device_pager.c revision 76166
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 76166 2001-05-01 08:13:21Z markm $ 401541Srgrimes */ 411541Srgrimes 421541Srgrimes#include <sys/param.h> 431541Srgrimes#include <sys/systm.h> 441541Srgrimes#include <sys/conf.h> 4576166Smarkm#include <sys/lock.h> 4676166Smarkm#include <sys/mutex.h> 471541Srgrimes#include <sys/mman.h> 4875675Salfred#include <sys/sx.h> 491541Srgrimes 501541Srgrimes#include <vm/vm.h> 5112662Sdg#include <vm/vm_object.h> 521541Srgrimes#include <vm/vm_page.h> 539507Sdg#include <vm/vm_pager.h> 5440558Sdg#include <vm/vm_zone.h> 551541Srgrimes 5612820Sphkstatic void dev_pager_init __P((void)); 5740286Sdgstatic vm_object_t dev_pager_alloc __P((void *, vm_ooffset_t, vm_prot_t, 5812820Sphk vm_ooffset_t)); 5912820Sphkstatic void dev_pager_dealloc __P((vm_object_t)); 6012820Sphkstatic int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 6143129Sdillonstatic void dev_pager_putpages __P((vm_object_t, vm_page_t *, int, 6212820Sphk boolean_t, int *)); 6312820Sphkstatic boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *, 6412820Sphk int *)); 651541Srgrimes 6612820Sphk/* list of device pager objects */ 6712820Sphkstatic struct pagerlst dev_pager_object_list; 6875675Salfred/* protect against object creation */ 6975675Salfredstatic struct sx dev_pager_sx; 7075675Salfred/* protect list manipulation */ 7175675Salfredstatic struct mtx dev_pager_mtx; 7212820Sphk 7375675Salfred 7440558Sdgstatic vm_zone_t fakepg_zone; 7540558Sdgstatic struct vm_zone fakepg_zone_store; 7612820Sphk 775455Sdgstatic vm_page_t dev_pager_getfake __P((vm_offset_t)); 785455Sdgstatic void dev_pager_putfake __P((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); 9640558Sdg fakepg_zone = &fakepg_zone_store; 9740558Sdg zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2); 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 1091541Srgrimes /* 1101541Srgrimes * Make sure this device can be mapped. 1111541Srgrimes */ 11247111Sbde dev = handle; 11346676Sphk mapfunc = devsw(dev)->d_mmap; 11412610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 11512610Sbde printf("obsolete map function %p\n", (void *)mapfunc); 1165455Sdg return (NULL); 11712610Sbde } 1181541Srgrimes 1191541Srgrimes /* 1201541Srgrimes * Offset should be page aligned. 1211541Srgrimes */ 12215583Sphk if (foff & PAGE_MASK) 1235455Sdg return (NULL); 1241541Srgrimes 12540286Sdg size = round_page(size); 12640286Sdg 1271541Srgrimes /* 1285455Sdg * Check that the specified range of the device allows the desired 1295455Sdg * protection. 1308876Srgrimes * 1311541Srgrimes * XXX assumes VM_PROT_* == PROT_* 1321541Srgrimes */ 13340286Sdg npages = OFF_TO_IDX(size); 1341541Srgrimes for (off = foff; npages--; off += PAGE_SIZE) 1355455Sdg if ((*mapfunc) (dev, off, (int) prot) == -1) 1365455Sdg return (NULL); 1371541Srgrimes 1381541Srgrimes /* 13958634Scharnier * Lock to prevent object creation race condition. 1409507Sdg */ 14175675Salfred sx_xlock(&dev_pager_sx); 1429507Sdg 1439507Sdg /* 1441541Srgrimes * Look up pager, creating as necessary. 1451541Srgrimes */ 1469507Sdg object = vm_pager_object_lookup(&dev_pager_object_list, handle); 1479507Sdg if (object == NULL) { 1481541Srgrimes /* 1491541Srgrimes * Allocate object and associate it with the pager. 1501541Srgrimes */ 15112767Sdyson object = vm_object_allocate(OBJT_DEVICE, 15240286Sdg OFF_TO_IDX(foff + size)); 1539507Sdg object->handle = handle; 1549507Sdg TAILQ_INIT(&object->un_pager.devp.devp_pglist); 15575675Salfred mtx_lock(&dev_pager_mtx); 1569507Sdg TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 15775675Salfred mtx_unlock(&dev_pager_mtx); 1581541Srgrimes } else { 1591541Srgrimes /* 1606585Sdg * Gain a reference to the object. 1611541Srgrimes */ 1629507Sdg vm_object_reference(object); 16340286Sdg if (OFF_TO_IDX(foff + size) > object->size) 16440286Sdg object->size = OFF_TO_IDX(foff + size); 1651541Srgrimes } 1669507Sdg 16775675Salfred sx_xunlock(&dev_pager_sx); 1689507Sdg 1699507Sdg return (object); 1701541Srgrimes} 1711541Srgrimes 17212820Sphkstatic void 1739507Sdgdev_pager_dealloc(object) 1749507Sdg vm_object_t object; 1751541Srgrimes{ 1761541Srgrimes vm_page_t m; 1771541Srgrimes 17875675Salfred mtx_lock(&dev_pager_mtx); 1799507Sdg TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 18075675Salfred mtx_unlock(&dev_pager_mtx); 1811541Srgrimes /* 1821541Srgrimes * Free up our fake pages. 1831541Srgrimes */ 18415809Sdyson while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 1859507Sdg TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 1861541Srgrimes dev_pager_putfake(m); 1871541Srgrimes } 1881541Srgrimes} 1891541Srgrimes 19012820Sphkstatic int 1919507Sdgdev_pager_getpages(object, m, count, reqpage) 1929507Sdg vm_object_t object; 1939507Sdg vm_page_t *m; 1949507Sdg int count; 1959507Sdg int reqpage; 1961541Srgrimes{ 19712767Sdyson vm_offset_t offset; 19812767Sdyson vm_offset_t paddr; 1991541Srgrimes vm_page_t page; 2001541Srgrimes dev_t dev; 2019507Sdg int i, s; 20212591Sbde d_mmap_t *mapfunc; 20312591Sbde int prot; 2041541Srgrimes 20547111Sbde dev = object->handle; 20642957Sdillon offset = m[reqpage]->pindex; 2071541Srgrimes prot = PROT_READ; /* XXX should pass in? */ 20846676Sphk mapfunc = devsw(dev)->d_mmap; 2091549Srgrimes 21012610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 2111541Srgrimes panic("dev_pager_getpage: no map function"); 2121549Srgrimes 21347028Sphk paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 21442408Seivind KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 2151541Srgrimes /* 2169507Sdg * Replace the passed in reqpage page with our own fake page and free up the 2179507Sdg * all of the original pages. 2181541Srgrimes */ 2191541Srgrimes page = dev_pager_getfake(paddr); 2209507Sdg TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 2219507Sdg for (i = 0; i < count; i++) { 2229507Sdg vm_page_free(m[i]); 2239507Sdg } 2241549Srgrimes s = splhigh(); 2251541Srgrimes vm_page_insert(page, object, offset); 2261549Srgrimes splx(s); 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 26240558Sdg m = zalloc(fakepg_zone); 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"); 28440558Sdg zfree(fakepg_zone, m); 2851541Srgrimes} 286