device_pager.c revision 12820
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 191541Srgrimes * 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 3912820Sphk * $Id: device_pager.c,v 1.18 1995/12/13 15:13:54 julian Exp $ 401541Srgrimes */ 411541Srgrimes 421541Srgrimes#include <sys/param.h> 431541Srgrimes#include <sys/systm.h> 441541Srgrimes#include <sys/conf.h> 451541Srgrimes#include <sys/mman.h> 461541Srgrimes#include <sys/malloc.h> 473311Sphk#include <sys/proc.h> 4812662Sdg#include <sys/queue.h> 491541Srgrimes 501541Srgrimes#include <vm/vm.h> 5112662Sdg#include <vm/vm_param.h> 5212662Sdg#include <vm/vm_prot.h> 531541Srgrimes#include <vm/vm_kern.h> 5412662Sdg#include <vm/vm_object.h> 551541Srgrimes#include <vm/vm_page.h> 569507Sdg#include <vm/vm_pager.h> 571541Srgrimes#include <vm/device_pager.h> 581541Srgrimes 5912820Sphkstatic void dev_pager_init __P((void)); 6012820Sphkstatic vm_object_t dev_pager_alloc __P((void *, vm_size_t, vm_prot_t, 6112820Sphk vm_ooffset_t)); 6212820Sphkstatic void dev_pager_dealloc __P((vm_object_t)); 6312820Sphkstatic int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 6412820Sphkstatic int dev_pager_putpages __P((vm_object_t, vm_page_t *, int, 6512820Sphk boolean_t, int *)); 6612820Sphkstatic boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *, 6712820Sphk int *)); 681541Srgrimes 6912820Sphk/* list of device pager objects */ 7012820Sphkstatic struct pagerlst dev_pager_object_list; 7112820Sphk 7212820Sphk/* list of available vm_page_t's */ 7312820Sphkstatic TAILQ_HEAD(, vm_page) dev_pager_fakelist; 7412820Sphk 755455Sdgstatic vm_page_t dev_pager_getfake __P((vm_offset_t)); 765455Sdgstatic void dev_pager_putfake __P((vm_page_t)); 771541Srgrimes 789507Sdgstatic int dev_pager_alloc_lock, dev_pager_alloc_lock_want; 799507Sdg 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); 941541Srgrimes TAILQ_INIT(&dev_pager_fakelist); 951541Srgrimes} 961541Srgrimes 9712820Sphkstatic vm_object_t 981541Srgrimesdev_pager_alloc(handle, size, prot, foff) 998416Sdg void *handle; 1001541Srgrimes vm_size_t size; 1011541Srgrimes vm_prot_t prot; 10212767Sdyson vm_ooffset_t foff; 1031541Srgrimes{ 1041541Srgrimes dev_t dev; 10512591Sbde d_mmap_t *mapfunc; 1061541Srgrimes vm_object_t object; 1071549Srgrimes unsigned int npages, off; 1081541Srgrimes 1091541Srgrimes /* 1101541Srgrimes * Make sure this device can be mapped. 1111541Srgrimes */ 1125455Sdg dev = (dev_t) (u_long) handle; 11312813Sjulian mapfunc = cdevsw[major(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 */ 1225455Sdg if (foff & (PAGE_SIZE - 1)) 1235455Sdg return (NULL); 1241541Srgrimes 1251541Srgrimes /* 1265455Sdg * Check that the specified range of the device allows the desired 1275455Sdg * protection. 1288876Srgrimes * 1291541Srgrimes * XXX assumes VM_PROT_* == PROT_* 1301541Srgrimes */ 1311541Srgrimes npages = atop(round_page(size)); 1321541Srgrimes for (off = foff; npages--; off += PAGE_SIZE) 1335455Sdg if ((*mapfunc) (dev, off, (int) prot) == -1) 1345455Sdg return (NULL); 1351541Srgrimes 1361541Srgrimes /* 1379507Sdg * Lock to prevent object creation race contion. 1389507Sdg */ 1399507Sdg while (dev_pager_alloc_lock) { 1409507Sdg dev_pager_alloc_lock_want++; 1419507Sdg tsleep(&dev_pager_alloc_lock, PVM, "dvpall", 0); 1429507Sdg dev_pager_alloc_lock_want--; 1439507Sdg } 1449507Sdg dev_pager_alloc_lock = 1; 1459507Sdg 1469507Sdg /* 1471541Srgrimes * Look up pager, creating as necessary. 1481541Srgrimes */ 1499507Sdg object = vm_pager_object_lookup(&dev_pager_object_list, handle); 1509507Sdg if (object == NULL) { 1511541Srgrimes /* 1521541Srgrimes * Allocate object and associate it with the pager. 1531541Srgrimes */ 15412767Sdyson object = vm_object_allocate(OBJT_DEVICE, 15512767Sdyson OFF_TO_IDX(foff + size)); 1569507Sdg object->handle = handle; 1579507Sdg TAILQ_INIT(&object->un_pager.devp.devp_pglist); 1589507Sdg TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 1591541Srgrimes } else { 1601541Srgrimes /* 1616585Sdg * Gain a reference to the object. 1621541Srgrimes */ 1639507Sdg vm_object_reference(object); 16412767Sdyson if (OFF_TO_IDX(foff + size) > object->size) 16512767Sdyson object->size = OFF_TO_IDX(foff + size); 1661541Srgrimes } 1679507Sdg 1689507Sdg dev_pager_alloc_lock = 0; 1699507Sdg if (dev_pager_alloc_lock_want) 1709507Sdg wakeup(&dev_pager_alloc_lock); 1719507Sdg 1729507Sdg return (object); 1731541Srgrimes} 1741541Srgrimes 17512820Sphkstatic void 1769507Sdgdev_pager_dealloc(object) 1779507Sdg vm_object_t object; 1781541Srgrimes{ 1791541Srgrimes vm_page_t m; 1801541Srgrimes 1819507Sdg TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 1821541Srgrimes /* 1831541Srgrimes * Free up our fake pages. 1841541Srgrimes */ 1859507Sdg while ((m = object->un_pager.devp.devp_pglist.tqh_first) != 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; 2029507Sdg int i, s; 20312591Sbde d_mmap_t *mapfunc; 20412591Sbde int prot; 2051541Srgrimes 2069507Sdg dev = (dev_t) (u_long) object->handle; 20712767Sdyson offset = m[reqpage]->pindex + OFF_TO_IDX(object->paging_offset); 2081541Srgrimes prot = PROT_READ; /* XXX should pass in? */ 20912813Sjulian mapfunc = cdevsw[major(dev)]->d_mmap; 2101549Srgrimes 21112610Sbde if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 2121541Srgrimes panic("dev_pager_getpage: no map function"); 2131549Srgrimes 21412767Sdyson paddr = pmap_phys_address((*mapfunc) ((dev_t) dev, (int) offset << PAGE_SHIFT, prot)); 2151541Srgrimes#ifdef DIAGNOSTIC 2161541Srgrimes if (paddr == -1) 2171541Srgrimes panic("dev_pager_getpage: map function returns error"); 2181541Srgrimes#endif 2191541Srgrimes /* 2209507Sdg * Replace the passed in reqpage page with our own fake page and free up the 2219507Sdg * all of the original pages. 2221541Srgrimes */ 2231541Srgrimes page = dev_pager_getfake(paddr); 2249507Sdg TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 2259507Sdg for (i = 0; i < count; i++) { 2269507Sdg PAGE_WAKEUP(m[i]); 2279507Sdg vm_page_free(m[i]); 2289507Sdg } 2291549Srgrimes s = splhigh(); 2301541Srgrimes vm_page_insert(page, object, offset); 2311549Srgrimes splx(s); 2321541Srgrimes 2335455Sdg return (VM_PAGER_OK); 2341541Srgrimes} 2351541Srgrimes 23612820Sphkstatic int 2379507Sdgdev_pager_putpages(object, m, count, sync, rtvals) 2389507Sdg vm_object_t object; 2399507Sdg vm_page_t *m; 2409507Sdg int count; 2411541Srgrimes boolean_t sync; 2429507Sdg int *rtvals; 2431541Srgrimes{ 2441541Srgrimes panic("dev_pager_putpage called"); 2451541Srgrimes} 2461541Srgrimes 24712820Sphkstatic boolean_t 24812767Sdysondev_pager_haspage(object, pindex, before, after) 2499507Sdg vm_object_t object; 25012767Sdyson vm_pindex_t pindex; 2519507Sdg int *before; 2529507Sdg int *after; 2531541Srgrimes{ 2549507Sdg if (before != NULL) 2559507Sdg *before = 0; 2569507Sdg if (after != NULL) 2579507Sdg *after = 0; 2585455Sdg return (TRUE); 2591541Srgrimes} 2601541Srgrimes 2611541Srgrimesstatic vm_page_t 2621541Srgrimesdev_pager_getfake(paddr) 2631541Srgrimes vm_offset_t paddr; 2641541Srgrimes{ 2651541Srgrimes vm_page_t m; 2661541Srgrimes int i; 2671541Srgrimes 2681541Srgrimes if (dev_pager_fakelist.tqh_first == NULL) { 2695455Sdg m = (vm_page_t) malloc(PAGE_SIZE * 2, M_VMPGDATA, M_WAITOK); 2705455Sdg for (i = (PAGE_SIZE * 2) / sizeof(*m); i > 0; i--) { 2711541Srgrimes TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq); 2721541Srgrimes m++; 2731541Srgrimes } 2741541Srgrimes } 2751541Srgrimes m = dev_pager_fakelist.tqh_first; 2761541Srgrimes TAILQ_REMOVE(&dev_pager_fakelist, m, pageq); 2771549Srgrimes 2785455Sdg m->flags = PG_BUSY | PG_FICTITIOUS; 2799507Sdg m->valid = VM_PAGE_BITS_ALL; 2805455Sdg m->dirty = 0; 2815455Sdg m->busy = 0; 2825455Sdg m->bmapped = 0; 2831549Srgrimes 2841549Srgrimes m->wire_count = 1; 2851541Srgrimes m->phys_addr = paddr; 2861549Srgrimes 2875455Sdg return (m); 2881541Srgrimes} 2891541Srgrimes 2901541Srgrimesstatic void 2911541Srgrimesdev_pager_putfake(m) 2921541Srgrimes vm_page_t m; 2931541Srgrimes{ 2941541Srgrimes if (!(m->flags & PG_FICTITIOUS)) 2951541Srgrimes panic("dev_pager_putfake: bad page"); 2961541Srgrimes TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq); 2971541Srgrimes} 298