device_pager.c revision 132884
11541Srgrimes/* 21541Srgrimes * Copyright (c) 1990 University of Utah. 31541Srgrimes * Copyright (c) 1991, 1993 41541Srgrimes * The Regents of the University of California. All rights reserved. 51541Srgrimes * 61541Srgrimes * This code is derived from software contributed to Berkeley by 71541Srgrimes * the Systems Programming Group of the University of Utah Computer 81541Srgrimes * Science Department. 91541Srgrimes * 101541Srgrimes * Redistribution and use in source and binary forms, with or without 111541Srgrimes * modification, are permitted provided that the following conditions 121541Srgrimes * are met: 131541Srgrimes * 1. Redistributions of source code must retain the above copyright 141541Srgrimes * notice, this list of conditions and the following disclaimer. 151541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 161541Srgrimes * notice, this list of conditions and the following disclaimer in the 171541Srgrimes * documentation and/or other materials provided with the distribution. 181541Srgrimes * 4. Neither the name of the University nor the names of its contributors 191541Srgrimes * may be used to endorse or promote products derived from this software 201541Srgrimes * without specific prior written permission. 211541Srgrimes * 221541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 231541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 241541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 251541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 261541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 271541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 281541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 291541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 301541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 311541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 321541Srgrimes * SUCH DAMAGE. 331541Srgrimes * 341549Srgrimes * @(#)device_pager.c 8.1 (Berkeley) 6/11/93 351541Srgrimes */ 361541Srgrimes 37116226Sobrien#include <sys/cdefs.h> 38116226Sobrien__FBSDID("$FreeBSD: head/sys/vm/device_pager.c 132884 2004-07-30 11:09:18Z dfr $"); 39116226Sobrien 401541Srgrimes#include <sys/param.h> 411541Srgrimes#include <sys/systm.h> 421541Srgrimes#include <sys/conf.h> 4376166Smarkm#include <sys/lock.h> 4479224Sdillon#include <sys/proc.h> 4576166Smarkm#include <sys/mutex.h> 461541Srgrimes#include <sys/mman.h> 4775675Salfred#include <sys/sx.h> 481541Srgrimes 491541Srgrimes#include <vm/vm.h> 5012662Sdg#include <vm/vm_object.h> 511541Srgrimes#include <vm/vm_page.h> 529507Sdg#include <vm/vm_pager.h> 5392748Sjeff#include <vm/uma.h> 541541Srgrimes 5592727Salfredstatic void dev_pager_init(void); 5692727Salfredstatic vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 5792727Salfred vm_ooffset_t); 5892727Salfredstatic void dev_pager_dealloc(vm_object_t); 5992727Salfredstatic int dev_pager_getpages(vm_object_t, vm_page_t *, int, int); 6092727Salfredstatic void dev_pager_putpages(vm_object_t, vm_page_t *, int, 6192727Salfred boolean_t, int *); 6292727Salfredstatic boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, 6392727Salfred int *); 641541Srgrimes 6512820Sphk/* list of device pager objects */ 6612820Sphkstatic struct pagerlst dev_pager_object_list; 6775675Salfred/* protect against object creation */ 6875675Salfredstatic struct sx dev_pager_sx; 6975675Salfred/* protect list manipulation */ 7075675Salfredstatic struct mtx dev_pager_mtx; 7112820Sphk 7275675Salfred 7392748Sjeffstatic uma_zone_t fakepg_zone; 7412820Sphk 75112569Sjakestatic vm_page_t dev_pager_getfake(vm_paddr_t); 7692727Salfredstatic void dev_pager_putfake(vm_page_t); 77132884Sdfrstatic void dev_pager_updatefake(vm_page_t, vm_paddr_t); 781541Srgrimes 791541Srgrimesstruct pagerops devicepagerops = { 80118466Sphk .pgo_init = dev_pager_init, 81118466Sphk .pgo_alloc = dev_pager_alloc, 82118466Sphk .pgo_dealloc = dev_pager_dealloc, 83118466Sphk .pgo_getpages = dev_pager_getpages, 84118466Sphk .pgo_putpages = dev_pager_putpages, 85118466Sphk .pgo_haspage = dev_pager_haspage, 861541Srgrimes}; 871541Srgrimes 8812820Sphkstatic void 891541Srgrimesdev_pager_init() 901541Srgrimes{ 919507Sdg TAILQ_INIT(&dev_pager_object_list); 9275675Salfred sx_init(&dev_pager_sx, "dev_pager create"); 9393818Sjhb mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 9492748Sjeff fakepg_zone = uma_zcreate("DP fakepg", sizeof(struct vm_page), 95120739Sjeff NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 96120739Sjeff UMA_ZONE_NOFREE|UMA_ZONE_VM); 971541Srgrimes} 981541Srgrimes 9998630Salc/* 10098630Salc * MPSAFE 10198630Salc */ 10212820Sphkstatic vm_object_t 10340286Sdgdev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 1041541Srgrimes{ 105130585Sphk struct cdev *dev; 10612591Sbde d_mmap_t *mapfunc; 1071541Srgrimes vm_object_t object; 108124133Salc vm_pindex_t pindex; 10941004Sdfr unsigned int npages; 110112569Sjake vm_paddr_t paddr; 111112569Sjake vm_offset_t off; 1121541Srgrimes 1131541Srgrimes /* 11498630Salc * Offset should be page aligned. 11598630Salc */ 11698630Salc if (foff & PAGE_MASK) 11798630Salc return (NULL); 11898630Salc 11998630Salc size = round_page(size); 120124133Salc pindex = OFF_TO_IDX(foff + size); 12198630Salc 12298630Salc /* 1231541Srgrimes * Make sure this device can be mapped. 1241541Srgrimes */ 12547111Sbde dev = handle; 12698630Salc mtx_lock(&Giant); 12746676Sphk mapfunc = devsw(dev)->d_mmap; 12812610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 12912610Sbde printf("obsolete map function %p\n", (void *)mapfunc); 13098630Salc mtx_unlock(&Giant); 1315455Sdg return (NULL); 13212610Sbde } 1331541Srgrimes 1341541Srgrimes /* 1355455Sdg * Check that the specified range of the device allows the desired 1365455Sdg * protection. 1378876Srgrimes * 1381541Srgrimes * XXX assumes VM_PROT_* == PROT_* 1391541Srgrimes */ 14040286Sdg npages = OFF_TO_IDX(size); 1411541Srgrimes for (off = foff; npages--; off += PAGE_SIZE) 142111462Smux if ((*mapfunc)(dev, off, &paddr, (int)prot) != 0) { 14398630Salc mtx_unlock(&Giant); 1445455Sdg return (NULL); 14598630Salc } 1461541Srgrimes 1471541Srgrimes /* 14858634Scharnier * Lock to prevent object creation race condition. 1499507Sdg */ 15075675Salfred sx_xlock(&dev_pager_sx); 1519507Sdg 1529507Sdg /* 1531541Srgrimes * Look up pager, creating as necessary. 1541541Srgrimes */ 1559507Sdg object = vm_pager_object_lookup(&dev_pager_object_list, handle); 1569507Sdg if (object == NULL) { 1571541Srgrimes /* 1581541Srgrimes * Allocate object and associate it with the pager. 1591541Srgrimes */ 160124133Salc object = vm_object_allocate(OBJT_DEVICE, pindex); 1619507Sdg object->handle = handle; 1629507Sdg TAILQ_INIT(&object->un_pager.devp.devp_pglist); 16375675Salfred mtx_lock(&dev_pager_mtx); 1649507Sdg TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 16575675Salfred mtx_unlock(&dev_pager_mtx); 1661541Srgrimes } else { 1671541Srgrimes /* 1686585Sdg * Gain a reference to the object. 1691541Srgrimes */ 1709507Sdg vm_object_reference(object); 171124133Salc if (pindex > object->size) 172124133Salc object->size = pindex; 1731541Srgrimes } 1749507Sdg 17575675Salfred sx_xunlock(&dev_pager_sx); 17698630Salc mtx_unlock(&Giant); 1779507Sdg return (object); 1781541Srgrimes} 1791541Srgrimes 18012820Sphkstatic void 1819507Sdgdev_pager_dealloc(object) 1829507Sdg vm_object_t object; 1831541Srgrimes{ 1841541Srgrimes vm_page_t m; 1851541Srgrimes 18675675Salfred mtx_lock(&dev_pager_mtx); 1879507Sdg TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 18875675Salfred mtx_unlock(&dev_pager_mtx); 1891541Srgrimes /* 1901541Srgrimes * Free up our fake pages. 1911541Srgrimes */ 19215809Sdyson while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 1939507Sdg TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 1941541Srgrimes dev_pager_putfake(m); 1951541Srgrimes } 1961541Srgrimes} 1971541Srgrimes 19812820Sphkstatic int 1999507Sdgdev_pager_getpages(object, m, count, reqpage) 2009507Sdg vm_object_t object; 2019507Sdg vm_page_t *m; 2029507Sdg int count; 2039507Sdg int reqpage; 2041541Srgrimes{ 20598824Siedowse vm_pindex_t offset; 206112569Sjake vm_paddr_t paddr; 2071541Srgrimes vm_page_t page; 208130585Sphk struct cdev *dev; 209111462Smux int i, ret; 21012591Sbde d_mmap_t *mapfunc; 21112591Sbde int prot; 2121541Srgrimes 213116793Salc VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 21447111Sbde dev = object->handle; 21542957Sdillon offset = m[reqpage]->pindex; 216116279Salc VM_OBJECT_UNLOCK(object); 217128570Salc mtx_lock(&Giant); 2181541Srgrimes prot = PROT_READ; /* XXX should pass in? */ 21946676Sphk mapfunc = devsw(dev)->d_mmap; 2201549Srgrimes 22112610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 2221541Srgrimes panic("dev_pager_getpage: no map function"); 2231549Srgrimes 224111462Smux ret = (*mapfunc)(dev, (vm_offset_t)offset << PAGE_SHIFT, &paddr, prot); 225111462Smux KASSERT(ret == 0, ("dev_pager_getpage: map function returns error")); 226128570Salc mtx_unlock(&Giant); 227128570Salc 228132884Sdfr if ((m[reqpage]->flags & PG_FICTITIOUS) != 0) { 229132884Sdfr /* 230132884Sdfr * If the passed in reqpage page is a fake page, update it with 231132884Sdfr * the new physical address. 232132884Sdfr */ 233132884Sdfr dev_pager_updatefake(m[reqpage], paddr); 234132884Sdfr VM_OBJECT_LOCK(object); 235132884Sdfr if (count > 1) { 236132884Sdfr vm_page_lock_queues(); 237132884Sdfr for (i = 0; i < count; i++) { 238132884Sdfr if (i != reqpage) 239132884Sdfr vm_page_free(m[i]); 240132884Sdfr } 241132884Sdfr vm_page_unlock_queues(); 242132884Sdfr } 243132884Sdfr } else { 244132884Sdfr /* 245132884Sdfr * Replace the passed in reqpage page with our own fake page and 246132884Sdfr * free up the all of the original pages. 247132884Sdfr */ 248132884Sdfr page = dev_pager_getfake(paddr); 249132884Sdfr VM_OBJECT_LOCK(object); 250132884Sdfr TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 251132884Sdfr vm_page_lock_queues(); 252132884Sdfr for (i = 0; i < count; i++) 253132884Sdfr vm_page_free(m[i]); 254132884Sdfr vm_page_unlock_queues(); 255132884Sdfr vm_page_insert(page, object, offset); 256132884Sdfr m[reqpage] = page; 257132884Sdfr } 2581541Srgrimes 2595455Sdg return (VM_PAGER_OK); 2601541Srgrimes} 2611541Srgrimes 26243129Sdillonstatic void 2639507Sdgdev_pager_putpages(object, m, count, sync, rtvals) 2649507Sdg vm_object_t object; 2659507Sdg vm_page_t *m; 2669507Sdg int count; 2671541Srgrimes boolean_t sync; 2689507Sdg int *rtvals; 2691541Srgrimes{ 2701541Srgrimes panic("dev_pager_putpage called"); 2711541Srgrimes} 2721541Srgrimes 27312820Sphkstatic boolean_t 27412767Sdysondev_pager_haspage(object, pindex, before, after) 2759507Sdg vm_object_t object; 27612767Sdyson vm_pindex_t pindex; 2779507Sdg int *before; 2789507Sdg int *after; 2791541Srgrimes{ 2809507Sdg if (before != NULL) 2819507Sdg *before = 0; 2829507Sdg if (after != NULL) 2839507Sdg *after = 0; 2845455Sdg return (TRUE); 2851541Srgrimes} 2861541Srgrimes 2871541Srgrimesstatic vm_page_t 2881541Srgrimesdev_pager_getfake(paddr) 289112569Sjake vm_paddr_t paddr; 2901541Srgrimes{ 2911541Srgrimes vm_page_t m; 2921541Srgrimes 293111119Simp m = uma_zalloc(fakepg_zone, M_WAITOK); 2941549Srgrimes 2955455Sdg m->flags = PG_BUSY | PG_FICTITIOUS; 2969507Sdg m->valid = VM_PAGE_BITS_ALL; 2975455Sdg m->dirty = 0; 2985455Sdg m->busy = 0; 29913490Sdyson m->queue = PQ_NONE; 30040557Sdg m->object = NULL; 3011549Srgrimes 3021549Srgrimes m->wire_count = 1; 30314430Sdyson m->hold_count = 0; 3041541Srgrimes m->phys_addr = paddr; 3051549Srgrimes 3065455Sdg return (m); 3071541Srgrimes} 3081541Srgrimes 3091541Srgrimesstatic void 3101541Srgrimesdev_pager_putfake(m) 3111541Srgrimes vm_page_t m; 3121541Srgrimes{ 3131541Srgrimes if (!(m->flags & PG_FICTITIOUS)) 3141541Srgrimes panic("dev_pager_putfake: bad page"); 31592748Sjeff uma_zfree(fakepg_zone, m); 3161541Srgrimes} 317132884Sdfr 318132884Sdfrstatic void 319132884Sdfrdev_pager_updatefake(m, paddr) 320132884Sdfr vm_page_t m; 321132884Sdfr vm_paddr_t paddr; 322132884Sdfr{ 323132884Sdfr if (!(m->flags & PG_FICTITIOUS)) 324132884Sdfr panic("dev_pager_updatefake: bad page"); 325132884Sdfr m->phys_addr = paddr; 326132884Sdfr} 327