1 /* $OpenBSD: uvm_object.c,v 1.18 2020/11/24 13:49:09 mpi 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/systm.h> 39 #include <sys/mman.h> 40 #include <sys/atomic.h> 41 42 #include <uvm/uvm.h> 43 44 /* We will fetch this page count per step */ 45 #define FETCH_PAGECOUNT 16 46 47 /* 48 * uvm_objinit: initialise a uvm object. 49 */ 50 void 51 uvm_objinit(struct uvm_object *uobj, const struct uvm_pagerops *pgops, int refs) 52 { 53 uobj->pgops = pgops; 54 RBT_INIT(uvm_objtree, &uobj->memt); 55 uobj->uo_npages = 0; 56 uobj->uo_refs = refs; 57 } 58 59 #ifndef SMALL_KERNEL 60 /* 61 * uvm_objwire: wire the pages of entire uobj 62 * 63 * => caller must pass page-aligned start and end values 64 * => if the caller passes in a pageq pointer, we'll return a list of 65 * wired pages. 66 */ 67 68 int 69 uvm_objwire(struct uvm_object *uobj, voff_t start, voff_t end, 70 struct pglist *pageq) 71 { 72 int i, npages, left, error; 73 struct vm_page *pgs[FETCH_PAGECOUNT]; 74 voff_t offset = start; 75 76 left = (end - start) >> PAGE_SHIFT; 77 78 while (left) { 79 80 npages = MIN(FETCH_PAGECOUNT, left); 81 82 /* Get the pages */ 83 memset(pgs, 0, sizeof(pgs)); 84 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0, 85 PROT_READ | PROT_WRITE, MADV_SEQUENTIAL, 86 PGO_ALLPAGES | PGO_SYNCIO); 87 88 if (error) 89 goto error; 90 91 for (i = 0; i < npages; i++) { 92 93 KASSERT(pgs[i] != NULL); 94 KASSERT(!(pgs[i]->pg_flags & PG_RELEASED)); 95 96 if (pgs[i]->pg_flags & PQ_AOBJ) { 97 atomic_clearbits_int(&pgs[i]->pg_flags, 98 PG_CLEAN); 99 uao_dropswap(uobj, i); 100 } 101 } 102 103 /* Wire the pages */ 104 uvm_lock_pageq(); 105 for (i = 0; i < npages; i++) { 106 uvm_pagewire(pgs[i]); 107 if (pageq != NULL) 108 TAILQ_INSERT_TAIL(pageq, pgs[i], pageq); 109 } 110 uvm_unlock_pageq(); 111 112 /* Unbusy the pages */ 113 uvm_page_unbusy(pgs, npages); 114 115 left -= npages; 116 offset += (voff_t)npages << PAGE_SHIFT; 117 } 118 119 return 0; 120 121 error: 122 /* Unwire the pages which have been wired */ 123 uvm_objunwire(uobj, start, offset); 124 125 return error; 126 } 127 128 /* 129 * uobj_unwirepages: unwire the pages of entire uobj 130 * 131 * => caller must pass page-aligned start and end values 132 */ 133 134 void 135 uvm_objunwire(struct uvm_object *uobj, voff_t start, voff_t end) 136 { 137 struct vm_page *pg; 138 off_t offset; 139 140 uvm_lock_pageq(); 141 for (offset = start; offset < end; offset += PAGE_SIZE) { 142 pg = uvm_pagelookup(uobj, offset); 143 144 KASSERT(pg != NULL); 145 KASSERT(!(pg->pg_flags & PG_RELEASED)); 146 147 uvm_pageunwire(pg); 148 } 149 uvm_unlock_pageq(); 150 } 151 #endif /* !SMALL_KERNEL */ 152 153 /* 154 * uvm_objfree: free all pages in a uvm object, used by the buffer 155 * cache to free all pages attached to a buffer. 156 */ 157 void 158 uvm_objfree(struct uvm_object *uobj) 159 { 160 struct vm_page *pg; 161 struct pglist pgl; 162 163 TAILQ_INIT(&pgl); 164 /* 165 * Extract from rb tree in offset order. The phys addresses 166 * usually increase in that order, which is better for 167 * uvm_pmr_freepageq. 168 */ 169 RBT_FOREACH(pg, uvm_objtree, &uobj->memt) { 170 /* 171 * clear PG_TABLED so we don't do work to remove 172 * this pg from the uobj we are throwing away 173 */ 174 atomic_clearbits_int(&pg->pg_flags, PG_TABLED); 175 uvm_lock_pageq(); 176 uvm_pageclean(pg); 177 uvm_unlock_pageq(); 178 TAILQ_INSERT_TAIL(&pgl, pg, pageq); 179 } 180 uvm_pmr_freepageq(&pgl); 181 } 182 183