1 /* $NetBSD: uvm_object.c,v 1.2 2006/10/12 10:13:35 yamt Exp $ */ 2 3 /* 4 * Copyright (c) 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the NetBSD 18 * Foundation, Inc. and its contributors. 19 * 4. Neither the name of The NetBSD Foundation nor the names of its 20 * contributors may be used to endorse or promote products derived 21 * from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /* 37 * uvm_object.c: operate with memory objects 38 * 39 * TODO: 40 * 1. Support PG_RELEASED-using objects 41 * 42 */ 43 44 #include <sys/cdefs.h> 45 __KERNEL_RCSID(0, "$NetBSD: uvm_object.c,v 1.2 2006/10/12 10:13:35 yamt Exp $"); 46 47 #include "opt_uvmhist.h" 48 49 #include <sys/param.h> 50 #include <sys/lock.h> 51 52 #include <uvm/uvm.h> 53 54 /* We will fetch this page count per step */ 55 #define FETCH_PAGECOUNT 16 56 57 /* 58 * uobj_wirepages: wire the pages of entire uobj 59 * 60 * => NOTE: this function should only be used for types of objects 61 * where PG_RELEASED flag is never set (aobj objects) 62 * => caller must pass page-aligned start and end values 63 */ 64 65 int 66 uobj_wirepages(struct uvm_object *uobj, off_t start, off_t end) 67 { 68 int i, npages, error; 69 struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL; 70 off_t offset = start, left; 71 72 left = (end - start) >> PAGE_SHIFT; 73 74 simple_lock(&uobj->vmobjlock); 75 while (left) { 76 77 npages = MIN(FETCH_PAGECOUNT, left); 78 79 /* Get the pages */ 80 memset(pgs, 0, sizeof(pgs)); 81 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0, 82 VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL, 83 PGO_ALLPAGES | PGO_SYNCIO); 84 85 if (error) 86 goto error; 87 88 simple_lock(&uobj->vmobjlock); 89 for (i = 0; i < npages; i++) { 90 91 KASSERT(pgs[i] != NULL); 92 KASSERT(!(pgs[i]->flags & PG_RELEASED)); 93 94 /* 95 * Loan break 96 */ 97 if (pgs[i]->loan_count) { 98 while (pgs[i]->loan_count) { 99 pg = uvm_loanbreak(pgs[i]); 100 if (!pg) { 101 simple_unlock(&uobj->vmobjlock); 102 uvm_wait("uobjwirepg"); 103 simple_lock(&uobj->vmobjlock); 104 continue; 105 } 106 } 107 pgs[i] = pg; 108 } 109 110 if (pgs[i]->pqflags & PQ_AOBJ) { 111 pgs[i]->flags &= ~(PG_CLEAN); 112 uao_dropswap(uobj, i); 113 } 114 } 115 116 /* Wire the pages */ 117 uvm_lock_pageq(); 118 for (i = 0; i < npages; i++) { 119 uvm_pagewire(pgs[i]); 120 } 121 uvm_unlock_pageq(); 122 123 /* Unbusy the pages */ 124 uvm_page_unbusy(pgs, npages); 125 126 left -= npages; 127 offset += npages << PAGE_SHIFT; 128 } 129 simple_unlock(&uobj->vmobjlock); 130 131 return 0; 132 133 error: 134 /* Unwire the pages which has been wired */ 135 uobj_unwirepages(uobj, start, offset); 136 137 return error; 138 } 139 140 /* 141 * uobj_unwirepages: unwire the pages of entire uobj 142 * 143 * => NOTE: this function should only be used for types of objects 144 * where PG_RELEASED flag is never set 145 * => caller must pass page-aligned start and end values 146 */ 147 148 void 149 uobj_unwirepages(struct uvm_object *uobj, off_t start, off_t end) 150 { 151 struct vm_page *pg; 152 off_t offset; 153 154 simple_lock(&uobj->vmobjlock); 155 uvm_lock_pageq(); 156 for (offset = start; offset < end; offset += PAGE_SIZE) { 157 pg = uvm_pagelookup(uobj, offset); 158 159 KASSERT(pg != NULL); 160 KASSERT(!(pg->flags & PG_RELEASED)); 161 162 uvm_pageunwire(pg); 163 } 164 uvm_unlock_pageq(); 165 simple_unlock(&uobj->vmobjlock); 166 } 167