1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 2000 Peter Wemm 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: src/sys/vm/phys_pager.c,v 1.3.2.3 2000/12/17 02:05:41 alfred Exp $ 28 */ 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/linker_set.h> 32 #include <sys/conf.h> 33 #include <sys/mman.h> 34 #include <sys/sysctl.h> 35 36 #include <vm/vm.h> 37 #include <vm/vm_object.h> 38 #include <vm/vm_page.h> 39 #include <vm/vm_pager.h> 40 #include <vm/vm_zone.h> 41 42 #include <sys/thread2.h> 43 44 /* 45 * No requirements. 46 */ 47 vm_object_t 48 phys_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff) 49 { 50 vm_object_t object; 51 52 /* 53 * Offset should be page aligned. 54 */ 55 if (foff & PAGE_MASK) 56 return (NULL); 57 58 size = round_page64(size); 59 60 KKASSERT(handle == NULL); 61 object = vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(foff + size)); 62 63 return (object); 64 } 65 66 /* 67 * No requirements. 68 */ 69 static void 70 phys_pager_dealloc(vm_object_t object) 71 { 72 KKASSERT(object->handle == NULL); 73 KKASSERT(object->swblock_count == 0); 74 } 75 76 /* 77 * No requirements. 78 */ 79 static int 80 phys_pager_getpage(vm_object_t object, vm_page_t *mpp, int seqaccess) 81 { 82 vm_page_t m = *mpp; 83 84 lwkt_gettoken(&vm_token); 85 crit_enter(); 86 if ((m->flags & PG_ZERO) == 0) 87 vm_page_zero_fill(m); 88 vm_page_flag_set(m, PG_ZERO); 89 /* Switch off pv_entries */ 90 vm_page_unmanage(m); 91 m->valid = VM_PAGE_BITS_ALL; 92 m->dirty = 0; 93 crit_exit(); 94 lwkt_reltoken(&vm_token); 95 96 return (VM_PAGER_OK); 97 } 98 99 /* 100 * No requirements. 101 */ 102 static void 103 phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, 104 boolean_t sync, int *rtvals) 105 { 106 107 panic("phys_pager_putpage called"); 108 } 109 110 /* 111 * Implement a pretty aggressive clustered getpages strategy. Hint that 112 * everything in an entire 4MB window should be prefaulted at once. 113 * 114 * XXX 4MB (1024 slots per page table page) is convenient for x86, 115 * but may not be for other arches. 116 */ 117 #ifndef PHYSCLUSTER 118 #define PHYSCLUSTER 1024 119 #endif 120 121 /* 122 * No requirements. 123 */ 124 static boolean_t 125 phys_pager_haspage(vm_object_t object, vm_pindex_t pindex) 126 { 127 return (TRUE); 128 } 129 130 struct pagerops physpagerops = { 131 phys_pager_dealloc, 132 phys_pager_getpage, 133 phys_pager_putpages, 134 phys_pager_haspage 135 }; 136