1 /* $NetBSD: uvm_object.c,v 1.11 2011/08/27 09:11:53 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2006, 2010 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 * TODO: 36 * 1. Support PG_RELEASED-using objects 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: uvm_object.c,v 1.11 2011/08/27 09:11:53 christos Exp $"); 41 42 #include "opt_ddb.h" 43 44 #include <sys/param.h> 45 #include <sys/mutex.h> 46 #include <sys/queue.h> 47 #include <sys/rbtree.h> 48 49 #include <uvm/uvm.h> 50 #include <uvm/uvm_ddb.h> 51 52 /* Page count to fetch per single step. */ 53 #define FETCH_PAGECOUNT 16 54 55 /* 56 * uvm_obj_init: initialize UVM memory object. 57 */ 58 void 59 uvm_obj_init(struct uvm_object *uo, const struct uvm_pagerops *ops, 60 bool alock, u_int refs) 61 { 62 63 if (alock) { 64 /* Allocate and assign a lock. */ 65 uo->vmobjlock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 66 } else { 67 /* The lock will need to be set via uvm_obj_setlock(). */ 68 uo->vmobjlock = NULL; 69 } 70 uo->pgops = ops; 71 TAILQ_INIT(&uo->memq); 72 LIST_INIT(&uo->uo_ubc); 73 uo->uo_npages = 0; 74 uo->uo_refs = refs; 75 rb_tree_init(&uo->rb_tree, &uvm_page_tree_ops); 76 } 77 78 /* 79 * uvm_obj_destroy: destroy UVM memory object. 80 */ 81 void 82 uvm_obj_destroy(struct uvm_object *uo, bool dlock) 83 { 84 85 KASSERT(rb_tree_iterate(&uo->rb_tree, NULL, RB_DIR_LEFT) == NULL); 86 87 /* Purge any UBC entries associated with this object. */ 88 ubc_purge(uo); 89 90 /* Destroy the lock, if requested. */ 91 if (dlock) { 92 mutex_obj_free(uo->vmobjlock); 93 } 94 } 95 96 /* 97 * uvm_obj_setlock: assign a vmobjlock to the UVM object. 98 * 99 * => Caller is responsible to ensure that UVM objects is not use. 100 * => Only dynamic lock may be previously set. We drop the reference then. 101 */ 102 void 103 uvm_obj_setlock(struct uvm_object *uo, kmutex_t *lockptr) 104 { 105 kmutex_t *olockptr = uo->vmobjlock; 106 107 if (olockptr) { 108 /* Drop the reference on the old lock. */ 109 mutex_obj_free(olockptr); 110 } 111 if (lockptr == NULL) { 112 /* If new lock is not passed - allocate default one. */ 113 lockptr = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 114 } 115 uo->vmobjlock = lockptr; 116 } 117 118 /* 119 * uvm_obj_wirepages: wire the pages of entire UVM object. 120 * 121 * => NOTE: this function should only be used for types of objects 122 * where PG_RELEASED flag is never set (aobj objects) 123 * => caller must pass page-aligned start and end values 124 */ 125 int 126 uvm_obj_wirepages(struct uvm_object *uobj, off_t start, off_t end, 127 struct pglist *list) 128 { 129 int i, npages, error; 130 struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL; 131 off_t offset = start, left; 132 133 left = (end - start) >> PAGE_SHIFT; 134 135 mutex_enter(uobj->vmobjlock); 136 while (left) { 137 138 npages = MIN(FETCH_PAGECOUNT, left); 139 140 /* Get the pages */ 141 memset(pgs, 0, sizeof(pgs)); 142 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0, 143 VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL, 144 PGO_ALLPAGES | PGO_SYNCIO); 145 146 if (error) 147 goto error; 148 149 mutex_enter(uobj->vmobjlock); 150 for (i = 0; i < npages; i++) { 151 152 KASSERT(pgs[i] != NULL); 153 KASSERT(!(pgs[i]->flags & PG_RELEASED)); 154 155 /* 156 * Loan break 157 */ 158 if (pgs[i]->loan_count) { 159 while (pgs[i]->loan_count) { 160 pg = uvm_loanbreak(pgs[i]); 161 if (!pg) { 162 mutex_exit(uobj->vmobjlock); 163 uvm_wait("uobjwirepg"); 164 mutex_enter(uobj->vmobjlock); 165 continue; 166 } 167 } 168 pgs[i] = pg; 169 } 170 171 if (pgs[i]->pqflags & PQ_AOBJ) { 172 pgs[i]->flags &= ~(PG_CLEAN); 173 uao_dropswap(uobj, i); 174 } 175 } 176 177 /* Wire the pages */ 178 mutex_enter(&uvm_pageqlock); 179 for (i = 0; i < npages; i++) { 180 uvm_pagewire(pgs[i]); 181 if (list != NULL) 182 TAILQ_INSERT_TAIL(list, pgs[i], pageq.queue); 183 } 184 mutex_exit(&uvm_pageqlock); 185 186 /* Unbusy the pages */ 187 uvm_page_unbusy(pgs, npages); 188 189 left -= npages; 190 offset += npages << PAGE_SHIFT; 191 } 192 mutex_exit(uobj->vmobjlock); 193 194 return 0; 195 196 error: 197 /* Unwire the pages which has been wired */ 198 uvm_obj_unwirepages(uobj, start, offset); 199 200 return error; 201 } 202 203 /* 204 * uvm_obj_unwirepages: unwire the pages of entire UVM object. 205 * 206 * => NOTE: this function should only be used for types of objects 207 * where PG_RELEASED flag is never set 208 * => caller must pass page-aligned start and end values 209 */ 210 void 211 uvm_obj_unwirepages(struct uvm_object *uobj, off_t start, off_t end) 212 { 213 struct vm_page *pg; 214 off_t offset; 215 216 mutex_enter(uobj->vmobjlock); 217 mutex_enter(&uvm_pageqlock); 218 for (offset = start; offset < end; offset += PAGE_SIZE) { 219 pg = uvm_pagelookup(uobj, offset); 220 221 KASSERT(pg != NULL); 222 KASSERT(!(pg->flags & PG_RELEASED)); 223 224 uvm_pageunwire(pg); 225 } 226 mutex_exit(&uvm_pageqlock); 227 mutex_exit(uobj->vmobjlock); 228 } 229 230 #if (defined(DDB) || defined(DEBUGPRINT)) && !defined(_RUMPKERNEL) 231 232 /* 233 * uvm_object_printit: actually prints the object 234 */ 235 void 236 uvm_object_printit(struct uvm_object *uobj, bool full, 237 void (*pr)(const char *, ...)) 238 { 239 struct vm_page *pg; 240 int cnt = 0; 241 242 (*pr)("OBJECT %p: locked=%d, pgops=%p, npages=%d, ", 243 uobj, mutex_owned(uobj->vmobjlock), uobj->pgops, uobj->uo_npages); 244 if (UVM_OBJ_IS_KERN_OBJECT(uobj)) 245 (*pr)("refs=<SYSTEM>\n"); 246 else 247 (*pr)("refs=%d\n", uobj->uo_refs); 248 249 if (!full) { 250 return; 251 } 252 (*pr)(" PAGES <pg,offset>:\n "); 253 TAILQ_FOREACH(pg, &uobj->memq, listq.queue) { 254 cnt++; 255 (*pr)("<%p,0x%llx> ", pg, (long long)pg->offset); 256 if ((cnt % 3) == 0) { 257 (*pr)("\n "); 258 } 259 } 260 if ((cnt % 3) != 0) { 261 (*pr)("\n"); 262 } 263 } 264 265 #endif /* DDB || DEBUGPRINT */ 266