device_pager.c revision 98630
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 98630 2002-06-22 18:36:51Z alc $ 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"); 9593818Sjhb mtx_init(&dev_pager_mtx, "dev_pager list", NULL, 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 10098630Salc/* 10198630Salc * MPSAFE 10298630Salc */ 10312820Sphkstatic vm_object_t 10440286Sdgdev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 1051541Srgrimes{ 1061541Srgrimes dev_t dev; 10712591Sbde d_mmap_t *mapfunc; 1081541Srgrimes vm_object_t object; 10941004Sdfr unsigned int npages; 11041004Sdfr vm_offset_t off; 1111541Srgrimes 1121541Srgrimes /* 11398630Salc * Offset should be page aligned. 11498630Salc */ 11598630Salc if (foff & PAGE_MASK) 11698630Salc return (NULL); 11798630Salc 11898630Salc size = round_page(size); 11998630Salc 12098630Salc /* 1211541Srgrimes * Make sure this device can be mapped. 1221541Srgrimes */ 12347111Sbde dev = handle; 12498630Salc mtx_lock(&Giant); 12546676Sphk mapfunc = devsw(dev)->d_mmap; 12612610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 12712610Sbde printf("obsolete map function %p\n", (void *)mapfunc); 12898630Salc mtx_unlock(&Giant); 1295455Sdg return (NULL); 13012610Sbde } 1311541Srgrimes 1321541Srgrimes /* 1335455Sdg * Check that the specified range of the device allows the desired 1345455Sdg * protection. 1358876Srgrimes * 1361541Srgrimes * XXX assumes VM_PROT_* == PROT_* 1371541Srgrimes */ 13840286Sdg npages = OFF_TO_IDX(size); 1391541Srgrimes for (off = foff; npages--; off += PAGE_SIZE) 14098630Salc if ((*mapfunc)(dev, off, (int) prot) == -1) { 14198630Salc mtx_unlock(&Giant); 1425455Sdg return (NULL); 14398630Salc } 1441541Srgrimes 1451541Srgrimes /* 14658634Scharnier * Lock to prevent object creation race condition. 1479507Sdg */ 14875675Salfred sx_xlock(&dev_pager_sx); 1499507Sdg 1509507Sdg /* 1511541Srgrimes * Look up pager, creating as necessary. 1521541Srgrimes */ 1539507Sdg object = vm_pager_object_lookup(&dev_pager_object_list, handle); 1549507Sdg if (object == NULL) { 1551541Srgrimes /* 1561541Srgrimes * Allocate object and associate it with the pager. 1571541Srgrimes */ 15812767Sdyson object = vm_object_allocate(OBJT_DEVICE, 15940286Sdg OFF_TO_IDX(foff + size)); 1609507Sdg object->handle = handle; 1619507Sdg TAILQ_INIT(&object->un_pager.devp.devp_pglist); 16275675Salfred mtx_lock(&dev_pager_mtx); 1639507Sdg TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 16475675Salfred mtx_unlock(&dev_pager_mtx); 1651541Srgrimes } else { 1661541Srgrimes /* 1676585Sdg * Gain a reference to the object. 1681541Srgrimes */ 1699507Sdg vm_object_reference(object); 17040286Sdg if (OFF_TO_IDX(foff + size) > object->size) 17140286Sdg object->size = OFF_TO_IDX(foff + size); 1721541Srgrimes } 1739507Sdg 17475675Salfred sx_xunlock(&dev_pager_sx); 17598630Salc mtx_unlock(&Giant); 1769507Sdg return (object); 1771541Srgrimes} 1781541Srgrimes 17912820Sphkstatic void 1809507Sdgdev_pager_dealloc(object) 1819507Sdg vm_object_t object; 1821541Srgrimes{ 1831541Srgrimes vm_page_t m; 1841541Srgrimes 18575675Salfred mtx_lock(&dev_pager_mtx); 1869507Sdg TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 18775675Salfred mtx_unlock(&dev_pager_mtx); 1881541Srgrimes /* 1891541Srgrimes * Free up our fake pages. 1901541Srgrimes */ 19115809Sdyson while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 1929507Sdg TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 1931541Srgrimes dev_pager_putfake(m); 1941541Srgrimes } 1951541Srgrimes} 1961541Srgrimes 19712820Sphkstatic int 1989507Sdgdev_pager_getpages(object, m, count, reqpage) 1999507Sdg vm_object_t object; 2009507Sdg vm_page_t *m; 2019507Sdg int count; 2029507Sdg int reqpage; 2031541Srgrimes{ 20412767Sdyson vm_offset_t offset; 20512767Sdyson vm_offset_t paddr; 2061541Srgrimes vm_page_t page; 2071541Srgrimes dev_t dev; 20877087Sjhb int i; 20912591Sbde d_mmap_t *mapfunc; 21012591Sbde int prot; 2111541Srgrimes 21277087Sjhb mtx_assert(&Giant, MA_OWNED); 21347111Sbde dev = object->handle; 21442957Sdillon offset = m[reqpage]->pindex; 2151541Srgrimes prot = PROT_READ; /* XXX should pass in? */ 21646676Sphk mapfunc = devsw(dev)->d_mmap; 2171549Srgrimes 21812610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 2191541Srgrimes panic("dev_pager_getpage: no map function"); 2201549Srgrimes 22147028Sphk paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 22242408Seivind KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 2231541Srgrimes /* 2249507Sdg * Replace the passed in reqpage page with our own fake page and free up the 2259507Sdg * all of the original pages. 2261541Srgrimes */ 2271541Srgrimes page = dev_pager_getfake(paddr); 2289507Sdg TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 2299507Sdg for (i = 0; i < count; i++) { 2309507Sdg vm_page_free(m[i]); 2319507Sdg } 2321541Srgrimes vm_page_insert(page, object, offset); 2331541Srgrimes 2345455Sdg return (VM_PAGER_OK); 2351541Srgrimes} 2361541Srgrimes 23743129Sdillonstatic void 2389507Sdgdev_pager_putpages(object, m, count, sync, rtvals) 2399507Sdg vm_object_t object; 2409507Sdg vm_page_t *m; 2419507Sdg int count; 2421541Srgrimes boolean_t sync; 2439507Sdg int *rtvals; 2441541Srgrimes{ 2451541Srgrimes panic("dev_pager_putpage called"); 2461541Srgrimes} 2471541Srgrimes 24812820Sphkstatic boolean_t 24912767Sdysondev_pager_haspage(object, pindex, before, after) 2509507Sdg vm_object_t object; 25112767Sdyson vm_pindex_t pindex; 2529507Sdg int *before; 2539507Sdg int *after; 2541541Srgrimes{ 2559507Sdg if (before != NULL) 2569507Sdg *before = 0; 2579507Sdg if (after != NULL) 2589507Sdg *after = 0; 2595455Sdg return (TRUE); 2601541Srgrimes} 2611541Srgrimes 2621541Srgrimesstatic vm_page_t 2631541Srgrimesdev_pager_getfake(paddr) 2641541Srgrimes vm_offset_t paddr; 2651541Srgrimes{ 2661541Srgrimes vm_page_t m; 2671541Srgrimes 26892748Sjeff m = uma_zalloc(fakepg_zone, M_WAITOK); 2691549Srgrimes 2705455Sdg m->flags = PG_BUSY | PG_FICTITIOUS; 2719507Sdg m->valid = VM_PAGE_BITS_ALL; 2725455Sdg m->dirty = 0; 2735455Sdg m->busy = 0; 27413490Sdyson m->queue = PQ_NONE; 27540557Sdg m->object = NULL; 2761549Srgrimes 2771549Srgrimes m->wire_count = 1; 27814430Sdyson m->hold_count = 0; 2791541Srgrimes m->phys_addr = paddr; 2801549Srgrimes 2815455Sdg return (m); 2821541Srgrimes} 2831541Srgrimes 2841541Srgrimesstatic void 2851541Srgrimesdev_pager_putfake(m) 2861541Srgrimes vm_page_t m; 2871541Srgrimes{ 2881541Srgrimes if (!(m->flags & PG_FICTITIOUS)) 2891541Srgrimes panic("dev_pager_putfake: bad page"); 29092748Sjeff uma_zfree(fakepg_zone, m); 2911541Srgrimes} 292