j]; if ((l1e & ATTR_DESCR_VALID) == 0) { sva += L1_SIZE; continue; } if ((l1e & ATTR_DESCR_MASK) == L1_BLOCK) { sva += L1_SIZE; continue; } pa1 = l1e & ~ATTR_MASK; m1 = PHYS_TO_VM_PAGE(pa1); l2 = (pd_entry_t *)PHYS_TO_DMAP(pa1); for (k = pmap_l2_index(sva); k < Ln_ENTRIES; k++) { l2e = l2[k]; if ((l2e & ATTR_DESCR_VALID) == 0) { sva += L2_SIZE; continue; } pa = l2e & ~ATTR_MASK; m = PHYS_TO_VM_PAGE(pa); l3 = (pt_entry_t *)PHYS_TO_DMAP(pa); for (l = pmap_l3_index(sva); l < Ln_ENTRIES; l++, sva += L3_SIZE) { l3e = l3[l]; if ((l3e & ATTR_DESCR_VALID) == 0) continue; panic("%s: l3e found for va %jx\n", __func__, sva); } vm_page_unwire_noq(m1); vm_page_unwire_noq(m); pmap_resident_count_dec(pmap, 1); vm_page_free(m); pmap_clear(&l2[k]); } vm_page_unwire_noq(m0); pmap_resident_count_dec(pmap, 1); vm_page_free(m1); pmap_clear(&l1[j]); } pmap_resident_count_dec(pmap, 1); vm_page_free(m0); pmap_clear(&pmap->pm_l0[i]); } KASSERT(pmap->pm_stats.resident_count == 0, ("Invalid resident count %jd", pmap->pm_stats.resident_count)); PMAP_UNLOCK(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. */ int pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, u_int flags, int8_t psind) { struct rwlock *lock; pd_entry_t *pde; pt_entry_t new_l3, orig_l3; pt_entry_t *l2, *l3; pv_entry_t pv; vm_paddr_t opa, pa; vm_page_t mpte, om; boolean_t nosleep; int lvl, rv; KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); va = trunc_page(va); if ((m->oflags & VPO_UNMANAGED) == 0) VM_PAGE_OBJECT_BUSY_ASSERT(m); pa = VM_PAGE_TO_PHYS(m); new_l3 = (pt_entry_t)(pa | ATTR_DEFAULT | L3_PAGE); new_l3 |= pmap_pte_memattr(pmap, m->md.pv_memattr); new_l3 |= pmap_pte_prot(pmap, prot); if ((flags & PMAP_ENTER_WIRED) != 0) new_l3 |= ATTR_SW_WIRED; if (pmap->pm_stage == PM_STAGE1) { if (!ADDR_IS_KERNEL(va)) new_l3 |= ATTR_S1_AP(ATTR_S1_AP_USER) | ATTR_S1_PXN; else new_l3 |= ATTR_S1_UXN; if (pmap != kernel_pmap) new_l3 |= ATTR_S1_nG; } else { /* * Clear the access flag on executable mappings, this will be * set later when the page is accessed. The fault handler is * required to invalidate the I-cache. * * TODO: Switch to the valid flag to allow hardware management * of the access flag. Much of the pmap code assumes the * valid flag is set and fails to destroy the old page tables * correctly if it is clear. */ if (prot & VM_PROT_EXECUTE) new_l3 &= ~ATTR_AF; } if ((m->oflags & VPO_UNMANAGED) == 0) { new_l3 |= ATTR_SW_MANAGED; if ((prot & VM_PROT_WRITE) != 0) { new_l3 |= ATTR_SW_DBM; if ((flags & VM_PROT_WRITE) == 0) { if (pmap->pm_stage == PM_STAGE1) new_l3 |= ATTR_S1_AP(ATTR_S1_AP_RO); else new_l3 &= ~ATTR_S2_S2AP(ATTR_S2_S2AP_WRITE); } } } CTR2(KTR_PMAP, "pmap_enter: %.16lx -> %.16lx", va, pa); lock = NULL; PMAP_LOCK(pmap); if ((flags & PMAP_ENTER_LARGEPAGE) != 0) { KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed largepage va %#lx flags %#x", va, flags)); new_l3 &= ~L3_PAGE; if (psind == 2) new_l3 |= L1_BLOCK; else /* (psind == 1) */ new_l3 |= L2_BLOCK; rv = pmap_enter_largepage(pmap, va, new_l3, flags, psind); goto out; } if (psind == 1) { /* Assert the required virtual and physical alignment. */ KASSERT((va & L2_OFFSET) == 0, ("pmap_enter: va unaligned")); KASSERT(m->psind > 0, ("pmap_enter: m->psind < psind")); rv = pmap_enter_l2(pmap, va, (new_l3 & ~L3_PAGE) | L2_BLOCK, flags, m, &lock); goto out; } mpte = NULL; /* * In the case that a page table page is not * resident, we are creating it here. */ retry: pde = pmap_pde(pmap, va, &lvl); if (pde != NULL && lvl == 2) { l3 = pmap_l2_to_l3(pde, va); if (!ADDR_IS_KERNEL(va) && mpte == NULL) { mpte = PHYS_TO_VM_PAGE(pmap_load(pde) & ~ATTR_MASK); mpte->ref_count++; } goto havel3; } else if (pde != NULL && lvl == 1) { l2 = pmap_l1_to_l2(pde, va); if ((pmap_load(l2) & ATTR_DESCR_MASK) == L2_BLOCK && (l3 = pmap_demote_l2_locked(pmap, l2, va, &lock)) != NULL) { l3 = &l3[pmap_l3_index(va)]; if (!ADDR_IS_KERNEL(va)) { mpte = PHYS_TO_VM_PAGE( pmap_load(l2) & ~ATTR_MASK); mpte->ref_count++; } goto havel3; } /* We need to allocate an L3 table. */ } if (!ADDR_IS_KERNEL(va)) { nosleep = (flags & PMAP_ENTER_NOSLEEP) != 0; /* * We use _pmap_alloc_l3() instead of pmap_alloc_l3() in order * to handle the possibility that a superpage mapping for "va" * was created while we slept. */ mpte = _pmap_alloc_l3(pmap, pmap_l2_pindex(va), nosleep ? NULL : &lock); if (mpte == NULL && nosleep) { CTR0(KTR_PMAP, "pmap_enter: mpte == NULL"); rv = KERN_RESOURCE_SHORTAGE; goto out; } goto retry; } else panic("pmap_enter: missing L3 table for kernel va %#lx", va); havel3: orig_l3 = pmap_load(l3); opa = orig_l3 & ~ATTR_MASK; pv = NULL; /* * Is the specified virtual address already mapped? */ if (pmap_l3_valid(orig_l3)) { /* * Only allow adding new entries on stage 2 tables for now. * This simplifies cache invalidation as we may need to call * into EL2 to perform such actions. */ PMAP_ASSERT_STAGE1(pmap); /* * 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 ((flags & PMAP_ENTER_WIRED) != 0 && (orig_l3 & ATTR_SW_WIRED) == 0) pmap->pm_stats.wired_count++; else if ((flags & PMAP_ENTER_WIRED) == 0 && (orig_l3 & ATTR_SW_WIRED) != 0) pmap->pm_stats.wired_count--; /* * Remove the extra PT page reference. */ if (mpte != NULL) { mpte->ref_count--; KASSERT(mpte->ref_count > 0, ("pmap_enter: missing reference to page table page," " va: 0x%lx", va)); } /* * Has the physical page changed? */ if (opa == pa) { /* * No, might be a protection or wiring change. */ if ((orig_l3 & ATTR_SW_MANAGED) != 0 && (new_l3 & ATTR_SW_DBM) != 0) vm_page_aflag_set(m, PGA_WRITEABLE); goto validate; } /* * The physical page has changed. Temporarily invalidate * the mapping. */ orig_l3 = pmap_load_clear(l3); KASSERT((orig_l3 & ~ATTR_MASK) == opa, ("pmap_enter: unexpected pa update for %#lx", va)); if ((orig_l3 & ATTR_SW_MANAGED) != 0) { om = PHYS_TO_VM_PAGE(opa); /* * The pmap lock is sufficient to synchronize with * concurrent calls to pmap_page_test_mappings() and * pmap_ts_referenced(). */ if (pmap_pte_dirty(pmap, orig_l3)) vm_page_dirty(om); if ((orig_l3 & ATTR_AF) != 0) { pmap_invalidate_page(pmap, va); vm_page_aflag_set(om, PGA_REFERENCED); } CHANGE_PV_LIST_LOCK_TO_PHYS(&lock, opa); pv = pmap_pvh_remove(&om->md, pmap, va); if ((m->oflags & VPO_UNMANAGED) != 0) free_pv_entry(pmap, pv); if ((om->a.flags & PGA_WRITEABLE) != 0 && TAILQ_EMPTY(&om->md.pv_list) && ((om->flags & PG_FICTITIOUS) != 0 || TAILQ_EMPTY(&page_to_pvh(om)->pv_list))) vm_page_aflag_clear(om, PGA_WRITEABLE); } else { KASSERT((orig_l3 & ATTR_AF) != 0, ("pmap_enter: unmanaged mapping lacks ATTR_AF")); pmap_invalidate_page(pmap, va); } orig_l3 = 0; } else { /* * Increment the counters. */ if ((new_l3 & ATTR_SW_WIRED) != 0) pmap->pm_stats.wired_count++; pmap_resident_count_inc(pmap, 1); } /* * Enter on the PV list if part of our managed memory. */ if ((m->oflags & VPO_UNMANAGED) == 0) { if (pv == NULL) { pv = get_pv_entry(pmap, &lock); pv->pv_va = va; } CHANGE_PV_LIST_LOCK_TO_PHYS(&lock, pa); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; if ((new_l3 & ATTR_SW_DBM) != 0) vm_page_aflag_set(m, PGA_WRITEABLE); } validate: if (pmap->pm_stage == PM_STAGE1) { /* * Sync icache if exec permission and attribute * VM_MEMATTR_WRITE_BACK is set. Do it now, before the mapping * is stored and made valid for hardware table walk. If done * later, then other can access this page before caches are * properly synced. Don't do it for kernel memory which is * mapped with exec permission even if the memory isn't going * to hold executable code. The only time when icache sync is * needed is after kernel module is loaded and the relocation * info is processed. And it's done in elf_cpu_load_file(). */ if ((prot & VM_PROT_EXECUTE) && pmap != kernel_pmap && m->md.pv_memattr == VM_MEMATTR_WRITE_BACK && (opa != pa || (orig_l3 & ATTR_S1_XN))) { PMAP_ASSERT_STAGE1(pmap); cpu_icache_sync_range(PHYS_TO_DMAP(pa), PAGE_SIZE); } } else { cpu_dcache_wb_range(PHYS_TO_DMAP(pa), PAGE_SIZE); } /* * Update the L3 entry */ if (pmap_l3_valid(orig_l3)) { PMAP_ASSERT_STAGE1(pmap); KASSERT(opa == pa, ("pmap_enter: invalid update")); if ((orig_l3 & ~ATTR_AF) != (new_l3 & ~ATTR_AF)) { /* same PA, different attributes */ orig_l3 = pmap_load_store(l3, new_l3); pmap_invalidate_page(pmap, va); if ((orig_l3 & ATTR_SW_MANAGED) != 0 && pmap_pte_dirty(pmap, orig_l3)) vm_page_dirty(m); } else { /* * orig_l3 == new_l3 * This can happens if multiple threads simultaneously * access not yet mapped page. This bad for performance * since this can cause full demotion-NOP-promotion * cycle. * Another possible reasons are: * - VM and pmap memory layout are diverged * - tlb flush is missing somewhere and CPU doesn't see * actual mapping. */ CTR4(KTR_PMAP, "%s: already mapped page - " "pmap %p va 0x%#lx pte 0x%lx", __func__, pmap, va, new_l3); } } else { /* New mapping */ pmap_store(l3, new_l3); dsb(ishst); } #if VM_NRESERVLEVEL > 0 /* * Try to promote from level 3 pages to a level 2 superpage. This * currently only works on stage 1 pmaps as pmap_promote_l2 looks at * stage 1 specific fields and performs a break-before-make sequence * that is incorrect a stage 2 pmap. */ if ((mpte == NULL || mpte->ref_count == NL3PG) && pmap_ps_enabled(pmap) && pmap->pm_stage == PM_STAGE1 && (m->flags & PG_FICTITIOUS) == 0 && vm_reserv_level_iffullpop(m) == 0) { pmap_promote_l2(pmap, pde, va, &lock); } #endif rv = KERN_SUCCESS; out: if (lock != NULL) rw_wunlock(lock); PMAP_UNLOCK(pmap); return (rv); } /* * Tries to create a read- and/or execute-only 2MB page mapping. Returns true * if successful. Returns false if (1) a page table page cannot be allocated * without sleeping, (2) a mapping already exists at the specified virtual * address, or (3) a PV entry cannot be allocated without reclaiming another * PV entry. */ static bool pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, struct rwlock **lockp) { pd_entry_t new_l2; PMAP_LOCK_ASSERT(pmap, MA_OWNED); PMAP_ASSERT_STAGE1(pmap); KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); new_l2 = (pd_entry_t)(VM_PAGE_TO_PHYS(m) | ATTR_DEFAULT | ATTR_S1_IDX(m->md.pv_memattr) | ATTR_S1_AP(ATTR_S1_AP_RO) | L2_BLOCK); if ((m->oflags & VPO_UNMANAGED) == 0) { new_l2 |= ATTR_SW_MANAGED; new_l2 &= ~ATTR_AF; } if ((prot & VM_PROT_EXECUTE) == 0 || m->md.pv_memattr == VM_MEMATTR_DEVICE) new_l2 |= ATTR_S1_XN; if (!ADDR_IS_KERNEL(va)) new_l2 |= ATTR_S1_AP(ATTR_S1_AP_USER) | ATTR_S1_PXN; else new_l2 |= ATTR_S1_UXN; if (pmap != kernel_pmap) new_l2 |= ATTR_S1_nG; return (pmap_enter_l2(pmap, va, new_l2, PMAP_ENTER_NOSLEEP | PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM, m, lockp) == KERN_SUCCESS); } /* * Returns true if every page table entry in the specified page table is * zero. */ static bool pmap_every_pte_zero(vm_paddr_t pa) { pt_entry_t *pt_end, *pte; KASSERT((pa & PAGE_MASK) == 0, ("pa is misaligned")); pte = (pt_entry_t *)PHYS_TO_DMAP(pa); for (pt_end = pte + Ln_ENTRIES; pte < pt_end; pte++) { if (*pte != 0) return (false); } return (true); } /* * Tries to create the specified 2MB page mapping. Returns KERN_SUCCESS if * the mapping was created, and either KERN_FAILURE or KERN_RESOURCE_SHORTAGE * otherwise. Returns KERN_FAILURE if PMAP_ENTER_NOREPLACE was specified and * a mapping already exists at the specified virtual address. Returns * KERN_RESOURCE_SHORTAGE if PMAP_ENTER_NOSLEEP was specified and a page table * page allocation failed. Returns KERN_RESOURCE_SHORTAGE if * PMAP_ENTER_NORECLAIM was specified and a PV entry allocation failed. */ static int pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2, u_int flags, vm_page_t m, struct rwlock **lockp) { struct spglist free; pd_entry_t *l2, old_l2; vm_page_t l2pg, mt; PMAP_LOCK_ASSERT(pmap, MA_OWNED); KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); if ((l2 = pmap_alloc_l2(pmap, va, &l2pg, (flags & PMAP_ENTER_NOSLEEP) != 0 ? NULL : lockp)) == NULL) { CTR2(KTR_PMAP, "pmap_enter_l2: failure for va %#lx in pmap %p", va, pmap); return (KERN_RESOURCE_SHORTAGE); } /* * If there are existing mappings, either abort or remove them. */ if ((old_l2 = pmap_load(l2)) != 0) { KASSERT(l2pg == NULL || l2pg->ref_count > 1, ("pmap_enter_l2: l2pg's ref count is too low")); if ((flags & PMAP_ENTER_NOREPLACE) != 0 && (!ADDR_IS_KERNEL(va) || (old_l2 & ATTR_DESCR_MASK) == L2_BLOCK || !pmap_every_pte_zero(old_l2 & ~ATTR_MASK))) { if (l2pg != NULL) l2pg->ref_count--; CTR2(KTR_PMAP, "pmap_enter_l2: failure for va %#lx" " in pmap %p", va, pmap); return (KERN_FAILURE); } SLIST_INIT(&free); if ((old_l2 & ATTR_DESCR_MASK) == L2_BLOCK) (void)pmap_remove_l2(pmap, l2, va, pmap_load(pmap_l1(pmap, va)), &free, lockp); else pmap_remove_l3_range(pmap, old_l2, va, va + L2_SIZE, &free, lockp); if (!ADDR_IS_KERNEL(va)) { vm_page_free_pages_toq(&free, true); KASSERT(pmap_load(l2) == 0, ("pmap_enter_l2: non-zero L2 entry %p", l2)); } else { KASSERT(SLIST_EMPTY(&free), ("pmap_enter_l2: freed kernel page table page")); /* * Both pmap_remove_l2() and pmap_remove_l3_range() * will leave the kernel page table page zero filled. * Nonetheless, the TLB could have an intermediate * entry for the kernel page table page. */ mt = PHYS_TO_VM_PAGE(pmap_load(l2) & ~ATTR_MASK); if (pmap_insert_pt_page(pmap, mt, false)) panic("pmap_enter_l2: trie insert failed"); pmap_clear(l2); pmap_invalidate_page(pmap, va); } } if ((new_l2 & ATTR_SW_MANAGED) != 0) { /* * Abort this mapping if its PV entry could not be created. */ if (!pmap_pv_insert_l2(pmap, va, new_l2, flags, lockp)) { if (l2pg != NULL) pmap_abort_ptp(pmap, va, l2pg); CTR2(KTR_PMAP, "pmap_enter_l2: failure for va %#lx in pmap %p", va, pmap); return (KERN_RESOURCE_SHORTAGE); } if ((new_l2 & ATTR_SW_DBM) != 0) for (mt = m; mt < &m[L2_SIZE / PAGE_SIZE]; mt++) vm_page_aflag_set(mt, PGA_WRITEABLE); } /* * Increment counters. */ if ((new_l2 & ATTR_SW_WIRED) != 0) pmap->pm_stats.wired_count += L2_SIZE / PAGE_SIZE; pmap->pm_stats.resident_count += L2_SIZE / PAGE_SIZE; /* * Conditionally sync the icache. See pmap_enter() for details. */ if ((new_l2 & ATTR_S1_XN) == 0 && ((new_l2 & ~ATTR_MASK) != (old_l2 & ~ATTR_MASK) || (old_l2 & ATTR_S1_XN) != 0) && pmap != kernel_pmap && m->md.pv_memattr == VM_MEMATTR_WRITE_BACK) { cpu_icache_sync_range(PHYS_TO_DMAP(new_l2 & ~ATTR_MASK), L2_SIZE); } /* * Map the superpage. */ pmap_store(l2, new_l2); dsb(ishst); atomic_add_long(&pmap_l2_mappings, 1); CTR2(KTR_PMAP, "pmap_enter_l2: success for va %#lx in pmap %p", va, pmap); return (KERN_SUCCESS); } /* * Maps a sequence of resident pages belonging to the same object. * The sequence begins with the given page m_start. This page is * mapped at the given virtual address start. Each subsequent page is * mapped at a virtual address that is offset from start by the same * amount as the page is offset from m_start within the object. The * last page in the sequence is the page with the largest offset from * m_start that can be mapped at a virtual address less than the given * virtual address end. Not every virtual page between start and end * is mapped; only those for which a resident page exists with the * corresponding offset from m_start are mapped. */ void pmap_enter_object(pmap_t pmap, vm_offset_t start, vm_offset_t end, vm_page_t m_start, vm_prot_t prot) { struct rwlock *lock; vm_offset_t va; vm_page_t m, mpte; vm_pindex_t diff, psize; VM_OBJECT_ASSERT_LOCKED(m_start->object); psize = atop(end - start); mpte = NULL; m = m_start; lock = NULL; PMAP_LOCK(pmap); while (m != NULL && (diff = m->pindex - m_start->pindex) < psize) { va = start + ptoa(diff); if ((va & L2_OFFSET) == 0 && va + L2_SIZE <= end && m->psind == 1 && pmap_ps_enabled(pmap) && pmap_enter_2mpage(pmap, va, m, prot, &lock)) m = &m[L2_SIZE / PAGE_SIZE - 1]; else mpte = pmap_enter_quick_locked(pmap, va, m, prot, mpte, &lock); m = TAILQ_NEXT(m, listq); } if (lock != NULL) rw_wunlock(lock); PMAP_UNLOCK(pmap); } /* * this code makes some *MAJOR* assumptions: * 1. Current pmap & pmap exists. * 2. Not wired. * 3. Read access. * 4. No page table pages. * but is *MUCH* faster than pmap_enter... */ void pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot) { struct rwlock *lock; lock = NULL; PMAP_LOCK(pmap); (void)pmap_enter_quick_locked(pmap, va, m, prot, NULL, &lock); if (lock != NULL) rw_wunlock(lock); PMAP_UNLOCK(pmap); } static vm_page_t pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, vm_page_t mpte, struct rwlock **lockp) { pd_entry_t *pde; pt_entry_t *l2, *l3, l3_val; vm_paddr_t pa; int lvl; KASSERT(va < kmi.clean_sva || va >= kmi.clean_eva || (m->oflags & VPO_UNMANAGED) != 0, ("pmap_enter_quick_locked: managed mapping within the clean submap")); PMAP_LOCK_ASSERT(pmap, MA_OWNED); PMAP_ASSERT_STAGE1(pmap); KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); CTR2(KTR_PMAP, "pmap_enter_quick_locked: %p %lx", pmap, va); /* * In the case that a page table page is not * resident, we are creating it here. */ if (!ADDR_IS_KERNEL(va)) { vm_pindex_t l2pindex; /* * Calculate pagetable page index */ l2pindex = pmap_l2_pindex(va); if (mpte && (mpte->pindex == l2pindex)) { mpte->ref_count++; } else { /* * Get the l2 entry */ pde = pmap_pde(pmap, va, &lvl); /* * If the page table page is mapped, we just increment * the hold count, and activate it. Otherwise, we * attempt to allocate a page table page. If this * attempt fails, we don't retry. Instead, we give up. */ if (lvl == 1) { l2 = pmap_l1_to_l2(pde, va); if ((pmap_load(l2) & ATTR_DESCR_MASK) == L2_BLOCK) return (NULL); } if (lvl == 2 && pmap_load(pde) != 0) { mpte = PHYS_TO_VM_PAGE(pmap_load(pde) & ~ATTR_MASK); mpte->ref_count++; } else { /* * Pass NULL instead of the PV list lock * pointer, because we don't intend to sleep. */ mpte = _pmap_alloc_l3(pmap, l2pindex, NULL); if (mpte == NULL) return (mpte); } } l3 = (pt_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(mpte)); l3 = &l3[pmap_l3_index(va)]; } else { mpte = NULL; pde = pmap_pde(kernel_pmap, va, &lvl); KASSERT(pde != NULL, ("pmap_enter_quick_locked: Invalid page entry, va: 0x%lx", va)); KASSERT(lvl == 2, ("pmap_enter_quick_locked: Invalid level %d", lvl)); l3 = pmap_l2_to_l3(pde, va); } /* * Abort if a mapping already exists. */ if (pmap_load(l3) != 0) { if (mpte != NULL) mpte->ref_count--; return (NULL); } /* * Enter on the PV list if part of our managed memory. */ if ((m->oflags & VPO_UNMANAGED) == 0 && !pmap_try_insert_pv_entry(pmap, va, m, lockp)) { if (mpte != NULL) pmap_abort_ptp(pmap, va, mpte); return (NULL); } /* * Increment counters */ pmap_resident_count_inc(pmap, 1); pa = VM_PAGE_TO_PHYS(m); l3_val = pa | ATTR_DEFAULT | ATTR_S1_IDX(m->md.pv_memattr) | ATTR_S1_AP(ATTR_S1_AP_RO) | L3_PAGE; if ((prot & VM_PROT_EXECUTE) == 0 || m->md.pv_memattr == VM_MEMATTR_DEVICE) l3_val |= ATTR_S1_XN; if (!ADDR_IS_KERNEL(va)) l3_val |= ATTR_S1_AP(ATTR_S1_AP_USER) | ATTR_S1_PXN; else l3_val |= ATTR_S1_UXN; if (pmap != kernel_pmap) l3_val |= ATTR_S1_nG; /* * Now validate mapping with RO protection */ if ((m->oflags & VPO_UNMANAGED) == 0) { l3_val |= ATTR_SW_MANAGED; l3_val &= ~ATTR_AF; } /* Sync icache before the mapping is stored to PTE */ if ((prot & VM_PROT_EXECUTE) && pmap != kernel_pmap && m->md.pv_memattr == VM_MEMATTR_WRITE_BACK) cpu_icache_sync_range(PHYS_TO_DMAP(pa), PAGE_SIZE); pmap_store(l3, l3_val); dsb(ishst); return (mpte); } /* * This code maps large physical mmap regions into the * processor address space. Note that some shortcuts * are taken, but the code works. */ void pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_object_t object, vm_pindex_t pindex, vm_size_t size) { VM_OBJECT_ASSERT_WLOCKED(object); KASSERT(object->type == OBJT_DEVICE || object->type == OBJT_SG, ("pmap_object_init_pt: non-device object")); } /* * Clear the wired attribute from the mappings for the specified range of * addresses in the given pmap. Every valid mapping within that range * must have the wired attribute set. In contrast, invalid mappings * cannot have the wired attribute set, so they are ignored. * * The wired attribute of the page table entry is not a hardware feature, * so there is no need to invalidate any TLB entries. */ void pmap_unwire(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { vm_offset_t va_next; pd_entry_t *l0, *l1, *l2; pt_entry_t *l3; PMAP_LOCK(pmap); for (; sva < eva; sva = va_next) { l0 = pmap_l0(pmap, sva); if (pmap_load(l0) == 0) { va_next = (sva + L0_SIZE) & ~L0_OFFSET; if (va_next < sva) va_next = eva; continue; } l1 = pmap_l0_to_l1(l0, sva); va_next = (sva + L1_SIZE) & ~L1_OFFSET; if (va_next < sva) va_next = eva; if (pmap_load(l1) == 0) continue; if ((pmap_load(l1) & ATTR_DESCR_MASK) == L1_BLOCK) { KASSERT(va_next <= eva, ("partial update of non-transparent 1G page " "l1 %#lx sva %#lx eva %#lx va_next %#lx", pmap_load(l1), sva, eva, va_next)); MPASS(pmap != kernel_pmap); MPASS((pmap_load(l1) & (ATTR_SW_MANAGED | ATTR_SW_WIRED)) == ATTR_SW_WIRED); pmap_clear_bits(l1, ATTR_SW_WIRED); pmap->pm_stats.wired_count -= L1_SIZE / PAGE_SIZE; continue; } va_next = (sva + L2_SIZE) & ~L2_OFFSET; if (va_next < sva) va_next = eva; l2 = pmap_l1_to_l2(l1, sva); if (pmap_load(l2) == 0) continue; if ((pmap_load(l2) & ATTR_DESCR_MASK) == L2_BLOCK) { if ((pmap_load(l2) & ATTR_SW_WIRED) == 0) panic("pmap_unwire: l2 %#jx is missing " "ATTR_SW_WIRED", (uintmax_t)pmap_load(l2)); /* * Are we unwiring the entire large page? If not, * demote the mapping and fall through. */ if (sva + L2_SIZE == va_next && eva >= va_next) { pmap_clear_bits(l2, ATTR_SW_WIRED); pmap->pm_stats.wired_count -= L2_SIZE / PAGE_SIZE; continue; } else if (pmap_demote_l2(pmap, l2, sva) == NULL) panic("pmap_unwire: demotion failed"); } KASSERT((pmap_load(l2) & ATTR_DESCR_MASK) == L2_TABLE, ("pmap_unwire: Invalid l2 entry after demotion")); if (va_next > eva) va_next = eva; for (l3 = pmap_l2_to_l3(l2, sva); sva != va_next; l3++, sva += L3_SIZE) { if (pmap_load(l3) == 0) continue; if ((pmap_load(l3) & ATTR_SW_WIRED) == 0) panic("pmap_unwire: l3 %#jx is missing " "ATTR_SW_WIRED", (uintmax_t)pmap_load(l3)); /* * ATTR_SW_WIRED must be cleared atomically. Although * the pmap lock synchronizes access to ATTR_SW_WIRED, * the System MMU may write to the entry concurrently. */ pmap_clear_bits(l3, ATTR_SW_WIRED); pmap->pm_stats.wired_count--; } } PMAP_UNLOCK(pmap); } /* * 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. * * Because the executable mappings created by this routine are copied, * it should not have to flush the instruction cache. */ 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) { struct rwlock *lock; pd_entry_t *l0, *l1, *l2, srcptepaddr; pt_entry_t *dst_pte, mask, nbits, ptetemp, *src_pte; vm_offset_t addr, end_addr, va_next; vm_page_t dst_m, dstmpte, srcmpte; PMAP_ASSERT_STAGE1(dst_pmap); PMAP_ASSERT_STAGE1(src_pmap); if (dst_addr != src_addr) return; end_addr = src_addr + len; lock = NULL; if (dst_pmap < src_pmap) { PMAP_LOCK(dst_pmap); PMAP_LOCK(src_pmap); } else { PMAP_LOCK(src_pmap); PMAP_LOCK(dst_pmap); } for (addr = src_addr; addr < end_addr; addr = va_next) { l0 = pmap_l0(src_pmap, addr); if (pmap_load(l0) == 0) { va_next = (addr + L0_SIZE) & ~L0_OFFSET; if (va_next < addr) va_next = end_addr; continue; } va_next = (addr + L1_SIZE) & ~L1_OFFSET; if (va_next < addr) va_next = end_addr; l1 = pmap_l0_to_l1(l0, addr); if (pmap_load(l1) == 0) continue; if ((pmap_load(l1) & ATTR_DESCR_MASK) == L1_BLOCK) { KASSERT(va_next <= end_addr, ("partial update of non-transparent 1G page " "l1 %#lx addr %#lx end_addr %#lx va_next %#lx", pmap_load(l1), addr, end_addr, va_next)); srcptepaddr = pmap_load(l1); l1 = pmap_l1(dst_pmap, addr); if (l1 == NULL) { if (_pmap_alloc_l3(dst_pmap, pmap_l0_pindex(addr), NULL) == NULL) break; l1 = pmap_l1(dst_pmap, addr); } else { l0 = pmap_l0(dst_pmap, addr); dst_m = PHYS_TO_VM_PAGE(pmap_load(l0) & ~ATTR_MASK); dst_m->ref_count++; } KASSERT(pmap_load(l1) == 0, ("1G mapping present in dst pmap " "l1 %#lx addr %#lx end_addr %#lx va_next %#lx", pmap_load(l1), addr, end_addr, va_next)); pmap_store(l1, srcptepaddr & ~ATTR_SW_WIRED); pmap_resident_count_inc(dst_pmap, L1_SIZE / PAGE_SIZE); continue; } va_next = (addr + L2_SIZE) & ~L2_OFFSET; if (va_next < addr) va_next = end_addr; l2 = pmap_l1_to_l2(l1, addr); srcptepaddr = pmap_load(l2); if (srcptepaddr == 0) continue; if ((srcptepaddr & ATTR_DESCR_MASK) == L2_BLOCK) { /* * We can only virtual copy whole superpages. */ if ((addr & L2_OFFSET) != 0 || addr + L2_SIZE > end_addr) continue; l2 = pmap_alloc_l2(dst_pmap, addr, &dst_m, NULL); if (l2 == NULL) break; if (pmap_load(l2) == 0 && ((srcptepaddr & ATTR_SW_MANAGED) == 0 || pmap_pv_insert_l2(dst_pmap, addr, srcptepaddr, PMAP_ENTER_NORECLAIM, &lock))) { /* * We leave the dirty bit unchanged because * managed read/write superpage mappings are * required to be dirty. However, managed * superpage mappings are not required to * have their accessed bit set, so we clear * it because we don't know if this mapping * will be used. */ srcptepaddr &= ~ATTR_SW_WIRED; if ((srcptepaddr & ATTR_SW_MANAGED) != 0) srcptepaddr &= ~ATTR_AF; pmap_store(l2, srcptepaddr); pmap_resident_count_inc(dst_pmap, L2_SIZE / PAGE_SIZE); atomic_add_long(&pmap_l2_mappings, 1); } else pmap_abort_ptp(dst_pmap, addr, dst_m); continue; } KASSERT((srcptepaddr & ATTR_DESCR_MASK) == L2_TABLE, ("pmap_copy: invalid L2 entry")); srcptepaddr &= ~ATTR_MASK; srcmpte = PHYS_TO_VM_PAGE(srcptepaddr); KASSERT(srcmpte->ref_count > 0, ("pmap_copy: source page table page is unused")); if (va_next > end_addr) va_next = end_addr; src_pte = (pt_entry_t *)PHYS_TO_DMAP(srcptepaddr); src_pte = &src_pte[pmap_l3_index(addr)]; dstmpte = NULL; for (; addr < va_next; addr += PAGE_SIZE, src_pte++) { ptetemp = pmap_load(src_pte); /* * We only virtual copy managed pages. */ if ((ptetemp & ATTR_SW_MANAGED) == 0) continue; if (dstmpte != NULL) { KASSERT(dstmpte->pindex == pmap_l2_pindex(addr), ("dstmpte pindex/addr mismatch")); dstmpte->ref_count++; } else if ((dstmpte = pmap_alloc_l3(dst_pmap, addr, NULL)) == NULL) goto out; dst_pte = (pt_entry_t *) PHYS_TO_DMAP(VM_PAGE_TO_PHYS(dstmpte)); dst_pte = &dst_pte[pmap_l3_index(addr)]; if (pmap_load(dst_pte) == 0 && pmap_try_insert_pv_entry(dst_pmap, addr, PHYS_TO_VM_PAGE(ptetemp & ~ATTR_MASK), &lock)) { /* * Clear the wired, modified, and accessed * (referenced) bits during the copy. */ mask = ATTR_AF | ATTR_SW_WIRED; nbits = 0; if ((ptetemp & ATTR_SW_DBM) != 0) nbits |= ATTR_S1_AP_RW_BIT; pmap_store(dst_pte, (ptetemp & ~mask) | nbits); pmap_resident_count_inc(dst_pmap, 1); } else { pmap_abort_ptp(dst_pmap, addr, dstmpte); goto out; } /* Have we copied all of the valid mappings? */ if (dstmpte->ref_count >= srcmpte->ref_count) break; } } out: /* * XXX This barrier may not be needed because the destination pmap is * not active. */ dsb(ishst); if (lock != NULL) rw_wunlock(lock); PMAP_UNLOCK(src_pmap); PMAP_UNLOCK(dst_pmap); } /* * 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 va = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); pagezero((void *)va); } /* * 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 va = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); if (off == 0 && size == PAGE_SIZE) pagezero((void *)va); else bzero((char *)va + off, size); } /* * 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 msrc, vm_page_t mdst) { vm_offset_t src = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(msrc)); vm_offset_t dst = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(mdst)); pagecopy((void *)src, (void *)dst); } int unmapped_buf_allowed = 1; void pmap_copy_pages(vm_page_t ma[], vm_offset_t a_offset, vm_page_t mb[], vm_offset_t b_offset, int xfersize) { void *a_cp, *b_cp; vm_page_t m_a, m_b; vm_paddr_t p_a, p_b; vm_offset_t a_pg_offset, b_pg_offset; int cnt; while (xfersize > 0) { a_pg_offset = a_offset & PAGE_MASK; m_a = ma[a_offset >> PAGE_SHIFT]; p_a = m_a->phys_addr; b_pg_offset = b_offset & PAGE_MASK; m_b = mb[b_offset >> PAGE_SHIFT]; p_b = m_b->phys_addr; cnt = min(xfersize, PAGE_SIZE - a_pg_offset); cnt = min(cnt, PAGE_SIZE - b_pg_offset); if (__predict_false(!PHYS_IN_DMAP(p_a))) { panic("!DMAP a %lx", p_a); } else { a_cp = (char *)PHYS_TO_DMAP(p_a) + a_pg_offset; } if (__predict_false(!PHYS_IN_DMAP(p_b))) { panic("!DMAP b %lx", p_b); } else { b_cp = (char *)PHYS_TO_DMAP(p_b) + b_pg_offset; } bcopy(a_cp, b_cp, cnt); a_offset += cnt; b_offset += cnt; xfersize -= cnt; } } vm_offset_t pmap_quick_enter_page(vm_page_t m) { return (PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m))); } void pmap_quick_remove_page(vm_offset_t addr) { } /* * 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_t pmap, vm_page_t m) { struct md_page *pvh; struct rwlock *lock; pv_entry_t pv; int loops = 0; boolean_t rv; KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_page_exists_quick: page %p is not managed", m)); rv = FALSE; lock = VM_PAGE_TO_PV_LIST_LOCK(m); rw_rlock(lock); TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) { if (PV_PMAP(pv) == pmap) { rv = TRUE; break; } loops++; if (loops >= 16) break; } if (!rv && loops < 16 && (m->flags & PG_FICTITIOUS) == 0) { pvh = page_to_pvh(m); TAILQ_FOREACH(pv, &pvh->pv_list, pv_next) { if (PV_PMAP(pv) == pmap) { rv = TRUE; break; } loops++; if (loops >= 16) break; } } rw_runlock(lock); return (rv); } /* * pmap_page_wired_mappings: * * Return the number of managed mappings to the given physical page * that are wired. */ int pmap_page_wired_mappings(vm_page_t m) { struct rwlock *lock; struct md_page *pvh; pmap_t pmap; pt_entry_t *pte; pv_entry_t pv; int count, lvl, md_gen, pvh_gen; if ((m->oflags & VPO_UNMANAGED) != 0) return (0); lock = VM_PAGE_TO_PV_LIST_LOCK(m); rw_rlock(lock); restart: count = 0; TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) { pmap = PV_PMAP(pv); if (!PMAP_TRYLOCK(pmap)) { md_gen = m->md.pv_gen; rw_runlock(lock); PMAP_LOCK(pmap); rw_rlock(lock); if (md_gen != m->md.pv_gen) { PMAP_UNLOCK(pmap); goto restart; } } pte = pmap_pte(pmap, pv->pv_va, &lvl); if (pte != NULL && (pmap_load(pte) & ATTR_SW_WIRED) != 0) count++; PMAP_UNLOCK(pmap); } if ((m->flags & PG_FICTITIOUS) == 0) { pvh = page_to_pvh(m); TAILQ_FOREACH(pv, &pvh->pv_list, pv_next) { pmap = PV_PMAP(pv); if (!PMAP_TRYLOCK(pmap)) { md_gen = m->md.pv_gen; pvh_gen = pvh->pv_gen; rw_runlock(lock); PMAP_LOCK(pmap); rw_rlock(lock); if (md_gen != m->md.pv_gen || pvh_gen != pvh->pv_gen) { PMAP_UNLOCK(pmap); goto restart; } } pte = pmap_pte(pmap, pv->pv_va, &lvl); if (pte != NULL && (pmap_load(pte) & ATTR_SW_WIRED) != 0) count++; PMAP_UNLOCK(pmap); } } rw_runlock(lock); return (count); } /* * Returns true if the given page is mapped individually or as part of * a 2mpage. Otherwise, returns false. */ bool pmap_page_is_mapped(vm_page_t m) { struct rwlock *lock; bool rv; if ((m->oflags & VPO_UNMANAGED) != 0) return (false); lock = VM_PAGE_TO_PV_LIST_LOCK(m); rw_rlock(lock); rv = !TAILQ_EMPTY(&m->md.pv_list) || ((m->flags & PG_FICTITIOUS) == 0 && !TAILQ_EMPTY(&page_to_pvh(m)->pv_list)); rw_runlock(lock); return (rv); } /* * Destroy all managed, non-wired mappings in the given user-space * pmap. This pmap cannot be active on any processor besides the * caller. * * This function cannot be applied to the kernel pmap. Moreover, it * is not intended for general use. It is only to be used during * process termination. Consequently, it can be implemented in ways * that make it faster than pmap_remove(). First, it can more quickly * destroy mappings by iterating over the pmap's collection of PV * entries, rather than searching the page table. Second, it doesn't * have to test and clear the page table entries atomically, because * no processor is currently accessing the user address space. In * particular, a page table entry's dirty bit won't change state once * this function starts. */ void pmap_remove_pages(pmap_t pmap) { pd_entry_t *pde; pt_entry_t *pte, tpte; struct spglist free; vm_page_t m, ml3, mt; pv_entry_t pv; struct md_page *pvh; struct pv_chunk *pc, *npc; struct rwlock *lock; int64_t bit; uint64_t inuse, bitmask; int allfree, field, freed, idx, lvl; vm_paddr_t pa; lock = NULL; SLIST_INIT(&free); PMAP_LOCK(pmap); TAILQ_FOREACH_SAFE(pc, &pmap->pm_pvchunk, pc_list, npc) { allfree = 1; freed = 0; for (field = 0; field < _NPCM; field++) { inuse = ~pc->pc_map[field] & pc_freemask[field]; while (inuse != 0) { bit = ffsl(inuse) - 1; bitmask = 1UL << bit; idx = field * 64 + bit; pv = &pc->pc_pventry[idx]; inuse &= ~bitmask; pde = pmap_pde(pmap, pv->pv_va, &lvl); KASSERT(pde != NULL, ("Attempting to remove an unmapped page")); switch(lvl) { case 1: pte = pmap_l1_to_l2(pde, pv->pv_va); tpte = pmap_load(pte); KASSERT((tpte & ATTR_DESCR_MASK) == L2_BLOCK, ("Attempting to remove an invalid " "block: %lx", tpte)); break; case 2: pte = pmap_l2_to_l3(pde, pv->pv_va); tpte = pmap_load(pte); KASSERT((tpte & ATTR_DESCR_MASK) == L3_PAGE, ("Attempting to remove an invalid " "page: %lx", tpte)); break; default: panic( "Invalid page directory level: %d", lvl); } /* * We cannot remove wired pages from a process' mapping at this time */ if (tpte & ATTR_SW_WIRED) { allfree = 0; continue; } /* Mark free */ pc->pc_map[field] |= bitmask; /* * Because this pmap is not active on other * processors, the dirty bit cannot have * changed state since we last loaded pte. */ pmap_clear(pte); pa = tpte & ~ATTR_MASK; m = PHYS_TO_VM_PAGE(pa); KASSERT(m->phys_addr == pa, ("vm_page_t %p phys_addr mismatch %016jx %016jx", m, (uintmax_t)m->phys_addr, (uintmax_t)tpte)); KASSERT((m->flags & PG_FICTITIOUS) != 0 || m < &vm_page_array[vm_page_array_size], ("pmap_remove_pages: bad pte %#jx", (uintmax_t)tpte)); /* * Update the vm_page_t clean/reference bits. */ if (pmap_pte_dirty(pmap, tpte)) { switch (lvl) { case 1: for (mt = m; mt < &m[L2_SIZE / PAGE_SIZE]; mt++) vm_page_dirty(mt); break; case 2: vm_page_dirty(m); break; } } CHANGE_PV_LIST_LOCK_TO_VM_PAGE(&lock, m); switch (lvl) { case 1: pmap_resident_count_dec(pmap, L2_SIZE / PAGE_SIZE); pvh = page_to_pvh(m); TAILQ_REMOVE(&pvh->pv_list, pv,pv_next); pvh->pv_gen++; if (TAILQ_EMPTY(&pvh->pv_list)) { for (mt = m; mt < &m[L2_SIZE / PAGE_SIZE]; mt++) if ((mt->a.flags & PGA_WRITEABLE) != 0 && TAILQ_EMPTY(&mt->md.pv_list)) vm_page_aflag_clear(mt, PGA_WRITEABLE); } ml3 = pmap_remove_pt_page(pmap, pv->pv_va); if (ml3 != NULL) { KASSERT(ml3->valid == VM_PAGE_BITS_ALL, ("pmap_remove_pages: l3 page not promoted")); pmap_resident_count_dec(pmap,1); KASSERT(ml3->ref_count == NL3PG, ("pmap_remove_pages: l3 page ref count error")); ml3->ref_count = 0; pmap_add_delayed_free_list(ml3, &free, FALSE); } break; case 2: pmap_resident_count_dec(pmap, 1); TAILQ_REMOVE(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; if ((m->a.flags & PGA_WRITEABLE) != 0 && TAILQ_EMPTY(&m->md.pv_list) && (m->flags & PG_FICTITIOUS) == 0) { pvh = page_to_pvh(m); if (TAILQ_EMPTY(&pvh->pv_list)) vm_page_aflag_clear(m, PGA_WRITEABLE); } break; } pmap_unuse_pt(pmap, pv->pv_va, pmap_load(pde), &free); freed++; } } PV_STAT(atomic_add_long(&pv_entry_frees, freed)); PV_STAT(atomic_add_int(&pv_entry_spare, freed)); PV_STAT(atomic_subtract_long(&pv_entry_count, freed)); if (allfree) { TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); free_pv_chunk(pc); } } if (lock != NULL) rw_wunlock(lock); pmap_invalidate_all(pmap); PMAP_UNLOCK(pmap); vm_page_free_pages_toq(&free, true); } /* * This is used to check if a page has been accessed or modified. */ static boolean_t pmap_page_test_mappings(vm_page_t m, boolean_t accessed, boolean_t modified) { struct rwlock *lock; pv_entry_t pv; struct md_page *pvh; pt_entry_t *pte, mask, value; pmap_t pmap; int lvl, md_gen, pvh_gen; boolean_t rv; rv = FALSE; lock = VM_PAGE_TO_PV_LIST_LOCK(m); rw_rlock(lock); restart: TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) { pmap = PV_PMAP(pv); PMAP_ASSERT_STAGE1(pmap); if (!PMAP_TRYLOCK(pmap)) { md_gen = m->md.pv_gen; rw_runlock(lock); PMAP_LOCK(pmap); rw_rlock(lock); if (md_gen != m->md.pv_gen) { PMAP_UNLOCK(pmap); goto restart; } } pte = pmap_pte(pmap, pv->pv_va, &lvl); KASSERT(lvl == 3, ("pmap_page_test_mappings: Invalid level %d", lvl)); mask = 0; value = 0; if (modified) { mask |= ATTR_S1_AP_RW_BIT; value |= ATTR_S1_AP(ATTR_S1_AP_RW); } if (accessed) { mask |= ATTR_AF | ATTR_DESCR_MASK; value |= ATTR_AF | L3_PAGE; } rv = (pmap_load(pte) & mask) == value; PMAP_UNLOCK(pmap); if (rv) goto out; } if ((m->flags & PG_FICTITIOUS) == 0) { pvh = page_to_pvh(m); TAILQ_FOREACH(pv, &pvh->pv_list, pv_next) { pmap = PV_PMAP(pv); PMAP_ASSERT_STAGE1(pmap); if (!PMAP_TRYLOCK(pmap)) { md_gen = m->md.pv_gen; pvh_gen = pvh->pv_gen; rw_runlock(lock); PMAP_LOCK(pmap); rw_rlock(lock); if (md_gen != m->md.pv_gen || pvh_gen != pvh->pv_gen) { PMAP_UNLOCK(pmap); goto restart; } } pte = pmap_pte(pmap, pv->pv_va, &lvl); KASSERT(lvl == 2, ("pmap_page_test_mappings: Invalid level %d", lvl)); mask = 0; value = 0; if (modified) { mask |= ATTR_S1_AP_RW_BIT; value |= ATTR_S1_AP(ATTR_S1_AP_RW); } if (accessed) { mask |= ATTR_AF | ATTR_DESCR_MASK; value |= ATTR_AF | L2_BLOCK; } rv = (pmap_load(pte) & mask) == value; PMAP_UNLOCK(pmap); if (rv) goto out; } } out: rw_runlock(lock); return (rv); } /* * 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) { KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_is_modified: page %p is not managed", m)); /* * If the page is not busied then this check is racy. */ if (!pmap_page_is_write_mapped(m)) return (FALSE); return (pmap_page_test_mappings(m, FALSE, TRUE)); } /* * pmap_is_prefaultable: * * Return whether or not the specified virtual address is eligible * for prefault. */ boolean_t pmap_is_prefaultable(pmap_t pmap, vm_offset_t addr) { pt_entry_t *pte; boolean_t rv; int lvl; rv = FALSE; PMAP_LOCK(pmap); pte = pmap_pte(pmap, addr, &lvl); if (pte != NULL && pmap_load(pte) != 0) { rv = TRUE; } PMAP_UNLOCK(pmap); return (rv); } /* * pmap_is_referenced: * * Return whether or not the specified physical page was referenced * in any physical maps. */ boolean_t pmap_is_referenced(vm_page_t m) { KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_is_referenced: page %p is not managed", m)); return (pmap_page_test_mappings(m, TRUE, FALSE)); } /* * Clear the write and modified bits in each of the given page's mappings. */ void pmap_remove_write(vm_page_t m) { struct md_page *pvh; pmap_t pmap; struct rwlock *lock; pv_entry_t next_pv, pv; pt_entry_t oldpte, *pte; vm_offset_t va; int lvl, md_gen, pvh_gen; KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_remove_write: page %p is not managed", m)); vm_page_assert_busied(m); if (!pmap_page_is_write_mapped(m)) return; lock = VM_PAGE_TO_PV_LIST_LOCK(m); pvh = (m->flags & PG_FICTITIOUS) != 0 ? &pv_dummy : page_to_pvh(m); rw_wlock(lock); retry: TAILQ_FOREACH_SAFE(pv, &pvh->pv_list, pv_next, next_pv) { pmap = PV_PMAP(pv); PMAP_ASSERT_STAGE1(pmap); if (!PMAP_TRYLOCK(pmap)) { pvh_gen = pvh->pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen) { PMAP_UNLOCK(pmap); goto retry; } } va = pv->pv_va; pte = pmap_pte(pmap, va, &lvl); if ((pmap_load(pte) & ATTR_SW_DBM) != 0) (void)pmap_demote_l2_locked(pmap, pte, va, &lock); KASSERT(lock == VM_PAGE_TO_PV_LIST_LOCK(m), ("inconsistent pv lock %p %p for page %p", lock, VM_PAGE_TO_PV_LIST_LOCK(m), m)); PMAP_UNLOCK(pmap); } TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) { pmap = PV_PMAP(pv); PMAP_ASSERT_STAGE1(pmap); if (!PMAP_TRYLOCK(pmap)) { pvh_gen = pvh->pv_gen; md_gen = m->md.pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen || md_gen != m->md.pv_gen) { PMAP_UNLOCK(pmap); goto retry; } } pte = pmap_pte(pmap, pv->pv_va, &lvl); oldpte = pmap_load(pte); if ((oldpte & ATTR_SW_DBM) != 0) { while (!atomic_fcmpset_64(pte, &oldpte, (oldpte | ATTR_S1_AP_RW_BIT) & ~ATTR_SW_DBM)) cpu_spinwait(); if ((oldpte & ATTR_S1_AP_RW_BIT) == ATTR_S1_AP(ATTR_S1_AP_RW)) vm_page_dirty(m); pmap_invalidate_page(pmap, pv->pv_va); } PMAP_UNLOCK(pmap); } rw_wunlock(lock); vm_page_aflag_clear(m, PGA_WRITEABLE); } /* * 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. * * As an optimization, update the page's dirty field if a modified bit is * found while counting reference bits. This opportunistic update can be * performed at low cost and can eliminate the need for some future calls * to pmap_is_modified(). However, since this function stops after * finding PMAP_TS_REFERENCED_MAX reference bits, it may not detect some * dirty pages. Those dirty pages will only be detected by a future call * to pmap_is_modified(). */ int pmap_ts_referenced(vm_page_t m) { struct md_page *pvh; pv_entry_t pv, pvf; pmap_t pmap; struct rwlock *lock; pd_entry_t *pde, tpde; pt_entry_t *pte, tpte; vm_offset_t va; vm_paddr_t pa; int cleared, lvl, md_gen, not_cleared, pvh_gen; struct spglist free; KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_ts_referenced: page %p is not managed", m)); SLIST_INIT(&free); cleared = 0; pa = VM_PAGE_TO_PHYS(m); lock = PHYS_TO_PV_LIST_LOCK(pa); pvh = (m->flags & PG_FICTITIOUS) != 0 ? &pv_dummy : page_to_pvh(m); rw_wlock(lock); retry: not_cleared = 0; if ((pvf = TAILQ_FIRST(&pvh->pv_list)) == NULL) goto small_mappings; pv = pvf; do { if (pvf == NULL) pvf = pv; pmap = PV_PMAP(pv); if (!PMAP_TRYLOCK(pmap)) { pvh_gen = pvh->pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen) { PMAP_UNLOCK(pmap); goto retry; } } va = pv->pv_va; pde = pmap_pde(pmap, pv->pv_va, &lvl); KASSERT(pde != NULL, ("pmap_ts_referenced: no l1 table found")); KASSERT(lvl == 1, ("pmap_ts_referenced: invalid pde level %d", lvl)); tpde = pmap_load(pde); KASSERT((tpde & ATTR_DESCR_MASK) == L1_TABLE, ("pmap_ts_referenced: found an invalid l1 table")); pte = pmap_l1_to_l2(pde, pv->pv_va); tpte = pmap_load(pte); if (pmap_pte_dirty(pmap, tpte)) { /* * Although "tpte" is mapping a 2MB page, because * this function is called at a 4KB page granularity, * we only update the 4KB page under test. */ vm_page_dirty(m); } if ((tpte & ATTR_AF) != 0) { /* * Since this reference bit is shared by 512 4KB pages, * it should not be cleared every time it is tested. * Apply a simple "hash" function on the physical page * number, the virtual superpage number, and the pmap * address to select one 4KB page out of the 512 on * which testing the reference bit will result in * clearing that reference bit. This function is * designed to avoid the selection of the same 4KB page * for every 2MB page mapping. * * On demotion, a mapping that hasn't been referenced * is simply destroyed. To avoid the possibility of a * subsequent page fault on a demoted wired mapping, * always leave its reference bit set. Moreover, * since the superpage is wired, the current state of * its reference bit won't affect page replacement. */ if ((((pa >> PAGE_SHIFT) ^ (pv->pv_va >> L2_SHIFT) ^ (uintptr_t)pmap) & (Ln_ENTRIES - 1)) == 0 && (tpte & ATTR_SW_WIRED) == 0) { pmap_clear_bits(pte, ATTR_AF); pmap_invalidate_page(pmap, pv->pv_va); cleared++; } else not_cleared++; } PMAP_UNLOCK(pmap); /* Rotate the PV list if it has more than one entry. */ if (pv != NULL && TAILQ_NEXT(pv, pv_next) != NULL) { TAILQ_REMOVE(&pvh->pv_list, pv, pv_next); TAILQ_INSERT_TAIL(&pvh->pv_list, pv, pv_next); pvh->pv_gen++; } if (cleared + not_cleared >= PMAP_TS_REFERENCED_MAX) goto out; } while ((pv = TAILQ_FIRST(&pvh->pv_list)) != pvf); small_mappings: if ((pvf = TAILQ_FIRST(&m->md.pv_list)) == NULL) goto out; pv = pvf; do { if (pvf == NULL) pvf = pv; pmap = PV_PMAP(pv); if (!PMAP_TRYLOCK(pmap)) { pvh_gen = pvh->pv_gen; md_gen = m->md.pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen || md_gen != m->md.pv_gen) { PMAP_UNLOCK(pmap); goto retry; } } pde = pmap_pde(pmap, pv->pv_va, &lvl); KASSERT(pde != NULL, ("pmap_ts_referenced: no l2 table found")); KASSERT(lvl == 2, ("pmap_ts_referenced: invalid pde level %d", lvl)); tpde = pmap_load(pde); KASSERT((tpde & ATTR_DESCR_MASK) == L2_TABLE, ("pmap_ts_referenced: found an invalid l2 table")); pte = pmap_l2_to_l3(pde, pv->pv_va); tpte = pmap_load(pte); if (pmap_pte_dirty(pmap, tpte)) vm_page_dirty(m); if ((tpte & ATTR_AF) != 0) { if ((tpte & ATTR_SW_WIRED) == 0) { pmap_clear_bits(pte, ATTR_AF); pmap_invalidate_page(pmap, pv->pv_va); cleared++; } else not_cleared++; } PMAP_UNLOCK(pmap); /* Rotate the PV list if it has more than one entry. */ if (pv != NULL && TAILQ_NEXT(pv, pv_next) != NULL) { TAILQ_REMOVE(&m->md.pv_list, pv, pv_next); TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; } } while ((pv = TAILQ_FIRST(&m->md.pv_list)) != pvf && cleared + not_cleared < PMAP_TS_REFERENCED_MAX); out: rw_wunlock(lock); vm_page_free_pages_toq(&free, true); return (cleared + not_cleared); } /* * Apply the given advice to the specified range of addresses within the * given pmap. Depending on the advice, clear the referenced and/or * modified flags in each mapping and set the mapped page's dirty field. */ void pmap_advise(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, int advice) { struct rwlock *lock; vm_offset_t va, va_next; vm_page_t m; pd_entry_t *l0, *l1, *l2, oldl2; pt_entry_t *l3, oldl3; PMAP_ASSERT_STAGE1(pmap); if (advice != MADV_DONTNEED && advice != MADV_FREE) return; PMAP_LOCK(pmap); for (; sva < eva; sva = va_next) { l0 = pmap_l0(pmap, sva); if (pmap_load(l0) == 0) { va_next = (sva + L0_SIZE) & ~L0_OFFSET; if (va_next < sva) va_next = eva; continue; } va_next = (sva + L1_SIZE) & ~L1_OFFSET; if (va_next < sva) va_next = eva; l1 = pmap_l0_to_l1(l0, sva); if (pmap_load(l1) == 0) continue; if ((pmap_load(l1) & ATTR_DESCR_MASK) == L1_BLOCK) { KASSERT(va_next <= eva, ("partial update of non-transparent 1G page " "l1 %#lx sva %#lx eva %#lx va_next %#lx", pmap_load(l1), sva, eva, va_next)); continue; } va_next = (sva + L2_SIZE) & ~L2_OFFSET; if (va_next < sva) va_next = eva; l2 = pmap_l1_to_l2(l1, sva); oldl2 = pmap_load(l2); if (oldl2 == 0) continue; if ((oldl2 & ATTR_DESCR_MASK) == L2_BLOCK) { if ((oldl2 & ATTR_SW_MANAGED) == 0) continue; lock = NULL; if (!pmap_demote_l2_locked(pmap, l2, sva, &lock)) { if (lock != NULL) rw_wunlock(lock); /* * The 2MB page mapping was destroyed. */ continue; } /* * Unless the page mappings are wired, remove the * mapping to a single page so that a subsequent * access may repromote. Choosing the last page * within the address range [sva, min(va_next, eva)) * generally results in more repromotions. Since the * underlying page table page is fully populated, this * removal never frees a page table page. */ if ((oldl2 & ATTR_SW_WIRED) == 0) { va = eva; if (va > va_next) va = va_next; va -= PAGE_SIZE; KASSERT(va >= sva, ("pmap_advise: no address gap")); l3 = pmap_l2_to_l3(l2, va); KASSERT(pmap_load(l3) != 0, ("pmap_advise: invalid PTE")); pmap_remove_l3(pmap, l3, va, pmap_load(l2), NULL, &lock); } if (lock != NULL) rw_wunlock(lock); } KASSERT((pmap_load(l2) & ATTR_DESCR_MASK) == L2_TABLE, ("pmap_advise: invalid L2 entry after demotion")); if (va_next > eva) va_next = eva; va = va_next; for (l3 = pmap_l2_to_l3(l2, sva); sva != va_next; l3++, sva += L3_SIZE) { oldl3 = pmap_load(l3); if ((oldl3 & (ATTR_SW_MANAGED | ATTR_DESCR_MASK)) != (ATTR_SW_MANAGED | L3_PAGE)) goto maybe_invlrng; else if (pmap_pte_dirty(pmap, oldl3)) { if (advice == MADV_DONTNEED) { /* * Future calls to pmap_is_modified() * can be avoided by making the page * dirty now. */ m = PHYS_TO_VM_PAGE(oldl3 & ~ATTR_MASK); vm_page_dirty(m); } while (!atomic_fcmpset_long(l3, &oldl3, (oldl3 & ~ATTR_AF) | ATTR_S1_AP(ATTR_S1_AP_RO))) cpu_spinwait(); } else if ((oldl3 & ATTR_AF) != 0) pmap_clear_bits(l3, ATTR_AF); else goto maybe_invlrng; if (va == va_next) va = sva; continue; maybe_invlrng: if (va != va_next) { pmap_invalidate_range(pmap, va, sva); va = va_next; } } if (va != va_next) pmap_invalidate_range(pmap, va, sva); } PMAP_UNLOCK(pmap); } /* * Clear the modify bits on the specified physical page. */ void pmap_clear_modify(vm_page_t m) { struct md_page *pvh; struct rwlock *lock; pmap_t pmap; pv_entry_t next_pv, pv; pd_entry_t *l2, oldl2; pt_entry_t *l3, oldl3; vm_offset_t va; int md_gen, pvh_gen; KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_clear_modify: page %p is not managed", m)); vm_page_assert_busied(m); if (!pmap_page_is_write_mapped(m)) return; pvh = (m->flags & PG_FICTITIOUS) != 0 ? &pv_dummy : page_to_pvh(m); lock = VM_PAGE_TO_PV_LIST_LOCK(m); rw_wlock(lock); restart: TAILQ_FOREACH_SAFE(pv, &pvh->pv_list, pv_next, next_pv) { pmap = PV_PMAP(pv); PMAP_ASSERT_STAGE1(pmap); if (!PMAP_TRYLOCK(pmap)) { pvh_gen = pvh->pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen) { PMAP_UNLOCK(pmap); goto restart; } } va = pv->pv_va; l2 = pmap_l2(pmap, va); oldl2 = pmap_load(l2); /* If oldl2 has ATTR_SW_DBM set, then it is also dirty. */ if ((oldl2 & ATTR_SW_DBM) != 0 && pmap_demote_l2_locked(pmap, l2, va, &lock) && (oldl2 & ATTR_SW_WIRED) == 0) { /* * Write protect the mapping to a single page so that * a subsequent write access may repromote. */ va += VM_PAGE_TO_PHYS(m) - (oldl2 & ~ATTR_MASK); l3 = pmap_l2_to_l3(l2, va); oldl3 = pmap_load(l3); while (!atomic_fcmpset_long(l3, &oldl3, (oldl3 & ~ATTR_SW_DBM) | ATTR_S1_AP(ATTR_S1_AP_RO))) cpu_spinwait(); vm_page_dirty(m); pmap_invalidate_page(pmap, va); } PMAP_UNLOCK(pmap); } TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) { pmap = PV_PMAP(pv); PMAP_ASSERT_STAGE1(pmap); if (!PMAP_TRYLOCK(pmap)) { md_gen = m->md.pv_gen; pvh_gen = pvh->pv_gen; rw_wunlock(lock); PMAP_LOCK(pmap); rw_wlock(lock); if (pvh_gen != pvh->pv_gen || md_gen != m->md.pv_gen) { PMAP_UNLOCK(pmap); goto restart; } } l2 = pmap_l2(pmap, pv->pv_va); l3 = pmap_l2_to_l3(l2, pv->pv_va); oldl3 = pmap_load(l3); if ((oldl3 & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) == ATTR_SW_DBM){ pmap_set_bits(l3, ATTR_S1_AP(ATTR_S1_AP_RO)); pmap_invalidate_page(pmap, pv->pv_va); } PMAP_UNLOCK(pmap); } rw_wunlock(lock); } void * pmap_mapbios(vm_paddr_t pa, vm_size_t size) { struct pmap_preinit_mapping *ppim; vm_offset_t va, offset; pd_entry_t *pde; pt_entry_t *l2; int i, lvl, l2_blocks, free_l2_count, start_idx; if (!vm_initialized) { /* * No L3 ptables so map entire L2 blocks where start VA is: * preinit_map_va + start_idx * L2_SIZE * There may be duplicate mappings (multiple VA -> same PA) but * ARM64 dcache is always PIPT so that's acceptable. */ if (size == 0) return (NULL); /* Calculate how many L2 blocks are needed for the mapping */ l2_blocks = (roundup2(pa + size, L2_SIZE) - rounddown2(pa, L2_SIZE)) >> L2_SHIFT; offset = pa & L2_OFFSET; if (preinit_map_va == 0) return (NULL); /* Map 2MiB L2 blocks from reserved VA space */ free_l2_count = 0; start_idx = -1; /* Find enough free contiguous VA space */ for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) { ppim = pmap_preinit_mapping + i; if (free_l2_count > 0 && ppim->pa != 0) { /* Not enough space here */ free_l2_count = 0; start_idx = -1; continue; } if (ppim->pa == 0) { /* Free L2 block */ if (start_idx == -1) start_idx = i; free_l2_count++; if (free_l2_count == l2_blocks) break; } } if (free_l2_count != l2_blocks) panic("%s: too many preinit mappings", __func__); va = preinit_map_va + (start_idx * L2_SIZE); for (i = start_idx; i < start_idx + l2_blocks; i++) { /* Mark entries as allocated */ ppim = pmap_preinit_mapping + i; ppim->pa = pa; ppim->va = va + offset; ppim->size = size; } /* Map L2 blocks */ pa = rounddown2(pa, L2_SIZE); for (i = 0; i < l2_blocks; i++) { pde = pmap_pde(kernel_pmap, va, &lvl); KASSERT(pde != NULL, ("pmap_mapbios: Invalid page entry, va: 0x%lx", va)); KASSERT(lvl == 1, ("pmap_mapbios: Invalid level %d", lvl)); /* Insert L2_BLOCK */ l2 = pmap_l1_to_l2(pde, va); pmap_load_store(l2, pa | ATTR_DEFAULT | ATTR_S1_XN | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK) | L2_BLOCK); va += L2_SIZE; pa += L2_SIZE; } pmap_invalidate_all(kernel_pmap); va = preinit_map_va + (start_idx * L2_SIZE); } else { /* kva_alloc may be used to map the pages */ offset = pa & PAGE_MASK; size = round_page(offset + size); va = kva_alloc(size); if (va == 0) panic("%s: Couldn't allocate KVA", __func__); pde = pmap_pde(kernel_pmap, va, &lvl); KASSERT(lvl == 2, ("pmap_mapbios: Invalid level %d", lvl)); /* L3 table is linked */ va = trunc_page(va); pa = trunc_page(pa); pmap_kenter(va, size, pa, memory_mapping_mode(pa)); } return ((void *)(va + offset)); } void pmap_unmapbios(vm_offset_t va, vm_size_t size) { struct pmap_preinit_mapping *ppim; vm_offset_t offset, tmpsize, va_trunc; pd_entry_t *pde; pt_entry_t *l2; int i, lvl, l2_blocks, block; bool preinit_map; l2_blocks = (roundup2(va + size, L2_SIZE) - rounddown2(va, L2_SIZE)) >> L2_SHIFT; KASSERT(l2_blocks > 0, ("pmap_unmapbios: invalid size %lx", size)); /* Remove preinit mapping */ preinit_map = false; block = 0; for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) { ppim = pmap_preinit_mapping + i; if (ppim->va == va) { KASSERT(ppim->size == size, ("pmap_unmapbios: size mismatch")); ppim->va = 0; ppim->pa = 0; ppim->size = 0; preinit_map = true; offset = block * L2_SIZE; va_trunc = rounddown2(va, L2_SIZE) + offset; /* Remove L2_BLOCK */ pde = pmap_pde(kernel_pmap, va_trunc, &lvl); KASSERT(pde != NULL, ("pmap_unmapbios: Invalid page entry, va: 0x%lx", va_trunc)); l2 = pmap_l1_to_l2(pde, va_trunc); pmap_clear(l2); if (block == (l2_blocks - 1)) break; block++; } } if (preinit_map) { pmap_invalidate_all(kernel_pmap); return; } /* Unmap the pages reserved with kva_alloc. */ if (vm_initialized) { offset = va & PAGE_MASK; size = round_page(offset + size); va = trunc_page(va); pde = pmap_pde(kernel_pmap, va, &lvl); KASSERT(pde != NULL, ("pmap_unmapbios: Invalid page entry, va: 0x%lx", va)); KASSERT(lvl == 2, ("pmap_unmapbios: Invalid level %d", lvl)); /* Unmap and invalidate the pages */ for (tmpsize = 0; tmpsize < size; tmpsize += PAGE_SIZE) pmap_kremove(va + tmpsize); kva_free(va, size); } } /* * Sets the memory attribute for the specified page. */ void pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma) { m->md.pv_memattr = ma; /* * If "m" is a normal page, update its direct mapping. This update * can be relied upon to perform any cache operations that are * required for data coherence. */ if ((m->flags & PG_FICTITIOUS) == 0 && pmap_change_attr(PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)), PAGE_SIZE, m->md.pv_memattr) != 0) panic("memory attribute change on the direct map failed"); } /* * Changes the specified virtual address range's memory type to that given by * the parameter "mode". The specified virtual address range must be * completely contained within either the direct map or the kernel map. If * the virtual address range is contained within the kernel map, then the * memory type for each of the corresponding ranges of the direct map is also * changed. (The corresponding ranges of the direct map are those ranges that * map the same physical pages as the specified virtual address range.) These * changes to the direct map are necessary because Intel describes the * behavior of their processors as "undefined" if two or more mappings to the * same physical page have different memory types. * * Returns zero if the change completed successfully, and either EINVAL or * ENOMEM if the change failed. Specifically, EINVAL is returned if some part * of the virtual address range was not mapped, and ENOMEM is returned if * there was insufficient memory available to complete the change. In the * latter case, the memory type may have been changed on some part of the * virtual address range or the direct map. */ int pmap_change_attr(vm_offset_t va, vm_size_t size, int mode) { int error; PMAP_LOCK(kernel_pmap); error = pmap_change_props_locked(va, size, PROT_NONE, mode); PMAP_UNLOCK(kernel_pmap); return (error); } /* * Changes the specified virtual address range's protections to those * specified by "prot". Like pmap_change_attr(), protections for aliases * in the direct map are updated as well. Protections on aliasing mappings may * be a subset of the requested protections; for example, mappings in the direct * map are never executable. */ int pmap_change_prot(vm_offset_t va, vm_size_t size, vm_prot_t prot) { int error; /* Only supported within the kernel map. */ if (va < VM_MIN_KERNEL_ADDRESS) return (EINVAL); PMAP_LOCK(kernel_pmap); error = pmap_change_props_locked(va, size, prot, -1); PMAP_UNLOCK(kernel_pmap); return (error); } static int pmap_change_props_locked(vm_offset_t va, vm_size_t size, vm_prot_t prot, int mode) { vm_offset_t base, offset, tmpva; - pt_entry_t l3, *pte, *newpte; + vm_size_t pte_size; + pt_entry_t pte, *ptep, *newpte; pt_entry_t bits, mask; int lvl, rv; PMAP_LOCK_ASSERT(kernel_pmap, MA_OWNED); base = trunc_page(va); offset = va & PAGE_MASK; size = round_page(offset + size); if (!VIRT_IN_DMAP(base) && !(base >= VM_MIN_KERNEL_ADDRESS && base < VM_MAX_KERNEL_ADDRESS)) return (EINVAL); bits = 0; mask = 0; if (mode != -1) { bits = ATTR_S1_IDX(mode); mask = ATTR_S1_IDX_MASK; if (mode == VM_MEMATTR_DEVICE) { mask |= ATTR_S1_XN; bits |= ATTR_S1_XN; } } if (prot != VM_PROT_NONE) { /* Don't mark the DMAP as executable. It never is on arm64. */ if (VIRT_IN_DMAP(base)) { prot &= ~VM_PROT_EXECUTE; /* * XXX Mark the DMAP as writable for now. We rely * on this in ddb & dtrace to insert breakpoint * instructions. */ prot |= VM_PROT_WRITE; } if ((prot & VM_PROT_WRITE) == 0) { bits |= ATTR_S1_AP(ATTR_S1_AP_RO); } if ((prot & VM_PROT_EXECUTE) == 0) { bits |= ATTR_S1_PXN; } bits |= ATTR_S1_UXN; mask |= ATTR_S1_AP_MASK | ATTR_S1_XN; } for (tmpva = base; tmpva < base + size; ) { - pte = pmap_pte(kernel_pmap, tmpva, &lvl); - if (pte == NULL) + ptep = pmap_pte(kernel_pmap, tmpva, &lvl); + if (ptep == NULL) return (EINVAL); - if ((pmap_load(pte) & mask) == bits) { + if ((pmap_load(ptep) & mask) == bits) { /* * We already have the correct attribute, * ignore this entry. */ switch (lvl) { default: panic("Invalid DMAP table level: %d\n", lvl); case 1: tmpva = (tmpva & ~L1_OFFSET) + L1_SIZE; break; case 2: tmpva = (tmpva & ~L2_OFFSET) + L2_SIZE; break; case 3: tmpva += PAGE_SIZE; break; } } else { /* * Split the entry to an level 3 table, then * set the new attribute. */ switch (lvl) { default: panic("Invalid DMAP table level: %d\n", lvl); case 1: - newpte = pmap_demote_l1(kernel_pmap, pte, + if ((tmpva & L1_OFFSET) == 0 && + (base + size - tmpva) >= L1_SIZE) { + pte_size = L1_SIZE; + break; + } + newpte = pmap_demote_l1(kernel_pmap, ptep, tmpva & ~L1_OFFSET); if (newpte == NULL) return (EINVAL); - pte = pmap_l1_to_l2(pte, tmpva); + ptep = pmap_l1_to_l2(ptep, tmpva); + /* FALLTHROUGH */ case 2: - newpte = pmap_demote_l2(kernel_pmap, pte, + if ((tmpva & L2_OFFSET) == 0 && + (base + size - tmpva) >= L2_SIZE) { + pte_size = L2_SIZE; + break; + } + newpte = pmap_demote_l2(kernel_pmap, ptep, tmpva); if (newpte == NULL) return (EINVAL); - pte = pmap_l2_to_l3(pte, tmpva); + ptep = pmap_l2_to_l3(ptep, tmpva); + /* FALLTHROUGH */ case 3: - /* Update the entry */ - l3 = pmap_load(pte); - l3 &= ~mask; - l3 |= bits; + pte_size = PAGE_SIZE; + break; + } - pmap_update_entry(kernel_pmap, pte, l3, tmpva, - PAGE_SIZE); + /* Update the entry */ + pte = pmap_load(ptep); + pte &= ~mask; + pte |= bits; - if (!VIRT_IN_DMAP(tmpva)) { - /* - * Keep the DMAP memory in sync. - */ - rv = pmap_change_props_locked( - PHYS_TO_DMAP(l3 & ~ATTR_MASK), - L3_SIZE, prot, mode); - if (rv != 0) - return (rv); - } + pmap_update_entry(kernel_pmap, ptep, pte, tmpva, + pte_size); + if (!VIRT_IN_DMAP(tmpva)) { /* - * If moving to a non-cacheable entry flush - * the cache. + * Keep the DMAP memory in sync. */ - if (mode == VM_MEMATTR_UNCACHEABLE) - cpu_dcache_wbinv_range(tmpva, L3_SIZE); - - break; + rv = pmap_change_props_locked( + PHYS_TO_DMAP(pte & ~ATTR_MASK), pte_size, + prot, mode); + if (rv != 0) + return (rv); } - tmpva += PAGE_SIZE; + + /* + * If moving to a non-cacheable entry flush + * the cache. + */ + if (mode == VM_MEMATTR_UNCACHEABLE) + cpu_dcache_wbinv_range(tmpva, pte_size); + tmpva += pte_size; } } return (0); } /* * Create an L2 table to map all addresses within an L1 mapping. */ static pt_entry_t * pmap_demote_l1(pmap_t pmap, pt_entry_t *l1, vm_offset_t va) { pt_entry_t *l2, newl2, oldl1; vm_offset_t tmpl1; vm_paddr_t l2phys, phys; vm_page_t ml2; int i; PMAP_LOCK_ASSERT(pmap, MA_OWNED); oldl1 = pmap_load(l1); KASSERT((oldl1 & ATTR_DESCR_MASK) == L1_BLOCK, ("pmap_demote_l1: Demoting a non-block entry")); KASSERT((va & L1_OFFSET) == 0, ("pmap_demote_l1: Invalid virtual address %#lx", va)); KASSERT((oldl1 & ATTR_SW_MANAGED) == 0, ("pmap_demote_l1: Level 1 table shouldn't be managed")); tmpl1 = 0; if (va <= (vm_offset_t)l1 && va + L1_SIZE > (vm_offset_t)l1) { tmpl1 = kva_alloc(PAGE_SIZE); if (tmpl1 == 0) return (NULL); } if ((ml2 = vm_page_alloc(NULL, 0, VM_ALLOC_INTERRUPT | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) { CTR2(KTR_PMAP, "pmap_demote_l1: failure for va %#lx" " in pmap %p", va, pmap); l2 = NULL; goto fail; } l2phys = VM_PAGE_TO_PHYS(ml2); l2 = (pt_entry_t *)PHYS_TO_DMAP(l2phys); /* Address the range points at */ phys = oldl1 & ~ATTR_MASK; /* The attributed from the old l1 table to be copied */ newl2 = oldl1 & ATTR_MASK; /* Create the new entries */ for (i = 0; i < Ln_ENTRIES; i++) { l2[i] = newl2 | phys; phys += L2_SIZE; } KASSERT(l2[0] == ((oldl1 & ~ATTR_DESCR_MASK) | L2_BLOCK), ("Invalid l2 page (%lx != %lx)", l2[0], (oldl1 & ~ATTR_DESCR_MASK) | L2_BLOCK)); if (tmpl1 != 0) { pmap_kenter(tmpl1, PAGE_SIZE, DMAP_TO_PHYS((vm_offset_t)l1) & ~L3_OFFSET, VM_MEMATTR_WRITE_BACK); l1 = (pt_entry_t *)(tmpl1 + ((vm_offset_t)l1 & PAGE_MASK)); } pmap_update_entry(pmap, l1, l2phys | L1_TABLE, va, PAGE_SIZE); fail: if (tmpl1 != 0) { pmap_kremove(tmpl1); kva_free(tmpl1, PAGE_SIZE); } return (l2); } static void pmap_fill_l3(pt_entry_t *firstl3, pt_entry_t newl3) { pt_entry_t *l3; for (l3 = firstl3; l3 - firstl3 < Ln_ENTRIES; l3++) { *l3 = newl3; newl3 += L3_SIZE; } } static void pmap_demote_l2_abort(pmap_t pmap, vm_offset_t va, pt_entry_t *l2, struct rwlock **lockp) { struct spglist free; SLIST_INIT(&free); (void)pmap_remove_l2(pmap, l2, va, pmap_load(pmap_l1(pmap, va)), &free, lockp); vm_page_free_pages_toq(&free, true); } /* * Create an L3 table to map all addresses within an L2 mapping. */ static pt_entry_t * pmap_demote_l2_locked(pmap_t pmap, pt_entry_t *l2, vm_offset_t va, struct rwlock **lockp) { pt_entry_t *l3, newl3, oldl2; vm_offset_t tmpl2; vm_paddr_t l3phys; vm_page_t ml3; PMAP_LOCK_ASSERT(pmap, MA_OWNED); PMAP_ASSERT_STAGE1(pmap); KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); l3 = NULL; oldl2 = pmap_load(l2); KASSERT((oldl2 & ATTR_DESCR_MASK) == L2_BLOCK, ("pmap_demote_l2: Demoting a non-block entry")); va &= ~L2_OFFSET; tmpl2 = 0; if (va <= (vm_offset_t)l2 && va + L2_SIZE > (vm_offset_t)l2) { tmpl2 = kva_alloc(PAGE_SIZE); if (tmpl2 == 0) return (NULL); } /* * Invalidate the 2MB page mapping and return "failure" if the * mapping was never accessed. */ if ((oldl2 & ATTR_AF) == 0) { KASSERT((oldl2 & ATTR_SW_WIRED) == 0, ("pmap_demote_l2: a wired mapping is missing ATTR_AF")); pmap_demote_l2_abort(pmap, va, l2, lockp); CTR2(KTR_PMAP, "pmap_demote_l2: failure for va %#lx in pmap %p", va, pmap); goto fail; } if ((ml3 = pmap_remove_pt_page(pmap, va)) == NULL) { KASSERT((oldl2 & ATTR_SW_WIRED) == 0, ("pmap_demote_l2: page table page for a wired mapping" " is missing")); /* * If the page table page is missing and the mapping * is for a kernel address, the mapping must belong to * either the direct map or the early kernel memory. * Page table pages are preallocated for every other * part of the kernel address space, so the direct map * region and early kernel memory are the only parts of the * kernel address space that must be handled here. */ KASSERT(!ADDR_IS_KERNEL(va) || VIRT_IN_DMAP(va) || (va >= VM_MIN_KERNEL_ADDRESS && va < kernel_vm_end), ("pmap_demote_l2: No saved mpte for va %#lx", va)); /* * If the 2MB page mapping belongs to the direct map * region of the kernel's address space, then the page * allocation request specifies the highest possible * priority (VM_ALLOC_INTERRUPT). Otherwise, the * priority is normal. */ ml3 = vm_page_alloc(NULL, pmap_l2_pindex(va), (VIRT_IN_DMAP(va) ? VM_ALLOC_INTERRUPT : VM_ALLOC_NORMAL) | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED); /* * If the allocation of the new page table page fails, * invalidate the 2MB page mapping and return "failure". */ if (ml3 == NULL) { pmap_demote_l2_abort(pmap, va, l2, lockp); CTR2(KTR_PMAP, "pmap_demote_l2: failure for va %#lx" " in pmap %p", va, pmap); goto fail; } if (!ADDR_IS_KERNEL(va)) { ml3->ref_count = NL3PG; pmap_resident_count_inc(pmap, 1); } } l3phys = VM_PAGE_TO_PHYS(ml3); l3 = (pt_entry_t *)PHYS_TO_DMAP(l3phys); newl3 = (oldl2 & ~ATTR_DESCR_MASK) | L3_PAGE; KASSERT((oldl2 & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) != (ATTR_S1_AP(ATTR_S1_AP_RO) | ATTR_SW_DBM), ("pmap_demote_l2: L2 entry is writeable but not dirty")); /* * If the page table page is not leftover from an earlier promotion, * or the mapping attributes have changed, (re)initialize the L3 table. * * When pmap_update_entry() clears the old L2 mapping, it (indirectly) * performs a dsb(). That dsb() ensures that the stores for filling * "l3" are visible before "l3" is added to the page table. */ if (ml3->valid == 0 || (l3[0] & ATTR_MASK) != (newl3 & ATTR_MASK)) pmap_fill_l3(l3, newl3); /* * Map the temporary page so we don't lose access to the l2 table. */ if (tmpl2 != 0) { pmap_kenter(tmpl2, PAGE_SIZE, DMAP_TO_PHYS((vm_offset_t)l2) & ~L3_OFFSET, VM_MEMATTR_WRITE_BACK); l2 = (pt_entry_t *)(tmpl2 + ((vm_offset_t)l2 & PAGE_MASK)); } /* * The spare PV entries must be reserved prior to demoting the * mapping, that is, prior to changing the PDE. Otherwise, the state * of the L2 and the PV lists will be inconsistent, which can result * in reclaim_pv_chunk() attempting to remove a PV entry from the * wrong PV list and pmap_pv_demote_l2() failing to find the expected * PV entry for the 2MB page mapping that is being demoted. */ if ((oldl2 & ATTR_SW_MANAGED) != 0) reserve_pv_entries(pmap, Ln_ENTRIES - 1, lockp); /* * Pass PAGE_SIZE so that a single TLB invalidation is performed on * the 2MB page mapping. */ pmap_update_entry(pmap, l2, l3phys | L2_TABLE, va, PAGE_SIZE); /* * Demote the PV entry. */ if ((oldl2 & ATTR_SW_MANAGED) != 0) pmap_pv_demote_l2(pmap, va, oldl2 & ~ATTR_MASK, lockp); atomic_add_long(&pmap_l2_demotions, 1); CTR3(KTR_PMAP, "pmap_demote_l2: success for va %#lx" " in pmap %p %lx", va, pmap, l3[0]); fail: if (tmpl2 != 0) { pmap_kremove(tmpl2); kva_free(tmpl2, PAGE_SIZE); } return (l3); } static pt_entry_t * pmap_demote_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t va) { struct rwlock *lock; pt_entry_t *l3; lock = NULL; l3 = pmap_demote_l2_locked(pmap, l2, va, &lock); if (lock != NULL) rw_wunlock(lock); return (l3); } /* * Perform the pmap work for mincore(2). If the page is not both referenced and * modified by this pmap, returns its physical address so that the caller can * find other mappings. */ int pmap_mincore(pmap_t pmap, vm_offset_t addr, vm_paddr_t *pap) { pt_entry_t *pte, tpte; vm_paddr_t mask, pa; int lvl, val; bool managed; PMAP_ASSERT_STAGE1(pmap); PMAP_LOCK(pmap); pte = pmap_pte(pmap, addr, &lvl); if (pte != NULL) { tpte = pmap_load(pte); switch (lvl) { case 3: mask = L3_OFFSET; break; case 2: mask = L2_OFFSET; break; case 1: mask = L1_OFFSET; break; default: panic("pmap_mincore: invalid level %d", lvl); } managed = (tpte & ATTR_SW_MANAGED) != 0; val = MINCORE_INCORE; if (lvl != 3) val |= MINCORE_PSIND(3 - lvl); if ((managed && pmap_pte_dirty(pmap, tpte)) || (!managed && (tpte & ATTR_S1_AP_RW_BIT) == ATTR_S1_AP(ATTR_S1_AP_RW))) val |= MINCORE_MODIFIED | MINCORE_MODIFIED_OTHER; if ((tpte & ATTR_AF) == ATTR_AF) val |= MINCORE_REFERENCED | MINCORE_REFERENCED_OTHER; pa = (tpte & ~ATTR_MASK) | (addr & mask); } else { managed = false; val = 0; } if ((val & (MINCORE_MODIFIED_OTHER | MINCORE_REFERENCED_OTHER)) != (MINCORE_MODIFIED_OTHER | MINCORE_REFERENCED_OTHER) && managed) { *pap = pa; } PMAP_UNLOCK(pmap); return (val); } /* * Garbage collect every ASID that is neither active on a processor nor * reserved. */ static void pmap_reset_asid_set(pmap_t pmap) { pmap_t curpmap; int asid, cpuid, epoch; struct asid_set *set; enum pmap_stage stage; set = pmap->pm_asid_set; stage = pmap->pm_stage; set = pmap->pm_asid_set; KASSERT(set != NULL, ("%s: NULL asid set", __func__)); mtx_assert(&set->asid_set_mutex, MA_OWNED); /* * Ensure that the store to asid_epoch is globally visible before the * loads from pc_curpmap are performed. */ epoch = set->asid_epoch + 1; if (epoch == INT_MAX) epoch = 0; set->asid_epoch = epoch; dsb(ishst); if (stage == PM_STAGE1) { __asm __volatile("tlbi vmalle1is"); } else { KASSERT(pmap_clean_stage2_tlbi != NULL, ("%s: Unset stage 2 tlb invalidation callback\n", __func__)); pmap_clean_stage2_tlbi(); } dsb(ish); bit_nclear(set->asid_set, ASID_FIRST_AVAILABLE, set->asid_set_size - 1); CPU_FOREACH(cpuid) { if (cpuid == curcpu) continue; if (stage == PM_STAGE1) { curpmap = pcpu_find(cpuid)->pc_curpmap; PMAP_ASSERT_STAGE1(pmap); } else { curpmap = pcpu_find(cpuid)->pc_curvmpmap; if (curpmap == NULL) continue; PMAP_ASSERT_STAGE2(pmap); } KASSERT(curpmap->pm_asid_set == set, ("Incorrect set")); asid = COOKIE_TO_ASID(curpmap->pm_cookie); if (asid == -1) continue; bit_set(set->asid_set, asid); curpmap->pm_cookie = COOKIE_FROM(asid, epoch); } } /* * Allocate a new ASID for the specified pmap. */ static void pmap_alloc_asid(pmap_t pmap) { struct asid_set *set; int new_asid; set = pmap->pm_asid_set; KASSERT(set != NULL, ("%s: NULL asid set", __func__)); mtx_lock_spin(&set->asid_set_mutex); /* * While this processor was waiting to acquire the asid set mutex, * pmap_reset_asid_set() running on another processor might have * updated this pmap's cookie to the current epoch. In which case, we * don't need to allocate a new ASID. */ if (COOKIE_TO_EPOCH(pmap->pm_cookie) == set->asid_epoch) goto out; bit_ffc_at(set->asid_set, set->asid_next, set->asid_set_size, &new_asid); if (new_asid == -1) { bit_ffc_at(set->asid_set, ASID_FIRST_AVAILABLE, set->asid_next, &new_asid); if (new_asid == -1) { pmap_reset_asid_set(pmap); bit_ffc_at(set->asid_set, ASID_FIRST_AVAILABLE, set->asid_set_size, &new_asid); KASSERT(new_asid != -1, ("ASID allocation failure")); } } bit_set(set->asid_set, new_asid); set->asid_next = new_asid + 1; pmap->pm_cookie = COOKIE_FROM(new_asid, set->asid_epoch); out: mtx_unlock_spin(&set->asid_set_mutex); } /* * Compute the value that should be stored in ttbr0 to activate the specified * pmap. This value may change from time to time. */ uint64_t pmap_to_ttbr0(pmap_t pmap) { return (ASID_TO_OPERAND(COOKIE_TO_ASID(pmap->pm_cookie)) | pmap->pm_ttbr); } static bool pmap_activate_int(pmap_t pmap) { struct asid_set *set; int epoch; KASSERT(PCPU_GET(curpmap) != NULL, ("no active pmap")); KASSERT(pmap != kernel_pmap, ("kernel pmap activation")); if ((pmap->pm_stage == PM_STAGE1 && pmap == PCPU_GET(curpmap)) || (pmap->pm_stage == PM_STAGE2 && pmap == PCPU_GET(curvmpmap))) { /* * Handle the possibility that the old thread was preempted * after an "ic" or "tlbi" instruction but before it performed * a "dsb" instruction. If the old thread migrates to a new * processor, its completion of a "dsb" instruction on that * new processor does not guarantee that the "ic" or "tlbi" * instructions performed on the old processor have completed. */ dsb(ish); return (false); } set = pmap->pm_asid_set; KASSERT(set != NULL, ("%s: NULL asid set", __func__)); /* * Ensure that the store to curpmap is globally visible before the * load from asid_epoch is performed. */ if (pmap->pm_stage == PM_STAGE1) PCPU_SET(curpmap, pmap); else PCPU_SET(curvmpmap, pmap); dsb(ish); epoch = COOKIE_TO_EPOCH(pmap->pm_cookie); if (epoch >= 0 && epoch != set->asid_epoch) pmap_alloc_asid(pmap); if (pmap->pm_stage == PM_STAGE1) { set_ttbr0(pmap_to_ttbr0(pmap)); if (PCPU_GET(bcast_tlbi_workaround) != 0) invalidate_local_icache(); } return (true); } void pmap_activate_vm(pmap_t pmap) { PMAP_ASSERT_STAGE2(pmap); (void)pmap_activate_int(pmap); } void pmap_activate(struct thread *td) { pmap_t pmap; pmap = vmspace_pmap(td->td_proc->p_vmspace); PMAP_ASSERT_STAGE1(pmap); critical_enter(); (void)pmap_activate_int(pmap); critical_exit(); } /* * To eliminate the unused parameter "old", we would have to add an instruction * to cpu_switch(). */ struct pcb * pmap_switch(struct thread *old __unused, struct thread *new) { pcpu_bp_harden bp_harden; struct pcb *pcb; /* Store the new curthread */ PCPU_SET(curthread, new); /* And the new pcb */ pcb = new->td_pcb; PCPU_SET(curpcb, pcb); /* * TODO: We may need to flush the cache here if switching * to a user process. */ if (pmap_activate_int(vmspace_pmap(new->td_proc->p_vmspace))) { /* * Stop userspace from training the branch predictor against * other processes. This will call into a CPU specific * function that clears the branch predictor state. */ bp_harden = PCPU_GET(bp_harden); if (bp_harden != NULL) bp_harden(); } return (pcb); } void pmap_sync_icache(pmap_t pmap, vm_offset_t va, vm_size_t sz) { PMAP_ASSERT_STAGE1(pmap); KASSERT(ADDR_IS_CANONICAL(va), ("%s: Address not in canonical form: %lx", __func__, va)); if (ADDR_IS_KERNEL(va)) { cpu_icache_sync_range(va, sz); } else { u_int len, offset; vm_paddr_t pa; /* Find the length of data in this page to flush */ offset = va & PAGE_MASK; len = imin(PAGE_SIZE - offset, sz); while (sz != 0) { /* Extract the physical address & find it in the DMAP */ pa = pmap_extract(pmap, va); if (pa != 0) cpu_icache_sync_range(PHYS_TO_DMAP(pa), len); /* Move to the next page */ sz -= len; va += len; /* Set the length for the next iteration */ len = imin(PAGE_SIZE, sz); } } } static int pmap_stage2_fault(pmap_t pmap, uint64_t esr, uint64_t far) { pd_entry_t *pdep; pt_entry_t *ptep, pte; int rv, lvl, dfsc; PMAP_ASSERT_STAGE2(pmap); rv = KERN_FAILURE; /* Data and insn aborts use same encoding for FSC field. */ dfsc = esr & ISS_DATA_DFSC_MASK; switch (dfsc) { case ISS_DATA_DFSC_TF_L0: case ISS_DATA_DFSC_TF_L1: case ISS_DATA_DFSC_TF_L2: case ISS_DATA_DFSC_TF_L3: PMAP_LOCK(pmap); pdep = pmap_pde(pmap, far, &lvl); if (pdep == NULL || lvl != (dfsc - ISS_DATA_DFSC_TF_L1)) { PMAP_LOCK(pmap); break; } switch (lvl) { case 0: ptep = pmap_l0_to_l1(pdep, far); break; case 1: ptep = pmap_l1_to_l2(pdep, far); break; case 2: ptep = pmap_l2_to_l3(pdep, far); break; default: panic("%s: Invalid pde level %d", __func__,lvl); } goto fault_exec; case ISS_DATA_DFSC_AFF_L1: case ISS_DATA_DFSC_AFF_L2: case ISS_DATA_DFSC_AFF_L3: PMAP_LOCK(pmap); ptep = pmap_pte(pmap, far, &lvl); fault_exec: if (ptep != NULL && (pte = pmap_load(ptep)) != 0) { if (icache_vmid) { pmap_invalidate_vpipt_icache(); } else { /* * If accessing an executable page invalidate * the I-cache so it will be valid when we * continue execution in the guest. The D-cache * is assumed to already be clean to the Point * of Coherency. */ if ((pte & ATTR_S2_XN_MASK) != ATTR_S2_XN(ATTR_S2_XN_NONE)) { invalidate_icache(); } } pmap_set_bits(ptep, ATTR_AF | ATTR_DESCR_VALID); rv = KERN_SUCCESS; } PMAP_UNLOCK(pmap); break; } return (rv); } int pmap_fault(pmap_t pmap, uint64_t esr, uint64_t far) { pt_entry_t pte, *ptep; register_t intr; uint64_t ec, par; int lvl, rv; rv = KERN_FAILURE; ec = ESR_ELx_EXCEPTION(esr); switch (ec) { case EXCP_INSN_ABORT_L: case EXCP_INSN_ABORT: case EXCP_DATA_ABORT_L: case EXCP_DATA_ABORT: break; default: return (rv); } if (pmap->pm_stage == PM_STAGE2) return (pmap_stage2_fault(pmap, esr, far)); /* Data and insn aborts use same encoding for FSC field. */ switch (esr & ISS_DATA_DFSC_MASK) { case ISS_DATA_DFSC_AFF_L1: case ISS_DATA_DFSC_AFF_L2: case ISS_DATA_DFSC_AFF_L3: PMAP_LOCK(pmap); ptep = pmap_pte(pmap, far, &lvl); if (ptep != NULL) { pmap_set_bits(ptep, ATTR_AF); rv = KERN_SUCCESS; /* * XXXMJ as an optimization we could mark the entry * dirty if this is a write fault. */ } PMAP_UNLOCK(pmap); break; case ISS_DATA_DFSC_PF_L1: case ISS_DATA_DFSC_PF_L2: case ISS_DATA_DFSC_PF_L3: if ((ec != EXCP_DATA_ABORT_L && ec != EXCP_DATA_ABORT) || (esr & ISS_DATA_WnR) == 0) return (rv); PMAP_LOCK(pmap); ptep = pmap_pte(pmap, far, &lvl); if (ptep != NULL && ((pte = pmap_load(ptep)) & ATTR_SW_DBM) != 0) { if ((pte & ATTR_S1_AP_RW_BIT) == ATTR_S1_AP(ATTR_S1_AP_RO)) { pmap_clear_bits(ptep, ATTR_S1_AP_RW_BIT); pmap_invalidate_page(pmap, far); } rv = KERN_SUCCESS; } PMAP_UNLOCK(pmap); break; case ISS_DATA_DFSC_TF_L0: case ISS_DATA_DFSC_TF_L1: case ISS_DATA_DFSC_TF_L2: case ISS_DATA_DFSC_TF_L3: /* * Retry the translation. A break-before-make sequence can * produce a transient fault. */ if (pmap == kernel_pmap) { /* * The translation fault may have occurred within a * critical section. Therefore, we must check the * address without acquiring the kernel pmap's lock. */ if (pmap_klookup(far, NULL)) rv = KERN_SUCCESS; } else { PMAP_LOCK(pmap); /* Ask the MMU to check the address. */ intr = intr_disable(); par = arm64_address_translate_s1e0r(far); intr_restore(intr); PMAP_UNLOCK(pmap); /* * If the translation was successful, then we can * return success to the trap handler. */ if (PAR_SUCCESS(par)) rv = KERN_SUCCESS; } break; } return (rv); } /* * Increase the starting virtual address of the given mapping if a * different alignment might result in more superpage mappings. */ void pmap_align_superpage(vm_object_t object, vm_ooffset_t offset, vm_offset_t *addr, vm_size_t size) { vm_offset_t superpage_offset; if (size < L2_SIZE) return; if (object != NULL && (object->flags & OBJ_COLORED) != 0) offset += ptoa(object->pg_color); superpage_offset = offset & L2_OFFSET; if (size - ((L2_SIZE - superpage_offset) & L2_OFFSET) < L2_SIZE || (*addr & L2_OFFSET) == superpage_offset) return; if ((*addr & L2_OFFSET) < superpage_offset) *addr = (*addr & ~L2_OFFSET) + superpage_offset; else *addr = ((*addr + L2_OFFSET) & ~L2_OFFSET) + superpage_offset; } /** * Get the kernel virtual address of a set of physical pages. If there are * physical addresses not covered by the DMAP perform a transient mapping * that will be removed when calling pmap_unmap_io_transient. * * \param page The pages the caller wishes to obtain the virtual * address on the kernel memory map. * \param vaddr On return contains the kernel virtual memory address * of the pages passed in the page parameter. * \param count Number of pages passed in. * \param can_fault TRUE if the thread using the mapped pages can take * page faults, FALSE otherwise. * * \returns TRUE if the caller must call pmap_unmap_io_transient when * finished or FALSE otherwise. * */ boolean_t pmap_map_io_transient(vm_page_t page[], vm_offset_t vaddr[], int count, boolean_t can_fault) { vm_paddr_t paddr; boolean_t needs_mapping; int error, i; /* * Allocate any KVA space that we need, this is done in a separate * loop to prevent calling vmem_alloc while pinned. */ needs_mapping = FALSE; for (i = 0; i < count; i++) { paddr = VM_PAGE_TO_PHYS(page[i]); if (__predict_false(!PHYS_IN_DMAP(paddr))) { error = vmem_alloc(kernel_arena, PAGE_SIZE, M_BESTFIT | M_WAITOK, &vaddr[i]); KASSERT(error == 0, ("vmem_alloc failed: %d", error)); needs_mapping = TRUE; } else { vaddr[i] = PHYS_TO_DMAP(paddr); } } /* Exit early if everything is covered by the DMAP */ if (!needs_mapping) return (FALSE); if (!can_fault) sched_pin(); for (i = 0; i < count; i++) { paddr = VM_PAGE_TO_PHYS(page[i]); if (!PHYS_IN_DMAP(paddr)) { panic( "pmap_map_io_transient: TODO: Map out of DMAP data"); } } return (needs_mapping); } void pmap_unmap_io_transient(vm_page_t page[], vm_offset_t vaddr[], int count, boolean_t can_fault) { vm_paddr_t paddr; int i; if (!can_fault) sched_unpin(); for (i = 0; i < count; i++) { paddr = VM_PAGE_TO_PHYS(page[i]); if (!PHYS_IN_DMAP(paddr)) { panic("ARM64TODO: pmap_unmap_io_transient: Unmap data"); } } } boolean_t pmap_is_valid_memattr(pmap_t pmap __unused, vm_memattr_t mode) { return (mode >= VM_MEMATTR_DEVICE && mode <= VM_MEMATTR_WRITE_THROUGH); } /* * Track a range of the kernel's virtual address space that is contiguous * in various mapping attributes. */ struct pmap_kernel_map_range { vm_offset_t sva; pt_entry_t attrs; int l3pages; int l3contig; int l2blocks; int l1blocks; }; static void sysctl_kmaps_dump(struct sbuf *sb, struct pmap_kernel_map_range *range, vm_offset_t eva) { const char *mode; int index; if (eva <= range->sva) return; index = range->attrs & ATTR_S1_IDX_MASK; switch (index) { case ATTR_S1_IDX(VM_MEMATTR_DEVICE): mode = "DEV"; break; case ATTR_S1_IDX(VM_MEMATTR_UNCACHEABLE): mode = "UC"; break; case ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK): mode = "WB"; break; case ATTR_S1_IDX(VM_MEMATTR_WRITE_THROUGH): mode = "WT"; break; default: printf( "%s: unknown memory type %x for range 0x%016lx-0x%016lx\n", __func__, index, range->sva, eva); mode = "??"; break; } sbuf_printf(sb, "0x%016lx-0x%016lx r%c%c%c %3s %d %d %d %d\n", range->sva, eva, (range->attrs & ATTR_S1_AP_RW_BIT) == ATTR_S1_AP_RW ? 'w' : '-', (range->attrs & ATTR_S1_PXN) != 0 ? '-' : 'x', (range->attrs & ATTR_S1_AP_USER) != 0 ? 'u' : 's', mode, range->l1blocks, range->l2blocks, range->l3contig, range->l3pages); /* Reset to sentinel value. */ range->sva = 0xfffffffffffffffful; } /* * Determine whether the attributes specified by a page table entry match those * being tracked by the current range. */ static bool sysctl_kmaps_match(struct pmap_kernel_map_range *range, pt_entry_t attrs) { return (range->attrs == attrs); } static void sysctl_kmaps_reinit(struct pmap_kernel_map_range *range, vm_offset_t va, pt_entry_t attrs) { memset(range, 0, sizeof(*range)); range->sva = va; range->attrs = attrs; } /* * Given a leaf PTE, derive the mapping's attributes. If they do not match * those of the current run, dump the address range and its attributes, and * begin a new run. */ static void sysctl_kmaps_check(struct sbuf *sb, struct pmap_kernel_map_range *range, vm_offset_t va, pd_entry_t l0e, pd_entry_t l1e, pd_entry_t l2e, pt_entry_t l3e) { pt_entry_t attrs; attrs = l0e & (ATTR_S1_AP_MASK | ATTR_S1_XN); attrs |= l1e & (ATTR_S1_AP_MASK | ATTR_S1_XN); if ((l1e & ATTR_DESCR_MASK) == L1_BLOCK) attrs |= l1e & ATTR_S1_IDX_MASK; attrs |= l2e & (ATTR_S1_AP_MASK | ATTR_S1_XN); if ((l2e & ATTR_DESCR_MASK) == L2_BLOCK) attrs |= l2e & ATTR_S1_IDX_MASK; attrs |= l3e & (ATTR_S1_AP_MASK | ATTR_S1_XN | ATTR_S1_IDX_MASK); if (range->sva > va || !sysctl_kmaps_match(range, attrs)) { sysctl_kmaps_dump(sb, range, va); sysctl_kmaps_reinit(range, va, attrs); } } static int sysctl_kmaps(SYSCTL_HANDLER_ARGS) { struct pmap_kernel_map_range range; struct sbuf sbuf, *sb; pd_entry_t l0e, *l1, l1e, *l2, l2e; pt_entry_t *l3, l3e; vm_offset_t sva; vm_paddr_t pa; int error, i, j, k, l; error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); sb = &sbuf; sbuf_new_for_sysctl(sb, NULL, PAGE_SIZE, req); /* Sentinel value. */ range.sva = 0xfffffffffffffffful; /* * Iterate over the kernel page tables without holding the kernel pmap * lock. Kernel page table pages are never freed, so at worst we will * observe inconsistencies in the output. */ for (sva = 0xffff000000000000ul, i = pmap_l0_index(sva); i < Ln_ENTRIES; i++) { if (i == pmap_l0_index(DMAP_MIN_ADDRESS)) sbuf_printf(sb, "\nDirect map:\n"); else if (i == pmap_l0_index(VM_MIN_KERNEL_ADDRESS)) sbuf_printf(sb, "\nKernel map:\n"); l0e = kernel_pmap->pm_l0[i]; if ((l0e & ATTR_DESCR_VALID) == 0) { sysctl_kmaps_dump(sb, &range, sva); sva += L0_SIZE; continue; } pa = l0e & ~ATTR_MASK; l1 = (pd_entry_t *)PHYS_TO_DMAP(pa); for (j = pmap_l1_index(sva); j < Ln_ENTRIES; j++) { l1e = l1[j]; if ((l1e & ATTR_DESCR_VALID) == 0) { sysctl_kmaps_dump(sb, &range, sva); sva += L1_SIZE; continue; } if ((l1e & ATTR_DESCR_MASK) == L1_BLOCK) { sysctl_kmaps_check(sb, &range, sva, l0e, l1e, 0, 0); range.l1blocks++; sva += L1_SIZE; continue; } pa = l1e & ~ATTR_MASK; l2 = (pd_entry_t *)PHYS_TO_DMAP(pa); for (k = pmap_l2_index(sva); k < Ln_ENTRIES; k++) { l2e = l2[k]; if ((l2e & ATTR_DESCR_VALID) == 0) { sysctl_kmaps_dump(sb, &range, sva); sva += L2_SIZE; continue; } if ((l2e & ATTR_DESCR_MASK) == L2_BLOCK) { sysctl_kmaps_check(sb, &range, sva, l0e, l1e, l2e, 0); range.l2blocks++; sva += L2_SIZE; continue; } pa = l2e & ~ATTR_MASK; l3 = (pt_entry_t *)PHYS_TO_DMAP(pa); for (l = pmap_l3_index(sva); l < Ln_ENTRIES; l++, sva += L3_SIZE) { l3e = l3[l]; if ((l3e & ATTR_DESCR_VALID) == 0) { sysctl_kmaps_dump(sb, &range, sva); continue; } sysctl_kmaps_check(sb, &range, sva, l0e, l1e, l2e, l3e); if ((l3e & ATTR_CONTIGUOUS) != 0) range.l3contig += l % 16 == 0 ? 1 : 0; else range.l3pages++; } } } } error = sbuf_finish(sb); sbuf_delete(sb); return (error); } SYSCTL_OID(_vm_pmap, OID_AUTO, kernel_maps, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_SKIP, NULL, 0, sysctl_kmaps, "A", "Dump kernel address layout");