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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/*-
* Copyright (c) 2009 Hudson River Trading LLC
* Written by: John H. Baldwin <jhb@FreeBSD.org>
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* This pager manages OBJT_SG objects. These objects are backed by
* a scatter/gather list of physical address ranges.
*/
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/sglist.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vm_phys.h>
#include <vm/uma.h>
static vm_object_t sg_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
static void sg_pager_dealloc(vm_object_t);
static int sg_pager_getpages(vm_object_t, vm_page_t *, int, int);
static void sg_pager_putpages(vm_object_t, vm_page_t *, int,
boolean_t, int *);
static boolean_t sg_pager_haspage(vm_object_t, vm_pindex_t, int *,
int *);
struct pagerops sgpagerops = {
.pgo_alloc = sg_pager_alloc,
.pgo_dealloc = sg_pager_dealloc,
.pgo_getpages = sg_pager_getpages,
.pgo_putpages = sg_pager_putpages,
.pgo_haspage = sg_pager_haspage,
};
static vm_object_t
sg_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred)
{
struct sglist *sg;
vm_object_t object;
vm_pindex_t npages, pindex;
int i;
/*
* Offset should be page aligned.
*/
if (foff & PAGE_MASK)
return (NULL);
/*
* The scatter/gather list must only include page-aligned
* ranges.
*/
npages = 0;
sg = handle;
for (i = 0; i < sg->sg_nseg; i++) {
if ((sg->sg_segs[i].ss_paddr % PAGE_SIZE) != 0 ||
(sg->sg_segs[i].ss_len % PAGE_SIZE) != 0)
return (NULL);
npages += sg->sg_segs[i].ss_len / PAGE_SIZE;
}
/*
* The scatter/gather list has a fixed size. Refuse requests
* to map beyond that.
*/
size = round_page(size);
pindex = OFF_TO_IDX(foff + size);
if (pindex > npages)
return (NULL);
/*
* Allocate a new object and associate it with the
* scatter/gather list. It is ok for our purposes to have
* multiple VM objects associated with the same scatter/gather
* list because scatter/gather lists are static. This is also
* simpler than ensuring a unique object per scatter/gather
* list.
*/
object = vm_object_allocate(OBJT_SG, npages);
object->handle = sglist_hold(sg);
TAILQ_INIT(&object->un_pager.sgp.sgp_pglist);
return (object);
}
static void
sg_pager_dealloc(vm_object_t object)
{
struct sglist *sg;
vm_page_t m;
/*
* Free up our fake pages.
*/
while ((m = TAILQ_FIRST(&object->un_pager.sgp.sgp_pglist)) != 0) {
TAILQ_REMOVE(&object->un_pager.sgp.sgp_pglist, m, plinks.q);
vm_page_putfake(m);
}
sg = object->handle;
sglist_free(sg);
object->handle = NULL;
object->type = OBJT_DEAD;
}
static int
sg_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
{
struct sglist *sg;
vm_page_t m_paddr, page;
vm_pindex_t offset;
vm_paddr_t paddr;
vm_memattr_t memattr;
size_t space;
int i;
VM_OBJECT_ASSERT_WLOCKED(object);
sg = object->handle;
memattr = object->memattr;
VM_OBJECT_WUNLOCK(object);
offset = m[reqpage]->pindex;
/*
* Lookup the physical address of the requested page. An initial
* value of '1' instead of '0' is used so we can assert that the
* page is found since '0' can be a valid page-aligned physical
* address.
*/
space = 0;
paddr = 1;
for (i = 0; i < sg->sg_nseg; i++) {
if (space + sg->sg_segs[i].ss_len <= (offset * PAGE_SIZE)) {
space += sg->sg_segs[i].ss_len;
continue;
}
paddr = sg->sg_segs[i].ss_paddr + offset * PAGE_SIZE - space;
break;
}
KASSERT(paddr != 1, ("invalid SG page index"));
/* If "paddr" is a real page, perform a sanity check on "memattr". */
if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
pmap_page_get_memattr(m_paddr) != memattr) {
memattr = pmap_page_get_memattr(m_paddr);
printf(
"WARNING: A device driver has set \"memattr\" inconsistently.\n");
}
/* Return a fake page for the requested page. */
KASSERT(!(m[reqpage]->flags & PG_FICTITIOUS),
("backing page for SG is fake"));
/* Construct a new fake page. */
page = vm_page_getfake(paddr, memattr);
VM_OBJECT_WLOCK(object);
TAILQ_INSERT_TAIL(&object->un_pager.sgp.sgp_pglist, page, plinks.q);
/* Free the original pages and insert this fake page into the object. */
for (i = 0; i < count; i++) {
if (i == reqpage &&
vm_page_replace(page, object, offset) != m[i])
panic("sg_pager_getpages: invalid place replacement");
vm_page_lock(m[i]);
vm_page_free(m[i]);
vm_page_unlock(m[i]);
}
m[reqpage] = page;
page->valid = VM_PAGE_BITS_ALL;
return (VM_PAGER_OK);
}
static void
sg_pager_putpages(vm_object_t object, vm_page_t *m, int count,
boolean_t sync, int *rtvals)
{
panic("sg_pager_putpage called");
}
static boolean_t
sg_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
int *after)
{
if (before != NULL)
*before = 0;
if (after != NULL)
*after = 0;
return (TRUE);
}
|
