1 /* $NetBSD: uvm_object.c,v 1.13 2015/08/24 22:50:32 pooka 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 1.13 2015/08/24 22:50:32 pooka 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 (alock) { 66 /* Allocate and assign a lock. */ 67 uo->vmobjlock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 68 } else { 69 /* The lock will need to be set via uvm_obj_setlock(). */ 70 uo->vmobjlock = NULL; 71 } 72 uo->pgops = ops; 73 TAILQ_INIT(&uo->memq); 74 LIST_INIT(&uo->uo_ubc); 75 uo->uo_npages = 0; 76 uo->uo_refs = refs; 77 rb_tree_init(&uo->rb_tree, &uvm_page_tree_ops); 78 } 79 80 /* 81 * uvm_obj_destroy: destroy UVM memory object. 82 */ 83 void 84 uvm_obj_destroy(struct uvm_object *uo, bool dlock) 85 { 86 87 KASSERT(rb_tree_iterate(&uo->rb_tree, NULL, RB_DIR_LEFT) == NULL); 88 89 /* Purge any UBC entries associated with this object. */ 90 ubc_purge(uo); 91 92 /* Destroy the lock, if requested. */ 93 if (dlock) { 94 mutex_obj_free(uo->vmobjlock); 95 } 96 } 97 98 /* 99 * uvm_obj_setlock: assign a vmobjlock to the UVM object. 100 * 101 * => Caller is responsible to ensure that UVM objects is not use. 102 * => Only dynamic lock may be previously set. We drop the reference then. 103 */ 104 void 105 uvm_obj_setlock(struct uvm_object *uo, kmutex_t *lockptr) 106 { 107 kmutex_t *olockptr = uo->vmobjlock; 108 109 if (olockptr) { 110 /* Drop the reference on the old lock. */ 111 mutex_obj_free(olockptr); 112 } 113 if (lockptr == NULL) { 114 /* If new lock is not passed - allocate default one. */ 115 lockptr = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 116 } 117 uo->vmobjlock = lockptr; 118 } 119 120 /* 121 * uvm_obj_wirepages: wire the pages of entire UVM object. 122 * 123 * => NOTE: this function should only be used for types of objects 124 * where PG_RELEASED flag is never set (aobj objects) 125 * => caller must pass page-aligned start and end values 126 */ 127 int 128 uvm_obj_wirepages(struct uvm_object *uobj, off_t start, off_t end, 129 struct pglist *list) 130 { 131 int i, npages, error; 132 struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL; 133 off_t offset = start, left; 134 135 left = (end - start) >> PAGE_SHIFT; 136 137 mutex_enter(uobj->vmobjlock); 138 while (left) { 139 140 npages = MIN(FETCH_PAGECOUNT, left); 141 142 /* Get the pages */ 143 memset(pgs, 0, sizeof(pgs)); 144 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0, 145 VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL, 146 PGO_ALLPAGES | PGO_SYNCIO); 147 148 if (error) 149 goto error; 150 151 mutex_enter(uobj->vmobjlock); 152 for (i = 0; i < npages; i++) { 153 154 KASSERT(pgs[i] != NULL); 155 KASSERT(!(pgs[i]->flags & PG_RELEASED)); 156 157 /* 158 * Loan break 159 */ 160 if (pgs[i]->loan_count) { 161 while (pgs[i]->loan_count) { 162 pg = uvm_loanbreak(pgs[i]); 163 if (!pg) { 164 mutex_exit(uobj->vmobjlock); 165 uvm_wait("uobjwirepg"); 166 mutex_enter(uobj->vmobjlock); 167 continue; 168 } 169 } 170 pgs[i] = pg; 171 } 172 173 if (pgs[i]->pqflags & PQ_AOBJ) { 174 pgs[i]->flags &= ~(PG_CLEAN); 175 uao_dropswap(uobj, i); 176 } 177 } 178 179 /* Wire the pages */ 180 mutex_enter(&uvm_pageqlock); 181 for (i = 0; i < npages; i++) { 182 uvm_pagewire(pgs[i]); 183 if (list != NULL) 184 TAILQ_INSERT_TAIL(list, pgs[i], pageq.queue); 185 } 186 mutex_exit(&uvm_pageqlock); 187 188 /* Unbusy the pages */ 189 uvm_page_unbusy(pgs, npages); 190 191 left -= npages; 192 offset += npages << PAGE_SHIFT; 193 } 194 mutex_exit(uobj->vmobjlock); 195 196 return 0; 197 198 error: 199 /* Unwire the pages which has been wired */ 200 uvm_obj_unwirepages(uobj, start, offset); 201 202 return error; 203 } 204 205 /* 206 * uvm_obj_unwirepages: unwire the pages of entire UVM object. 207 * 208 * => NOTE: this function should only be used for types of objects 209 * where PG_RELEASED flag is never set 210 * => caller must pass page-aligned start and end values 211 */ 212 void 213 uvm_obj_unwirepages(struct uvm_object *uobj, off_t start, off_t end) 214 { 215 struct vm_page *pg; 216 off_t offset; 217 218 mutex_enter(uobj->vmobjlock); 219 mutex_enter(&uvm_pageqlock); 220 for (offset = start; offset < end; offset += PAGE_SIZE) { 221 pg = uvm_pagelookup(uobj, offset); 222 223 KASSERT(pg != NULL); 224 KASSERT(!(pg->flags & PG_RELEASED)); 225 226 uvm_pageunwire(pg); 227 } 228 mutex_exit(&uvm_pageqlock); 229 mutex_exit(uobj->vmobjlock); 230 } 231 232 #if defined(DDB) || defined(DEBUGPRINT) 233 234 /* 235 * uvm_object_printit: actually prints the object 236 */ 237 void 238 uvm_object_printit(struct uvm_object *uobj, bool full, 239 void (*pr)(const char *, ...)) 240 { 241 struct vm_page *pg; 242 int cnt = 0; 243 244 (*pr)("OBJECT %p: locked=%d, pgops=%p, npages=%d, ", 245 uobj, mutex_owned(uobj->vmobjlock), uobj->pgops, uobj->uo_npages); 246 if (UVM_OBJ_IS_KERN_OBJECT(uobj)) 247 (*pr)("refs=<SYSTEM>\n"); 248 else 249 (*pr)("refs=%d\n", uobj->uo_refs); 250 251 if (!full) { 252 return; 253 } 254 (*pr)(" PAGES <pg,offset>:\n "); 255 TAILQ_FOREACH(pg, &uobj->memq, listq.queue) { 256 cnt++; 257 (*pr)("<%p,0x%llx> ", pg, (long long)pg->offset); 258 if ((cnt % 3) == 0) { 259 (*pr)("\n "); 260 } 261 } 262 if ((cnt % 3) != 0) { 263 (*pr)("\n"); 264 } 265 } 266 267 #endif /* DDB || DEBUGPRINT */ 268