device_pager.c revision 92748
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 * 3. All advertising materials mentioning features or use of this software 1958705Scharnier * must display the following acknowledgement: 201541Srgrimes * This product includes software developed by the University of 211541Srgrimes * California, Berkeley and its contributors. 221541Srgrimes * 4. Neither the name of the University nor the names of its contributors 231541Srgrimes * may be used to endorse or promote products derived from this software 241541Srgrimes * without specific prior written permission. 251541Srgrimes * 261541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 271541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 281541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 291541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 301541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 311541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 321541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 331541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 341541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 351541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 361541Srgrimes * SUCH DAMAGE. 371541Srgrimes * 381549Srgrimes * @(#)device_pager.c 8.1 (Berkeley) 6/11/93 3950477Speter * $FreeBSD: head/sys/vm/device_pager.c 92748 2002-03-20 04:02:59Z jeff $ 401541Srgrimes */ 411541Srgrimes 421541Srgrimes#include <sys/param.h> 431541Srgrimes#include <sys/systm.h> 441541Srgrimes#include <sys/conf.h> 4576166Smarkm#include <sys/lock.h> 4679224Sdillon#include <sys/proc.h> 4776166Smarkm#include <sys/mutex.h> 481541Srgrimes#include <sys/mman.h> 4975675Salfred#include <sys/sx.h> 501541Srgrimes 511541Srgrimes#include <vm/vm.h> 5212662Sdg#include <vm/vm_object.h> 531541Srgrimes#include <vm/vm_page.h> 549507Sdg#include <vm/vm_pager.h> 5592748Sjeff#include <vm/uma.h> 561541Srgrimes 5792727Salfredstatic void dev_pager_init(void); 5892727Salfredstatic vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 5992727Salfred vm_ooffset_t); 6092727Salfredstatic void dev_pager_dealloc(vm_object_t); 6192727Salfredstatic int dev_pager_getpages(vm_object_t, vm_page_t *, int, int); 6292727Salfredstatic void dev_pager_putpages(vm_object_t, vm_page_t *, int, 6392727Salfred boolean_t, int *); 6492727Salfredstatic boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, 6592727Salfred int *); 661541Srgrimes 6712820Sphk/* list of device pager objects */ 6812820Sphkstatic struct pagerlst dev_pager_object_list; 6975675Salfred/* protect against object creation */ 7075675Salfredstatic struct sx dev_pager_sx; 7175675Salfred/* protect list manipulation */ 7275675Salfredstatic struct mtx dev_pager_mtx; 7312820Sphk 7475675Salfred 7592748Sjeffstatic uma_zone_t fakepg_zone; 7612820Sphk 7792727Salfredstatic vm_page_t dev_pager_getfake(vm_offset_t); 7892727Salfredstatic void dev_pager_putfake(vm_page_t); 791541Srgrimes 801541Srgrimesstruct pagerops devicepagerops = { 811541Srgrimes dev_pager_init, 821541Srgrimes dev_pager_alloc, 831541Srgrimes dev_pager_dealloc, 849507Sdg dev_pager_getpages, 859507Sdg dev_pager_putpages, 869507Sdg dev_pager_haspage, 879507Sdg NULL 881541Srgrimes}; 891541Srgrimes 9012820Sphkstatic void 911541Srgrimesdev_pager_init() 921541Srgrimes{ 939507Sdg TAILQ_INIT(&dev_pager_object_list); 9475675Salfred sx_init(&dev_pager_sx, "dev_pager create"); 9575675Salfred mtx_init(&dev_pager_mtx, "dev_pager list", MTX_DEF); 9692748Sjeff fakepg_zone = uma_zcreate("DP fakepg", sizeof(struct vm_page), 9792748Sjeff NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 981541Srgrimes} 991541Srgrimes 10012820Sphkstatic vm_object_t 10140286Sdgdev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 1021541Srgrimes{ 1031541Srgrimes dev_t dev; 10412591Sbde d_mmap_t *mapfunc; 1051541Srgrimes vm_object_t object; 10641004Sdfr unsigned int npages; 10741004Sdfr vm_offset_t off; 1081541Srgrimes 10977087Sjhb mtx_assert(&Giant, MA_OWNED); 1101541Srgrimes /* 1111541Srgrimes * Make sure this device can be mapped. 1121541Srgrimes */ 11347111Sbde dev = handle; 11446676Sphk mapfunc = devsw(dev)->d_mmap; 11512610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 11612610Sbde printf("obsolete map function %p\n", (void *)mapfunc); 1175455Sdg return (NULL); 11812610Sbde } 1191541Srgrimes 1201541Srgrimes /* 1211541Srgrimes * Offset should be page aligned. 1221541Srgrimes */ 12315583Sphk if (foff & PAGE_MASK) 1245455Sdg return (NULL); 1251541Srgrimes 12640286Sdg size = round_page(size); 12740286Sdg 1281541Srgrimes /* 1295455Sdg * Check that the specified range of the device allows the desired 1305455Sdg * protection. 1318876Srgrimes * 1321541Srgrimes * XXX assumes VM_PROT_* == PROT_* 1331541Srgrimes */ 13440286Sdg npages = OFF_TO_IDX(size); 1351541Srgrimes for (off = foff; npages--; off += PAGE_SIZE) 1365455Sdg if ((*mapfunc) (dev, off, (int) prot) == -1) 1375455Sdg return (NULL); 1381541Srgrimes 1391541Srgrimes /* 14058634Scharnier * Lock to prevent object creation race condition. 1419507Sdg */ 14275675Salfred sx_xlock(&dev_pager_sx); 1439507Sdg 1449507Sdg /* 1451541Srgrimes * Look up pager, creating as necessary. 1461541Srgrimes */ 1479507Sdg object = vm_pager_object_lookup(&dev_pager_object_list, handle); 1489507Sdg if (object == NULL) { 1491541Srgrimes /* 1501541Srgrimes * Allocate object and associate it with the pager. 1511541Srgrimes */ 15212767Sdyson object = vm_object_allocate(OBJT_DEVICE, 15340286Sdg OFF_TO_IDX(foff + size)); 1549507Sdg object->handle = handle; 1559507Sdg TAILQ_INIT(&object->un_pager.devp.devp_pglist); 15675675Salfred mtx_lock(&dev_pager_mtx); 1579507Sdg TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 15875675Salfred mtx_unlock(&dev_pager_mtx); 1591541Srgrimes } else { 1601541Srgrimes /* 1616585Sdg * Gain a reference to the object. 1621541Srgrimes */ 1639507Sdg vm_object_reference(object); 16440286Sdg if (OFF_TO_IDX(foff + size) > object->size) 16540286Sdg object->size = OFF_TO_IDX(foff + size); 1661541Srgrimes } 1679507Sdg 16875675Salfred sx_xunlock(&dev_pager_sx); 1699507Sdg 1709507Sdg return (object); 1711541Srgrimes} 1721541Srgrimes 17312820Sphkstatic void 1749507Sdgdev_pager_dealloc(object) 1759507Sdg vm_object_t object; 1761541Srgrimes{ 1771541Srgrimes vm_page_t m; 1781541Srgrimes 17975675Salfred mtx_lock(&dev_pager_mtx); 1809507Sdg TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 18175675Salfred mtx_unlock(&dev_pager_mtx); 1821541Srgrimes /* 1831541Srgrimes * Free up our fake pages. 1841541Srgrimes */ 18515809Sdyson while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 1869507Sdg TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 1871541Srgrimes dev_pager_putfake(m); 1881541Srgrimes } 1891541Srgrimes} 1901541Srgrimes 19112820Sphkstatic int 1929507Sdgdev_pager_getpages(object, m, count, reqpage) 1939507Sdg vm_object_t object; 1949507Sdg vm_page_t *m; 1959507Sdg int count; 1969507Sdg int reqpage; 1971541Srgrimes{ 19812767Sdyson vm_offset_t offset; 19912767Sdyson vm_offset_t paddr; 2001541Srgrimes vm_page_t page; 2011541Srgrimes dev_t dev; 20277087Sjhb int i; 20312591Sbde d_mmap_t *mapfunc; 20412591Sbde int prot; 2051541Srgrimes 20677087Sjhb mtx_assert(&Giant, MA_OWNED); 20747111Sbde dev = object->handle; 20842957Sdillon offset = m[reqpage]->pindex; 2091541Srgrimes prot = PROT_READ; /* XXX should pass in? */ 21046676Sphk mapfunc = devsw(dev)->d_mmap; 2111549Srgrimes 21212610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 2131541Srgrimes panic("dev_pager_getpage: no map function"); 2141549Srgrimes 21547028Sphk paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 21642408Seivind KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 2171541Srgrimes /* 2189507Sdg * Replace the passed in reqpage page with our own fake page and free up the 2199507Sdg * all of the original pages. 2201541Srgrimes */ 2211541Srgrimes page = dev_pager_getfake(paddr); 2229507Sdg TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 2239507Sdg for (i = 0; i < count; i++) { 2249507Sdg vm_page_free(m[i]); 2259507Sdg } 2261541Srgrimes vm_page_insert(page, object, offset); 2271541Srgrimes 2285455Sdg return (VM_PAGER_OK); 2291541Srgrimes} 2301541Srgrimes 23143129Sdillonstatic void 2329507Sdgdev_pager_putpages(object, m, count, sync, rtvals) 2339507Sdg vm_object_t object; 2349507Sdg vm_page_t *m; 2359507Sdg int count; 2361541Srgrimes boolean_t sync; 2379507Sdg int *rtvals; 2381541Srgrimes{ 2391541Srgrimes panic("dev_pager_putpage called"); 2401541Srgrimes} 2411541Srgrimes 24212820Sphkstatic boolean_t 24312767Sdysondev_pager_haspage(object, pindex, before, after) 2449507Sdg vm_object_t object; 24512767Sdyson vm_pindex_t pindex; 2469507Sdg int *before; 2479507Sdg int *after; 2481541Srgrimes{ 2499507Sdg if (before != NULL) 2509507Sdg *before = 0; 2519507Sdg if (after != NULL) 2529507Sdg *after = 0; 2535455Sdg return (TRUE); 2541541Srgrimes} 2551541Srgrimes 2561541Srgrimesstatic vm_page_t 2571541Srgrimesdev_pager_getfake(paddr) 2581541Srgrimes vm_offset_t paddr; 2591541Srgrimes{ 2601541Srgrimes vm_page_t m; 2611541Srgrimes 26292748Sjeff m = uma_zalloc(fakepg_zone, M_WAITOK); 2631549Srgrimes 2645455Sdg m->flags = PG_BUSY | PG_FICTITIOUS; 2659507Sdg m->valid = VM_PAGE_BITS_ALL; 2665455Sdg m->dirty = 0; 2675455Sdg m->busy = 0; 26813490Sdyson m->queue = PQ_NONE; 26940557Sdg m->object = NULL; 2701549Srgrimes 2711549Srgrimes m->wire_count = 1; 27214430Sdyson m->hold_count = 0; 2731541Srgrimes m->phys_addr = paddr; 2741549Srgrimes 2755455Sdg return (m); 2761541Srgrimes} 2771541Srgrimes 2781541Srgrimesstatic void 2791541Srgrimesdev_pager_putfake(m) 2801541Srgrimes vm_page_t m; 2811541Srgrimes{ 2821541Srgrimes if (!(m->flags & PG_FICTITIOUS)) 2831541Srgrimes panic("dev_pager_putfake: bad page"); 28492748Sjeff uma_zfree(fakepg_zone, m); 2851541Srgrimes} 286