device_pager.c revision 92727
150477Speter/* 21817Sdg * Copyright (c) 1990 University of Utah. 31817Sdg * 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 7160798Sjhb * the Systems Programming Group of the University of Utah Computer 81541Srgrimes * Science Department. 9146806Srwatson * 10146806Srwatson * Redistribution and use in source and binary forms, with or without 11146806Srwatson * modification, are permitted provided that the following conditions 12146806Srwatson * are met: 13146806Srwatson * 1. Redistributions of source code must retain the above copyright 14194390Sjhb * notice, this list of conditions and the following disclaimer. 15203660Sed * 2. Redistributions in binary form must reproduce the above copyright 16194390Sjhb * notice, this list of conditions and the following disclaimer in the 17194390Sjhb * documentation and/or other materials provided with the distribution. 1811294Sswallace * 3. All advertising materials mentioning features or use of this software 1910905Sbde * must display the following acknowledgement: 201541Srgrimes * This product includes software developed by the University of 2110905Sbde * California, Berkeley and its contributors. 2210905Sbde * 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 2899855Salfred * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29194645Sjhb * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30194833Sjhb * 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) 3369449Salfred * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34194383Sjhb * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35160797Sjhb * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36181972Sobrien * SUCH DAMAGE. 37181972Sobrien * 38183361Sjhb * @(#)device_pager.c 8.1 (Berkeley) 6/11/93 39181972Sobrien * $FreeBSD: head/sys/vm/device_pager.c 92727 2002-03-19 22:20:14Z alfred $ 40181972Sobrien */ 41181972Sobrien 42181972Sobrien#include <sys/param.h> 43211838Skib#include <sys/systm.h> 44104747Srwatson#include <sys/conf.h> 45104747Srwatson#include <sys/lock.h> 46123408Speter#include <sys/proc.h> 47123408Speter#include <sys/mutex.h> 481541Srgrimes#include <sys/mman.h> 491541Srgrimes#include <sys/sx.h> 5011294Sswallace 5111294Sswallace#include <vm/vm.h> 5211294Sswallace#include <vm/vm_object.h> 5311294Sswallace#include <vm/vm_page.h> 541541Srgrimes#include <vm/vm_pager.h> 551541Srgrimes#include <vm/vm_zone.h> 561541Srgrimes 571541Srgrimesstatic void dev_pager_init(void); 581541Srgrimesstatic vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 591541Srgrimes vm_ooffset_t); 60160798Sjhbstatic void dev_pager_dealloc(vm_object_t); 61160798Sjhbstatic int dev_pager_getpages(vm_object_t, vm_page_t *, int, int); 62146806Srwatsonstatic void dev_pager_putpages(vm_object_t, vm_page_t *, int, 63160798Sjhb boolean_t, int *); 64160798Sjhbstatic boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, 65146806Srwatson int *); 66160798Sjhb 67146806Srwatson/* list of device pager objects */ 68160798Sjhbstatic struct pagerlst dev_pager_object_list; 6912216Sbde/* protect against object creation */ 7012216Sbdestatic struct sx dev_pager_sx; 7112216Sbde/* protect list manipulation */ 72160798Sjhbstatic struct mtx dev_pager_mtx; 73160798Sjhb 74242958Skib 75162991Srwatsonstatic vm_zone_t fakepg_zone; 76160798Sjhb#if 0 77160798Sjhbstatic struct vm_zone fakepg_zone_store; 78146806Srwatson#endif 79160798Sjhb 80160798Sjhbstatic vm_page_t dev_pager_getfake(vm_offset_t); 81160798Sjhbstatic void dev_pager_putfake(vm_page_t); 82160798Sjhb 83160798Sjhbstruct pagerops devicepagerops = { 84160798Sjhb dev_pager_init, 85146806Srwatson dev_pager_alloc, 86160798Sjhb dev_pager_dealloc, 87146806Srwatson dev_pager_getpages, 88160798Sjhb dev_pager_putpages, 89146806Srwatson dev_pager_haspage, 90160798Sjhb NULL 91160798Sjhb}; 92146806Srwatson 9312216Sbdestatic void 94160798Sjhbdev_pager_init() 95160798Sjhb{ 96160798Sjhb TAILQ_INIT(&dev_pager_object_list); 97160798Sjhb sx_init(&dev_pager_sx, "dev_pager create"); 98160798Sjhb mtx_init(&dev_pager_mtx, "dev_pager list", MTX_DEF); 99146806Srwatson#if 0 100160798Sjhb fakepg_zone = &fakepg_zone_store; 101146806Srwatson zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2); 102160798Sjhb#endif 103146806Srwatson fakepg_zone = zinit("DP fakepg", sizeof(struct vm_page), 0, 0, 0); 104160798Sjhb} 105146806Srwatson 106146806Srwatsonstatic vm_object_t 107146806Srwatsondev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 108160798Sjhb{ 109146806Srwatson dev_t dev; 110146806Srwatson d_mmap_t *mapfunc; 111160798Sjhb vm_object_t object; 112146806Srwatson unsigned int npages; 113146806Srwatson vm_offset_t off; 114160798Sjhb 115146806Srwatson mtx_assert(&Giant, MA_OWNED); 116146806Srwatson /* 117227691Sed * Make sure this device can be mapped. 118248597Spjd */ 119248597Spjd dev = handle; 120160798Sjhb mapfunc = devsw(dev)->d_mmap; 121160798Sjhb if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 122160798Sjhb printf("obsolete map function %p\n", (void *)mapfunc); 123160798Sjhb return (NULL); 124160798Sjhb } 125160798Sjhb 126160798Sjhb /* 127160798Sjhb * Offset should be page aligned. 128160798Sjhb */ 129146806Srwatson if (foff & PAGE_MASK) 130160798Sjhb return (NULL); 131146806Srwatson 132160798Sjhb size = round_page(size); 133146806Srwatson 134146806Srwatson /* 135160798Sjhb * Check that the specified range of the device allows the desired 136160798Sjhb * protection. 13721776Sbde * 13821776Sbde * XXX assumes VM_PROT_* == PROT_* 13921776Sbde */ 140160798Sjhb npages = OFF_TO_IDX(size); 141146806Srwatson for (off = foff; npages--; off += PAGE_SIZE) 142160798Sjhb if ((*mapfunc) (dev, off, (int) prot) == -1) 143160798Sjhb return (NULL); 144160798Sjhb 145162373Srwatson /* 146146806Srwatson * Lock to prevent object creation race condition. 147160798Sjhb */ 148146806Srwatson sx_xlock(&dev_pager_sx); 149160798Sjhb 150160798Sjhb /* 151160798Sjhb * Look up pager, creating as necessary. 152176215Sru */ 153176215Sru object = vm_pager_object_lookup(&dev_pager_object_list, handle); 154160798Sjhb if (object == NULL) { 155146806Srwatson /* 156160798Sjhb * Allocate object and associate it with the pager. 157146806Srwatson */ 158160798Sjhb object = vm_object_allocate(OBJT_DEVICE, 159160798Sjhb OFF_TO_IDX(foff + size)); 160160798Sjhb object->handle = handle; 161146806Srwatson TAILQ_INIT(&object->un_pager.devp.devp_pglist); 162146806Srwatson mtx_lock(&dev_pager_mtx); 163162991Srwatson TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 164146806Srwatson mtx_unlock(&dev_pager_mtx); 165160798Sjhb } else { 166146806Srwatson /* 167160798Sjhb * Gain a reference to the object. 168146806Srwatson */ 169146806Srwatson vm_object_reference(object); 170160798Sjhb if (OFF_TO_IDX(foff + size) > object->size) 171160798Sjhb object->size = OFF_TO_IDX(foff + size); 172160798Sjhb } 173146806Srwatson 174160798Sjhb sx_xunlock(&dev_pager_sx); 175146806Srwatson 176160798Sjhb return (object); 177160798Sjhb} 178146806Srwatson 179160798Sjhbstatic void 180146806Srwatsondev_pager_dealloc(object) 181146806Srwatson vm_object_t object; 182146806Srwatson{ 183160798Sjhb vm_page_t m; 184146806Srwatson 185160798Sjhb mtx_lock(&dev_pager_mtx); 186146806Srwatson TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 187160798Sjhb mtx_unlock(&dev_pager_mtx); 188146806Srwatson /* 189160798Sjhb * Free up our fake pages. 190160798Sjhb */ 191160798Sjhb while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 192146806Srwatson TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 193160798Sjhb dev_pager_putfake(m); 194160798Sjhb } 195160798Sjhb} 196146806Srwatson 197160798Sjhbstatic int 198146806Srwatsondev_pager_getpages(object, m, count, reqpage) 199146806Srwatson vm_object_t object; 200160798Sjhb vm_page_t *m; 201146806Srwatson int count; 202146806Srwatson int reqpage; 203160798Sjhb{ 204160798Sjhb vm_offset_t offset; 205146806Srwatson vm_offset_t paddr; 206160798Sjhb vm_page_t page; 207123750Speter dev_t dev; 20812216Sbde int i; 209160798Sjhb d_mmap_t *mapfunc; 210146806Srwatson int prot; 211146806Srwatson 212160798Sjhb mtx_assert(&Giant, MA_OWNED); 213160798Sjhb dev = object->handle; 214146806Srwatson offset = m[reqpage]->pindex; 215160798Sjhb prot = PROT_READ; /* XXX should pass in? */ 216146806Srwatson mapfunc = devsw(dev)->d_mmap; 217160798Sjhb 218146806Srwatson if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 219194390Sjhb panic("dev_pager_getpage: no map function"); 220146806Srwatson 221160798Sjhb paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 222160798Sjhb KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 223146806Srwatson /* 224160798Sjhb * Replace the passed in reqpage page with our own fake page and free up the 225146806Srwatson * all of the original pages. 226160798Sjhb */ 227146806Srwatson page = dev_pager_getfake(paddr); 228160798Sjhb TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 229146806Srwatson for (i = 0; i < count; i++) { 230160798Sjhb vm_page_free(m[i]); 231146806Srwatson } 232160798Sjhb vm_page_insert(page, object, offset); 233146806Srwatson 234160798Sjhb return (VM_PAGER_OK); 235146806Srwatson} 236160798Sjhb 237160798Sjhbstatic void 238160798Sjhbdev_pager_putpages(object, m, count, sync, rtvals) 23921776Sbde vm_object_t object; 24021776Sbde vm_page_t *m; 241160798Sjhb int count; 242146806Srwatson boolean_t sync; 243160798Sjhb int *rtvals; 244146806Srwatson{ 245160798Sjhb panic("dev_pager_putpage called"); 246146806Srwatson} 247146806Srwatson 248160798Sjhbstatic boolean_t 249146806Srwatsondev_pager_haspage(object, pindex, before, after) 250160798Sjhb vm_object_t object; 251146806Srwatson vm_pindex_t pindex; 252160798Sjhb int *before; 253146806Srwatson int *after; 254146806Srwatson{ 255160798Sjhb if (before != NULL) 256146806Srwatson *before = 0; 257160798Sjhb if (after != NULL) 258146806Srwatson *after = 0; 259160798Sjhb return (TRUE); 260146806Srwatson} 261160798Sjhb 262160798Sjhbstatic vm_page_t 263194390Sjhbdev_pager_getfake(paddr) 264146806Srwatson vm_offset_t paddr; 265146806Srwatson{ 266146806Srwatson vm_page_t m; 267160798Sjhb 268160798Sjhb m = zalloc(fakepg_zone); 269160798Sjhb 270160798Sjhb m->flags = PG_BUSY | PG_FICTITIOUS; 271160798Sjhb m->valid = VM_PAGE_BITS_ALL; 272160798Sjhb m->dirty = 0; 273160798Sjhb m->busy = 0; 274160798Sjhb m->queue = PQ_NONE; 275146806Srwatson m->object = NULL; 276160798Sjhb 277160798Sjhb m->wire_count = 1; 278146806Srwatson m->hold_count = 0; 279160798Sjhb m->phys_addr = paddr; 280160798Sjhb 281160798Sjhb return (m); 282146806Srwatson} 283146806Srwatson 284160798Sjhbstatic void 285146806Srwatsondev_pager_putfake(m) 286160798Sjhb vm_page_t m; 287146806Srwatson{ 288160798Sjhb if (!(m->flags & PG_FICTITIOUS)) 289160798Sjhb panic("dev_pager_putfake: bad page"); 290160798Sjhb zfree(fakepg_zone, m); 291146806Srwatson} 292160798Sjhb