1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/* $OpenBSD: uvm_object.c,v 1.22 2021/10/23 14:42:08 mpi Exp $ */
/*
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Mindaugas Rasiukevicius.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* uvm_object.c: operate with memory objects
*
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mman.h>
#include <sys/atomic.h>
#include <uvm/uvm.h>
/* Dummy object used by some pmaps for sanity checks. */
const struct uvm_pagerops pmap_pager = {
/* nothing */
};
/* Dummy object used by the buffer cache for sanity checks. */
const struct uvm_pagerops bufcache_pager = {
/* nothing */
};
/* We will fetch this page count per step */
#define FETCH_PAGECOUNT 16
/*
* uvm_obj_init: initialise a uvm object.
*/
void
uvm_obj_init(struct uvm_object *uobj, const struct uvm_pagerops *pgops, int refs)
{
uobj->pgops = pgops;
RBT_INIT(uvm_objtree, &uobj->memt);
uobj->uo_npages = 0;
uobj->uo_refs = refs;
}
/*
* uvm_obj_destroy: destroy UVM memory object.
*/
void
uvm_obj_destroy(struct uvm_object *uo)
{
KASSERT(RBT_EMPTY(uvm_objtree, &uo->memt));
}
#ifndef SMALL_KERNEL
/*
* uvm_obj_wire: wire the pages of entire uobj
*
* => caller must pass page-aligned start and end values
* => if the caller passes in a pageq pointer, we'll return a list of
* wired pages.
*/
int
uvm_obj_wire(struct uvm_object *uobj, voff_t start, voff_t end,
struct pglist *pageq)
{
int i, npages, left, error;
struct vm_page *pgs[FETCH_PAGECOUNT];
voff_t offset = start;
left = (end - start) >> PAGE_SHIFT;
while (left) {
npages = MIN(FETCH_PAGECOUNT, left);
/* Get the pages */
memset(pgs, 0, sizeof(pgs));
error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0,
PROT_READ | PROT_WRITE, MADV_SEQUENTIAL,
PGO_ALLPAGES | PGO_SYNCIO);
if (error)
goto error;
for (i = 0; i < npages; i++) {
KASSERT(pgs[i] != NULL);
KASSERT(!(pgs[i]->pg_flags & PG_RELEASED));
if (pgs[i]->pg_flags & PQ_AOBJ) {
atomic_clearbits_int(&pgs[i]->pg_flags,
PG_CLEAN);
uao_dropswap(uobj, i);
}
}
/* Wire the pages */
uvm_lock_pageq();
for (i = 0; i < npages; i++) {
uvm_pagewire(pgs[i]);
if (pageq != NULL)
TAILQ_INSERT_TAIL(pageq, pgs[i], pageq);
}
uvm_unlock_pageq();
/* Unbusy the pages */
uvm_page_unbusy(pgs, npages);
left -= npages;
offset += (voff_t)npages << PAGE_SHIFT;
}
return 0;
error:
/* Unwire the pages which have been wired */
uvm_obj_unwire(uobj, start, offset);
return error;
}
/*
* uobj_unwirepages: unwire the pages of entire uobj
*
* => caller must pass page-aligned start and end values
*/
void
uvm_obj_unwire(struct uvm_object *uobj, voff_t start, voff_t end)
{
struct vm_page *pg;
off_t offset;
uvm_lock_pageq();
for (offset = start; offset < end; offset += PAGE_SIZE) {
pg = uvm_pagelookup(uobj, offset);
KASSERT(pg != NULL);
KASSERT(!(pg->pg_flags & PG_RELEASED));
uvm_pageunwire(pg);
}
uvm_unlock_pageq();
}
#endif /* !SMALL_KERNEL */
/*
* uvm_obj_free: free all pages in a uvm object, used by the buffer
* cache to free all pages attached to a buffer.
*/
void
uvm_obj_free(struct uvm_object *uobj)
{
struct vm_page *pg;
struct pglist pgl;
KASSERT(UVM_OBJ_IS_BUFCACHE(uobj));
KERNEL_ASSERT_LOCKED();
TAILQ_INIT(&pgl);
/*
* Extract from rb tree in offset order. The phys addresses
* usually increase in that order, which is better for
* uvm_pmr_freepageq.
*/
RBT_FOREACH(pg, uvm_objtree, &uobj->memt) {
/*
* clear PG_TABLED so we don't do work to remove
* this pg from the uobj we are throwing away
*/
atomic_clearbits_int(&pg->pg_flags, PG_TABLED);
uvm_lock_pageq();
uvm_pageclean(pg);
uvm_unlock_pageq();
TAILQ_INSERT_TAIL(&pgl, pg, pageq);
}
uvm_pmr_freepageq(&pgl);
}
|
