1 /* $OpenBSD: uvm_object.c,v 1.13 2015/08/21 16:04:35 visa Exp $ */ 2 3 /* 4 * Copyright (c) 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Mindaugas Rasiukevicius. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * uvm_object.c: operate with memory objects 34 * 35 */ 36 37 #include <sys/param.h> 38 #include <sys/mman.h> 39 #include <sys/atomic.h> 40 41 #include <uvm/uvm.h> 42 43 /* We will fetch this page count per step */ 44 #define FETCH_PAGECOUNT 16 45 46 /* 47 * uvm_objinit: initialise a uvm object. 48 */ 49 void 50 uvm_objinit(struct uvm_object *uobj, struct uvm_pagerops *pgops, int refs) 51 { 52 uobj->pgops = pgops; 53 RB_INIT(&uobj->memt); 54 uobj->uo_npages = 0; 55 uobj->uo_refs = refs; 56 } 57 58 #ifndef SMALL_KERNEL 59 /* 60 * uvm_objwire: wire the pages of entire uobj 61 * 62 * => caller must pass page-aligned start and end values 63 * => if the caller passes in a pageq pointer, we'll return a list of 64 * wired pages. 65 */ 66 67 int 68 uvm_objwire(struct uvm_object *uobj, voff_t start, voff_t end, 69 struct pglist *pageq) 70 { 71 int i, npages, left, error; 72 struct vm_page *pgs[FETCH_PAGECOUNT]; 73 voff_t offset = start; 74 75 left = (end - start) >> PAGE_SHIFT; 76 77 while (left) { 78 79 npages = MIN(FETCH_PAGECOUNT, left); 80 81 /* Get the pages */ 82 memset(pgs, 0, sizeof(pgs)); 83 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0, 84 PROT_READ | PROT_WRITE, MADV_SEQUENTIAL, 85 PGO_ALLPAGES | PGO_SYNCIO); 86 87 if (error) 88 goto error; 89 90 for (i = 0; i < npages; i++) { 91 92 KASSERT(pgs[i] != NULL); 93 KASSERT(!(pgs[i]->pg_flags & PG_RELEASED)); 94 95 if (pgs[i]->pg_flags & PQ_AOBJ) { 96 atomic_clearbits_int(&pgs[i]->pg_flags, 97 PG_CLEAN); 98 uao_dropswap(uobj, i); 99 } 100 } 101 102 /* Wire the pages */ 103 uvm_lock_pageq(); 104 for (i = 0; i < npages; i++) { 105 uvm_pagewire(pgs[i]); 106 if (pageq != NULL) 107 TAILQ_INSERT_TAIL(pageq, pgs[i], pageq); 108 } 109 uvm_unlock_pageq(); 110 111 /* Unbusy the pages */ 112 uvm_page_unbusy(pgs, npages); 113 114 left -= npages; 115 offset += (voff_t)npages << PAGE_SHIFT; 116 } 117 118 return 0; 119 120 error: 121 /* Unwire the pages which have been wired */ 122 uvm_objunwire(uobj, start, offset); 123 124 return error; 125 } 126 127 /* 128 * uobj_unwirepages: unwire the pages of entire uobj 129 * 130 * => caller must pass page-aligned start and end values 131 */ 132 133 void 134 uvm_objunwire(struct uvm_object *uobj, voff_t start, voff_t end) 135 { 136 struct vm_page *pg; 137 off_t offset; 138 139 uvm_lock_pageq(); 140 for (offset = start; offset < end; offset += PAGE_SIZE) { 141 pg = uvm_pagelookup(uobj, offset); 142 143 KASSERT(pg != NULL); 144 KASSERT(!(pg->pg_flags & PG_RELEASED)); 145 146 uvm_pageunwire(pg); 147 } 148 uvm_unlock_pageq(); 149 } 150 #endif /* !SMALL_KERNEL */ 151