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
uvm_obj_init(struct uvm_object * uo,const struct uvm_pagerops * ops,bool alock,u_int refs)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
uvm_obj_destroy(struct uvm_object * uo,bool dlock)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
uvm_obj_setlock(struct uvm_object * uo,kmutex_t * lockptr)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
uvm_obj_wirepages(struct uvm_object * uobj,off_t start,off_t end,struct pglist * list)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
uvm_obj_unwirepages(struct uvm_object * uobj,off_t start,off_t end)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
uvm_object_printit(struct uvm_object * uobj,bool full,void (* pr)(const char *,...))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