2 * Copyright (c) 2006 The DragonFly Project. All rights reserved.
3 * Copyright (c) 1991 Regents of the University of California.
5 * Copyright (c) 1994 John S. Dyson
7 * Copyright (c) 1994 David Greenman
9 * Copyright (c) 2004-2006 Matthew Dillon
10 * All rights reserved.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in
20 * the documentation and/or other materials provided with the
22 * 3. Neither the name of The DragonFly Project nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific, prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
29 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
30 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
31 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
32 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
33 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
34 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
35 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
36 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
40 * $FreeBSD: src/sys/i386/i386/pmap.c,v 1.250.2.18 2002/03/06 22:48:53 silby Exp $
41 * $DragonFly: src/sys/platform/vkernel/platform/pmap.c,v 1.29 2008/05/09 07:24:47 dillon Exp $
44 * NOTE: PMAP_INVAL_ADD: In pc32 this function is called prior to adjusting
45 * the PTE in the page table, because a cpu synchronization might be required.
46 * The actual invalidation is delayed until the following call or flush. In
47 * the VKERNEL build this function is called prior to adjusting the PTE and
48 * invalidates the table synchronously (not delayed), and is not SMP safe
52 #include <sys/types.h>
53 #include <sys/systm.h>
54 #include <sys/kernel.h>
57 #include <sys/vkernel.h>
59 #include <sys/thread.h>
61 #include <sys/vmspace.h>
64 #include <vm/vm_page.h>
65 #include <vm/vm_extern.h>
66 #include <vm/vm_kern.h>
67 #include <vm/vm_object.h>
68 #include <vm/vm_zone.h>
69 #include <vm/vm_pageout.h>
71 #include <machine/md_var.h>
72 #include <machine/pcb.h>
73 #include <machine/pmap_inval.h>
74 #include <machine/globaldata.h>
76 #include <sys/sysref2.h>
80 struct pmap kernel_pmap;
82 static struct vm_zone pvzone;
83 static struct vm_object pvzone_obj;
84 static TAILQ_HEAD(,pmap) pmap_list = TAILQ_HEAD_INITIALIZER(pmap_list);
85 static int pv_entry_count;
86 static int pv_entry_max;
87 static int pv_entry_high_water;
88 static int pmap_pagedaemon_waken;
89 static boolean_t pmap_initialized = FALSE;
90 static int protection_codes[8];
92 static void i386_protection_init(void);
93 static void pmap_remove_all(vm_page_t m);
94 static int pmap_release_free_page(struct pmap *pmap, vm_page_t p);
97 #ifndef PMAP_SHPGPERPROC
98 #define PMAP_SHPGPERPROC 200
101 #define pmap_pde(m, v) (&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT]))
103 #define pte_prot(m, p) \
104 (protection_codes[p & (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)])
110 struct pv_entry *pvinit;
112 for (i = 0; i < vm_page_array_size; i++) {
115 m = &vm_page_array[i];
116 TAILQ_INIT(&m->md.pv_list);
117 m->md.pv_list_count = 0;
120 i = vm_page_array_size;
123 pvinit = (struct pv_entry *)kmem_alloc(&kernel_map, i*sizeof(*pvinit));
124 zbootinit(&pvzone, "PV ENTRY", sizeof(*pvinit), pvinit, i);
125 pmap_initialized = TRUE;
131 int shpgperproc = PMAP_SHPGPERPROC;
133 TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
134 pv_entry_max = shpgperproc * maxproc + vm_page_array_size;
135 TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
136 pv_entry_high_water = 9 * (pv_entry_max / 10);
137 zinitna(&pvzone, &pvzone_obj, NULL, 0, pv_entry_max, ZONE_INTERRUPT, 1);
141 * Bootstrap the kernel_pmap so it can be used with pmap_enter().
143 * NOTE! pm_pdir for the kernel pmap is offset so VA's translate
144 * directly into PTD indexes (PTA is also offset for the same reason).
145 * This is necessary because, for now, KVA is not mapped at address 0.
147 * Page table pages are not managed like they are in normal pmaps, so
148 * no pteobj is needed.
153 vm_pindex_t i = (vm_offset_t)KernelPTD >> PAGE_SHIFT;
155 kernel_pmap.pm_pdir = KernelPTD - (KvaStart >> SEG_SHIFT);
156 kernel_pmap.pm_pdirpte = KernelPTA[i];
157 kernel_pmap.pm_count = 1;
158 kernel_pmap.pm_active = (cpumask_t)-1;
159 TAILQ_INIT(&kernel_pmap.pm_pvlist);
160 i386_protection_init();
164 * Initialize pmap0/vmspace0 . Since process 0 never enters user mode we
165 * just dummy it up so it works well enough for fork().
167 * In DragonFly, process pmaps may only be used to manipulate user address
168 * space, never kernel address space.
171 pmap_pinit0(struct pmap *pmap)
176 /************************************************************************
177 * Procedures to manage whole physical maps *
178 ************************************************************************
180 * Initialize a preallocated and zeroed pmap structure,
181 * such as one in a vmspace structure.
184 pmap_pinit(struct pmap *pmap)
190 * No need to allocate page table space yet but we do need a valid
191 * page directory table.
193 if (pmap->pm_pdir == NULL) {
195 (pd_entry_t *)kmem_alloc_pageable(&kernel_map, PAGE_SIZE);
199 * allocate object for the pte array and page directory
201 npages = VPTE_PAGETABLE_SIZE +
202 (VM_MAX_USER_ADDRESS / PAGE_SIZE) * sizeof(vpte_t);
203 npages = (npages + PAGE_MASK) / PAGE_SIZE;
205 if (pmap->pm_pteobj == NULL)
206 pmap->pm_pteobj = vm_object_allocate(OBJT_DEFAULT, npages);
207 pmap->pm_pdindex = npages - 1;
210 * allocate the page directory page
212 ptdpg = vm_page_grab(pmap->pm_pteobj, pmap->pm_pdindex,
213 VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
215 ptdpg->wire_count = 1;
216 ++vmstats.v_wire_count;
218 /* not usually mapped */
219 vm_page_flag_clear(ptdpg, PG_MAPPED | PG_BUSY);
220 ptdpg->valid = VM_PAGE_BITS_ALL;
222 pmap_kenter((vm_offset_t)pmap->pm_pdir, VM_PAGE_TO_PHYS(ptdpg));
223 pmap->pm_pdirpte = KernelPTA[(vm_offset_t)pmap->pm_pdir >> PAGE_SHIFT];
224 if ((ptdpg->flags & PG_ZERO) == 0)
225 bzero(pmap->pm_pdir, PAGE_SIZE);
229 pmap->pm_ptphint = NULL;
230 pmap->pm_cpucachemask = 0;
231 TAILQ_INIT(&pmap->pm_pvlist);
232 bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
233 pmap->pm_stats.resident_count = 1;
237 * Clean up a pmap structure so it can be physically freed
240 pmap_puninit(pmap_t pmap)
243 kmem_free(&kernel_map, (vm_offset_t)pmap->pm_pdir, PAGE_SIZE);
244 pmap->pm_pdir = NULL;
246 if (pmap->pm_pteobj) {
247 vm_object_deallocate(pmap->pm_pteobj);
248 pmap->pm_pteobj = NULL;
254 * Wire in kernel global address entries. To avoid a race condition
255 * between pmap initialization and pmap_growkernel, this procedure
256 * adds the pmap to the master list (which growkernel scans to update),
257 * then copies the template.
259 * In a virtual kernel there are no kernel global address entries.
262 pmap_pinit2(struct pmap *pmap)
265 TAILQ_INSERT_TAIL(&pmap_list, pmap, pm_pmnode);
270 * Release all resources held by the given physical map.
272 * Should only be called if the map contains no valid mappings.
274 static int pmap_release_callback(struct vm_page *p, void *data);
277 pmap_release(struct pmap *pmap)
279 struct mdglobaldata *gd = mdcpu;
280 vm_object_t object = pmap->pm_pteobj;
281 struct rb_vm_page_scan_info info;
283 KKASSERT(pmap != &kernel_pmap);
285 #if defined(DIAGNOSTIC)
286 if (object->ref_count != 1)
287 panic("pmap_release: pteobj reference count != 1");
290 * Once we destroy the page table, the mapping becomes invalid.
291 * Don't waste time doing a madvise to invalidate the mapping, just
292 * set cpucachemask to 0.
294 if (pmap->pm_pdir == gd->gd_PT1pdir) {
295 gd->gd_PT1pdir = NULL;
297 /* madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL); */
299 if (pmap->pm_pdir == gd->gd_PT2pdir) {
300 gd->gd_PT2pdir = NULL;
302 /* madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL); */
304 if (pmap->pm_pdir == gd->gd_PT3pdir) {
305 gd->gd_PT3pdir = NULL;
307 /* madvise(gd->gd_PT3map, SEG_SIZE, MADV_INVAL); */
311 info.object = object;
313 TAILQ_REMOVE(&pmap_list, pmap, pm_pmnode);
320 info.limit = object->generation;
322 vm_page_rb_tree_RB_SCAN(&object->rb_memq, NULL,
323 pmap_release_callback, &info);
324 if (info.error == 0 && info.mpte) {
325 if (!pmap_release_free_page(pmap, info.mpte))
329 } while (info.error);
332 * Leave the KVA reservation for pm_pdir cached for later reuse.
334 pmap->pm_pdirpte = 0;
335 pmap->pm_cpucachemask = 0;
339 * Callback to release a page table page backing a directory
343 pmap_release_callback(struct vm_page *p, void *data)
345 struct rb_vm_page_scan_info *info = data;
347 if (p->pindex == info->pmap->pm_pdindex) {
351 if (!pmap_release_free_page(info->pmap, p)) {
355 if (info->object->generation != info->limit) {
363 * Retire the given physical map from service. Should only be called if
364 * the map contains no valid mappings.
367 pmap_destroy(pmap_t pmap)
374 count = --pmap->pm_count;
377 panic("destroying a pmap is not yet implemented");
382 * Add a reference to the specified pmap.
385 pmap_reference(pmap_t pmap)
392 /************************************************************************
393 * VMSPACE MANAGEMENT *
394 ************************************************************************
396 * The VMSPACE management we do in our virtual kernel must be reflected
397 * in the real kernel. This is accomplished by making vmspace system
398 * calls to the real kernel.
401 cpu_vmspace_alloc(struct vmspace *vm)
406 #define LAST_EXTENT (VM_MAX_USER_ADDRESS - 0x80000000)
408 if (vmspace_create(&vm->vm_pmap, 0, NULL) < 0)
409 panic("vmspace_create() failed");
411 rp = vmspace_mmap(&vm->vm_pmap, (void *)0x00000000, 0x40000000,
412 PROT_READ|PROT_WRITE,
413 MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED,
415 if (rp == MAP_FAILED)
416 panic("vmspace_mmap: failed1");
417 vmspace_mcontrol(&vm->vm_pmap, (void *)0x00000000, 0x40000000,
419 rp = vmspace_mmap(&vm->vm_pmap, (void *)0x40000000, 0x40000000,
420 PROT_READ|PROT_WRITE,
421 MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED,
422 MemImageFd, 0x40000000);
423 if (rp == MAP_FAILED)
424 panic("vmspace_mmap: failed2");
425 vmspace_mcontrol(&vm->vm_pmap, (void *)0x40000000, 0x40000000,
427 rp = vmspace_mmap(&vm->vm_pmap, (void *)0x80000000, LAST_EXTENT,
428 PROT_READ|PROT_WRITE,
429 MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED,
430 MemImageFd, 0x80000000);
431 vmspace_mcontrol(&vm->vm_pmap, (void *)0x80000000, LAST_EXTENT,
433 if (rp == MAP_FAILED)
434 panic("vmspace_mmap: failed3");
436 r = vmspace_mcontrol(&vm->vm_pmap, (void *)0x00000000, 0x40000000,
437 MADV_SETMAP, vmspace_pmap(vm)->pm_pdirpte);
439 panic("vmspace_mcontrol: failed1");
440 r = vmspace_mcontrol(&vm->vm_pmap, (void *)0x40000000, 0x40000000,
441 MADV_SETMAP, vmspace_pmap(vm)->pm_pdirpte);
443 panic("vmspace_mcontrol: failed2");
444 r = vmspace_mcontrol(&vm->vm_pmap, (void *)0x80000000, LAST_EXTENT,
445 MADV_SETMAP, vmspace_pmap(vm)->pm_pdirpte);
447 panic("vmspace_mcontrol: failed3");
451 cpu_vmspace_free(struct vmspace *vm)
453 if (vmspace_destroy(&vm->vm_pmap) < 0)
454 panic("vmspace_destroy() failed");
457 /************************************************************************
458 * Procedures which operate directly on the kernel PMAP *
459 ************************************************************************/
462 * This maps the requested page table and gives us access to it.
464 * This routine can be called from a potentially preempting interrupt
465 * thread or from a normal thread.
468 get_ptbase(struct pmap *pmap, vm_offset_t va)
470 struct mdglobaldata *gd = mdcpu;
472 if (pmap == &kernel_pmap) {
473 KKASSERT(va >= KvaStart && va < KvaEnd);
474 return(KernelPTA + (va >> PAGE_SHIFT));
475 } else if (pmap->pm_pdir == gd->gd_PT1pdir) {
476 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
477 *gd->gd_PT1pde = pmap->pm_pdirpte;
478 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
479 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
481 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
482 } else if (pmap->pm_pdir == gd->gd_PT2pdir) {
483 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
484 *gd->gd_PT2pde = pmap->pm_pdirpte;
485 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
486 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
488 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
492 * If we aren't running from a potentially preempting interrupt,
493 * load a new page table directory into the page table cache
495 if (gd->mi.gd_intr_nesting_level == 0 &&
496 (gd->mi.gd_curthread->td_flags & TDF_INTTHREAD) == 0) {
498 * Choose one or the other and map the page table
499 * in the KVA space reserved for it.
501 if ((gd->gd_PTflip = 1 - gd->gd_PTflip) == 0) {
502 gd->gd_PT1pdir = pmap->pm_pdir;
503 *gd->gd_PT1pde = pmap->pm_pdirpte;
504 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
505 atomic_set_int(&pmap->pm_cpucachemask,
507 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
509 gd->gd_PT2pdir = pmap->pm_pdir;
510 *gd->gd_PT2pde = pmap->pm_pdirpte;
511 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
512 atomic_set_int(&pmap->pm_cpucachemask,
514 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
519 * If we are running from a preempting interrupt use a private
520 * map. The caller must be in a critical section.
522 KKASSERT(IN_CRITICAL_SECT(curthread));
523 if (pmap->pm_pdir == gd->gd_PT3pdir) {
524 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
525 *gd->gd_PT3pde = pmap->pm_pdirpte;
526 madvise(gd->gd_PT3map, SEG_SIZE, MADV_INVAL);
527 atomic_set_int(&pmap->pm_cpucachemask,
531 gd->gd_PT3pdir = pmap->pm_pdir;
532 *gd->gd_PT3pde = pmap->pm_pdirpte;
533 madvise(gd->gd_PT3map, SEG_SIZE, MADV_INVAL);
534 atomic_set_int(&pmap->pm_cpucachemask,
537 return(gd->gd_PT3map + (va >> PAGE_SHIFT));
541 get_ptbase1(struct pmap *pmap, vm_offset_t va)
543 struct mdglobaldata *gd = mdcpu;
545 if (pmap == &kernel_pmap) {
546 KKASSERT(va >= KvaStart && va < KvaEnd);
547 return(KernelPTA + (va >> PAGE_SHIFT));
548 } else if (pmap->pm_pdir == gd->gd_PT1pdir) {
549 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
550 *gd->gd_PT1pde = pmap->pm_pdirpte;
551 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
552 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
554 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
556 KKASSERT(gd->mi.gd_intr_nesting_level == 0 &&
557 (gd->mi.gd_curthread->td_flags & TDF_INTTHREAD) == 0);
558 gd->gd_PT1pdir = pmap->pm_pdir;
559 *gd->gd_PT1pde = pmap->pm_pdirpte;
560 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
561 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
565 get_ptbase2(struct pmap *pmap, vm_offset_t va)
567 struct mdglobaldata *gd = mdcpu;
569 if (pmap == &kernel_pmap) {
570 KKASSERT(va >= KvaStart && va < KvaEnd);
571 return(KernelPTA + (va >> PAGE_SHIFT));
572 } else if (pmap->pm_pdir == gd->gd_PT2pdir) {
573 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
574 *gd->gd_PT2pde = pmap->pm_pdirpte;
575 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
576 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
578 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
580 KKASSERT(gd->mi.gd_intr_nesting_level == 0 &&
581 (gd->mi.gd_curthread->td_flags & TDF_INTTHREAD) == 0);
582 gd->gd_PT2pdir = pmap->pm_pdir;
583 *gd->gd_PT2pde = pmap->pm_pdirpte;
584 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
585 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
589 * Return a pointer to the page table entry for the specified va in the
590 * specified pmap. NULL is returned if there is no valid page table page
593 static __inline vpte_t *
594 pmap_pte(struct pmap *pmap, vm_offset_t va)
598 ptep = &pmap->pm_pdir[va >> SEG_SHIFT];
602 return (get_ptbase(pmap, va));
608 * Enter a mapping into kernel_pmap. Mappings created in this fashion
609 * are not managed. Mappings must be immediately accessible on all cpus.
611 * Call pmap_inval_pte() to invalidate the virtual pte and clean out the
612 * real pmap and handle related races before storing the new vpte.
615 pmap_kenter(vm_offset_t va, vm_paddr_t pa)
620 KKASSERT(va >= KvaStart && va < KvaEnd);
621 npte = (vpte_t)pa | VPTE_R | VPTE_W | VPTE_V;
622 ptep = KernelPTA + (va >> PAGE_SHIFT);
624 pmap_inval_pte(ptep, &kernel_pmap, va);
629 * Synchronize a kvm mapping originally made for the private use on
630 * some other cpu so it can be used on all cpus.
632 * XXX add MADV_RESYNC to improve performance.
635 pmap_kenter_sync(vm_offset_t va)
637 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
641 * Synchronize a kvm mapping originally made for the private use on
642 * some other cpu so it can be used on our cpu. Turns out to be the
643 * same madvise() call, because we have to sync the real pmaps anyway.
645 * XXX add MADV_RESYNC to improve performance.
648 pmap_kenter_sync_quick(vm_offset_t va)
650 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
655 * Make a previously read-only kernel mapping R+W (not implemented by
659 pmap_kmodify_rw(vm_offset_t va)
661 *pmap_kpte(va) |= VPTE_R | VPTE_W;
662 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
666 * Make a kernel mapping non-cacheable (not applicable to virtual kernels)
669 pmap_kmodify_nc(vm_offset_t va)
671 *pmap_kpte(va) |= VPTE_N;
672 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
678 * Map a contiguous range of physical memory to a KVM
681 pmap_map(vm_offset_t virt, vm_paddr_t start, vm_paddr_t end, int prot)
683 while (start < end) {
684 pmap_kenter(virt, start);
692 pmap_kpte(vm_offset_t va)
696 KKASSERT(va >= KvaStart && va < KvaEnd);
697 ptep = KernelPTA + (va >> PAGE_SHIFT);
702 * Enter an unmanaged KVA mapping for the private use of the current
703 * cpu only. pmap_kenter_sync() may be called to make the mapping usable
706 * It is illegal for the mapping to be accessed by other cpus unleess
707 * pmap_kenter_sync*() is called.
710 pmap_kenter_quick(vm_offset_t va, vm_paddr_t pa)
715 KKASSERT(va >= KvaStart && va < KvaEnd);
717 npte = (vpte_t)pa | VPTE_R | VPTE_W | VPTE_V;
718 ptep = KernelPTA + (va >> PAGE_SHIFT);
720 pmap_inval_pte_quick(ptep, &kernel_pmap, va);
725 * Make a temporary mapping for a physical address. This is only intended
726 * to be used for panic dumps.
729 pmap_kenter_temporary(vm_paddr_t pa, int i)
731 pmap_kenter(crashdumpmap + (i * PAGE_SIZE), pa);
732 return ((void *)crashdumpmap);
736 * Remove an unmanaged mapping created with pmap_kenter*().
739 pmap_kremove(vm_offset_t va)
743 KKASSERT(va >= KvaStart && va < KvaEnd);
745 ptep = KernelPTA + (va >> PAGE_SHIFT);
747 pmap_inval_pte(ptep, &kernel_pmap, va);
752 * Remove an unmanaged mapping created with pmap_kenter*() but synchronize
753 * only with this cpu.
755 * Unfortunately because we optimize new entries by testing VPTE_V later
756 * on, we actually still have to synchronize with all the cpus. XXX maybe
757 * store a junk value and test against 0 in the other places instead?
760 pmap_kremove_quick(vm_offset_t va)
764 KKASSERT(va >= KvaStart && va < KvaEnd);
766 ptep = KernelPTA + (va >> PAGE_SHIFT);
768 pmap_inval_pte(ptep, &kernel_pmap, va); /* NOT _quick */
773 * Extract the physical address from the kernel_pmap that is associated
774 * with the specified virtual address.
777 pmap_kextract(vm_offset_t va)
782 KKASSERT(va >= KvaStart && va < KvaEnd);
784 ptep = KernelPTA + (va >> PAGE_SHIFT);
785 pa = (vm_paddr_t)(*ptep & VPTE_FRAME) | (va & PAGE_MASK);
790 * Map a set of unmanaged VM pages into KVM.
793 pmap_qenter(vm_offset_t va, struct vm_page **m, int count)
795 KKASSERT(va >= KvaStart && va + count * PAGE_SIZE < KvaEnd);
799 ptep = KernelPTA + (va >> PAGE_SHIFT);
801 pmap_inval_pte(ptep, &kernel_pmap, va);
802 *ptep = (vpte_t)(*m)->phys_addr | VPTE_R | VPTE_W | VPTE_V;
810 * Map a set of VM pages to kernel virtual memory. If a mapping changes
811 * clear the supplied mask. The caller handles any SMP interactions.
812 * The mask is used to provide the caller with hints on what SMP interactions
816 pmap_qenter2(vm_offset_t va, struct vm_page **m, int count, cpumask_t *mask)
818 cpumask_t cmask = mycpu->gd_cpumask;
820 KKASSERT(va >= KvaStart && va + count * PAGE_SIZE < KvaEnd);
825 ptep = KernelPTA + (va >> PAGE_SHIFT);
826 npte = (vpte_t)(*m)->phys_addr | VPTE_R | VPTE_W | VPTE_V;
829 pmap_inval_pte_quick(ptep, &kernel_pmap, va);
831 } else if ((*mask & cmask) == 0) {
832 pmap_kenter_sync_quick(va);
842 * Undo the effects of pmap_qenter*().
845 pmap_qremove(vm_offset_t va, int count)
847 KKASSERT(va >= KvaStart && va + count * PAGE_SIZE < KvaEnd);
851 ptep = KernelPTA + (va >> PAGE_SHIFT);
853 pmap_inval_pte(ptep, &kernel_pmap, va);
860 /************************************************************************
861 * Misc support glue called by machine independant code *
862 ************************************************************************
864 * These routines are called by machine independant code to operate on
865 * certain machine-dependant aspects of processes, threads, and pmaps.
869 * Initialize MD portions of the thread structure.
872 pmap_init_thread(thread_t td)
874 /* enforce pcb placement */
875 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_size) - 1;
876 td->td_savefpu = &td->td_pcb->pcb_save;
877 td->td_sp = (char *)td->td_pcb - 16;
881 * This routine directly affects the fork perf for a process.
884 pmap_init_proc(struct proc *p)
889 * Destroy the UPAGES for a process that has exited and disassociate
890 * the process from its thread.
893 pmap_dispose_proc(struct proc *p)
895 KASSERT(p->p_lock == 0, ("attempt to dispose referenced proc! %p", p));
899 * We pre-allocate all page table pages for kernel virtual memory so
900 * this routine will only be called if KVM has been exhausted.
903 pmap_growkernel(vm_offset_t addr)
905 addr = (addr + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
907 if (addr > virtual_end - SEG_SIZE)
908 panic("KVM exhausted");
909 kernel_vm_end = addr;
913 * The modification bit is not tracked for any pages in this range. XXX
914 * such pages in this maps should always use pmap_k*() functions and not
917 * XXX User and kernel address spaces are independant for virtual kernels,
918 * this function only applies to the kernel pmap.
921 pmap_track_modified(pmap_t pmap, vm_offset_t va)
923 if (pmap != &kernel_pmap)
925 if ((va < clean_sva) || (va >= clean_eva))
931 /************************************************************************
932 * Procedures supporting managed page table pages *
933 ************************************************************************
935 * These procedures are used to track managed page table pages. These pages
936 * use the page table page's vm_page_t to track PTEs in the page. The
937 * page table pages themselves are arranged in a VM object, pmap->pm_pteobj.
939 * This allows the system to throw away page table pages for user processes
940 * at will and reinstantiate them on demand.
944 * This routine works like vm_page_lookup() but also blocks as long as the
945 * page is busy. This routine does not busy the page it returns.
947 * Unless the caller is managing objects whos pages are in a known state,
948 * the call should be made with a critical section held so the page's object
949 * association remains valid on return.
952 pmap_page_lookup(vm_object_t object, vm_pindex_t pindex)
957 m = vm_page_lookup(object, pindex);
958 if (m && vm_page_sleep_busy(m, FALSE, "pplookp"))
964 * This routine unholds page table pages, and if the hold count
965 * drops to zero, then it decrements the wire count.
967 * We must recheck that this is the last hold reference after busy-sleeping
971 _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
973 while (vm_page_sleep_busy(m, FALSE, "pmuwpt"))
975 KASSERT(m->queue == PQ_NONE,
976 ("_pmap_unwire_pte_hold: %p->queue != PQ_NONE", m));
978 if (m->hold_count == 1) {
980 * Unmap the page table page.
983 KKASSERT(pmap->pm_pdir[m->pindex] != 0);
984 pmap_inval_pde(&pmap->pm_pdir[m->pindex], pmap,
985 (vm_offset_t)m->pindex << SEG_SHIFT);
986 KKASSERT(pmap->pm_stats.resident_count > 0);
987 --pmap->pm_stats.resident_count;
989 if (pmap->pm_ptphint == m)
990 pmap->pm_ptphint = NULL;
993 * This was our last hold, the page had better be unwired
994 * after we decrement wire_count.
996 * FUTURE NOTE: shared page directory page could result in
997 * multiple wire counts.
1001 KKASSERT(m->wire_count == 0);
1002 --vmstats.v_wire_count;
1003 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1005 vm_page_free_zero(m);
1008 KKASSERT(m->hold_count > 1);
1014 pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
1016 KKASSERT(m->hold_count > 0);
1017 if (m->hold_count > 1) {
1021 return _pmap_unwire_pte_hold(pmap, m);
1026 * After removing a page table entry, this routine is used to
1027 * conditionally free the page, and manage the hold/wire counts.
1030 pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t mpte)
1036 * page table pages in the kernel_pmap are not managed.
1038 if (pmap == &kernel_pmap)
1040 ptepindex = (va >> PDRSHIFT);
1041 if (pmap->pm_ptphint &&
1042 (pmap->pm_ptphint->pindex == ptepindex)) {
1043 mpte = pmap->pm_ptphint;
1045 mpte = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1046 pmap->pm_ptphint = mpte;
1049 return pmap_unwire_pte_hold(pmap, mpte);
1053 * Attempt to release and free the vm_page backing a page directory page
1054 * in a pmap. Returns 1 on success, 0 on failure (if the procedure had
1058 pmap_release_free_page(struct pmap *pmap, vm_page_t p)
1060 vpte_t *pde = pmap->pm_pdir;
1063 * This code optimizes the case of freeing non-busy
1064 * page-table pages. Those pages are zero now, and
1065 * might as well be placed directly into the zero queue.
1067 if (vm_page_sleep_busy(p, FALSE, "pmaprl"))
1071 KKASSERT(pmap->pm_stats.resident_count > 0);
1072 --pmap->pm_stats.resident_count;
1074 if (p->hold_count) {
1075 panic("pmap_release: freeing held page table page");
1078 * Page directory pages need to have the kernel stuff cleared, so
1079 * they can go into the zero queue also.
1081 * In virtual kernels there is no 'kernel stuff'. For the moment
1082 * I just make sure the whole thing has been zero'd even though
1083 * it should already be completely zero'd.
1085 * pmaps for vkernels do not self-map because they do not share
1086 * their address space with the vkernel. Clearing of pde[] thus
1087 * only applies to page table pages and not to the page directory
1090 if (p->pindex == pmap->pm_pdindex) {
1091 bzero(pde, VPTE_PAGETABLE_SIZE);
1092 pmap_kremove((vm_offset_t)pmap->pm_pdir);
1094 KKASSERT(pde[p->pindex] != 0);
1095 pmap_inval_pde(&pde[p->pindex], pmap,
1096 (vm_offset_t)p->pindex << SEG_SHIFT);
1100 * Clear the matching hint
1102 if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == p->pindex))
1103 pmap->pm_ptphint = NULL;
1106 * And throw the page away. The page is completely zero'd out so
1107 * optimize the free call.
1110 vmstats.v_wire_count--;
1111 vm_page_free_zero(p);
1116 * This routine is called if the page table page is not mapped in the page
1119 * The routine is broken up into two parts for readability.
1121 * It must return a held mpte and map the page directory page as required.
1122 * Because vm_page_grab() can block, we must re-check pm_pdir[ptepindex]
1125 _pmap_allocpte(pmap_t pmap, unsigned ptepindex)
1131 * Find or fabricate a new pagetable page. A busied page will be
1132 * returned. This call may block.
1134 m = vm_page_grab(pmap->pm_pteobj, ptepindex,
1135 VM_ALLOC_NORMAL | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
1137 KASSERT(m->queue == PQ_NONE,
1138 ("_pmap_allocpte: %p->queue != PQ_NONE", m));
1141 * Increment the hold count for the page we will be returning to
1147 * It is possible that someone else got in and mapped by the page
1148 * directory page while we were blocked, if so just unbusy and
1149 * return the held page.
1151 if ((ptepa = pmap->pm_pdir[ptepindex]) != 0) {
1152 Debugger("PTEPA RACE");
1153 KKASSERT((ptepa & VPTE_FRAME) == VM_PAGE_TO_PHYS(m));
1158 if (m->wire_count == 0)
1159 vmstats.v_wire_count++;
1163 * Map the pagetable page into the process address space, if
1164 * it isn't already there.
1166 ++pmap->pm_stats.resident_count;
1168 ptepa = VM_PAGE_TO_PHYS(m);
1169 pmap->pm_pdir[ptepindex] = (vpte_t)ptepa | VPTE_R | VPTE_W | VPTE_V |
1173 * We are likely about to access this page table page, so set the
1174 * page table hint to reduce overhead.
1176 pmap->pm_ptphint = m;
1179 * Try to use the new mapping, but if we cannot, then
1180 * do it with the routine that maps the page explicitly.
1182 if ((m->flags & PG_ZERO) == 0)
1183 pmap_zero_page(ptepa);
1185 m->valid = VM_PAGE_BITS_ALL;
1186 vm_page_flag_clear(m, PG_ZERO);
1187 vm_page_flag_set(m, PG_MAPPED);
1194 * Determine the page table page required to access the VA in the pmap
1195 * and allocate it if necessary. Return a held vm_page_t for the page.
1197 * Only used with user pmaps.
1200 pmap_allocpte(pmap_t pmap, vm_offset_t va)
1207 * Calculate pagetable page index
1209 ptepindex = va >> PDRSHIFT;
1212 * Get the page directory entry
1214 ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex];
1217 * This supports switching from a 4MB page to a
1220 if (ptepa & VPTE_PS) {
1221 KKASSERT(pmap->pm_pdir[ptepindex] != 0);
1222 pmap_inval_pde(&pmap->pm_pdir[ptepindex], pmap,
1223 (vm_offset_t)ptepindex << SEG_SHIFT);
1228 * If the page table page is mapped, we just increment the
1229 * hold count, and activate it.
1233 * In order to get the page table page, try the
1236 if (pmap->pm_ptphint &&
1237 (pmap->pm_ptphint->pindex == ptepindex)) {
1238 m = pmap->pm_ptphint;
1240 m = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1241 pmap->pm_ptphint = m;
1247 * Here if the pte page isn't mapped, or if it has been deallocated.
1249 return _pmap_allocpte(pmap, ptepindex);
1252 /************************************************************************
1253 * Managed pages in pmaps *
1254 ************************************************************************
1256 * All pages entered into user pmaps and some pages entered into the kernel
1257 * pmap are managed, meaning that pmap_protect() and other related management
1258 * functions work on these pages.
1262 * free the pv_entry back to the free list. This function may be
1263 * called from an interrupt.
1265 static __inline void
1266 free_pv_entry(pv_entry_t pv)
1273 * get a new pv_entry, allocating a block from the system
1274 * when needed. This function may be called from an interrupt.
1280 if (pv_entry_high_water &&
1281 (pv_entry_count > pv_entry_high_water) &&
1282 (pmap_pagedaemon_waken == 0)) {
1283 pmap_pagedaemon_waken = 1;
1284 wakeup (&vm_pages_needed);
1286 return zalloc(&pvzone);
1290 * This routine is very drastic, but can save the system
1298 static int warningdone=0;
1300 if (pmap_pagedaemon_waken == 0)
1303 if (warningdone < 5) {
1304 kprintf("pmap_collect: collecting pv entries -- suggest increasing PMAP_SHPGPERPROC\n");
1308 for(i = 0; i < vm_page_array_size; i++) {
1309 m = &vm_page_array[i];
1310 if (m->wire_count || m->hold_count || m->busy ||
1311 (m->flags & PG_BUSY))
1315 pmap_pagedaemon_waken = 0;
1319 * If it is the first entry on the list, it is actually
1320 * in the header and we must copy the following entry up
1321 * to the header. Otherwise we must search the list for
1322 * the entry. In either case we free the now unused entry.
1325 pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va)
1331 if (m->md.pv_list_count < pmap->pm_stats.resident_count) {
1332 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
1333 if (pmap == pv->pv_pmap && va == pv->pv_va)
1337 TAILQ_FOREACH(pv, &pmap->pm_pvlist, pv_plist) {
1338 if (va == pv->pv_va)
1344 * Note that pv_ptem is NULL if the page table page itself is not
1345 * managed, even if the page being removed IS managed.
1349 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1350 m->md.pv_list_count--;
1351 TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
1352 if (TAILQ_EMPTY(&m->md.pv_list))
1353 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1354 ++pmap->pm_generation;
1355 rtval = pmap_unuse_pt(pmap, va, pv->pv_ptem);
1363 * Create a pv entry for page at pa for (pmap, va). If the page table page
1364 * holding the VA is managed, mpte will be non-NULL.
1367 pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m)
1372 pv = get_pv_entry();
1377 TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist);
1378 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
1379 m->md.pv_list_count++;
1385 * pmap_remove_pte: do the things to unmap a page in a process
1388 pmap_remove_pte(struct pmap *pmap, vpte_t *ptq, vm_offset_t va)
1393 oldpte = pmap_inval_loadandclear(ptq, pmap, va);
1394 if (oldpte & VPTE_WIRED)
1395 --pmap->pm_stats.wired_count;
1396 KKASSERT(pmap->pm_stats.wired_count >= 0);
1400 * Machines that don't support invlpg, also don't support
1401 * VPTE_G. XXX VPTE_G is disabled for SMP so don't worry about
1404 if (oldpte & VPTE_G)
1405 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
1407 KKASSERT(pmap->pm_stats.resident_count > 0);
1408 --pmap->pm_stats.resident_count;
1409 if (oldpte & VPTE_MANAGED) {
1410 m = PHYS_TO_VM_PAGE(oldpte);
1411 if (oldpte & VPTE_M) {
1412 #if defined(PMAP_DIAGNOSTIC)
1413 if (pmap_nw_modified((pt_entry_t) oldpte)) {
1415 "pmap_remove: modified page not writable: va: 0x%x, pte: 0x%x\n",
1419 if (pmap_track_modified(pmap, va))
1422 if (oldpte & VPTE_A)
1423 vm_page_flag_set(m, PG_REFERENCED);
1424 return pmap_remove_entry(pmap, m, va);
1426 return pmap_unuse_pt(pmap, va, NULL);
1435 * Remove a single page from a process address space.
1437 * This function may not be called from an interrupt if the pmap is
1441 pmap_remove_page(struct pmap *pmap, vm_offset_t va)
1446 * if there is no pte for this address, just skip it!!! Otherwise
1447 * get a local va for mappings for this pmap and remove the entry.
1449 if (*pmap_pde(pmap, va) != 0) {
1450 ptq = get_ptbase(pmap, va);
1452 pmap_remove_pte(pmap, ptq, va);
1460 * Remove the given range of addresses from the specified map.
1462 * It is assumed that the start and end are properly
1463 * rounded to the page size.
1465 * This function may not be called from an interrupt if the pmap is
1469 pmap_remove(struct pmap *pmap, vm_offset_t sva, vm_offset_t eva)
1473 vm_offset_t ptpaddr;
1474 vm_pindex_t sindex, eindex;
1479 KKASSERT(pmap->pm_stats.resident_count >= 0);
1480 if (pmap->pm_stats.resident_count == 0)
1484 * special handling of removing one page. a very
1485 * common operation and easy to short circuit some
1488 if (((sva + PAGE_SIZE) == eva) &&
1489 ((pmap->pm_pdir[(sva >> PDRSHIFT)] & VPTE_PS) == 0)) {
1490 pmap_remove_page(pmap, sva);
1495 * Get a local virtual address for the mappings that are being
1498 * XXX this is really messy because the kernel pmap is not relative
1501 sindex = (sva >> PAGE_SHIFT);
1502 eindex = (eva >> PAGE_SHIFT);
1504 for (; sindex < eindex; sindex = pdnxt) {
1508 * Calculate index for next page table.
1510 pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
1511 if (pmap->pm_stats.resident_count == 0)
1514 pdirindex = sindex / NPDEPG;
1515 if (((ptpaddr = pmap->pm_pdir[pdirindex]) & VPTE_PS) != 0) {
1516 KKASSERT(pmap->pm_pdir[pdirindex] != 0);
1517 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1518 pmap_inval_pde(&pmap->pm_pdir[pdirindex], pmap,
1519 (vm_offset_t)pdirindex << SEG_SHIFT);
1524 * Weed out invalid mappings. Note: we assume that the page
1525 * directory table is always allocated, and in kernel virtual.
1531 * Limit our scan to either the end of the va represented
1532 * by the current page table page, or to the end of the
1533 * range being removed.
1539 * NOTE: pmap_remove_pte() can block.
1541 for (; sindex != pdnxt; sindex++) {
1544 ptbase = get_ptbase(pmap, sindex << PAGE_SHIFT);
1547 va = i386_ptob(sindex);
1548 if (pmap_remove_pte(pmap, ptbase, va))
1557 * Removes this physical page from all physical maps in which it resides.
1558 * Reflects back modify bits to the pager.
1560 * This routine may not be called from an interrupt.
1563 pmap_remove_all(vm_page_t m)
1568 #if defined(PMAP_DIAGNOSTIC)
1570 * XXX this makes pmap_page_protect(NONE) illegal for non-managed
1573 if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) {
1574 panic("pmap_page_protect: illegal for unmanaged page, va: 0x%08llx", (long long)VM_PAGE_TO_PHYS(m));
1579 while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
1580 KKASSERT(pv->pv_pmap->pm_stats.resident_count > 0);
1581 --pv->pv_pmap->pm_stats.resident_count;
1583 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
1584 KKASSERT(pte != NULL);
1586 tpte = pmap_inval_loadandclear(pte, pv->pv_pmap, pv->pv_va);
1587 if (tpte & VPTE_WIRED)
1588 --pv->pv_pmap->pm_stats.wired_count;
1589 KKASSERT(pv->pv_pmap->pm_stats.wired_count >= 0);
1592 vm_page_flag_set(m, PG_REFERENCED);
1595 * Update the vm_page_t clean and reference bits.
1597 if (tpte & VPTE_M) {
1598 #if defined(PMAP_DIAGNOSTIC)
1599 if (pmap_nw_modified((pt_entry_t) tpte)) {
1601 "pmap_remove_all: modified page not writable: va: 0x%x, pte: 0x%x\n",
1605 if (pmap_track_modified(pv->pv_pmap, pv->pv_va))
1608 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1609 TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
1610 ++pv->pv_pmap->pm_generation;
1611 m->md.pv_list_count--;
1612 if (TAILQ_EMPTY(&m->md.pv_list))
1613 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1614 pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
1617 KKASSERT((m->flags & (PG_MAPPED | PG_WRITEABLE)) == 0);
1624 * Set the physical protection on the specified range of this map
1627 * This function may not be called from an interrupt if the map is
1628 * not the kernel_pmap.
1631 pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
1635 vm_offset_t pdnxt, ptpaddr;
1636 vm_pindex_t sindex, eindex;
1642 if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
1643 pmap_remove(pmap, sva, eva);
1647 if (prot & VM_PROT_WRITE)
1650 ptbase = get_ptbase(pmap, sva);
1652 sindex = (sva >> PAGE_SHIFT);
1653 eindex = (eva >> PAGE_SHIFT);
1656 for (; sindex < eindex; sindex = pdnxt) {
1660 pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
1662 pdirindex = sindex / NPDEPG;
1665 * Clear the modified and writable bits for a 4m page.
1666 * Throw away the modified bit (?)
1668 if (((ptpaddr = pmap->pm_pdir[pdirindex]) & VPTE_PS) != 0) {
1669 pmap_clean_pde(&pmap->pm_pdir[pdirindex], pmap,
1670 (vm_offset_t)pdirindex << SEG_SHIFT);
1671 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1676 * Weed out invalid mappings. Note: we assume that the page
1677 * directory table is always allocated, and in kernel virtual.
1682 if (pdnxt > eindex) {
1686 for (; sindex != pdnxt; sindex++) {
1691 * Clean managed pages and also check the accessed
1692 * bit. Just remove write perms for unmanaged
1693 * pages. Be careful of races, turning off write
1694 * access will force a fault rather then setting
1695 * the modified bit at an unexpected time.
1697 ptep = &ptbase[sindex - sbase];
1698 if (*ptep & VPTE_MANAGED) {
1699 pbits = pmap_clean_pte(ptep, pmap,
1702 if (pbits & VPTE_A) {
1703 m = PHYS_TO_VM_PAGE(pbits);
1704 vm_page_flag_set(m, PG_REFERENCED);
1705 atomic_clear_int(ptep, VPTE_A);
1707 if (pbits & VPTE_M) {
1708 if (pmap_track_modified(pmap, i386_ptob(sindex))) {
1710 m = PHYS_TO_VM_PAGE(pbits);
1715 pbits = pmap_setro_pte(ptep, pmap,
1723 * Enter a managed page into a pmap. If the page is not wired related pmap
1724 * data can be destroyed at any time for later demand-operation.
1726 * Insert the vm_page (m) at virtual address (v) in (pmap), with the
1727 * specified protection, and wire the mapping if requested.
1729 * NOTE: This routine may not lazy-evaluate or lose information. The
1730 * page must actually be inserted into the given map NOW.
1732 * NOTE: When entering a page at a KVA address, the pmap must be the
1736 pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
1742 vm_offset_t origpte, newpte;
1751 * Get the page table page. The kernel_pmap's page table pages
1752 * are preallocated and have no associated vm_page_t.
1754 if (pmap == &kernel_pmap)
1757 mpte = pmap_allocpte(pmap, va);
1759 pte = pmap_pte(pmap, va);
1762 * Page Directory table entry not valid, we need a new PT page
1763 * and pmap_allocpte() didn't give us one. Oops!
1766 panic("pmap_enter: invalid page directory pmap=%p, va=0x%p\n",
1771 * Deal with races on the original mapping (though don't worry
1772 * about VPTE_A races) by cleaning it. This will force a fault
1773 * if an attempt is made to write to the page.
1775 pa = VM_PAGE_TO_PHYS(m) & VPTE_FRAME;
1776 origpte = pmap_clean_pte(pte, pmap, va);
1777 opa = origpte & VPTE_FRAME;
1779 if (origpte & VPTE_PS)
1780 panic("pmap_enter: attempted pmap_enter on 4MB page");
1783 * Mapping has not changed, must be protection or wiring change.
1785 if (origpte && (opa == pa)) {
1787 * Wiring change, just update stats. We don't worry about
1788 * wiring PT pages as they remain resident as long as there
1789 * are valid mappings in them. Hence, if a user page is wired,
1790 * the PT page will be also.
1792 if (wired && ((origpte & VPTE_WIRED) == 0))
1793 ++pmap->pm_stats.wired_count;
1794 else if (!wired && (origpte & VPTE_WIRED))
1795 --pmap->pm_stats.wired_count;
1796 KKASSERT(pmap->pm_stats.wired_count >= 0);
1799 * Remove the extra pte reference. Note that we cannot
1800 * optimize the RO->RW case because we have adjusted the
1801 * wiring count above and may need to adjust the wiring
1808 * We might be turning off write access to the page,
1809 * so we go ahead and sense modify status.
1811 if (origpte & VPTE_MANAGED) {
1812 if ((origpte & VPTE_M) &&
1813 pmap_track_modified(pmap, va)) {
1815 om = PHYS_TO_VM_PAGE(opa);
1819 KKASSERT(m->flags & PG_MAPPED);
1824 * Mapping has changed, invalidate old range and fall through to
1825 * handle validating new mapping.
1829 err = pmap_remove_pte(pmap, pte, va);
1831 panic("pmap_enter: pte vanished, va: 0x%x", va);
1835 * Enter on the PV list if part of our managed memory. Note that we
1836 * raise IPL while manipulating pv_table since pmap_enter can be
1837 * called at interrupt time.
1839 if (pmap_initialized &&
1840 (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) {
1841 pmap_insert_entry(pmap, va, mpte, m);
1843 vm_page_flag_set(m, PG_MAPPED);
1847 * Increment counters
1849 ++pmap->pm_stats.resident_count;
1851 pmap->pm_stats.wired_count++;
1855 * Now validate mapping with desired protection/wiring.
1857 newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | VPTE_V);
1860 newpte |= VPTE_WIRED;
1861 if (pmap != &kernel_pmap)
1865 * If the mapping or permission bits are different from the
1866 * (now cleaned) original pte, an update is needed. We've
1867 * already downgraded or invalidated the page so all we have
1868 * to do now is update the bits.
1870 * XXX should we synchronize RO->RW changes to avoid another
1873 if ((origpte & ~(VPTE_W|VPTE_M|VPTE_A)) != newpte) {
1874 *pte = newpte | VPTE_A;
1875 if (newpte & VPTE_W)
1876 vm_page_flag_set(m, PG_WRITEABLE);
1878 KKASSERT((newpte & VPTE_MANAGED) == 0 || m->flags & PG_MAPPED);
1882 * This code works like pmap_enter() but assumes VM_PROT_READ and not-wired.
1884 * Currently this routine may only be used on user pmaps, not kernel_pmap.
1887 pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m)
1895 KKASSERT(pmap != &kernel_pmap);
1897 KKASSERT(va >= VM_MIN_USER_ADDRESS && va < VM_MAX_USER_ADDRESS);
1900 * Calculate pagetable page (mpte), allocating it if necessary.
1902 * A held page table page (mpte), or NULL, is passed onto the
1903 * section following.
1905 ptepindex = va >> PDRSHIFT;
1909 * Get the page directory entry
1911 ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex];
1914 * If the page table page is mapped, we just increment
1915 * the hold count, and activate it.
1918 if (ptepa & VPTE_PS)
1919 panic("pmap_enter_quick: unexpected mapping into 4MB page");
1920 if (pmap->pm_ptphint &&
1921 (pmap->pm_ptphint->pindex == ptepindex)) {
1922 mpte = pmap->pm_ptphint;
1924 mpte = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1925 pmap->pm_ptphint = mpte;
1930 mpte = _pmap_allocpte(pmap, ptepindex);
1932 } while (mpte == NULL);
1935 * Ok, now that the page table page has been validated, get the pte.
1936 * If the pte is already mapped undo mpte's hold_count and
1939 pte = pmap_pte(pmap, va);
1941 pmap_unwire_pte_hold(pmap, mpte);
1946 * Enter on the PV list if part of our managed memory. Note that we
1947 * raise IPL while manipulating pv_table since pmap_enter can be
1948 * called at interrupt time.
1950 if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) {
1951 pmap_insert_entry(pmap, va, mpte, m);
1952 vm_page_flag_set(m, PG_MAPPED);
1956 * Increment counters
1958 ++pmap->pm_stats.resident_count;
1960 pa = VM_PAGE_TO_PHYS(m);
1963 * Now validate mapping with RO protection
1965 if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED))
1966 *pte = (vpte_t)pa | VPTE_V | VPTE_U;
1968 *pte = (vpte_t)pa | VPTE_V | VPTE_U | VPTE_MANAGED;
1969 /*pmap_inval_add(&info, pmap, va); shouldn't be needed 0->valid */
1970 /*pmap_inval_flush(&info); don't need for vkernel */
1974 * Extract the physical address for the translation at the specified
1975 * virtual address in the pmap.
1978 pmap_extract(pmap_t pmap, vm_offset_t va)
1983 if (pmap && (pte = pmap->pm_pdir[va >> SEG_SHIFT]) != 0) {
1984 if (pte & VPTE_PS) {
1985 rtval = pte & ~((vpte_t)(1 << SEG_SHIFT) - 1);
1986 rtval |= va & SEG_MASK;
1988 pte = *get_ptbase(pmap, va);
1989 rtval = (pte & VPTE_FRAME) | (va & PAGE_MASK);
1996 #define MAX_INIT_PT (96)
1999 * This routine preloads the ptes for a given object into the specified pmap.
2000 * This eliminates the blast of soft faults on process startup and
2001 * immediately after an mmap.
2003 static int pmap_object_init_pt_callback(vm_page_t p, void *data);
2006 pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_prot_t prot,
2007 vm_object_t object, vm_pindex_t pindex,
2008 vm_size_t size, int limit)
2010 struct rb_vm_page_scan_info info;
2015 * We can't preinit if read access isn't set or there is no pmap
2018 if ((prot & VM_PROT_READ) == 0 || pmap == NULL || object == NULL)
2022 * We can't preinit if the pmap is not the current pmap
2024 lp = curthread->td_lwp;
2025 if (lp == NULL || pmap != vmspace_pmap(lp->lwp_vmspace))
2028 psize = size >> PAGE_SHIFT;
2030 if ((object->type != OBJT_VNODE) ||
2031 ((limit & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) &&
2032 (object->resident_page_count > MAX_INIT_PT))) {
2036 if (psize + pindex > object->size) {
2037 if (object->size < pindex)
2039 psize = object->size - pindex;
2046 * Use a red-black scan to traverse the requested range and load
2047 * any valid pages found into the pmap.
2049 * We cannot safely scan the object's memq unless we are in a
2050 * critical section since interrupts can remove pages from objects.
2052 info.start_pindex = pindex;
2053 info.end_pindex = pindex + psize - 1;
2060 vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp,
2061 pmap_object_init_pt_callback, &info);
2067 pmap_object_init_pt_callback(vm_page_t p, void *data)
2069 struct rb_vm_page_scan_info *info = data;
2070 vm_pindex_t rel_index;
2072 * don't allow an madvise to blow away our really
2073 * free pages allocating pv entries.
2075 if ((info->limit & MAP_PREFAULT_MADVISE) &&
2076 vmstats.v_free_count < vmstats.v_free_reserved) {
2079 if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
2080 (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
2081 if ((p->queue - p->pc) == PQ_CACHE)
2082 vm_page_deactivate(p);
2084 rel_index = p->pindex - info->start_pindex;
2085 pmap_enter_quick(info->pmap,
2086 info->addr + i386_ptob(rel_index), p);
2093 * pmap_prefault provides a quick way of clustering pagefaults into a
2094 * processes address space. It is a "cousin" of pmap_object_init_pt,
2095 * except it runs at page fault time instead of mmap time.
2099 #define PAGEORDER_SIZE (PFBAK+PFFOR)
2101 static int pmap_prefault_pageorder[] = {
2102 -PAGE_SIZE, PAGE_SIZE,
2103 -2 * PAGE_SIZE, 2 * PAGE_SIZE,
2104 -3 * PAGE_SIZE, 3 * PAGE_SIZE,
2105 -4 * PAGE_SIZE, 4 * PAGE_SIZE
2109 pmap_prefault(pmap_t pmap, vm_offset_t addra, vm_map_entry_t entry)
2120 * We do not currently prefault mappings that use virtual page
2121 * tables. We do not prefault foreign pmaps.
2123 if (entry->maptype == VM_MAPTYPE_VPAGETABLE)
2125 lp = curthread->td_lwp;
2126 if (lp == NULL || pmap != vmspace_pmap(lp->lwp_vmspace))
2129 object = entry->object.vm_object;
2131 starta = addra - PFBAK * PAGE_SIZE;
2132 if (starta < entry->start)
2133 starta = entry->start;
2134 else if (starta > addra)
2138 * critical section protection is required to maintain the
2139 * page/object association, interrupts can free pages and remove
2140 * them from their objects.
2143 for (i = 0; i < PAGEORDER_SIZE; i++) {
2144 vm_object_t lobject;
2147 addr = addra + pmap_prefault_pageorder[i];
2148 if (addr > addra + (PFFOR * PAGE_SIZE))
2151 if (addr < starta || addr >= entry->end)
2155 * Make sure the page table page already exists
2157 if ((*pmap_pde(pmap, addr)) == NULL)
2161 * Get a pointer to the pte and make sure that no valid page
2164 pte = get_ptbase(pmap, addr);
2169 * Get the page to be mapped
2171 pindex = ((addr - entry->start) + entry->offset) >> PAGE_SHIFT;
2174 for (m = vm_page_lookup(lobject, pindex);
2175 (!m && (lobject->type == OBJT_DEFAULT) &&
2176 (lobject->backing_object));
2177 lobject = lobject->backing_object
2179 if (lobject->backing_object_offset & PAGE_MASK)
2181 pindex += (lobject->backing_object_offset >> PAGE_SHIFT);
2182 m = vm_page_lookup(lobject->backing_object, pindex);
2186 * give-up when a page is not in memory
2192 * If everything meets the requirements for pmap_enter_quick(),
2193 * then enter the page.
2196 if (((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
2198 (m->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
2200 if ((m->queue - m->pc) == PQ_CACHE) {
2201 vm_page_deactivate(m);
2204 pmap_enter_quick(pmap, addr, m);
2212 * Routine: pmap_change_wiring
2213 * Function: Change the wiring attribute for a map/virtual-address
2215 * In/out conditions:
2216 * The mapping must already exist in the pmap.
2219 pmap_change_wiring(pmap_t pmap, vm_offset_t va, boolean_t wired)
2226 pte = get_ptbase(pmap, va);
2228 if (wired && (*pte & VPTE_WIRED) == 0)
2229 ++pmap->pm_stats.wired_count;
2230 else if (!wired && (*pte & VPTE_WIRED))
2231 --pmap->pm_stats.wired_count;
2232 KKASSERT(pmap->pm_stats.wired_count >= 0);
2235 * Wiring is not a hardware characteristic so there is no need to
2236 * invalidate TLB. However, in an SMP environment we must use
2237 * a locked bus cycle to update the pte (if we are not using
2238 * the pmap_inval_*() API that is)... it's ok to do this for simple
2242 atomic_set_int(pte, VPTE_WIRED);
2244 atomic_clear_int(pte, VPTE_WIRED);
2248 * Copy the range specified by src_addr/len
2249 * from the source map to the range dst_addr/len
2250 * in the destination map.
2252 * This routine is only advisory and need not do anything.
2255 pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr,
2256 vm_size_t len, vm_offset_t src_addr)
2259 vm_offset_t end_addr = src_addr + len;
2266 * XXX BUGGY. Amoung other things srcmpte is assumed to remain
2267 * valid through blocking calls, and that's just not going to
2274 if (dst_addr != src_addr)
2276 if (dst_pmap->pm_pdir == NULL)
2278 if (src_pmap->pm_pdir == NULL)
2283 src_frame = get_ptbase1(src_pmap, src_addr);
2284 dst_frame = get_ptbase2(dst_pmap, src_addr);
2287 * critical section protection is required to maintain the page/object
2288 * association, interrupts can free pages and remove them from
2291 for (addr = src_addr; addr < end_addr; addr = pdnxt) {
2292 vpte_t *src_pte, *dst_pte;
2293 vm_page_t dstmpte, srcmpte;
2294 vm_offset_t srcptepaddr;
2297 if (addr >= VM_MAX_USER_ADDRESS)
2298 panic("pmap_copy: invalid to pmap_copy page tables\n");
2301 * Don't let optional prefaulting of pages make us go
2302 * way below the low water mark of free pages or way
2303 * above high water mark of used pv entries.
2305 if (vmstats.v_free_count < vmstats.v_free_reserved ||
2306 pv_entry_count > pv_entry_high_water)
2309 pdnxt = ((addr + PAGE_SIZE*NPTEPG) & ~(PAGE_SIZE*NPTEPG - 1));
2310 ptepindex = addr >> PDRSHIFT;
2312 srcptepaddr = (vm_offset_t) src_pmap->pm_pdir[ptepindex];
2313 if (srcptepaddr == 0)
2316 if (srcptepaddr & VPTE_PS) {
2317 if (dst_pmap->pm_pdir[ptepindex] == 0) {
2318 dst_pmap->pm_pdir[ptepindex] = (pd_entry_t) srcptepaddr;
2319 dst_pmap->pm_stats.resident_count += NBPDR / PAGE_SIZE;
2324 srcmpte = vm_page_lookup(src_pmap->pm_pteobj, ptepindex);
2325 if ((srcmpte == NULL) || (srcmpte->hold_count == 0) ||
2326 (srcmpte->flags & PG_BUSY)) {
2330 if (pdnxt > end_addr)
2333 src_pte = src_frame + ((addr - src_addr) >> PAGE_SHIFT);
2334 dst_pte = dst_frame + ((addr - src_addr) >> PAGE_SHIFT);
2335 while (addr < pdnxt) {
2340 * we only virtual copy managed pages
2342 if ((ptetemp & VPTE_MANAGED) != 0) {
2344 * We have to check after allocpte for the
2345 * pte still being around... allocpte can
2348 * pmap_allocpte can block, unfortunately
2349 * we have to reload the tables.
2351 dstmpte = pmap_allocpte(dst_pmap, addr);
2352 src_frame = get_ptbase1(src_pmap, src_addr);
2353 dst_frame = get_ptbase2(dst_pmap, src_addr);
2355 if ((*dst_pte == 0) && (ptetemp = *src_pte) &&
2356 (ptetemp & VPTE_MANAGED) != 0) {
2358 * Clear the modified and accessed
2359 * (referenced) bits during the copy.
2361 * We do not have to clear the write
2362 * bit to force a fault-on-modify
2363 * because the real kernel's target
2364 * pmap is empty and will fault anyway.
2366 m = PHYS_TO_VM_PAGE(ptetemp);
2367 *dst_pte = ptetemp & ~(VPTE_M | VPTE_A);
2368 ++dst_pmap->pm_stats.resident_count;
2369 pmap_insert_entry(dst_pmap, addr,
2371 KKASSERT(m->flags & PG_MAPPED);
2373 pmap_unwire_pte_hold(dst_pmap, dstmpte);
2375 if (dstmpte->hold_count >= srcmpte->hold_count)
2389 * Zero the specified PA by mapping the page into KVM and clearing its
2392 * This function may be called from an interrupt and no locking is
2396 pmap_zero_page(vm_paddr_t phys)
2398 struct mdglobaldata *gd = mdcpu;
2402 panic("pmap_zero_page: CMAP3 busy");
2403 *gd->gd_CMAP3 = VPTE_V | VPTE_R | VPTE_W | (phys & VPTE_FRAME) | VPTE_A | VPTE_M;
2404 madvise(gd->gd_CADDR3, PAGE_SIZE, MADV_INVAL);
2406 bzero(gd->gd_CADDR3, PAGE_SIZE);
2412 * pmap_page_assertzero:
2414 * Assert that a page is empty, panic if it isn't.
2417 pmap_page_assertzero(vm_paddr_t phys)
2419 struct mdglobaldata *gd = mdcpu;
2424 panic("pmap_zero_page: CMAP3 busy");
2425 *gd->gd_CMAP3 = VPTE_V | VPTE_R | VPTE_W |
2426 (phys & VPTE_FRAME) | VPTE_A | VPTE_M;
2427 madvise(gd->gd_CADDR3, PAGE_SIZE, MADV_INVAL);
2428 for (i = 0; i < PAGE_SIZE; i += 4) {
2429 if (*(int *)((char *)gd->gd_CADDR3 + i) != 0) {
2430 panic("pmap_page_assertzero() @ %p not zero!\n",
2431 (void *)gd->gd_CADDR3);
2441 * Zero part of a physical page by mapping it into memory and clearing
2442 * its contents with bzero.
2444 * off and size may not cover an area beyond a single hardware page.
2447 pmap_zero_page_area(vm_paddr_t phys, int off, int size)
2449 struct mdglobaldata *gd = mdcpu;
2453 panic("pmap_zero_page: CMAP3 busy");
2454 *gd->gd_CMAP3 = VPTE_V | VPTE_R | VPTE_W |
2455 (phys & VPTE_FRAME) | VPTE_A | VPTE_M;
2456 madvise(gd->gd_CADDR3, PAGE_SIZE, MADV_INVAL);
2458 bzero((char *)gd->gd_CADDR3 + off, size);
2466 * Copy the physical page from the source PA to the target PA.
2467 * This function may be called from an interrupt. No locking
2471 pmap_copy_page(vm_paddr_t src, vm_paddr_t dst)
2473 struct mdglobaldata *gd = mdcpu;
2476 if (*(int *) gd->gd_CMAP1)
2477 panic("pmap_copy_page: CMAP1 busy");
2478 if (*(int *) gd->gd_CMAP2)
2479 panic("pmap_copy_page: CMAP2 busy");
2481 *(int *) gd->gd_CMAP1 = VPTE_V | VPTE_R | (src & PG_FRAME) | VPTE_A;
2482 *(int *) gd->gd_CMAP2 = VPTE_V | VPTE_R | VPTE_W | (dst & VPTE_FRAME) | VPTE_A | VPTE_M;
2484 madvise(gd->gd_CADDR1, PAGE_SIZE, MADV_INVAL);
2485 madvise(gd->gd_CADDR2, PAGE_SIZE, MADV_INVAL);
2487 bcopy(gd->gd_CADDR1, gd->gd_CADDR2, PAGE_SIZE);
2489 *(int *) gd->gd_CMAP1 = 0;
2490 *(int *) gd->gd_CMAP2 = 0;
2495 * pmap_copy_page_frag:
2497 * Copy the physical page from the source PA to the target PA.
2498 * This function may be called from an interrupt. No locking
2502 pmap_copy_page_frag(vm_paddr_t src, vm_paddr_t dst, size_t bytes)
2504 struct mdglobaldata *gd = mdcpu;
2507 if (*(int *) gd->gd_CMAP1)
2508 panic("pmap_copy_page: CMAP1 busy");
2509 if (*(int *) gd->gd_CMAP2)
2510 panic("pmap_copy_page: CMAP2 busy");
2512 *(int *) gd->gd_CMAP1 = VPTE_V | (src & VPTE_FRAME) | VPTE_A;
2513 *(int *) gd->gd_CMAP2 = VPTE_V | VPTE_R | VPTE_W | (dst & VPTE_FRAME) | VPTE_A | VPTE_M;
2515 madvise(gd->gd_CADDR1, PAGE_SIZE, MADV_INVAL);
2516 madvise(gd->gd_CADDR2, PAGE_SIZE, MADV_INVAL);
2518 bcopy((char *)gd->gd_CADDR1 + (src & PAGE_MASK),
2519 (char *)gd->gd_CADDR2 + (dst & PAGE_MASK),
2522 *(int *) gd->gd_CMAP1 = 0;
2523 *(int *) gd->gd_CMAP2 = 0;
2528 * Returns true if the pmap's pv is one of the first
2529 * 16 pvs linked to from this page. This count may
2530 * be changed upwards or downwards in the future; it
2531 * is only necessary that true be returned for a small
2532 * subset of pmaps for proper page aging.
2535 pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
2540 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2545 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2546 if (pv->pv_pmap == pmap) {
2559 * Remove all pages from specified address space
2560 * this aids process exit speeds. Also, this code
2561 * is special cased for current process only, but
2562 * can have the more generic (and slightly slower)
2563 * mode enabled. This is much faster than pmap_remove
2564 * in the case of running down an entire address space.
2567 pmap_remove_pages(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
2573 int32_t save_generation;
2576 lp = curthread->td_lwp;
2577 if (lp && pmap == vmspace_pmap(lp->lwp_vmspace))
2583 for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) {
2584 if (pv->pv_va >= eva || pv->pv_va < sva) {
2585 npv = TAILQ_NEXT(pv, pv_plist);
2589 KKASSERT(pmap == pv->pv_pmap);
2591 pte = pmap_pte(pmap, pv->pv_va);
2594 * We cannot remove wired pages from a process' mapping
2597 if (*pte & VPTE_WIRED) {
2598 npv = TAILQ_NEXT(pv, pv_plist);
2601 tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);
2603 m = PHYS_TO_VM_PAGE(tpte);
2605 KASSERT(m < &vm_page_array[vm_page_array_size],
2606 ("pmap_remove_pages: bad tpte %x", tpte));
2608 KKASSERT(pmap->pm_stats.resident_count > 0);
2609 --pmap->pm_stats.resident_count;
2612 * Update the vm_page_t clean and reference bits.
2614 if (tpte & VPTE_M) {
2618 npv = TAILQ_NEXT(pv, pv_plist);
2619 TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
2620 save_generation = ++pmap->pm_generation;
2622 m->md.pv_list_count--;
2623 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2624 if (TAILQ_FIRST(&m->md.pv_list) == NULL)
2625 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
2627 pmap_unuse_pt(pmap, pv->pv_va, pv->pv_ptem);
2631 * Restart the scan if we blocked during the unuse or free
2632 * calls and other removals were made.
2634 if (save_generation != pmap->pm_generation) {
2635 kprintf("Warning: pmap_remove_pages race-A avoided\n");
2636 pv = TAILQ_FIRST(&pmap->pm_pvlist);
2643 * pmap_testbit tests bits in active mappings of a VM page.
2646 pmap_testbit(vm_page_t m, int bit)
2651 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2654 if (TAILQ_FIRST(&m->md.pv_list) == NULL)
2659 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2661 * if the bit being tested is the modified bit, then
2662 * mark clean_map and ptes as never
2665 if (bit & (VPTE_A|VPTE_M)) {
2666 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va))
2670 #if defined(PMAP_DIAGNOSTIC)
2672 kprintf("Null pmap (tb) at va: 0x%x\n", pv->pv_va);
2676 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
2687 * This routine is used to clear bits in ptes. Certain bits require special
2688 * handling, in particular (on virtual kernels) the VPTE_M (modify) bit.
2690 * This routine is only called with certain VPTE_* bit combinations.
2692 static __inline void
2693 pmap_clearbit(vm_page_t m, int bit)
2699 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2705 * Loop over all current mappings setting/clearing as appropos If
2706 * setting RO do we need to clear the VAC?
2708 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2710 * don't write protect pager mappings
2712 if (bit == VPTE_W) {
2713 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va))
2717 #if defined(PMAP_DIAGNOSTIC)
2719 kprintf("Null pmap (cb) at va: 0x%x\n", pv->pv_va);
2725 * Careful here. We can use a locked bus instruction to
2726 * clear VPTE_A or VPTE_M safely but we need to synchronize
2727 * with the target cpus when we mess with VPTE_W.
2729 * On virtual kernels we must force a new fault-on-write
2730 * in the real kernel if we clear the Modify bit ourselves,
2731 * otherwise the real kernel will not get a new fault and
2732 * will never set our Modify bit again.
2734 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
2736 if (bit == VPTE_W) {
2738 * We must also clear VPTE_M when clearing
2741 pbits = pmap_clean_pte(pte, pv->pv_pmap,
2745 } else if (bit == VPTE_M) {
2747 * We do not have to make the page read-only
2748 * when clearing the Modify bit. The real
2749 * kernel will make the real PTE read-only
2750 * or otherwise detect the write and set
2751 * our VPTE_M again simply by us invalidating
2752 * the real kernel VA for the pmap (as we did
2753 * above). This allows the real kernel to
2754 * handle the write fault without forwarding
2757 atomic_clear_int(pte, VPTE_M);
2758 } else if ((bit & (VPTE_W|VPTE_M)) == (VPTE_W|VPTE_M)) {
2760 * We've been asked to clear W & M, I guess
2761 * the caller doesn't want us to update
2762 * the dirty status of the VM page.
2764 pmap_clean_pte(pte, pv->pv_pmap, pv->pv_va);
2767 * We've been asked to clear bits that do
2768 * not interact with hardware.
2770 atomic_clear_int(pte, bit);
2778 * pmap_page_protect:
2780 * Lower the permission for all mappings to a given page.
2783 pmap_page_protect(vm_page_t m, vm_prot_t prot)
2785 if ((prot & VM_PROT_WRITE) == 0) {
2786 if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
2787 pmap_clearbit(m, VPTE_W);
2788 vm_page_flag_clear(m, PG_WRITEABLE);
2796 pmap_phys_address(int ppn)
2798 return (i386_ptob(ppn));
2802 * pmap_ts_referenced:
2804 * Return a count of reference bits for a page, clearing those bits.
2805 * It is not necessary for every reference bit to be cleared, but it
2806 * is necessary that 0 only be returned when there are truly no
2807 * reference bits set.
2809 * XXX: The exact number of bits to check and clear is a matter that
2810 * should be tested and standardized at some point in the future for
2811 * optimal aging of shared pages.
2814 pmap_ts_referenced(vm_page_t m)
2816 pv_entry_t pv, pvf, pvn;
2820 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2825 if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
2830 pvn = TAILQ_NEXT(pv, pv_list);
2832 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2834 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
2836 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va))
2839 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
2841 if (pte && (*pte & VPTE_A)) {
2843 atomic_clear_int(pte, VPTE_A);
2845 atomic_clear_int_nonlocked(pte, VPTE_A);
2852 } while ((pv = pvn) != NULL && pv != pvf);
2862 * Return whether or not the specified physical page was modified
2863 * in any physical maps.
2866 pmap_is_modified(vm_page_t m)
2868 return pmap_testbit(m, VPTE_M);
2872 * Clear the modify bits on the specified physical page.
2875 pmap_clear_modify(vm_page_t m)
2877 pmap_clearbit(m, VPTE_M);
2881 * pmap_clear_reference:
2883 * Clear the reference bit on the specified physical page.
2886 pmap_clear_reference(vm_page_t m)
2888 pmap_clearbit(m, VPTE_A);
2892 * Miscellaneous support routines follow
2896 i386_protection_init(void)
2900 kp = protection_codes;
2901 for (prot = 0; prot < 8; prot++) {
2902 if (prot & VM_PROT_READ)
2904 if (prot & VM_PROT_WRITE)
2906 if (prot & VM_PROT_EXECUTE)
2915 * Map a set of physical memory pages into the kernel virtual
2916 * address space. Return a pointer to where it is mapped. This
2917 * routine is intended to be used for mapping device memory,
2920 * NOTE: we can't use pgeflag unless we invalidate the pages one at
2924 pmap_mapdev(vm_paddr_t pa, vm_size_t size)
2926 vm_offset_t va, tmpva, offset;
2929 offset = pa & PAGE_MASK;
2930 size = roundup(offset + size, PAGE_SIZE);
2932 va = kmem_alloc_nofault(&kernel_map, size);
2934 panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
2936 pa = pa & VPTE_FRAME;
2937 for (tmpva = va; size > 0;) {
2938 pte = KernelPTA + (tmpva >> PAGE_SHIFT);
2939 *pte = pa | VPTE_R | VPTE_W | VPTE_V; /* | pgeflag; */
2947 return ((void *)(va + offset));
2951 pmap_unmapdev(vm_offset_t va, vm_size_t size)
2953 vm_offset_t base, offset;
2955 base = va & VPTE_FRAME;
2956 offset = va & PAGE_MASK;
2957 size = roundup(offset + size, PAGE_SIZE);
2958 pmap_qremove(va, size >> PAGE_SHIFT);
2959 kmem_free(&kernel_map, base, size);
2965 * perform the pmap work for mincore
2968 pmap_mincore(pmap_t pmap, vm_offset_t addr)
2974 ptep = pmap_pte(pmap, addr);
2979 if ((pte = *ptep) != 0) {
2982 val = MINCORE_INCORE;
2983 if ((pte & VPTE_MANAGED) == 0)
2986 pa = pte & VPTE_FRAME;
2988 m = PHYS_TO_VM_PAGE(pa);
2994 val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
2996 * Modified by someone
2998 else if (m->dirty || pmap_is_modified(m))
2999 val |= MINCORE_MODIFIED_OTHER;
3004 val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
3007 * Referenced by someone
3009 else if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) {
3010 val |= MINCORE_REFERENCED_OTHER;
3011 vm_page_flag_set(m, PG_REFERENCED);
3018 pmap_replacevm(struct proc *p, struct vmspace *newvm, int adjrefs)
3020 struct vmspace *oldvm;
3023 oldvm = p->p_vmspace;
3025 if (oldvm != newvm) {
3026 p->p_vmspace = newvm;
3027 KKASSERT(p->p_nthreads == 1);
3028 lp = RB_ROOT(&p->p_lwp_tree);
3029 pmap_setlwpvm(lp, newvm);
3031 sysref_get(&newvm->vm_sysref);
3032 sysref_put(&oldvm->vm_sysref);
3039 pmap_setlwpvm(struct lwp *lp, struct vmspace *newvm)
3041 struct vmspace *oldvm;
3045 oldvm = lp->lwp_vmspace;
3047 if (oldvm != newvm) {
3048 lp->lwp_vmspace = newvm;
3049 if (curthread->td_lwp == lp) {
3050 pmap = vmspace_pmap(newvm);
3052 atomic_set_int(&pmap->pm_active, 1 << mycpu->gd_cpuid);
3054 pmap->pm_active |= 1;
3056 #if defined(SWTCH_OPTIM_STATS)
3059 pmap = vmspace_pmap(oldvm);
3061 atomic_clear_int(&pmap->pm_active,
3062 1 << mycpu->gd_cpuid);
3064 pmap->pm_active &= ~1;
3073 pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size)
3076 if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) {
3080 addr = (addr + (NBPDR - 1)) & ~(NBPDR - 1);
3087 static void pads (pmap_t pm);
3088 void pmap_pvdump (vm_paddr_t pa);
3090 /* print address space of pmap*/
3098 if (pm == &kernel_pmap)
3100 for (i = 0; i < 1024; i++)
3102 for (j = 0; j < 1024; j++) {
3103 va = (i << PDRSHIFT) + (j << PAGE_SHIFT);
3104 if (pm == &kernel_pmap && va < KERNBASE)
3106 if (pm != &kernel_pmap && va > UPT_MAX_ADDRESS)
3108 ptep = pmap_pte(pm, va);
3109 if (ptep && (*ptep & VPTE_V)) {
3111 (void *)va, (unsigned)*ptep);
3118 pmap_pvdump(vm_paddr_t pa)
3123 kprintf("pa %08llx", (long long)pa);
3124 m = PHYS_TO_VM_PAGE(pa);
3125 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
3127 kprintf(" -> pmap %p, va %x, flags %x",
3128 (void *)pv->pv_pmap, pv->pv_va, pv->pv_flags);
3130 kprintf(" -> pmap %p, va %x", (void *)pv->pv_pmap, pv->pv_va);