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
|
/*
* SPU file system -- SPU context management
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/spu.h>
#include <asm/spu_csa.h>
#include "spufs.h"
struct spu_context *alloc_spu_context(struct spu_gang *gang)
{
struct spu_context *ctx;
ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
if (!ctx)
goto out;
/* Binding to physical processor deferred
* until spu_activate().
*/
spu_init_csa(&ctx->csa);
if (!ctx->csa.lscsa) {
goto out_free;
}
spin_lock_init(&ctx->mmio_lock);
kref_init(&ctx->kref);
init_rwsem(&ctx->state_sema);
init_MUTEX(&ctx->run_sema);
init_waitqueue_head(&ctx->ibox_wq);
init_waitqueue_head(&ctx->wbox_wq);
init_waitqueue_head(&ctx->stop_wq);
init_waitqueue_head(&ctx->mfc_wq);
ctx->state = SPU_STATE_SAVED;
ctx->ops = &spu_backing_ops;
ctx->owner = get_task_mm(current);
if (gang)
spu_gang_add_ctx(gang, ctx);
goto out;
out_free:
kfree(ctx);
ctx = NULL;
out:
return ctx;
}
void destroy_spu_context(struct kref *kref)
{
struct spu_context *ctx;
ctx = container_of(kref, struct spu_context, kref);
down_write(&ctx->state_sema);
spu_deactivate(ctx);
up_write(&ctx->state_sema);
spu_fini_csa(&ctx->csa);
if (ctx->gang)
spu_gang_remove_ctx(ctx->gang, ctx);
kfree(ctx);
}
struct spu_context * get_spu_context(struct spu_context *ctx)
{
kref_get(&ctx->kref);
return ctx;
}
int put_spu_context(struct spu_context *ctx)
{
return kref_put(&ctx->kref, &destroy_spu_context);
}
/* give up the mm reference when the context is about to be destroyed */
void spu_forget(struct spu_context *ctx)
{
struct mm_struct *mm;
spu_acquire_saved(ctx);
mm = ctx->owner;
ctx->owner = NULL;
mmput(mm);
spu_release(ctx);
}
void spu_acquire(struct spu_context *ctx)
{
down_read(&ctx->state_sema);
}
void spu_release(struct spu_context *ctx)
{
up_read(&ctx->state_sema);
}
void spu_unmap_mappings(struct spu_context *ctx)
{
if (ctx->local_store)
unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
if (ctx->mfc)
unmap_mapping_range(ctx->mfc, 0, 0x1000, 1);
if (ctx->cntl)
unmap_mapping_range(ctx->cntl, 0, 0x1000, 1);
if (ctx->signal1)
unmap_mapping_range(ctx->signal1, 0, PAGE_SIZE, 1);
if (ctx->signal2)
unmap_mapping_range(ctx->signal2, 0, PAGE_SIZE, 1);
if (ctx->mss)
unmap_mapping_range(ctx->mss, 0, 0x1000, 1);
if (ctx->psmap)
unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
}
int spu_acquire_exclusive(struct spu_context *ctx)
{
int ret = 0;
down_write(&ctx->state_sema);
/* ctx is about to be freed, can't acquire any more */
if (!ctx->owner) {
ret = -EINVAL;
goto out;
}
if (ctx->state == SPU_STATE_SAVED) {
ret = spu_activate(ctx, 0);
if (ret)
goto out;
ctx->state = SPU_STATE_RUNNABLE;
} else {
/* We need to exclude userspace access to the context. */
spu_unmap_mappings(ctx);
}
out:
if (ret)
up_write(&ctx->state_sema);
return ret;
}
int spu_acquire_runnable(struct spu_context *ctx)
{
int ret = 0;
down_read(&ctx->state_sema);
if (ctx->state == SPU_STATE_RUNNABLE) {
ctx->spu->prio = current->prio;
return 0;
}
up_read(&ctx->state_sema);
down_write(&ctx->state_sema);
/* ctx is about to be freed, can't acquire any more */
if (!ctx->owner) {
ret = -EINVAL;
goto out;
}
if (ctx->state == SPU_STATE_SAVED) {
ret = spu_activate(ctx, 0);
if (ret)
goto out;
ctx->state = SPU_STATE_RUNNABLE;
}
downgrade_write(&ctx->state_sema);
/* On success, we return holding the lock */
return ret;
out:
/* Release here, to simplify calling code. */
up_write(&ctx->state_sema);
return ret;
}
void spu_acquire_saved(struct spu_context *ctx)
{
down_read(&ctx->state_sema);
if (ctx->state == SPU_STATE_SAVED)
return;
up_read(&ctx->state_sema);
down_write(&ctx->state_sema);
if (ctx->state == SPU_STATE_RUNNABLE) {
spu_deactivate(ctx);
ctx->state = SPU_STATE_SAVED;
}
downgrade_write(&ctx->state_sema);
}
|
