4 * Copyright (c) 2006 The DragonFly Project. All rights reserved.
5 * Copyright (c) 1991 Regents of the University of California.
7 * Copyright (c) 1994 John S. Dyson
9 * Copyright (c) 1994 David Greenman
10 * All rights reserved.
11 * Copyright (c) 2004-2006 Matthew Dillon
12 * All rights reserved.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in
22 * the documentation and/or other materials provided with the
24 * 3. Neither the name of The DragonFly Project nor the names of its
25 * contributors may be used to endorse or promote products derived
26 * from this software without specific, prior written permission.
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
31 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
32 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
33 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
34 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
35 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
36 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
37 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
38 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41 * from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
42 * $FreeBSD: src/sys/i386/i386/pmap.c,v 1.250.2.18 2002/03/06 22:48:53 silby Exp $
45 * NOTE: PMAP_INVAL_ADD: In pc32 this function is called prior to adjusting
46 * the PTE in the page table, because a cpu synchronization might be required.
47 * The actual invalidation is delayed until the following call or flush. In
48 * the VKERNEL build this function is called prior to adjusting the PTE and
49 * invalidates the table synchronously (not delayed), and is not SMP safe
53 #include <sys/types.h>
54 #include <sys/systm.h>
55 #include <sys/kernel.h>
58 #include <sys/vkernel.h>
60 #include <sys/thread.h>
62 #include <sys/vmspace.h>
65 #include <vm/vm_page.h>
66 #include <vm/vm_extern.h>
67 #include <vm/vm_kern.h>
68 #include <vm/vm_object.h>
69 #include <vm/vm_zone.h>
70 #include <vm/vm_pageout.h>
72 #include <machine/md_var.h>
73 #include <machine/pcb.h>
74 #include <machine/pmap_inval.h>
75 #include <machine/globaldata.h>
77 #include <sys/sysref2.h>
81 struct pmap kernel_pmap;
83 static struct vm_zone pvzone;
84 static struct vm_object pvzone_obj;
85 static TAILQ_HEAD(,pmap) pmap_list = TAILQ_HEAD_INITIALIZER(pmap_list);
86 static int pv_entry_count;
87 static int pv_entry_max;
88 static int pv_entry_high_water;
89 static int pmap_pagedaemon_waken;
90 static boolean_t pmap_initialized = FALSE;
91 static int protection_codes[8];
93 static void i386_protection_init(void);
94 static void pmap_remove_all(vm_page_t m);
95 static int pmap_release_free_page(struct pmap *pmap, vm_page_t p);
98 #ifndef PMAP_SHPGPERPROC
99 #define PMAP_SHPGPERPROC 200
102 #define pmap_pde(m, v) (&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT]))
104 #define pte_prot(m, p) \
105 (protection_codes[p & (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)])
111 struct pv_entry *pvinit;
113 for (i = 0; i < vm_page_array_size; i++) {
116 m = &vm_page_array[i];
117 TAILQ_INIT(&m->md.pv_list);
118 m->md.pv_list_count = 0;
121 i = vm_page_array_size;
124 pvinit = (struct pv_entry *)kmem_alloc(&kernel_map, i*sizeof(*pvinit));
125 zbootinit(&pvzone, "PV ENTRY", sizeof(*pvinit), pvinit, i);
126 pmap_initialized = TRUE;
132 int shpgperproc = PMAP_SHPGPERPROC;
134 TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
135 pv_entry_max = shpgperproc * maxproc + vm_page_array_size;
136 TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
137 pv_entry_high_water = 9 * (pv_entry_max / 10);
138 zinitna(&pvzone, &pvzone_obj, NULL, 0, pv_entry_max, ZONE_INTERRUPT, 1);
142 * Bootstrap the kernel_pmap so it can be used with pmap_enter().
144 * NOTE! pm_pdir for the kernel pmap is offset so VA's translate
145 * directly into PTD indexes (PTA is also offset for the same reason).
146 * This is necessary because, for now, KVA is not mapped at address 0.
148 * Page table pages are not managed like they are in normal pmaps, so
149 * no pteobj is needed.
154 vm_pindex_t i = (vm_offset_t)KernelPTD >> PAGE_SHIFT;
156 kernel_pmap.pm_pdir = KernelPTD - (KvaStart >> SEG_SHIFT);
157 kernel_pmap.pm_pdirpte = KernelPTA[i];
158 kernel_pmap.pm_count = 1;
159 kernel_pmap.pm_active = (cpumask_t)-1 & ~CPUMASK_LOCK;
160 TAILQ_INIT(&kernel_pmap.pm_pvlist);
161 i386_protection_init();
165 * Initialize pmap0/vmspace0 . Since process 0 never enters user mode we
166 * just dummy it up so it works well enough for fork().
168 * In DragonFly, process pmaps may only be used to manipulate user address
169 * space, never kernel address space.
172 pmap_pinit0(struct pmap *pmap)
177 /************************************************************************
178 * Procedures to manage whole physical maps *
179 ************************************************************************
181 * Initialize a preallocated and zeroed pmap structure,
182 * such as one in a vmspace structure.
185 pmap_pinit(struct pmap *pmap)
191 * No need to allocate page table space yet but we do need a valid
192 * page directory table.
194 if (pmap->pm_pdir == NULL) {
196 (vpte_t *)kmem_alloc_pageable(&kernel_map, PAGE_SIZE);
200 * allocate object for the pte array and page directory
202 npages = VPTE_PAGETABLE_SIZE +
203 (VM_MAX_USER_ADDRESS / PAGE_SIZE) * sizeof(vpte_t);
204 npages = (npages + PAGE_MASK) / PAGE_SIZE;
206 if (pmap->pm_pteobj == NULL)
207 pmap->pm_pteobj = vm_object_allocate(OBJT_DEFAULT, npages);
208 pmap->pm_pdindex = npages - 1;
211 * allocate the page directory page
213 ptdpg = vm_page_grab(pmap->pm_pteobj, pmap->pm_pdindex,
214 VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
216 ptdpg->wire_count = 1;
217 ++vmstats.v_wire_count;
219 /* not usually mapped */
220 vm_page_flag_clear(ptdpg, PG_MAPPED | PG_BUSY);
221 ptdpg->valid = VM_PAGE_BITS_ALL;
223 pmap_kenter((vm_offset_t)pmap->pm_pdir, VM_PAGE_TO_PHYS(ptdpg));
224 pmap->pm_pdirpte = KernelPTA[(vm_offset_t)pmap->pm_pdir >> PAGE_SHIFT];
225 if ((ptdpg->flags & PG_ZERO) == 0)
226 bzero(pmap->pm_pdir, PAGE_SIZE);
230 pmap->pm_ptphint = NULL;
231 pmap->pm_cpucachemask = 0;
232 TAILQ_INIT(&pmap->pm_pvlist);
233 bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
234 pmap->pm_stats.resident_count = 1;
238 * Clean up a pmap structure so it can be physically freed
243 pmap_puninit(pmap_t pmap)
245 lwkt_gettoken(&vm_token);
247 kmem_free(&kernel_map, (vm_offset_t)pmap->pm_pdir, PAGE_SIZE);
248 pmap->pm_pdir = NULL;
250 if (pmap->pm_pteobj) {
251 vm_object_deallocate(pmap->pm_pteobj);
252 pmap->pm_pteobj = NULL;
254 lwkt_reltoken(&vm_token);
259 * Wire in kernel global address entries. To avoid a race condition
260 * between pmap initialization and pmap_growkernel, this procedure
261 * adds the pmap to the master list (which growkernel scans to update),
262 * then copies the template.
264 * In a virtual kernel there are no kernel global address entries.
269 pmap_pinit2(struct pmap *pmap)
272 lwkt_gettoken(&vm_token);
273 TAILQ_INSERT_TAIL(&pmap_list, pmap, pm_pmnode);
274 lwkt_reltoken(&vm_token);
279 * Release all resources held by the given physical map.
281 * Should only be called if the map contains no valid mappings.
285 static int pmap_release_callback(struct vm_page *p, void *data);
288 pmap_release(struct pmap *pmap)
290 struct mdglobaldata *gd = mdcpu;
291 vm_object_t object = pmap->pm_pteobj;
292 struct rb_vm_page_scan_info info;
294 KKASSERT(pmap != &kernel_pmap);
296 #if defined(DIAGNOSTIC)
297 if (object->ref_count != 1)
298 panic("pmap_release: pteobj reference count != 1");
301 * Once we destroy the page table, the mapping becomes invalid.
302 * Don't waste time doing a madvise to invalidate the mapping, just
303 * set cpucachemask to 0.
305 if (pmap->pm_pdir == gd->gd_PT1pdir) {
306 gd->gd_PT1pdir = NULL;
308 /* madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL); */
310 if (pmap->pm_pdir == gd->gd_PT2pdir) {
311 gd->gd_PT2pdir = NULL;
313 /* madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL); */
315 if (pmap->pm_pdir == gd->gd_PT3pdir) {
316 gd->gd_PT3pdir = NULL;
318 /* madvise(gd->gd_PT3map, SEG_SIZE, MADV_INVAL); */
322 info.object = object;
324 lwkt_gettoken(&vm_token);
325 TAILQ_REMOVE(&pmap_list, pmap, pm_pmnode);
332 info.limit = object->generation;
334 vm_page_rb_tree_RB_SCAN(&object->rb_memq, NULL,
335 pmap_release_callback, &info);
336 if (info.error == 0 && info.mpte) {
337 if (!pmap_release_free_page(pmap, info.mpte))
341 } while (info.error);
344 * Leave the KVA reservation for pm_pdir cached for later reuse.
346 pmap->pm_pdirpte = 0;
347 pmap->pm_cpucachemask = 0;
348 lwkt_reltoken(&vm_token);
352 * Callback to release a page table page backing a directory
356 pmap_release_callback(struct vm_page *p, void *data)
358 struct rb_vm_page_scan_info *info = data;
360 if (p->pindex == info->pmap->pm_pdindex) {
364 if (!pmap_release_free_page(info->pmap, p)) {
368 if (info->object->generation != info->limit) {
376 * Retire the given physical map from service. Should only be called if
377 * the map contains no valid mappings.
382 pmap_destroy(pmap_t pmap)
387 lwkt_gettoken(&vm_token);
388 if (--pmap->pm_count == 0) {
390 panic("destroying a pmap is not yet implemented");
392 lwkt_reltoken(&vm_token);
396 * Add a reference to the specified pmap.
401 pmap_reference(pmap_t pmap)
404 lwkt_gettoken(&vm_token);
406 lwkt_reltoken(&vm_token);
410 /************************************************************************
411 * VMSPACE MANAGEMENT *
412 ************************************************************************
414 * The VMSPACE management we do in our virtual kernel must be reflected
415 * in the real kernel. This is accomplished by making vmspace system
416 * calls to the real kernel.
419 cpu_vmspace_alloc(struct vmspace *vm)
424 #define LAST_EXTENT (VM_MAX_USER_ADDRESS - 0x80000000)
426 if (vmspace_create(&vm->vm_pmap, 0, NULL) < 0)
427 panic("vmspace_create() failed");
429 rp = vmspace_mmap(&vm->vm_pmap, (void *)0x00000000, 0x40000000,
430 PROT_READ|PROT_WRITE,
431 MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED,
433 if (rp == MAP_FAILED)
434 panic("vmspace_mmap: failed1");
435 vmspace_mcontrol(&vm->vm_pmap, (void *)0x00000000, 0x40000000,
437 rp = vmspace_mmap(&vm->vm_pmap, (void *)0x40000000, 0x40000000,
438 PROT_READ|PROT_WRITE,
439 MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED,
440 MemImageFd, 0x40000000);
441 if (rp == MAP_FAILED)
442 panic("vmspace_mmap: failed2");
443 vmspace_mcontrol(&vm->vm_pmap, (void *)0x40000000, 0x40000000,
445 rp = vmspace_mmap(&vm->vm_pmap, (void *)0x80000000, LAST_EXTENT,
446 PROT_READ|PROT_WRITE,
447 MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED,
448 MemImageFd, 0x80000000);
449 vmspace_mcontrol(&vm->vm_pmap, (void *)0x80000000, LAST_EXTENT,
451 if (rp == MAP_FAILED)
452 panic("vmspace_mmap: failed3");
454 r = vmspace_mcontrol(&vm->vm_pmap, (void *)0x00000000, 0x40000000,
455 MADV_SETMAP, vmspace_pmap(vm)->pm_pdirpte);
457 panic("vmspace_mcontrol: failed1");
458 r = vmspace_mcontrol(&vm->vm_pmap, (void *)0x40000000, 0x40000000,
459 MADV_SETMAP, vmspace_pmap(vm)->pm_pdirpte);
461 panic("vmspace_mcontrol: failed2");
462 r = vmspace_mcontrol(&vm->vm_pmap, (void *)0x80000000, LAST_EXTENT,
463 MADV_SETMAP, vmspace_pmap(vm)->pm_pdirpte);
465 panic("vmspace_mcontrol: failed3");
469 cpu_vmspace_free(struct vmspace *vm)
471 if (vmspace_destroy(&vm->vm_pmap) < 0)
472 panic("vmspace_destroy() failed");
475 /************************************************************************
476 * Procedures which operate directly on the kernel PMAP *
477 ************************************************************************/
480 * This maps the requested page table and gives us access to it.
482 * This routine can be called from a potentially preempting interrupt
483 * thread or from a normal thread.
486 get_ptbase(struct pmap *pmap, vm_offset_t va)
488 struct mdglobaldata *gd = mdcpu;
490 if (pmap == &kernel_pmap) {
491 KKASSERT(va >= KvaStart && va < KvaEnd);
492 return(KernelPTA + (va >> PAGE_SHIFT));
493 } else if (pmap->pm_pdir == gd->gd_PT1pdir) {
494 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
495 *gd->gd_PT1pde = pmap->pm_pdirpte;
496 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
497 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
499 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
500 } else if (pmap->pm_pdir == gd->gd_PT2pdir) {
501 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
502 *gd->gd_PT2pde = pmap->pm_pdirpte;
503 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
504 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
506 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
510 * If we aren't running from a potentially preempting interrupt,
511 * load a new page table directory into the page table cache
513 if (gd->mi.gd_intr_nesting_level == 0 &&
514 (gd->mi.gd_curthread->td_flags & TDF_INTTHREAD) == 0) {
516 * Choose one or the other and map the page table
517 * in the KVA space reserved for it.
519 if ((gd->gd_PTflip = 1 - gd->gd_PTflip) == 0) {
520 gd->gd_PT1pdir = pmap->pm_pdir;
521 *gd->gd_PT1pde = pmap->pm_pdirpte;
522 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
523 atomic_set_int(&pmap->pm_cpucachemask,
525 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
527 gd->gd_PT2pdir = pmap->pm_pdir;
528 *gd->gd_PT2pde = pmap->pm_pdirpte;
529 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
530 atomic_set_int(&pmap->pm_cpucachemask,
532 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
537 * If we are running from a preempting interrupt use a private
538 * map. The caller must be in a critical section.
540 KKASSERT(IN_CRITICAL_SECT(curthread));
541 if (pmap->pm_pdir == gd->gd_PT3pdir) {
542 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
543 *gd->gd_PT3pde = pmap->pm_pdirpte;
544 madvise(gd->gd_PT3map, SEG_SIZE, MADV_INVAL);
545 atomic_set_int(&pmap->pm_cpucachemask,
549 gd->gd_PT3pdir = pmap->pm_pdir;
550 *gd->gd_PT3pde = pmap->pm_pdirpte;
551 madvise(gd->gd_PT3map, SEG_SIZE, MADV_INVAL);
552 atomic_set_int(&pmap->pm_cpucachemask,
555 return(gd->gd_PT3map + (va >> PAGE_SHIFT));
559 get_ptbase1(struct pmap *pmap, vm_offset_t va)
561 struct mdglobaldata *gd = mdcpu;
563 if (pmap == &kernel_pmap) {
564 KKASSERT(va >= KvaStart && va < KvaEnd);
565 return(KernelPTA + (va >> PAGE_SHIFT));
566 } else if (pmap->pm_pdir == gd->gd_PT1pdir) {
567 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
568 *gd->gd_PT1pde = pmap->pm_pdirpte;
569 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
570 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
572 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
574 KKASSERT(gd->mi.gd_intr_nesting_level == 0 &&
575 (gd->mi.gd_curthread->td_flags & TDF_INTTHREAD) == 0);
576 gd->gd_PT1pdir = pmap->pm_pdir;
577 *gd->gd_PT1pde = pmap->pm_pdirpte;
578 madvise(gd->gd_PT1map, SEG_SIZE, MADV_INVAL);
579 return(gd->gd_PT1map + (va >> PAGE_SHIFT));
583 get_ptbase2(struct pmap *pmap, vm_offset_t va)
585 struct mdglobaldata *gd = mdcpu;
587 if (pmap == &kernel_pmap) {
588 KKASSERT(va >= KvaStart && va < KvaEnd);
589 return(KernelPTA + (va >> PAGE_SHIFT));
590 } else if (pmap->pm_pdir == gd->gd_PT2pdir) {
591 if ((pmap->pm_cpucachemask & gd->mi.gd_cpumask) == 0) {
592 *gd->gd_PT2pde = pmap->pm_pdirpte;
593 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
594 atomic_set_int(&pmap->pm_cpucachemask, gd->mi.gd_cpumask);
596 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
598 KKASSERT(gd->mi.gd_intr_nesting_level == 0 &&
599 (gd->mi.gd_curthread->td_flags & TDF_INTTHREAD) == 0);
600 gd->gd_PT2pdir = pmap->pm_pdir;
601 *gd->gd_PT2pde = pmap->pm_pdirpte;
602 madvise(gd->gd_PT2map, SEG_SIZE, MADV_INVAL);
603 return(gd->gd_PT2map + (va >> PAGE_SHIFT));
607 * Return a pointer to the page table entry for the specified va in the
608 * specified pmap. NULL is returned if there is no valid page table page
611 static __inline vpte_t *
612 pmap_pte(struct pmap *pmap, vm_offset_t va)
616 ptep = &pmap->pm_pdir[va >> SEG_SHIFT];
620 return (get_ptbase(pmap, va));
626 * Enter a mapping into kernel_pmap. Mappings created in this fashion
627 * are not managed. Mappings must be immediately accessible on all cpus.
629 * Call pmap_inval_pte() to invalidate the virtual pte and clean out the
630 * real pmap and handle related races before storing the new vpte.
633 pmap_kenter(vm_offset_t va, vm_paddr_t pa)
638 KKASSERT(va >= KvaStart && va < KvaEnd);
639 npte = (vpte_t)pa | VPTE_R | VPTE_W | VPTE_V;
640 ptep = KernelPTA + (va >> PAGE_SHIFT);
642 pmap_inval_pte(ptep, &kernel_pmap, va);
647 * Synchronize a kvm mapping originally made for the private use on
648 * some other cpu so it can be used on all cpus.
650 * XXX add MADV_RESYNC to improve performance.
653 pmap_kenter_sync(vm_offset_t va)
655 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
659 * Synchronize a kvm mapping originally made for the private use on
660 * some other cpu so it can be used on our cpu. Turns out to be the
661 * same madvise() call, because we have to sync the real pmaps anyway.
663 * XXX add MADV_RESYNC to improve performance.
666 pmap_kenter_sync_quick(vm_offset_t va)
668 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
673 * Make a previously read-only kernel mapping R+W (not implemented by
677 pmap_kmodify_rw(vm_offset_t va)
679 *pmap_kpte(va) |= VPTE_R | VPTE_W;
680 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
684 * Make a kernel mapping non-cacheable (not applicable to virtual kernels)
687 pmap_kmodify_nc(vm_offset_t va)
689 *pmap_kpte(va) |= VPTE_N;
690 madvise((void *)va, PAGE_SIZE, MADV_INVAL);
696 * Map a contiguous range of physical memory to a KVM
699 pmap_map(vm_offset_t *virtp, vm_paddr_t start, vm_paddr_t end, int prot)
701 vm_offset_t sva, virt;
704 while (start < end) {
705 pmap_kenter(virt, start);
714 pmap_kpte(vm_offset_t va)
718 KKASSERT(va >= KvaStart && va < KvaEnd);
719 ptep = KernelPTA + (va >> PAGE_SHIFT);
724 * Enter an unmanaged KVA mapping for the private use of the current
725 * cpu only. pmap_kenter_sync() may be called to make the mapping usable
728 * It is illegal for the mapping to be accessed by other cpus unleess
729 * pmap_kenter_sync*() is called.
732 pmap_kenter_quick(vm_offset_t va, vm_paddr_t pa)
737 KKASSERT(va >= KvaStart && va < KvaEnd);
739 npte = (vpte_t)pa | VPTE_R | VPTE_W | VPTE_V;
740 ptep = KernelPTA + (va >> PAGE_SHIFT);
742 pmap_inval_pte_quick(ptep, &kernel_pmap, va);
747 * Make a temporary mapping for a physical address. This is only intended
748 * to be used for panic dumps.
751 pmap_kenter_temporary(vm_paddr_t pa, int i)
753 pmap_kenter(crashdumpmap + (i * PAGE_SIZE), pa);
754 return ((void *)crashdumpmap);
758 * Remove an unmanaged mapping created with pmap_kenter*().
761 pmap_kremove(vm_offset_t va)
765 KKASSERT(va >= KvaStart && va < KvaEnd);
767 ptep = KernelPTA + (va >> PAGE_SHIFT);
769 pmap_inval_pte(ptep, &kernel_pmap, va);
774 * Remove an unmanaged mapping created with pmap_kenter*() but synchronize
775 * only with this cpu.
777 * Unfortunately because we optimize new entries by testing VPTE_V later
778 * on, we actually still have to synchronize with all the cpus. XXX maybe
779 * store a junk value and test against 0 in the other places instead?
782 pmap_kremove_quick(vm_offset_t va)
786 KKASSERT(va >= KvaStart && va < KvaEnd);
788 ptep = KernelPTA + (va >> PAGE_SHIFT);
790 pmap_inval_pte(ptep, &kernel_pmap, va); /* NOT _quick */
795 * Extract the physical address from the kernel_pmap that is associated
796 * with the specified virtual address.
799 pmap_kextract(vm_offset_t va)
804 KKASSERT(va >= KvaStart && va < KvaEnd);
806 ptep = KernelPTA + (va >> PAGE_SHIFT);
807 pa = (vm_paddr_t)(*ptep & VPTE_FRAME) | (va & PAGE_MASK);
812 * Map a set of unmanaged VM pages into KVM.
815 pmap_qenter(vm_offset_t va, struct vm_page **m, int count)
817 KKASSERT(va >= KvaStart && va + count * PAGE_SIZE < KvaEnd);
821 ptep = KernelPTA + (va >> PAGE_SHIFT);
823 pmap_inval_pte(ptep, &kernel_pmap, va);
824 *ptep = (vpte_t)(*m)->phys_addr | VPTE_R | VPTE_W | VPTE_V;
832 * Undo the effects of pmap_qenter*().
835 pmap_qremove(vm_offset_t va, int count)
837 KKASSERT(va >= KvaStart && va + count * PAGE_SIZE < KvaEnd);
841 ptep = KernelPTA + (va >> PAGE_SHIFT);
843 pmap_inval_pte(ptep, &kernel_pmap, va);
850 /************************************************************************
851 * Misc support glue called by machine independant code *
852 ************************************************************************
854 * These routines are called by machine independant code to operate on
855 * certain machine-dependant aspects of processes, threads, and pmaps.
859 * Initialize MD portions of the thread structure.
862 pmap_init_thread(thread_t td)
864 /* enforce pcb placement */
865 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_size) - 1;
866 td->td_savefpu = &td->td_pcb->pcb_save;
867 td->td_sp = (char *)td->td_pcb - 16;
871 * This routine directly affects the fork perf for a process.
874 pmap_init_proc(struct proc *p)
879 * Destroy the UPAGES for a process that has exited and disassociate
880 * the process from its thread.
883 pmap_dispose_proc(struct proc *p)
885 KASSERT(p->p_lock == 0, ("attempt to dispose referenced proc! %p", p));
889 * We pre-allocate all page table pages for kernel virtual memory so
890 * this routine will only be called if KVM has been exhausted.
895 pmap_growkernel(vm_offset_t kstart, vm_offset_t kend)
899 addr = (kend + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
901 lwkt_gettoken(&vm_token);
902 if (addr > virtual_end - SEG_SIZE)
903 panic("KVM exhausted");
904 kernel_vm_end = addr;
905 lwkt_reltoken(&vm_token);
909 * The modification bit is not tracked for any pages in this range. XXX
910 * such pages in this maps should always use pmap_k*() functions and not
913 * XXX User and kernel address spaces are independant for virtual kernels,
914 * this function only applies to the kernel pmap.
917 pmap_track_modified(pmap_t pmap, vm_offset_t va)
919 if (pmap != &kernel_pmap)
921 if ((va < clean_sva) || (va >= clean_eva))
927 /************************************************************************
928 * Procedures supporting managed page table pages *
929 ************************************************************************
931 * These procedures are used to track managed page table pages. These pages
932 * use the page table page's vm_page_t to track PTEs in the page. The
933 * page table pages themselves are arranged in a VM object, pmap->pm_pteobj.
935 * This allows the system to throw away page table pages for user processes
936 * at will and reinstantiate them on demand.
940 * This routine works like vm_page_lookup() but also blocks as long as the
941 * page is busy. This routine does not busy the page it returns.
943 * Unless the caller is managing objects whos pages are in a known state,
944 * the call should be made with a critical section held so the page's object
945 * association remains valid on return.
948 pmap_page_lookup(vm_object_t object, vm_pindex_t pindex)
953 m = vm_page_lookup(object, pindex);
954 if (m && vm_page_sleep_busy(m, FALSE, "pplookp"))
960 * This routine unholds page table pages, and if the hold count
961 * drops to zero, then it decrements the wire count.
963 * We must recheck that this is the last hold reference after busy-sleeping
967 _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
969 while (vm_page_sleep_busy(m, FALSE, "pmuwpt"))
971 KASSERT(m->queue == PQ_NONE,
972 ("_pmap_unwire_pte_hold: %p->queue != PQ_NONE", m));
974 if (m->hold_count == 1) {
976 * Unmap the page table page.
979 KKASSERT(pmap->pm_pdir[m->pindex] != 0);
980 pmap_inval_pde(&pmap->pm_pdir[m->pindex], pmap,
981 (vm_offset_t)m->pindex << SEG_SHIFT);
982 KKASSERT(pmap->pm_stats.resident_count > 0);
983 --pmap->pm_stats.resident_count;
985 if (pmap->pm_ptphint == m)
986 pmap->pm_ptphint = NULL;
989 * This was our last hold, the page had better be unwired
990 * after we decrement wire_count.
992 * FUTURE NOTE: shared page directory page could result in
993 * multiple wire counts.
997 KKASSERT(m->wire_count == 0);
998 --vmstats.v_wire_count;
999 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1001 vm_page_free_zero(m);
1004 KKASSERT(m->hold_count > 1);
1010 pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
1012 KKASSERT(m->hold_count > 0);
1013 if (m->hold_count > 1) {
1017 return _pmap_unwire_pte_hold(pmap, m);
1022 * After removing a page table entry, this routine is used to
1023 * conditionally free the page, and manage the hold/wire counts.
1026 pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t mpte)
1032 * page table pages in the kernel_pmap are not managed.
1034 if (pmap == &kernel_pmap)
1036 ptepindex = (va >> PDRSHIFT);
1037 if (pmap->pm_ptphint &&
1038 (pmap->pm_ptphint->pindex == ptepindex)) {
1039 mpte = pmap->pm_ptphint;
1041 mpte = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1042 pmap->pm_ptphint = mpte;
1045 return pmap_unwire_pte_hold(pmap, mpte);
1049 * Attempt to release and free the vm_page backing a page directory page
1050 * in a pmap. Returns 1 on success, 0 on failure (if the procedure had
1054 pmap_release_free_page(struct pmap *pmap, vm_page_t p)
1056 vpte_t *pde = pmap->pm_pdir;
1059 * This code optimizes the case of freeing non-busy
1060 * page-table pages. Those pages are zero now, and
1061 * might as well be placed directly into the zero queue.
1063 if (vm_page_sleep_busy(p, FALSE, "pmaprl"))
1067 KKASSERT(pmap->pm_stats.resident_count > 0);
1068 --pmap->pm_stats.resident_count;
1070 if (p->hold_count) {
1071 panic("pmap_release: freeing held page table page");
1074 * Page directory pages need to have the kernel stuff cleared, so
1075 * they can go into the zero queue also.
1077 * In virtual kernels there is no 'kernel stuff'. For the moment
1078 * I just make sure the whole thing has been zero'd even though
1079 * it should already be completely zero'd.
1081 * pmaps for vkernels do not self-map because they do not share
1082 * their address space with the vkernel. Clearing of pde[] thus
1083 * only applies to page table pages and not to the page directory
1086 if (p->pindex == pmap->pm_pdindex) {
1087 bzero(pde, VPTE_PAGETABLE_SIZE);
1088 pmap_kremove((vm_offset_t)pmap->pm_pdir);
1090 KKASSERT(pde[p->pindex] != 0);
1091 pmap_inval_pde(&pde[p->pindex], pmap,
1092 (vm_offset_t)p->pindex << SEG_SHIFT);
1096 * Clear the matching hint
1098 if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == p->pindex))
1099 pmap->pm_ptphint = NULL;
1102 * And throw the page away. The page is completely zero'd out so
1103 * optimize the free call.
1106 vmstats.v_wire_count--;
1107 vm_page_free_zero(p);
1112 * This routine is called if the page table page is not mapped in the page
1115 * The routine is broken up into two parts for readability.
1117 * It must return a held mpte and map the page directory page as required.
1118 * Because vm_page_grab() can block, we must re-check pm_pdir[ptepindex]
1121 _pmap_allocpte(pmap_t pmap, unsigned ptepindex)
1127 * Find or fabricate a new pagetable page. A busied page will be
1128 * returned. This call may block.
1130 m = vm_page_grab(pmap->pm_pteobj, ptepindex,
1131 VM_ALLOC_NORMAL | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
1133 KASSERT(m->queue == PQ_NONE,
1134 ("_pmap_allocpte: %p->queue != PQ_NONE", m));
1137 * Increment the hold count for the page we will be returning to
1143 * It is possible that someone else got in and mapped by the page
1144 * directory page while we were blocked, if so just unbusy and
1145 * return the held page.
1147 if ((ptepa = pmap->pm_pdir[ptepindex]) != 0) {
1148 KKASSERT((ptepa & VPTE_FRAME) == VM_PAGE_TO_PHYS(m));
1153 if (m->wire_count == 0)
1154 vmstats.v_wire_count++;
1158 * Map the pagetable page into the process address space, if
1159 * it isn't already there.
1161 ++pmap->pm_stats.resident_count;
1163 ptepa = VM_PAGE_TO_PHYS(m);
1164 pmap->pm_pdir[ptepindex] = (vpte_t)ptepa | VPTE_R | VPTE_W | VPTE_V |
1168 * We are likely about to access this page table page, so set the
1169 * page table hint to reduce overhead.
1171 pmap->pm_ptphint = m;
1174 * Try to use the new mapping, but if we cannot, then
1175 * do it with the routine that maps the page explicitly.
1177 if ((m->flags & PG_ZERO) == 0)
1178 pmap_zero_page(ptepa);
1180 m->valid = VM_PAGE_BITS_ALL;
1181 vm_page_flag_clear(m, PG_ZERO);
1182 vm_page_flag_set(m, PG_MAPPED);
1189 * Determine the page table page required to access the VA in the pmap
1190 * and allocate it if necessary. Return a held vm_page_t for the page.
1192 * Only used with user pmaps.
1195 pmap_allocpte(pmap_t pmap, vm_offset_t va)
1202 * Calculate pagetable page index
1204 ptepindex = va >> PDRSHIFT;
1207 * Get the page directory entry
1209 ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex];
1212 * This supports switching from a 4MB page to a
1215 if (ptepa & VPTE_PS) {
1216 KKASSERT(pmap->pm_pdir[ptepindex] != 0);
1217 pmap_inval_pde(&pmap->pm_pdir[ptepindex], pmap,
1218 (vm_offset_t)ptepindex << SEG_SHIFT);
1223 * If the page table page is mapped, we just increment the
1224 * hold count, and activate it.
1228 * In order to get the page table page, try the
1231 if (pmap->pm_ptphint &&
1232 (pmap->pm_ptphint->pindex == ptepindex)) {
1233 m = pmap->pm_ptphint;
1235 m = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1236 pmap->pm_ptphint = m;
1242 * Here if the pte page isn't mapped, or if it has been deallocated.
1244 return _pmap_allocpte(pmap, ptepindex);
1247 /************************************************************************
1248 * Managed pages in pmaps *
1249 ************************************************************************
1251 * All pages entered into user pmaps and some pages entered into the kernel
1252 * pmap are managed, meaning that pmap_protect() and other related management
1253 * functions work on these pages.
1257 * free the pv_entry back to the free list. This function may be
1258 * called from an interrupt.
1260 static __inline void
1261 free_pv_entry(pv_entry_t pv)
1268 * get a new pv_entry, allocating a block from the system
1269 * when needed. This function may be called from an interrupt.
1275 if (pv_entry_high_water &&
1276 (pv_entry_count > pv_entry_high_water) &&
1277 (pmap_pagedaemon_waken == 0)) {
1278 pmap_pagedaemon_waken = 1;
1279 wakeup (&vm_pages_needed);
1281 return zalloc(&pvzone);
1285 * This routine is very drastic, but can save the system
1295 static int warningdone=0;
1297 if (pmap_pagedaemon_waken == 0)
1299 lwkt_gettoken(&vm_token);
1300 pmap_pagedaemon_waken = 0;
1302 if (warningdone < 5) {
1303 kprintf("pmap_collect: collecting pv entries -- suggest increasing PMAP_SHPGPERPROC\n");
1307 for(i = 0; i < vm_page_array_size; i++) {
1308 m = &vm_page_array[i];
1309 if (m->wire_count || m->hold_count || m->busy ||
1310 (m->flags & PG_BUSY))
1314 lwkt_reltoken(&vm_token);
1318 * If it is the first entry on the list, it is actually
1319 * in the header and we must copy the following entry up
1320 * to the header. Otherwise we must search the list for
1321 * the entry. In either case we free the now unused entry.
1324 pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va)
1330 if (m->md.pv_list_count < pmap->pm_stats.resident_count) {
1331 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
1332 if (pmap == pv->pv_pmap && va == pv->pv_va)
1336 TAILQ_FOREACH(pv, &pmap->pm_pvlist, pv_plist) {
1337 if (va == pv->pv_va)
1343 * Note that pv_ptem is NULL if the page table page itself is not
1344 * managed, even if the page being removed IS managed.
1348 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1349 m->md.pv_list_count--;
1350 TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
1351 if (TAILQ_EMPTY(&m->md.pv_list))
1352 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1353 ++pmap->pm_generation;
1354 rtval = pmap_unuse_pt(pmap, va, pv->pv_ptem);
1362 * Create a pv entry for page at pa for (pmap, va). If the page table page
1363 * holding the VA is managed, mpte will be non-NULL.
1366 pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m)
1371 pv = get_pv_entry();
1376 TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist);
1377 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
1378 ++pmap->pm_generation;
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);
1458 * Remove the given range of addresses from the specified map.
1460 * It is assumed that the start and end are properly rounded to the
1463 * 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 lwkt_gettoken(&vm_token);
1480 KKASSERT(pmap->pm_stats.resident_count >= 0);
1481 if (pmap->pm_stats.resident_count == 0) {
1482 lwkt_reltoken(&vm_token);
1487 * special handling of removing one page. a very
1488 * common operation and easy to short circuit some
1491 if (((sva + PAGE_SIZE) == eva) &&
1492 ((pmap->pm_pdir[(sva >> PDRSHIFT)] & VPTE_PS) == 0)) {
1493 pmap_remove_page(pmap, sva);
1494 lwkt_reltoken(&vm_token);
1499 * Get a local virtual address for the mappings that are being
1502 * XXX this is really messy because the kernel pmap is not relative
1505 sindex = (sva >> PAGE_SHIFT);
1506 eindex = (eva >> PAGE_SHIFT);
1508 for (; sindex < eindex; sindex = pdnxt) {
1512 * Calculate index for next page table.
1514 pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
1515 if (pmap->pm_stats.resident_count == 0)
1518 pdirindex = sindex / NPDEPG;
1519 if (((ptpaddr = pmap->pm_pdir[pdirindex]) & VPTE_PS) != 0) {
1520 KKASSERT(pmap->pm_pdir[pdirindex] != 0);
1521 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1522 pmap_inval_pde(&pmap->pm_pdir[pdirindex], pmap,
1523 (vm_offset_t)pdirindex << SEG_SHIFT);
1528 * Weed out invalid mappings. Note: we assume that the page
1529 * directory table is always allocated, and in kernel virtual.
1535 * Limit our scan to either the end of the va represented
1536 * by the current page table page, or to the end of the
1537 * range being removed.
1543 * NOTE: pmap_remove_pte() can block.
1545 for (; sindex != pdnxt; sindex++) {
1548 ptbase = get_ptbase(pmap, sindex << PAGE_SHIFT);
1551 va = i386_ptob(sindex);
1552 if (pmap_remove_pte(pmap, ptbase, va))
1556 lwkt_reltoken(&vm_token);
1560 * Removes this physical page from all physical maps in which it resides.
1561 * Reflects back modify bits to the pager.
1563 * This routine may not be called from an interrupt.
1568 pmap_remove_all(vm_page_t m)
1573 #if defined(PMAP_DIAGNOSTIC)
1575 * XXX this makes pmap_page_protect(NONE) illegal for non-managed
1578 if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) {
1579 panic("pmap_page_protect: illegal for unmanaged page, va: 0x%08llx", (long long)VM_PAGE_TO_PHYS(m));
1584 lwkt_gettoken(&vm_token);
1585 while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
1586 KKASSERT(pv->pv_pmap->pm_stats.resident_count > 0);
1587 --pv->pv_pmap->pm_stats.resident_count;
1589 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
1590 KKASSERT(pte != NULL);
1592 tpte = pmap_inval_loadandclear(pte, pv->pv_pmap, pv->pv_va);
1593 if (tpte & VPTE_WIRED)
1594 --pv->pv_pmap->pm_stats.wired_count;
1595 KKASSERT(pv->pv_pmap->pm_stats.wired_count >= 0);
1598 vm_page_flag_set(m, PG_REFERENCED);
1601 * Update the vm_page_t clean and reference bits.
1603 if (tpte & VPTE_M) {
1604 #if defined(PMAP_DIAGNOSTIC)
1605 if (pmap_nw_modified((pt_entry_t) tpte)) {
1607 "pmap_remove_all: modified page not writable: va: 0x%x, pte: 0x%x\n",
1611 if (pmap_track_modified(pv->pv_pmap, pv->pv_va))
1614 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1615 TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
1616 ++pv->pv_pmap->pm_generation;
1617 m->md.pv_list_count--;
1618 if (TAILQ_EMPTY(&m->md.pv_list))
1619 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1620 pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
1623 KKASSERT((m->flags & (PG_MAPPED | PG_WRITEABLE)) == 0);
1624 lwkt_reltoken(&vm_token);
1629 * Set the physical protection on the specified range of this map
1632 * This function may not be called from an interrupt if the map is
1633 * not the kernel_pmap.
1638 pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
1642 vm_offset_t pdnxt, ptpaddr;
1643 vm_pindex_t sindex, eindex;
1649 if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
1650 pmap_remove(pmap, sva, eva);
1654 if (prot & VM_PROT_WRITE)
1657 lwkt_gettoken(&vm_token);
1658 ptbase = get_ptbase(pmap, sva);
1660 sindex = (sva >> PAGE_SHIFT);
1661 eindex = (eva >> PAGE_SHIFT);
1664 for (; sindex < eindex; sindex = pdnxt) {
1668 pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
1670 pdirindex = sindex / NPDEPG;
1673 * Clear the modified and writable bits for a 4m page.
1674 * Throw away the modified bit (?)
1676 if (((ptpaddr = pmap->pm_pdir[pdirindex]) & VPTE_PS) != 0) {
1677 pmap_clean_pde(&pmap->pm_pdir[pdirindex], pmap,
1678 (vm_offset_t)pdirindex << SEG_SHIFT);
1679 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1684 * Weed out invalid mappings. Note: we assume that the page
1685 * directory table is always allocated, and in kernel virtual.
1690 if (pdnxt > eindex) {
1694 for (; sindex != pdnxt; sindex++) {
1699 * Clean managed pages and also check the accessed
1700 * bit. Just remove write perms for unmanaged
1701 * pages. Be careful of races, turning off write
1702 * access will force a fault rather then setting
1703 * the modified bit at an unexpected time.
1705 ptep = &ptbase[sindex - sbase];
1706 if (*ptep & VPTE_MANAGED) {
1707 pbits = pmap_clean_pte(ptep, pmap,
1710 if (pbits & VPTE_A) {
1711 m = PHYS_TO_VM_PAGE(pbits);
1712 vm_page_flag_set(m, PG_REFERENCED);
1713 atomic_clear_long(ptep, VPTE_A);
1715 if (pbits & VPTE_M) {
1716 if (pmap_track_modified(pmap, i386_ptob(sindex))) {
1718 m = PHYS_TO_VM_PAGE(pbits);
1723 pbits = pmap_setro_pte(ptep, pmap,
1728 lwkt_reltoken(&vm_token);
1732 * Enter a managed page into a pmap. If the page is not wired related pmap
1733 * data can be destroyed at any time for later demand-operation.
1735 * Insert the vm_page (m) at virtual address (v) in (pmap), with the
1736 * specified protection, and wire the mapping if requested.
1738 * NOTE: This routine may not lazy-evaluate or lose information. The
1739 * page must actually be inserted into the given map NOW.
1741 * NOTE: When entering a page at a KVA address, the pmap must be the
1747 pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
1753 vpte_t origpte, newpte;
1761 lwkt_gettoken(&vm_token);
1764 * Get the page table page. The kernel_pmap's page table pages
1765 * are preallocated and have no associated vm_page_t.
1767 if (pmap == &kernel_pmap)
1770 mpte = pmap_allocpte(pmap, va);
1772 pte = pmap_pte(pmap, va);
1775 * Page Directory table entry not valid, we need a new PT page
1776 * and pmap_allocpte() didn't give us one. Oops!
1779 panic("pmap_enter: invalid page directory pmap=%p, va=0x%p\n",
1784 * Deal with races on the original mapping (though don't worry
1785 * about VPTE_A races) by cleaning it. This will force a fault
1786 * if an attempt is made to write to the page.
1788 pa = VM_PAGE_TO_PHYS(m) & VPTE_FRAME;
1789 origpte = pmap_clean_pte(pte, pmap, va);
1790 opa = origpte & VPTE_FRAME;
1792 if (origpte & VPTE_PS)
1793 panic("pmap_enter: attempted pmap_enter on 4MB page");
1796 * Mapping has not changed, must be protection or wiring change.
1798 if (origpte && (opa == pa)) {
1800 * Wiring change, just update stats. We don't worry about
1801 * wiring PT pages as they remain resident as long as there
1802 * are valid mappings in them. Hence, if a user page is wired,
1803 * the PT page will be also.
1805 if (wired && ((origpte & VPTE_WIRED) == 0))
1806 ++pmap->pm_stats.wired_count;
1807 else if (!wired && (origpte & VPTE_WIRED))
1808 --pmap->pm_stats.wired_count;
1809 KKASSERT(pmap->pm_stats.wired_count >= 0);
1812 * Remove the extra pte reference. Note that we cannot
1813 * optimize the RO->RW case because we have adjusted the
1814 * wiring count above and may need to adjust the wiring
1821 * We might be turning off write access to the page,
1822 * so we go ahead and sense modify status.
1824 if (origpte & VPTE_MANAGED) {
1825 if ((origpte & VPTE_M) &&
1826 pmap_track_modified(pmap, va)) {
1828 om = PHYS_TO_VM_PAGE(opa);
1832 KKASSERT(m->flags & PG_MAPPED);
1837 * Mapping has changed, invalidate old range and fall through to
1838 * handle validating new mapping.
1842 err = pmap_remove_pte(pmap, pte, va);
1844 panic("pmap_enter: pte vanished, va: %p", (void *)va);
1845 pte = pmap_pte(pmap, va);
1846 origpte = pmap_clean_pte(pte, pmap, va);
1847 opa = origpte & VPTE_FRAME;
1849 kprintf("pmap_enter: Warning, raced pmap %p va %p\n",
1855 * Enter on the PV list if part of our managed memory. Note that we
1856 * raise IPL while manipulating pv_table since pmap_enter can be
1857 * called at interrupt time.
1859 if (pmap_initialized &&
1860 (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) {
1861 pmap_insert_entry(pmap, va, mpte, m);
1863 vm_page_flag_set(m, PG_MAPPED);
1867 * Increment counters
1869 ++pmap->pm_stats.resident_count;
1871 pmap->pm_stats.wired_count++;
1875 * Now validate mapping with desired protection/wiring.
1877 newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | VPTE_V);
1880 newpte |= VPTE_WIRED;
1881 if (pmap != &kernel_pmap)
1885 * If the mapping or permission bits are different from the
1886 * (now cleaned) original pte, an update is needed. We've
1887 * already downgraded or invalidated the page so all we have
1888 * to do now is update the bits.
1890 * XXX should we synchronize RO->RW changes to avoid another
1893 if ((origpte & ~(VPTE_W|VPTE_M|VPTE_A)) != newpte) {
1894 *pte = newpte | VPTE_A;
1895 if (newpte & VPTE_W)
1896 vm_page_flag_set(m, PG_WRITEABLE);
1898 KKASSERT((newpte & VPTE_MANAGED) == 0 || m->flags & PG_MAPPED);
1899 lwkt_reltoken(&vm_token);
1903 * This code works like pmap_enter() but assumes VM_PROT_READ and not-wired.
1905 * Currently this routine may only be used on user pmaps, not kernel_pmap.
1908 pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m)
1916 KKASSERT(pmap != &kernel_pmap);
1918 KKASSERT(va >= VM_MIN_USER_ADDRESS && va < VM_MAX_USER_ADDRESS);
1921 * Calculate pagetable page (mpte), allocating it if necessary.
1923 * A held page table page (mpte), or NULL, is passed onto the
1924 * section following.
1926 ptepindex = va >> PDRSHIFT;
1928 lwkt_gettoken(&vm_token);
1932 * Get the page directory entry
1934 ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex];
1937 * If the page table page is mapped, we just increment
1938 * the hold count, and activate it.
1941 if (ptepa & VPTE_PS)
1942 panic("pmap_enter_quick: unexpected mapping into 4MB page");
1943 if (pmap->pm_ptphint &&
1944 (pmap->pm_ptphint->pindex == ptepindex)) {
1945 mpte = pmap->pm_ptphint;
1947 mpte = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1948 pmap->pm_ptphint = mpte;
1953 mpte = _pmap_allocpte(pmap, ptepindex);
1955 } while (mpte == NULL);
1958 * Ok, now that the page table page has been validated, get the pte.
1959 * If the pte is already mapped undo mpte's hold_count and
1962 pte = pmap_pte(pmap, va);
1964 pmap_unwire_pte_hold(pmap, mpte);
1965 lwkt_reltoken(&vm_token);
1970 * Enter on the PV list if part of our managed memory. Note that we
1971 * raise IPL while manipulating pv_table since pmap_enter can be
1972 * called at interrupt time.
1974 if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) {
1975 pmap_insert_entry(pmap, va, mpte, m);
1976 vm_page_flag_set(m, PG_MAPPED);
1980 * Increment counters
1982 ++pmap->pm_stats.resident_count;
1984 pa = VM_PAGE_TO_PHYS(m);
1987 * Now validate mapping with RO protection
1989 if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED))
1990 *pte = (vpte_t)pa | VPTE_V | VPTE_U;
1992 *pte = (vpte_t)pa | VPTE_V | VPTE_U | VPTE_MANAGED;
1993 /*pmap_inval_add(&info, pmap, va); shouldn't be needed 0->valid */
1994 /*pmap_inval_flush(&info); don't need for vkernel */
1995 lwkt_reltoken(&vm_token);
1999 * Extract the physical address for the translation at the specified
2000 * virtual address in the pmap.
2002 * The caller must hold vm_token if non-blocking operation is desired.
2006 pmap_extract(pmap_t pmap, vm_offset_t va)
2011 lwkt_gettoken(&vm_token);
2012 if (pmap && (pte = pmap->pm_pdir[va >> SEG_SHIFT]) != 0) {
2013 if (pte & VPTE_PS) {
2014 rtval = pte & ~((vpte_t)(1 << SEG_SHIFT) - 1);
2015 rtval |= va & SEG_MASK;
2017 pte = *get_ptbase(pmap, va);
2018 rtval = (pte & VPTE_FRAME) | (va & PAGE_MASK);
2023 lwkt_reltoken(&vm_token);
2027 #define MAX_INIT_PT (96)
2030 * This routine preloads the ptes for a given object into the specified pmap.
2031 * This eliminates the blast of soft faults on process startup and
2032 * immediately after an mmap.
2036 static int pmap_object_init_pt_callback(vm_page_t p, void *data);
2039 pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_prot_t prot,
2040 vm_object_t object, vm_pindex_t pindex,
2041 vm_size_t size, int limit)
2043 struct rb_vm_page_scan_info info;
2048 * We can't preinit if read access isn't set or there is no pmap
2051 if ((prot & VM_PROT_READ) == 0 || pmap == NULL || object == NULL)
2055 * We can't preinit if the pmap is not the current pmap
2057 lp = curthread->td_lwp;
2058 if (lp == NULL || pmap != vmspace_pmap(lp->lwp_vmspace))
2061 psize = size >> PAGE_SHIFT;
2063 if ((object->type != OBJT_VNODE) ||
2064 ((limit & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) &&
2065 (object->resident_page_count > MAX_INIT_PT))) {
2069 if (psize + pindex > object->size) {
2070 if (object->size < pindex)
2072 psize = object->size - pindex;
2079 * Use a red-black scan to traverse the requested range and load
2080 * any valid pages found into the pmap.
2082 * We cannot safely scan the object's memq unless we are in a
2083 * critical section since interrupts can remove pages from objects.
2085 info.start_pindex = pindex;
2086 info.end_pindex = pindex + psize - 1;
2093 lwkt_gettoken(&vm_token);
2094 vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp,
2095 pmap_object_init_pt_callback, &info);
2096 lwkt_reltoken(&vm_token);
2101 * The caller must hold vm_token.
2105 pmap_object_init_pt_callback(vm_page_t p, void *data)
2107 struct rb_vm_page_scan_info *info = data;
2108 vm_pindex_t rel_index;
2110 * don't allow an madvise to blow away our really
2111 * free pages allocating pv entries.
2113 if ((info->limit & MAP_PREFAULT_MADVISE) &&
2114 vmstats.v_free_count < vmstats.v_free_reserved) {
2117 if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
2118 (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
2119 if ((p->queue - p->pc) == PQ_CACHE)
2120 vm_page_deactivate(p);
2122 rel_index = p->pindex - info->start_pindex;
2123 pmap_enter_quick(info->pmap,
2124 info->addr + i386_ptob(rel_index), p);
2131 * Return TRUE if the pmap is in shape to trivially
2132 * pre-fault the specified address.
2134 * Returns FALSE if it would be non-trivial or if a
2135 * pte is already loaded into the slot.
2140 pmap_prefault_ok(pmap_t pmap, vm_offset_t addr)
2145 lwkt_gettoken(&vm_token);
2146 if ((*pmap_pde(pmap, addr)) == 0) {
2149 pte = get_ptbase(pmap, addr);
2150 ret = (*pte) ? 0 : 1;
2152 lwkt_reltoken(&vm_token);
2157 * Change the wiring attribute for a map/virtual-address pair.
2158 * The mapping must already exist in the pmap.
2160 * No other requirements.
2163 pmap_change_wiring(pmap_t pmap, vm_offset_t va, boolean_t wired)
2170 lwkt_gettoken(&vm_token);
2171 pte = get_ptbase(pmap, va);
2173 if (wired && (*pte & VPTE_WIRED) == 0)
2174 ++pmap->pm_stats.wired_count;
2175 else if (!wired && (*pte & VPTE_WIRED))
2176 --pmap->pm_stats.wired_count;
2177 KKASSERT(pmap->pm_stats.wired_count >= 0);
2180 * Wiring is not a hardware characteristic so there is no need to
2181 * invalidate TLB. However, in an SMP environment we must use
2182 * a locked bus cycle to update the pte (if we are not using
2183 * the pmap_inval_*() API that is)... it's ok to do this for simple
2187 atomic_set_long(pte, VPTE_WIRED);
2189 atomic_clear_long(pte, VPTE_WIRED);
2190 lwkt_reltoken(&vm_token);
2194 * Copy the range specified by src_addr/len
2195 * from the source map to the range dst_addr/len
2196 * in the destination map.
2198 * This routine is only advisory and need not do anything.
2201 pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr,
2202 vm_size_t len, vm_offset_t src_addr)
2205 vm_offset_t end_addr = src_addr + len;
2212 * XXX BUGGY. Amoung other things srcmpte is assumed to remain
2213 * valid through blocking calls, and that's just not going to
2220 if (dst_addr != src_addr)
2222 if (dst_pmap->pm_pdir == NULL)
2224 if (src_pmap->pm_pdir == NULL)
2229 src_frame = get_ptbase1(src_pmap, src_addr);
2230 dst_frame = get_ptbase2(dst_pmap, src_addr);
2233 * critical section protection is required to maintain the page/object
2234 * association, interrupts can free pages and remove them from
2237 for (addr = src_addr; addr < end_addr; addr = pdnxt) {
2238 vpte_t *src_pte, *dst_pte;
2239 vm_page_t dstmpte, srcmpte;
2240 vm_offset_t srcptepaddr;
2243 if (addr >= VM_MAX_USER_ADDRESS)
2244 panic("pmap_copy: invalid to pmap_copy page tables\n");
2247 * Don't let optional prefaulting of pages make us go
2248 * way below the low water mark of free pages or way
2249 * above high water mark of used pv entries.
2251 if (vmstats.v_free_count < vmstats.v_free_reserved ||
2252 pv_entry_count > pv_entry_high_water)
2255 pdnxt = ((addr + PAGE_SIZE*NPTEPG) & ~(PAGE_SIZE*NPTEPG - 1));
2256 ptepindex = addr >> PDRSHIFT;
2258 srcptepaddr = (vm_offset_t) src_pmap->pm_pdir[ptepindex];
2259 if (srcptepaddr == 0)
2262 if (srcptepaddr & VPTE_PS) {
2263 if (dst_pmap->pm_pdir[ptepindex] == 0) {
2264 dst_pmap->pm_pdir[ptepindex] = (vpte_t)srcptepaddr;
2265 dst_pmap->pm_stats.resident_count += NBPDR / PAGE_SIZE;
2270 srcmpte = vm_page_lookup(src_pmap->pm_pteobj, ptepindex);
2271 if ((srcmpte == NULL) || (srcmpte->hold_count == 0) ||
2272 (srcmpte->flags & PG_BUSY)) {
2276 if (pdnxt > end_addr)
2279 src_pte = src_frame + ((addr - src_addr) >> PAGE_SHIFT);
2280 dst_pte = dst_frame + ((addr - src_addr) >> PAGE_SHIFT);
2281 while (addr < pdnxt) {
2286 * we only virtual copy managed pages
2288 if ((ptetemp & VPTE_MANAGED) != 0) {
2290 * We have to check after allocpte for the
2291 * pte still being around... allocpte can
2294 * pmap_allocpte can block, unfortunately
2295 * we have to reload the tables.
2297 dstmpte = pmap_allocpte(dst_pmap, addr);
2298 src_frame = get_ptbase1(src_pmap, src_addr);
2299 dst_frame = get_ptbase2(dst_pmap, src_addr);
2301 if ((*dst_pte == 0) && (ptetemp = *src_pte) &&
2302 (ptetemp & VPTE_MANAGED) != 0) {
2304 * Clear the modified and accessed
2305 * (referenced) bits during the copy.
2307 * We do not have to clear the write
2308 * bit to force a fault-on-modify
2309 * because the real kernel's target
2310 * pmap is empty and will fault anyway.
2312 m = PHYS_TO_VM_PAGE(ptetemp);
2313 *dst_pte = ptetemp & ~(VPTE_M | VPTE_A);
2314 ++dst_pmap->pm_stats.resident_count;
2315 pmap_insert_entry(dst_pmap, addr,
2317 KKASSERT(m->flags & PG_MAPPED);
2319 pmap_unwire_pte_hold(dst_pmap, dstmpte);
2321 if (dstmpte->hold_count >= srcmpte->hold_count)
2335 * Zero the specified PA by mapping the page into KVM and clearing its
2338 * This function may be called from an interrupt and no locking is
2342 pmap_zero_page(vm_paddr_t phys)
2344 struct mdglobaldata *gd = mdcpu;
2348 panic("pmap_zero_page: CMAP3 busy");
2349 *gd->gd_CMAP3 = VPTE_V | VPTE_R | VPTE_W | (phys & VPTE_FRAME) | VPTE_A | VPTE_M;
2350 madvise(gd->gd_CADDR3, PAGE_SIZE, MADV_INVAL);
2352 bzero(gd->gd_CADDR3, PAGE_SIZE);
2358 * pmap_page_assertzero:
2360 * Assert that a page is empty, panic if it isn't.
2363 pmap_page_assertzero(vm_paddr_t phys)
2365 struct mdglobaldata *gd = mdcpu;
2370 panic("pmap_zero_page: CMAP3 busy");
2371 *gd->gd_CMAP3 = VPTE_V | VPTE_R | VPTE_W |
2372 (phys & VPTE_FRAME) | VPTE_A | VPTE_M;
2373 madvise(gd->gd_CADDR3, PAGE_SIZE, MADV_INVAL);
2374 for (i = 0; i < PAGE_SIZE; i += 4) {
2375 if (*(int *)((char *)gd->gd_CADDR3 + i) != 0) {
2376 panic("pmap_page_assertzero() @ %p not zero!\n",
2377 (void *)gd->gd_CADDR3);
2387 * Zero part of a physical page by mapping it into memory and clearing
2388 * its contents with bzero.
2390 * off and size may not cover an area beyond a single hardware page.
2393 pmap_zero_page_area(vm_paddr_t phys, int off, int size)
2395 struct mdglobaldata *gd = mdcpu;
2399 panic("pmap_zero_page: CMAP3 busy");
2400 *gd->gd_CMAP3 = VPTE_V | VPTE_R | VPTE_W |
2401 (phys & VPTE_FRAME) | VPTE_A | VPTE_M;
2402 madvise(gd->gd_CADDR3, PAGE_SIZE, MADV_INVAL);
2404 bzero((char *)gd->gd_CADDR3 + off, size);
2412 * Copy the physical page from the source PA to the target PA.
2413 * This function may be called from an interrupt. No locking
2417 pmap_copy_page(vm_paddr_t src, vm_paddr_t dst)
2419 struct mdglobaldata *gd = mdcpu;
2422 if (*(int *) gd->gd_CMAP1)
2423 panic("pmap_copy_page: CMAP1 busy");
2424 if (*(int *) gd->gd_CMAP2)
2425 panic("pmap_copy_page: CMAP2 busy");
2427 *(int *) gd->gd_CMAP1 = VPTE_V | VPTE_R | (src & PG_FRAME) | VPTE_A;
2428 *(int *) gd->gd_CMAP2 = VPTE_V | VPTE_R | VPTE_W | (dst & VPTE_FRAME) | VPTE_A | VPTE_M;
2430 madvise(gd->gd_CADDR1, PAGE_SIZE, MADV_INVAL);
2431 madvise(gd->gd_CADDR2, PAGE_SIZE, MADV_INVAL);
2433 bcopy(gd->gd_CADDR1, gd->gd_CADDR2, PAGE_SIZE);
2435 *(int *) gd->gd_CMAP1 = 0;
2436 *(int *) gd->gd_CMAP2 = 0;
2441 * pmap_copy_page_frag:
2443 * Copy the physical page from the source PA to the target PA.
2444 * This function may be called from an interrupt. No locking
2448 pmap_copy_page_frag(vm_paddr_t src, vm_paddr_t dst, size_t bytes)
2450 struct mdglobaldata *gd = mdcpu;
2453 if (*(int *) gd->gd_CMAP1)
2454 panic("pmap_copy_page: CMAP1 busy");
2455 if (*(int *) gd->gd_CMAP2)
2456 panic("pmap_copy_page: CMAP2 busy");
2458 *(int *) gd->gd_CMAP1 = VPTE_V | (src & VPTE_FRAME) | VPTE_A;
2459 *(int *) gd->gd_CMAP2 = VPTE_V | VPTE_R | VPTE_W | (dst & VPTE_FRAME) | VPTE_A | VPTE_M;
2461 madvise(gd->gd_CADDR1, PAGE_SIZE, MADV_INVAL);
2462 madvise(gd->gd_CADDR2, PAGE_SIZE, MADV_INVAL);
2464 bcopy((char *)gd->gd_CADDR1 + (src & PAGE_MASK),
2465 (char *)gd->gd_CADDR2 + (dst & PAGE_MASK),
2468 *(int *) gd->gd_CMAP1 = 0;
2469 *(int *) gd->gd_CMAP2 = 0;
2474 * Returns true if the pmap's pv is one of the first
2475 * 16 pvs linked to from this page. This count may
2476 * be changed upwards or downwards in the future; it
2477 * is only necessary that true be returned for a small
2478 * subset of pmaps for proper page aging.
2483 pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
2488 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2492 lwkt_gettoken(&vm_token);
2494 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2495 if (pv->pv_pmap == pmap) {
2496 lwkt_reltoken(&vm_token);
2504 lwkt_reltoken(&vm_token);
2510 * Remove all pages from specified address space
2511 * this aids process exit speeds. Also, this code
2512 * is special cased for current process only, but
2513 * can have the more generic (and slightly slower)
2514 * mode enabled. This is much faster than pmap_remove
2515 * in the case of running down an entire address space.
2520 pmap_remove_pages(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
2525 int32_t save_generation;
2528 lwkt_gettoken(&vm_token);
2529 for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) {
2530 if (pv->pv_va >= eva || pv->pv_va < sva) {
2531 npv = TAILQ_NEXT(pv, pv_plist);
2535 KKASSERT(pmap == pv->pv_pmap);
2537 pte = pmap_pte(pmap, pv->pv_va);
2540 * We cannot remove wired pages from a process' mapping
2543 if (*pte & VPTE_WIRED) {
2544 npv = TAILQ_NEXT(pv, pv_plist);
2547 tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);
2549 m = PHYS_TO_VM_PAGE(tpte);
2551 KASSERT(m < &vm_page_array[vm_page_array_size],
2552 ("pmap_remove_pages: bad tpte %lx", tpte));
2554 KKASSERT(pmap->pm_stats.resident_count > 0);
2555 --pmap->pm_stats.resident_count;
2558 * Update the vm_page_t clean and reference bits.
2560 if (tpte & VPTE_M) {
2564 npv = TAILQ_NEXT(pv, pv_plist);
2565 TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
2566 save_generation = ++pmap->pm_generation;
2568 m->md.pv_list_count--;
2569 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2570 if (TAILQ_FIRST(&m->md.pv_list) == NULL)
2571 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
2573 pmap_unuse_pt(pmap, pv->pv_va, pv->pv_ptem);
2577 * Restart the scan if we blocked during the unuse or free
2578 * calls and other removals were made.
2580 if (save_generation != pmap->pm_generation) {
2581 kprintf("Warning: pmap_remove_pages race-A avoided\n");
2582 npv = TAILQ_FIRST(&pmap->pm_pvlist);
2585 lwkt_reltoken(&vm_token);
2590 * pmap_testbit tests bits in active mappings of a VM page.
2592 * The caller must hold vm_token
2595 pmap_testbit(vm_page_t m, int bit)
2600 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2603 if (TAILQ_FIRST(&m->md.pv_list) == NULL)
2608 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2610 * if the bit being tested is the modified bit, then
2611 * mark clean_map and ptes as never
2614 if (bit & (VPTE_A|VPTE_M)) {
2615 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va))
2619 #if defined(PMAP_DIAGNOSTIC)
2621 kprintf("Null pmap (tb) at va: 0x%x\n", pv->pv_va);
2625 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
2636 * This routine is used to clear bits in ptes. Certain bits require special
2637 * handling, in particular (on virtual kernels) the VPTE_M (modify) bit.
2639 * This routine is only called with certain VPTE_* bit combinations.
2641 * The caller must hold vm_token
2643 static __inline void
2644 pmap_clearbit(vm_page_t m, int bit)
2650 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2656 * Loop over all current mappings setting/clearing as appropos If
2657 * setting RO do we need to clear the VAC?
2659 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2661 * don't write protect pager mappings
2663 if (bit == VPTE_W) {
2664 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va))
2668 #if defined(PMAP_DIAGNOSTIC)
2670 kprintf("Null pmap (cb) at va: 0x%x\n", pv->pv_va);
2676 * Careful here. We can use a locked bus instruction to
2677 * clear VPTE_A or VPTE_M safely but we need to synchronize
2678 * with the target cpus when we mess with VPTE_W.
2680 * On virtual kernels we must force a new fault-on-write
2681 * in the real kernel if we clear the Modify bit ourselves,
2682 * otherwise the real kernel will not get a new fault and
2683 * will never set our Modify bit again.
2685 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
2687 if (bit == VPTE_W) {
2689 * We must also clear VPTE_M when clearing
2692 pbits = pmap_clean_pte(pte, pv->pv_pmap,
2696 } else if (bit == VPTE_M) {
2698 * We do not have to make the page read-only
2699 * when clearing the Modify bit. The real
2700 * kernel will make the real PTE read-only
2701 * or otherwise detect the write and set
2702 * our VPTE_M again simply by us invalidating
2703 * the real kernel VA for the pmap (as we did
2704 * above). This allows the real kernel to
2705 * handle the write fault without forwarding
2708 atomic_clear_long(pte, VPTE_M);
2709 } else if ((bit & (VPTE_W|VPTE_M)) == (VPTE_W|VPTE_M)) {
2711 * We've been asked to clear W & M, I guess
2712 * the caller doesn't want us to update
2713 * the dirty status of the VM page.
2715 pmap_clean_pte(pte, pv->pv_pmap, pv->pv_va);
2718 * We've been asked to clear bits that do
2719 * not interact with hardware.
2721 atomic_clear_long(pte, bit);
2729 * Lower the permission for all mappings to a given page.
2734 pmap_page_protect(vm_page_t m, vm_prot_t prot)
2736 if ((prot & VM_PROT_WRITE) == 0) {
2737 lwkt_gettoken(&vm_token);
2738 if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
2739 pmap_clearbit(m, VPTE_W);
2740 vm_page_flag_clear(m, PG_WRITEABLE);
2744 lwkt_reltoken(&vm_token);
2749 pmap_phys_address(vm_pindex_t ppn)
2751 return (i386_ptob(ppn));
2755 * Return a count of reference bits for a page, clearing those bits.
2756 * It is not necessary for every reference bit to be cleared, but it
2757 * is necessary that 0 only be returned when there are truly no
2758 * reference bits set.
2760 * XXX: The exact number of bits to check and clear is a matter that
2761 * should be tested and standardized at some point in the future for
2762 * optimal aging of shared pages.
2767 pmap_ts_referenced(vm_page_t m)
2769 pv_entry_t pv, pvf, pvn;
2773 if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2777 lwkt_gettoken(&vm_token);
2779 if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
2784 pvn = TAILQ_NEXT(pv, pv_list);
2786 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2788 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
2790 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va))
2793 pte = pmap_pte(pv->pv_pmap, pv->pv_va);
2795 if (pte && (*pte & VPTE_A)) {
2797 atomic_clear_long(pte, VPTE_A);
2799 atomic_clear_long_nonlocked(pte, VPTE_A);
2806 } while ((pv = pvn) != NULL && pv != pvf);
2808 lwkt_reltoken(&vm_token);
2815 * Return whether or not the specified physical page was modified
2816 * in any physical maps.
2821 pmap_is_modified(vm_page_t m)
2825 lwkt_gettoken(&vm_token);
2826 res = pmap_testbit(m, VPTE_M);
2827 lwkt_reltoken(&vm_token);
2832 * Clear the modify bits on the specified physical page.
2837 pmap_clear_modify(vm_page_t m)
2839 lwkt_gettoken(&vm_token);
2840 pmap_clearbit(m, VPTE_M);
2841 lwkt_reltoken(&vm_token);
2845 * Clear the reference bit on the specified physical page.
2850 pmap_clear_reference(vm_page_t m)
2852 lwkt_gettoken(&vm_token);
2853 pmap_clearbit(m, VPTE_A);
2854 lwkt_reltoken(&vm_token);
2858 * Miscellaneous support routines follow
2862 i386_protection_init(void)
2866 kp = protection_codes;
2867 for (prot = 0; prot < 8; prot++) {
2868 if (prot & VM_PROT_READ)
2870 if (prot & VM_PROT_WRITE)
2872 if (prot & VM_PROT_EXECUTE)
2881 * Map a set of physical memory pages into the kernel virtual
2882 * address space. Return a pointer to where it is mapped. This
2883 * routine is intended to be used for mapping device memory,
2886 * NOTE: we can't use pgeflag unless we invalidate the pages one at
2890 pmap_mapdev(vm_paddr_t pa, vm_size_t size)
2892 vm_offset_t va, tmpva, offset;
2895 offset = pa & PAGE_MASK;
2896 size = roundup(offset + size, PAGE_SIZE);
2898 va = kmem_alloc_nofault(&kernel_map, size, PAGE_SIZE);
2900 panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
2902 pa = pa & VPTE_FRAME;
2903 for (tmpva = va; size > 0;) {
2904 pte = KernelPTA + (tmpva >> PAGE_SHIFT);
2905 *pte = pa | VPTE_R | VPTE_W | VPTE_V; /* | pgeflag; */
2913 return ((void *)(va + offset));
2917 pmap_unmapdev(vm_offset_t va, vm_size_t size)
2919 vm_offset_t base, offset;
2921 base = va & VPTE_FRAME;
2922 offset = va & PAGE_MASK;
2923 size = roundup(offset + size, PAGE_SIZE);
2924 pmap_qremove(va, size >> PAGE_SHIFT);
2925 kmem_free(&kernel_map, base, size);
2931 * Perform the pmap work for mincore
2936 pmap_mincore(pmap_t pmap, vm_offset_t addr)
2942 lwkt_gettoken(&vm_token);
2944 ptep = pmap_pte(pmap, addr);
2946 lwkt_reltoken(&vm_token);
2950 if ((pte = *ptep) != 0) {
2953 val = MINCORE_INCORE;
2954 if ((pte & VPTE_MANAGED) == 0)
2957 pa = pte & VPTE_FRAME;
2959 m = PHYS_TO_VM_PAGE(pa);
2965 val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
2967 * Modified by someone
2969 else if (m->dirty || pmap_is_modified(m))
2970 val |= MINCORE_MODIFIED_OTHER;
2975 val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
2978 * Referenced by someone
2980 else if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) {
2981 val |= MINCORE_REFERENCED_OTHER;
2982 vm_page_flag_set(m, PG_REFERENCED);
2986 lwkt_reltoken(&vm_token);
2991 pmap_replacevm(struct proc *p, struct vmspace *newvm, int adjrefs)
2993 struct vmspace *oldvm;
2996 oldvm = p->p_vmspace;
2998 if (oldvm != newvm) {
2999 p->p_vmspace = newvm;
3000 KKASSERT(p->p_nthreads == 1);
3001 lp = RB_ROOT(&p->p_lwp_tree);
3002 pmap_setlwpvm(lp, newvm);
3004 sysref_get(&newvm->vm_sysref);
3005 sysref_put(&oldvm->vm_sysref);
3012 pmap_setlwpvm(struct lwp *lp, struct vmspace *newvm)
3014 struct vmspace *oldvm;
3018 oldvm = lp->lwp_vmspace;
3020 if (oldvm != newvm) {
3021 lp->lwp_vmspace = newvm;
3022 if (curthread->td_lwp == lp) {
3023 pmap = vmspace_pmap(newvm);
3025 atomic_set_int(&pmap->pm_active, mycpu->gd_cpumask);
3027 pmap->pm_active |= 1;
3029 #if defined(SWTCH_OPTIM_STATS)
3032 pmap = vmspace_pmap(oldvm);
3034 atomic_clear_int(&pmap->pm_active, mycpu->gd_cpumask);
3036 pmap->pm_active &= ~1;
3045 pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size)
3048 if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) {
3052 addr = (addr + (NBPDR - 1)) & ~(NBPDR - 1);
3057 * Used by kmalloc/kfree, page already exists at va
3060 pmap_kvtom(vm_offset_t va)
3064 KKASSERT(va >= KvaStart && va < KvaEnd);
3065 ptep = KernelPTA + (va >> PAGE_SHIFT);
3066 return(PHYS_TO_VM_PAGE(*ptep & PG_FRAME));