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 #include <vm/vm_page2.h> 44 45 /* 46 * No requirements. 47 */ 48 vm_object_t 49 phys_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff) 50 { 51 vm_object_t object; 52 53 /* 54 * Offset should be page aligned. 55 */ 56 if (foff & PAGE_MASK) 57 return (NULL); 58 59 size = round_page64(size); 60 61 KKASSERT(handle == NULL); 62 object = vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(foff + size)); 63 64 return (object); 65 } 66 67 /* 68 * No requirements. 69 */ 70 static void 71 phys_pager_dealloc(vm_object_t object) 72 { 73 KKASSERT(object->handle == NULL); 74 KKASSERT(object->swblock_count == 0); 75 } 76 77 /* 78 * No requirements. 79 */ 80 static int 81 phys_pager_getpage(vm_object_t object, vm_page_t *mpp, int seqaccess) 82 { 83 vm_page_t m = *mpp; 84 85 vm_page_zero_fill(m); 86 /* Switch off pv_entries */ 87 vm_page_unmanage(m); 88 m->valid = VM_PAGE_BITS_ALL; 89 m->dirty = VM_PAGE_BITS_ALL; 90 91 return (VM_PAGER_OK); 92 } 93 94 /* 95 * No requirements. 96 */ 97 static void 98 phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, 99 int sync, int *rtvals) 100 { 101 102 panic("phys_pager_putpage called"); 103 } 104 105 /* 106 * Implement a pretty aggressive clustered getpages strategy. Hint that 107 * everything in an entire 4MB window should be prefaulted at once. 108 * 109 * XXX 4MB (1024 slots per page table page) is convenient for x86, 110 * but may not be for other arches. 111 */ 112 #ifndef PHYSCLUSTER 113 #define PHYSCLUSTER 1024 114 #endif 115 116 /* 117 * No requirements. 118 */ 119 static boolean_t 120 phys_pager_haspage(vm_object_t object, vm_pindex_t pindex) 121 { 122 return (TRUE); 123 } 124 125 struct pagerops physpagerops = { 126 phys_pager_dealloc, 127 phys_pager_getpage, 128 phys_pager_putpages, 129 phys_pager_haspage 130 }; 131