| 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 | |