1 /* $NetBSD: uvm_object.c,v 1.15 2015/10/26 09:02:49 mrg 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 1.15 2015/10/26 09:02:49 mrg Exp $"); 41 42 #ifdef _KERNEL_OPT 43 #include "opt_ddb.h" 44 #endif 45 46 #include <sys/param.h> 47 #include <sys/mutex.h> 48 #include <sys/queue.h> 49 #include <sys/rbtree.h> 50 51 #include <uvm/uvm.h> 52 #include <uvm/uvm_ddb.h> 53 54 /* Page count to fetch per single step. */ 55 #define FETCH_PAGECOUNT 16 56 57 /* 58 * uvm_obj_init: initialize UVM memory object. 59 */ 60 void 61 uvm_obj_init(struct uvm_object *uo, const struct uvm_pagerops *ops, 62 bool alock, u_int refs) 63 { 64 65 #if 0 /* notyet */ 66 KASSERT(ops); 67 #endif 68 if (alock) { 69 /* Allocate and assign a lock. */ 70 uo->vmobjlock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 71 } else { 72 /* The lock will need to be set via uvm_obj_setlock(). */ 73 uo->vmobjlock = NULL; 74 } 75 uo->pgops = ops; 76 TAILQ_INIT(&uo->memq); 77 LIST_INIT(&uo->uo_ubc); 78 uo->uo_npages = 0; 79 uo->uo_refs = refs; 80 rb_tree_init(&uo->rb_tree, &uvm_page_tree_ops); 81 } 82 83 /* 84 * uvm_obj_destroy: destroy UVM memory object. 85 */ 86 void 87 uvm_obj_destroy(struct uvm_object *uo, bool dlock) 88 { 89 90 KASSERT(rb_tree_iterate(&uo->rb_tree, NULL, RB_DIR_LEFT) == NULL); 91 92 /* Purge any UBC entries associated with this object. */ 93 ubc_purge(uo); 94 95 /* Destroy the lock, if requested. */ 96 if (dlock) { 97 mutex_obj_free(uo->vmobjlock); 98 } 99 } 100 101 /* 102 * uvm_obj_setlock: assign a vmobjlock to the UVM object. 103 * 104 * => Caller is responsible to ensure that UVM objects is not use. 105 * => Only dynamic lock may be previously set. We drop the reference then. 106 */ 107 void 108 uvm_obj_setlock(struct uvm_object *uo, kmutex_t *lockptr) 109 { 110 kmutex_t *olockptr = uo->vmobjlock; 111 112 if (olockptr) { 113 /* Drop the reference on the old lock. */ 114 mutex_obj_free(olockptr); 115 } 116 if (lockptr == NULL) { 117 /* If new lock is not passed - allocate default one. */ 118 lockptr = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 119 } 120 uo->vmobjlock = lockptr; 121 } 122 123 /* 124 * uvm_obj_wirepages: wire the pages of entire UVM object. 125 * 126 * => NOTE: this function should only be used for types of objects 127 * where PG_RELEASED flag is never set (aobj objects) 128 * => caller must pass page-aligned start and end values 129 */ 130 int 131 uvm_obj_wirepages(struct uvm_object *uobj, off_t start, off_t end, 132 struct pglist *list) 133 { 134 int i, npages, error; 135 struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL; 136 off_t offset = start, left; 137 138 left = (end - start) >> PAGE_SHIFT; 139 140 mutex_enter(uobj->vmobjlock); 141 while (left) { 142 143 npages = MIN(FETCH_PAGECOUNT, left); 144 145 /* Get the pages */ 146 memset(pgs, 0, sizeof(pgs)); 147 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0, 148 VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL, 149 PGO_ALLPAGES | PGO_SYNCIO); 150 151 if (error) 152 goto error; 153 154 mutex_enter(uobj->vmobjlock); 155 for (i = 0; i < npages; i++) { 156 157 KASSERT(pgs[i] != NULL); 158 KASSERT(!(pgs[i]->flags & PG_RELEASED)); 159 160 /* 161 * Loan break 162 */ 163 if (pgs[i]->loan_count) { 164 while (pgs[i]->loan_count) { 165 pg = uvm_loanbreak(pgs[i]); 166 if (!pg) { 167 mutex_exit(uobj->vmobjlock); 168 uvm_wait("uobjwirepg"); 169 mutex_enter(uobj->vmobjlock); 170 continue; 171 } 172 } 173 pgs[i] = pg; 174 } 175 176 if (pgs[i]->pqflags & PQ_AOBJ) { 177 pgs[i]->flags &= ~(PG_CLEAN); 178 uao_dropswap(uobj, i); 179 } 180 } 181 182 /* Wire the pages */ 183 mutex_enter(&uvm_pageqlock); 184 for (i = 0; i < npages; i++) { 185 uvm_pagewire(pgs[i]); 186 if (list != NULL) 187 TAILQ_INSERT_TAIL(list, pgs[i], pageq.queue); 188 } 189 mutex_exit(&uvm_pageqlock); 190 191 /* Unbusy the pages */ 192 uvm_page_unbusy(pgs, npages); 193 194 left -= npages; 195 offset += npages << PAGE_SHIFT; 196 } 197 mutex_exit(uobj->vmobjlock); 198 199 return 0; 200 201 error: 202 /* Unwire the pages which has been wired */ 203 uvm_obj_unwirepages(uobj, start, offset); 204 205 return error; 206 } 207 208 /* 209 * uvm_obj_unwirepages: unwire the pages of entire UVM object. 210 * 211 * => NOTE: this function should only be used for types of objects 212 * where PG_RELEASED flag is never set 213 * => caller must pass page-aligned start and end values 214 */ 215 void 216 uvm_obj_unwirepages(struct uvm_object *uobj, off_t start, off_t end) 217 { 218 struct vm_page *pg; 219 off_t offset; 220 221 mutex_enter(uobj->vmobjlock); 222 mutex_enter(&uvm_pageqlock); 223 for (offset = start; offset < end; offset += PAGE_SIZE) { 224 pg = uvm_pagelookup(uobj, offset); 225 226 KASSERT(pg != NULL); 227 KASSERT(!(pg->flags & PG_RELEASED)); 228 229 uvm_pageunwire(pg); 230 } 231 mutex_exit(&uvm_pageqlock); 232 mutex_exit(uobj->vmobjlock); 233 } 234 235 #if defined(DDB) || defined(DEBUGPRINT) 236 237 /* 238 * uvm_object_printit: actually prints the object 239 */ 240 void 241 uvm_object_printit(struct uvm_object *uobj, bool full, 242 void (*pr)(const char *, ...)) 243 { 244 struct vm_page *pg; 245 int cnt = 0; 246 247 (*pr)("OBJECT %p: locked=%d, pgops=%p, npages=%d, ", 248 uobj, mutex_owned(uobj->vmobjlock), uobj->pgops, uobj->uo_npages); 249 if (UVM_OBJ_IS_KERN_OBJECT(uobj)) 250 (*pr)("refs=<SYSTEM>\n"); 251 else 252 (*pr)("refs=%d\n", uobj->uo_refs); 253 254 if (!full) { 255 return; 256 } 257 (*pr)(" PAGES <pg,offset>:\n "); 258 TAILQ_FOREACH(pg, &uobj->memq, listq.queue) { 259 cnt++; 260 (*pr)("<%p,0x%llx> ", pg, (long long)pg->offset); 261 if ((cnt % 3) == 0) { 262 (*pr)("\n "); 263 } 264 } 265 if ((cnt % 3) != 0) { 266 (*pr)("\n"); 267 } 268 } 269 270 #endif /* DDB || DEBUGPRINT */ 271