1 /* $NetBSD: uvm_object.c,v 1.3 2007/02/17 20:45:36 rmind 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * uvm_object.c: operate with memory objects 41 * 42 * TODO: 43 * 1. Support PG_RELEASED-using objects 44 * 45 */ 46 47 #include <sys/cdefs.h> 48 __KERNEL_RCSID(0, "$NetBSD: uvm_object.c,v 1.3 2007/02/17 20:45:36 rmind Exp $"); 49 50 #include "opt_uvmhist.h" 51 52 #include <sys/param.h> 53 #include <sys/lock.h> 54 55 #include <uvm/uvm.h> 56 57 /* We will fetch this page count per step */ 58 #define FETCH_PAGECOUNT 16 59 60 /* 61 * uobj_wirepages: wire the pages of entire uobj 62 * 63 * => NOTE: this function should only be used for types of objects 64 * where PG_RELEASED flag is never set (aobj objects) 65 * => caller must pass page-aligned start and end values 66 */ 67 68 int 69 uobj_wirepages(struct uvm_object *uobj, off_t start, off_t end) 70 { 71 int i, npages, error; 72 struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL; 73 off_t offset = start, left; 74 75 left = (end - start) >> PAGE_SHIFT; 76 77 simple_lock(&uobj->vmobjlock); 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 VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL, 86 PGO_ALLPAGES | PGO_SYNCIO); 87 88 if (error) 89 goto error; 90 91 simple_lock(&uobj->vmobjlock); 92 for (i = 0; i < npages; i++) { 93 94 KASSERT(pgs[i] != NULL); 95 KASSERT(!(pgs[i]->flags & PG_RELEASED)); 96 97 /* 98 * Loan break 99 */ 100 if (pgs[i]->loan_count) { 101 while (pgs[i]->loan_count) { 102 pg = uvm_loanbreak(pgs[i]); 103 if (!pg) { 104 simple_unlock(&uobj->vmobjlock); 105 uvm_wait("uobjwirepg"); 106 simple_lock(&uobj->vmobjlock); 107 continue; 108 } 109 } 110 pgs[i] = pg; 111 } 112 113 if (pgs[i]->pqflags & PQ_AOBJ) { 114 pgs[i]->flags &= ~(PG_CLEAN); 115 uao_dropswap(uobj, i); 116 } 117 } 118 119 /* Wire the pages */ 120 uvm_lock_pageq(); 121 for (i = 0; i < npages; i++) { 122 uvm_pagewire(pgs[i]); 123 } 124 uvm_unlock_pageq(); 125 126 /* Unbusy the pages */ 127 uvm_page_unbusy(pgs, npages); 128 129 left -= npages; 130 offset += npages << PAGE_SHIFT; 131 } 132 simple_unlock(&uobj->vmobjlock); 133 134 return 0; 135 136 error: 137 /* Unwire the pages which has been wired */ 138 uobj_unwirepages(uobj, start, offset); 139 140 return error; 141 } 142 143 /* 144 * uobj_unwirepages: unwire the pages of entire uobj 145 * 146 * => NOTE: this function should only be used for types of objects 147 * where PG_RELEASED flag is never set 148 * => caller must pass page-aligned start and end values 149 */ 150 151 void 152 uobj_unwirepages(struct uvm_object *uobj, off_t start, off_t end) 153 { 154 struct vm_page *pg; 155 off_t offset; 156 157 simple_lock(&uobj->vmobjlock); 158 uvm_lock_pageq(); 159 for (offset = start; offset < end; offset += PAGE_SIZE) { 160 pg = uvm_pagelookup(uobj, offset); 161 162 KASSERT(pg != NULL); 163 KASSERT(!(pg->flags & PG_RELEASED)); 164 165 uvm_pageunwire(pg); 166 } 167 uvm_unlock_pageq(); 168 simple_unlock(&uobj->vmobjlock); 169 } 170