phys_pager.c revision 171887
147133Sobrien/*- 247133Sobrien * Copyright (c) 2000 Peter Wemm 347133Sobrien * 447133Sobrien * Redistribution and use in source and binary forms, with or without 547133Sobrien * modification, are permitted provided that the following conditions 647133Sobrien * are met: 747133Sobrien * 1. Redistributions of source code must retain the above copyright 847133Sobrien * notice, this list of conditions and the following disclaimer. 947133Sobrien * 2. Redistributions in binary form must reproduce the above copyright 1047133Sobrien * notice, this list of conditions and the following disclaimer in the 1147133Sobrien * documentation and/or other materials provided with the distribution. 1247133Sobrien * 1347133Sobrien * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 1447133Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1547133Sobrien * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1647133Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 1747133Sobrien * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1847133Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 1947133Sobrien * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2047133Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2147133Sobrien * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2247133Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2347133Sobrien * SUCH DAMAGE. 2447133Sobrien */ 2547133Sobrien 2651594Speter#include <sys/cdefs.h> 2750477Speter__FBSDID("$FreeBSD: head/sys/vm/phys_pager.c 171887 2007-08-18 16:40:33Z kib $"); 2847133Sobrien 2955723Simp#include <sys/param.h> 3055723Simp#include <sys/systm.h> 3147133Sobrien#include <sys/linker_set.h> 3247133Sobrien#include <sys/conf.h> 3348114Sobrien#include <sys/kernel.h> 3448114Sobrien#include <sys/lock.h> 3548114Sobrien#include <sys/proc.h> 3648114Sobrien#include <sys/mutex.h> 3748114Sobrien#include <sys/mman.h> 3848114Sobrien#include <sys/sysctl.h> 3948114Sobrien 4048114Sobrien#include <vm/vm.h> 4148114Sobrien#include <vm/vm_object.h> 4248114Sobrien#include <vm/vm_page.h> 4348114Sobrien#include <vm/vm_pager.h> 4448114Sobrien 4548114Sobrien/* list of device pager objects */ 4648114Sobrienstatic struct pagerlst phys_pager_object_list; 4748114Sobrien/* protect access to phys_pager_object_list */ 4848114Sobrienstatic struct mtx phys_pager_mtx; 4948114Sobrien 5048114Sobrienstatic void 5148114Sobrienphys_pager_init(void) 5248114Sobrien{ 5348114Sobrien 5448114Sobrien TAILQ_INIT(&phys_pager_object_list); 5548114Sobrien mtx_init(&phys_pager_mtx, "phys_pager list", NULL, MTX_DEF); 5648114Sobrien} 5748114Sobrien 5848114Sobrien/* 5948114Sobrien * MPSAFE 6048114Sobrien */ 6148114Sobrienstatic vm_object_t 6248114Sobrienphys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 6348114Sobrien vm_ooffset_t foff) 6448114Sobrien{ 6548114Sobrien vm_object_t object, object1; 6648114Sobrien vm_pindex_t pindex; 6748114Sobrien 6848114Sobrien /* 6947133Sobrien * Offset should be page aligned. 7047133Sobrien */ 7148114Sobrien if (foff & PAGE_MASK) 7248114Sobrien return (NULL); 7348114Sobrien 7448114Sobrien pindex = OFF_TO_IDX(foff + PAGE_MASK + size); 7547133Sobrien 7648114Sobrien if (handle != NULL) { 7748114Sobrien mtx_lock(&phys_pager_mtx); 7848114Sobrien /* 7947133Sobrien * Look up pager, creating as necessary. 8048114Sobrien */ 8148114Sobrien object1 = NULL; 8248114Sobrien object = vm_pager_object_lookup(&phys_pager_object_list, handle); 8348114Sobrien if (object == NULL) { 8447133Sobrien /* 8548114Sobrien * Allocate object and associate it with the pager. 8647133Sobrien */ 8748114Sobrien mtx_unlock(&phys_pager_mtx); 8847133Sobrien object1 = vm_object_allocate(OBJT_PHYS, pindex); 8948114Sobrien mtx_lock(&phys_pager_mtx); 9048114Sobrien object = vm_pager_object_lookup(&phys_pager_object_list, 9148114Sobrien handle); 9248114Sobrien if (object != NULL) { 9347133Sobrien /* 9448114Sobrien * We raced with other thread while 9548114Sobrien * allocating object. 9648114Sobrien */ 9748114Sobrien if (pindex > object->size) 9848114Sobrien object->size = pindex; 9948114Sobrien } else { 10048114Sobrien object = object1; 10148114Sobrien object1 = NULL; 10248114Sobrien object->handle = handle; 10348114Sobrien TAILQ_INSERT_TAIL(&phys_pager_object_list, object, 10448114Sobrien pager_object_list); 10548114Sobrien } 10648114Sobrien } else { 10748114Sobrien if (pindex > object->size) 10848114Sobrien object->size = pindex; 10947133Sobrien } 11048114Sobrien mtx_unlock(&phys_pager_mtx); 11148114Sobrien vm_object_deallocate(object1); 11247133Sobrien } else { 11347133Sobrien object = vm_object_allocate(OBJT_PHYS, pindex); 11448114Sobrien } 11547133Sobrien 11648114Sobrien return (object); 11747133Sobrien} 11848114Sobrien 11948114Sobrien/* 12048114Sobrien * MPSAFE 12148114Sobrien */ 12248114Sobrienstatic void 12347133Sobrienphys_pager_dealloc(vm_object_t object) 12448114Sobrien{ 12548114Sobrien 12648114Sobrien if (object->handle != NULL) { 12748114Sobrien VM_OBJECT_UNLOCK(object); 12848114Sobrien mtx_lock(&phys_pager_mtx); 12948114Sobrien TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list); 13048114Sobrien mtx_unlock(&phys_pager_mtx); 13148114Sobrien VM_OBJECT_LOCK(object); 13247133Sobrien } 13348114Sobrien} 13448114Sobrien 13548114Sobrien/* 13648114Sobrien * Fill as many pages as vm_fault has allocated for us. 13748114Sobrien */ 13848114Sobrienstatic int 13948114Sobrienphys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage) 14048114Sobrien{ 14148114Sobrien int i; 14248114Sobrien 14348114Sobrien VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 14448114Sobrien for (i = 0; i < count; i++) { 14548114Sobrien if (m[i]->valid == 0) { 14648114Sobrien if ((m[i]->flags & PG_ZERO) == 0) 14748114Sobrien pmap_zero_page(m[i]); 14847133Sobrien m[i]->valid = VM_PAGE_BITS_ALL; 14948114Sobrien } 15048114Sobrien KASSERT(m[i]->valid == VM_PAGE_BITS_ALL, 15148114Sobrien ("phys_pager_getpages: partially valid page %p", m[i])); 15247133Sobrien m[i]->dirty = 0; 15347133Sobrien /* The requested page must remain busy, the others not. */ 15448114Sobrien if (reqpage != i) { 15547133Sobrien m[i]->oflags &= ~VPO_BUSY; 15648114Sobrien m[i]->busy = 0; 15747133Sobrien } 15848114Sobrien } 15948114Sobrien return (VM_PAGER_OK); 16048114Sobrien} 16148114Sobrien 16248114Sobrienstatic void 16347133Sobrienphys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync, 16448114Sobrien int *rtvals) 16548114Sobrien{ 16648114Sobrien 16748114Sobrien panic("phys_pager_putpage called"); 16848114Sobrien} 16948114Sobrien 17048114Sobrien/* 17148114Sobrien * Implement a pretty aggressive clustered getpages strategy. Hint that 17248114Sobrien * everything in an entire 4MB window should be prefaulted at once. 17347133Sobrien * 17448114Sobrien * XXX 4MB (1024 slots per page table page) is convenient for x86, 17548114Sobrien * but may not be for other arches. 17648114Sobrien */ 17748114Sobrien#ifndef PHYSCLUSTER 17848114Sobrien#define PHYSCLUSTER 1024 17947133Sobrien#endif 18048114Sobrienstatic boolean_t 18148114Sobrienphys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 18247133Sobrien int *after) 18347133Sobrien{ 18447133Sobrien vm_pindex_t base, end; 18548114Sobrien 18648114Sobrien base = pindex & (~(PHYSCLUSTER - 1)); 18747133Sobrien end = base + (PHYSCLUSTER - 1); 18847133Sobrien if (before != NULL) 18947133Sobrien *before = pindex - base; 19048114Sobrien if (after != NULL) 19148114Sobrien *after = end - pindex; 19248114Sobrien return (TRUE); 19348114Sobrien} 19448114Sobrien 19547133Sobrienstruct pagerops physpagerops = { 19648114Sobrien .pgo_init = phys_pager_init, 19748114Sobrien .pgo_alloc = phys_pager_alloc, 19848114Sobrien .pgo_dealloc = phys_pager_dealloc, 19948114Sobrien .pgo_getpages = phys_pager_getpages, 20048114Sobrien .pgo_putpages = phys_pager_putpages, 20148114Sobrien .pgo_haspage = phys_pager_haspage, 20248114Sobrien}; 20348114Sobrien