device_pager.c revision 93818
150397Sobrien/* 250397Sobrien * Copyright (c) 1990 University of Utah. 3117395Skan * Copyright (c) 1991, 1993 450397Sobrien * The Regents of the University of California. All rights reserved. 518334Speter * 618334Speter * This code is derived from software contributed to Berkeley by 718334Speter * the Systems Programming Group of the University of Utah Computer 818334Speter * Science Department. 918334Speter * 1018334Speter * Redistribution and use in source and binary forms, with or without 1118334Speter * modification, are permitted provided that the following conditions 1218334Speter * are met: 1318334Speter * 1. Redistributions of source code must retain the above copyright 1418334Speter * notice, this list of conditions and the following disclaimer. 1518334Speter * 2. Redistributions in binary form must reproduce the above copyright 1618334Speter * notice, this list of conditions and the following disclaimer in the 1718334Speter * documentation and/or other materials provided with the distribution. 1818334Speter * 3. All advertising materials mentioning features or use of this software 1918334Speter * must display the following acknowledgement: 2018334Speter * This product includes software developed by the University of 2118334Speter * California, Berkeley and its contributors. 2218334Speter * 4. Neither the name of the University nor the names of its contributors 2318334Speter * may be used to endorse or promote products derived from this software 2418334Speter * without specific prior written permission. 2518334Speter * 2618334Speter * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2718334Speter * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2818334Speter * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2918334Speter * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 3018334Speter * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 3118334Speter * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3218334Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3318334Speter * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3418334Speter * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3518334Speter * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3618334Speter * SUCH DAMAGE. 3718334Speter * 3818334Speter * @(#)device_pager.c 8.1 (Berkeley) 6/11/93 3918334Speter * $FreeBSD: head/sys/vm/device_pager.c 93818 2002-04-04 21:03:38Z jhb $ 4018334Speter */ 4118334Speter 4218334Speter#include <sys/param.h> 4318334Speter#include <sys/systm.h> 4418334Speter#include <sys/conf.h> 4518334Speter#include <sys/lock.h> 4618334Speter#include <sys/proc.h> 4718334Speter#include <sys/mutex.h> 4818334Speter#include <sys/mman.h> 4918334Speter#include <sys/sx.h> 5018334Speter 5118334Speter#include <vm/vm.h> 5218334Speter#include <vm/vm_object.h> 5318334Speter#include <vm/vm_page.h> 5418334Speter#include <vm/vm_pager.h> 5518334Speter#include <vm/uma.h> 5618334Speter 5718334Speterstatic void dev_pager_init(void); 5818334Speterstatic vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 5918334Speter vm_ooffset_t); 6018334Speterstatic void dev_pager_dealloc(vm_object_t); 6118334Speterstatic int dev_pager_getpages(vm_object_t, vm_page_t *, int, int); 6218334Speterstatic void dev_pager_putpages(vm_object_t, vm_page_t *, int, 6318334Speter boolean_t, int *); 6490075Sobrienstatic boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, 6518334Speter int *); 6618334Speter 6718334Speter/* list of device pager objects */ 6818334Speterstatic struct pagerlst dev_pager_object_list; 6918334Speter/* protect against object creation */ 7018334Speterstatic struct sx dev_pager_sx; 7118334Speter/* protect list manipulation */ 7218334Speterstatic struct mtx dev_pager_mtx; 7318334Speter 7418334Speter 7518334Speterstatic uma_zone_t fakepg_zone; 7618334Speter 7718334Speterstatic vm_page_t dev_pager_getfake(vm_offset_t); 7818334Speterstatic void dev_pager_putfake(vm_page_t); 7918334Speter 8018334Speterstruct pagerops devicepagerops = { 8118334Speter dev_pager_init, 8218334Speter dev_pager_alloc, 8318334Speter dev_pager_dealloc, 8418334Speter dev_pager_getpages, 8518334Speter dev_pager_putpages, 8618334Speter dev_pager_haspage, 8718334Speter NULL 8818334Speter}; 8918334Speter 9018334Speterstatic void 9118334Speterdev_pager_init() 9218334Speter{ 9318334Speter TAILQ_INIT(&dev_pager_object_list); 9418334Speter sx_init(&dev_pager_sx, "dev_pager create"); 9518334Speter mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 9618334Speter fakepg_zone = uma_zcreate("DP fakepg", sizeof(struct vm_page), 9718334Speter NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 9818334Speter} 9918334Speter 10018334Speterstatic vm_object_t 10118334Speterdev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 10218334Speter{ 10318334Speter dev_t dev; 10418334Speter d_mmap_t *mapfunc; 10550397Sobrien vm_object_t object; 10650397Sobrien unsigned int npages; 10750397Sobrien vm_offset_t off; 10818334Speter 10950397Sobrien mtx_assert(&Giant, MA_OWNED); 11018334Speter /* 11118334Speter * Make sure this device can be mapped. 11218334Speter */ 11318334Speter dev = handle; 11418334Speter mapfunc = devsw(dev)->d_mmap; 11518334Speter if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 11618334Speter printf("obsolete map function %p\n", (void *)mapfunc); 11718334Speter return (NULL); 11890075Sobrien } 11918334Speter 12018334Speter /* 12118334Speter * Offset should be page aligned. 12218334Speter */ 12318334Speter if (foff & PAGE_MASK) 12418334Speter return (NULL); 12518334Speter 12618334Speter size = round_page(size); 12718334Speter 12818334Speter /* 12918334Speter * Check that the specified range of the device allows the desired 13018334Speter * protection. 13118334Speter * 132117395Skan * XXX assumes VM_PROT_* == PROT_* 13318334Speter */ 13418334Speter npages = OFF_TO_IDX(size); 13518334Speter for (off = foff; npages--; off += PAGE_SIZE) 13618334Speter if ((*mapfunc) (dev, off, (int) prot) == -1) 13718334Speter return (NULL); 13818334Speter 13918334Speter /* 14018334Speter * Lock to prevent object creation race condition. 14118334Speter */ 14218334Speter sx_xlock(&dev_pager_sx); 14318334Speter 14418334Speter /* 14518334Speter * Look up pager, creating as necessary. 14618334Speter */ 14718334Speter object = vm_pager_object_lookup(&dev_pager_object_list, handle); 14818334Speter if (object == NULL) { 14918334Speter /* 15018334Speter * Allocate object and associate it with the pager. 15118334Speter */ 15218334Speter object = vm_object_allocate(OBJT_DEVICE, 15350397Sobrien OFF_TO_IDX(foff + size)); 15418334Speter object->handle = handle; 15518334Speter TAILQ_INIT(&object->un_pager.devp.devp_pglist); 15618334Speter mtx_lock(&dev_pager_mtx); 15718334Speter TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 15850397Sobrien mtx_unlock(&dev_pager_mtx); 15950397Sobrien } else { 16018334Speter /* 16118334Speter * Gain a reference to the object. 16218334Speter */ 16318334Speter vm_object_reference(object); 16418334Speter if (OFF_TO_IDX(foff + size) > object->size) 16518334Speter object->size = OFF_TO_IDX(foff + size); 16618334Speter } 16718334Speter 16818334Speter sx_xunlock(&dev_pager_sx); 16918334Speter 17018334Speter return (object); 17118334Speter} 17218334Speter 17318334Speterstatic void 17418334Speterdev_pager_dealloc(object) 17518334Speter vm_object_t object; 17618334Speter{ 17718334Speter vm_page_t m; 17818334Speter 17918334Speter mtx_lock(&dev_pager_mtx); 18018334Speter TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 18190075Sobrien mtx_unlock(&dev_pager_mtx); 18218334Speter /* 18318334Speter * Free up our fake pages. 18418334Speter */ 18518334Speter while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 18618334Speter TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 187117395Skan dev_pager_putfake(m); 18818334Speter } 18918334Speter} 19018334Speter 19118334Speterstatic int 19218334Speterdev_pager_getpages(object, m, count, reqpage) 19318334Speter vm_object_t object; 19418334Speter vm_page_t *m; 19518334Speter int count; 19690075Sobrien int reqpage; 19718334Speter{ 19890075Sobrien vm_offset_t offset; 19990075Sobrien vm_offset_t paddr; 20018334Speter vm_page_t page; 20118334Speter dev_t dev; 20218334Speter int i; 20318334Speter d_mmap_t *mapfunc; 20418334Speter int prot; 20518334Speter 20618334Speter mtx_assert(&Giant, MA_OWNED); 20718334Speter dev = object->handle; 20818334Speter offset = m[reqpage]->pindex; 20918334Speter prot = PROT_READ; /* XXX should pass in? */ 21018334Speter mapfunc = devsw(dev)->d_mmap; 21118334Speter 21218334Speter if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 21318334Speter panic("dev_pager_getpage: no map function"); 21418334Speter 21518334Speter paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 21618334Speter KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 21718334Speter /* 21818334Speter * Replace the passed in reqpage page with our own fake page and free up the 21918334Speter * all of the original pages. 22018334Speter */ 22118334Speter page = dev_pager_getfake(paddr); 22218334Speter TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 22318334Speter for (i = 0; i < count; i++) { 22418334Speter vm_page_free(m[i]); 22518334Speter } 22618334Speter vm_page_insert(page, object, offset); 22718334Speter 22818334Speter return (VM_PAGER_OK); 22918334Speter} 23018334Speter 231117395Skanstatic void 23218334Speterdev_pager_putpages(object, m, count, sync, rtvals) 23318334Speter vm_object_t object; 23418334Speter vm_page_t *m; 23518334Speter int count; 23618334Speter boolean_t sync; 23718334Speter int *rtvals; 23818334Speter{ 23918334Speter panic("dev_pager_putpage called"); 24018334Speter} 24118334Speter 24218334Speterstatic boolean_t 24318334Speterdev_pager_haspage(object, pindex, before, after) 24490075Sobrien vm_object_t object; 24518334Speter vm_pindex_t pindex; 24618334Speter int *before; 24718334Speter int *after; 24818334Speter{ 24918334Speter if (before != NULL) 25018334Speter *before = 0; 25118334Speter if (after != NULL) 25218334Speter *after = 0; 25318334Speter return (TRUE); 25418334Speter} 25590075Sobrien 25618334Speterstatic vm_page_t 25718334Speterdev_pager_getfake(paddr) 25818334Speter vm_offset_t paddr; 259{ 260 vm_page_t m; 261 262 m = uma_zalloc(fakepg_zone, M_WAITOK); 263 264 m->flags = PG_BUSY | PG_FICTITIOUS; 265 m->valid = VM_PAGE_BITS_ALL; 266 m->dirty = 0; 267 m->busy = 0; 268 m->queue = PQ_NONE; 269 m->object = NULL; 270 271 m->wire_count = 1; 272 m->hold_count = 0; 273 m->phys_addr = paddr; 274 275 return (m); 276} 277 278static void 279dev_pager_putfake(m) 280 vm_page_t m; 281{ 282 if (!(m->flags & PG_FICTITIOUS)) 283 panic("dev_pager_putfake: bad page"); 284 uma_zfree(fakepg_zone, m); 285} 286