Loading...
1/**************************************************************************
2 *
3 * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27/*
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29 */
30
31#include "ttm/ttm_lock.h"
32#include "ttm/ttm_module.h"
33#include <linux/atomic.h>
34#include <linux/errno.h>
35#include <linux/wait.h>
36#include <linux/sched.h>
37#include <linux/module.h>
38
39#define TTM_WRITE_LOCK_PENDING (1 << 0)
40#define TTM_VT_LOCK_PENDING (1 << 1)
41#define TTM_SUSPEND_LOCK_PENDING (1 << 2)
42#define TTM_VT_LOCK (1 << 3)
43#define TTM_SUSPEND_LOCK (1 << 4)
44
45void ttm_lock_init(struct ttm_lock *lock)
46{
47 spin_lock_init(&lock->lock);
48 init_waitqueue_head(&lock->queue);
49 lock->rw = 0;
50 lock->flags = 0;
51 lock->kill_takers = false;
52 lock->signal = SIGKILL;
53}
54EXPORT_SYMBOL(ttm_lock_init);
55
56void ttm_read_unlock(struct ttm_lock *lock)
57{
58 spin_lock(&lock->lock);
59 if (--lock->rw == 0)
60 wake_up_all(&lock->queue);
61 spin_unlock(&lock->lock);
62}
63EXPORT_SYMBOL(ttm_read_unlock);
64
65static bool __ttm_read_lock(struct ttm_lock *lock)
66{
67 bool locked = false;
68
69 spin_lock(&lock->lock);
70 if (unlikely(lock->kill_takers)) {
71 send_sig(lock->signal, current, 0);
72 spin_unlock(&lock->lock);
73 return false;
74 }
75 if (lock->rw >= 0 && lock->flags == 0) {
76 ++lock->rw;
77 locked = true;
78 }
79 spin_unlock(&lock->lock);
80 return locked;
81}
82
83int ttm_read_lock(struct ttm_lock *lock, bool interruptible)
84{
85 int ret = 0;
86
87 if (interruptible)
88 ret = wait_event_interruptible(lock->queue,
89 __ttm_read_lock(lock));
90 else
91 wait_event(lock->queue, __ttm_read_lock(lock));
92 return ret;
93}
94EXPORT_SYMBOL(ttm_read_lock);
95
96static bool __ttm_read_trylock(struct ttm_lock *lock, bool *locked)
97{
98 bool block = true;
99
100 *locked = false;
101
102 spin_lock(&lock->lock);
103 if (unlikely(lock->kill_takers)) {
104 send_sig(lock->signal, current, 0);
105 spin_unlock(&lock->lock);
106 return false;
107 }
108 if (lock->rw >= 0 && lock->flags == 0) {
109 ++lock->rw;
110 block = false;
111 *locked = true;
112 } else if (lock->flags == 0) {
113 block = false;
114 }
115 spin_unlock(&lock->lock);
116
117 return !block;
118}
119
120int ttm_read_trylock(struct ttm_lock *lock, bool interruptible)
121{
122 int ret = 0;
123 bool locked;
124
125 if (interruptible)
126 ret = wait_event_interruptible
127 (lock->queue, __ttm_read_trylock(lock, &locked));
128 else
129 wait_event(lock->queue, __ttm_read_trylock(lock, &locked));
130
131 if (unlikely(ret != 0)) {
132 BUG_ON(locked);
133 return ret;
134 }
135
136 return (locked) ? 0 : -EBUSY;
137}
138
139void ttm_write_unlock(struct ttm_lock *lock)
140{
141 spin_lock(&lock->lock);
142 lock->rw = 0;
143 wake_up_all(&lock->queue);
144 spin_unlock(&lock->lock);
145}
146EXPORT_SYMBOL(ttm_write_unlock);
147
148static bool __ttm_write_lock(struct ttm_lock *lock)
149{
150 bool locked = false;
151
152 spin_lock(&lock->lock);
153 if (unlikely(lock->kill_takers)) {
154 send_sig(lock->signal, current, 0);
155 spin_unlock(&lock->lock);
156 return false;
157 }
158 if (lock->rw == 0 && ((lock->flags & ~TTM_WRITE_LOCK_PENDING) == 0)) {
159 lock->rw = -1;
160 lock->flags &= ~TTM_WRITE_LOCK_PENDING;
161 locked = true;
162 } else {
163 lock->flags |= TTM_WRITE_LOCK_PENDING;
164 }
165 spin_unlock(&lock->lock);
166 return locked;
167}
168
169int ttm_write_lock(struct ttm_lock *lock, bool interruptible)
170{
171 int ret = 0;
172
173 if (interruptible) {
174 ret = wait_event_interruptible(lock->queue,
175 __ttm_write_lock(lock));
176 if (unlikely(ret != 0)) {
177 spin_lock(&lock->lock);
178 lock->flags &= ~TTM_WRITE_LOCK_PENDING;
179 wake_up_all(&lock->queue);
180 spin_unlock(&lock->lock);
181 }
182 } else
183 wait_event(lock->queue, __ttm_read_lock(lock));
184
185 return ret;
186}
187EXPORT_SYMBOL(ttm_write_lock);
188
189void ttm_write_lock_downgrade(struct ttm_lock *lock)
190{
191 spin_lock(&lock->lock);
192 lock->rw = 1;
193 wake_up_all(&lock->queue);
194 spin_unlock(&lock->lock);
195}
196
197static int __ttm_vt_unlock(struct ttm_lock *lock)
198{
199 int ret = 0;
200
201 spin_lock(&lock->lock);
202 if (unlikely(!(lock->flags & TTM_VT_LOCK)))
203 ret = -EINVAL;
204 lock->flags &= ~TTM_VT_LOCK;
205 wake_up_all(&lock->queue);
206 spin_unlock(&lock->lock);
207
208 return ret;
209}
210
211static void ttm_vt_lock_remove(struct ttm_base_object **p_base)
212{
213 struct ttm_base_object *base = *p_base;
214 struct ttm_lock *lock = container_of(base, struct ttm_lock, base);
215 int ret;
216
217 *p_base = NULL;
218 ret = __ttm_vt_unlock(lock);
219 BUG_ON(ret != 0);
220}
221
222static bool __ttm_vt_lock(struct ttm_lock *lock)
223{
224 bool locked = false;
225
226 spin_lock(&lock->lock);
227 if (lock->rw == 0) {
228 lock->flags &= ~TTM_VT_LOCK_PENDING;
229 lock->flags |= TTM_VT_LOCK;
230 locked = true;
231 } else {
232 lock->flags |= TTM_VT_LOCK_PENDING;
233 }
234 spin_unlock(&lock->lock);
235 return locked;
236}
237
238int ttm_vt_lock(struct ttm_lock *lock,
239 bool interruptible,
240 struct ttm_object_file *tfile)
241{
242 int ret = 0;
243
244 if (interruptible) {
245 ret = wait_event_interruptible(lock->queue,
246 __ttm_vt_lock(lock));
247 if (unlikely(ret != 0)) {
248 spin_lock(&lock->lock);
249 lock->flags &= ~TTM_VT_LOCK_PENDING;
250 wake_up_all(&lock->queue);
251 spin_unlock(&lock->lock);
252 return ret;
253 }
254 } else
255 wait_event(lock->queue, __ttm_vt_lock(lock));
256
257 /*
258 * Add a base-object, the destructor of which will
259 * make sure the lock is released if the client dies
260 * while holding it.
261 */
262
263 ret = ttm_base_object_init(tfile, &lock->base, false,
264 ttm_lock_type, &ttm_vt_lock_remove, NULL);
265 if (ret)
266 (void)__ttm_vt_unlock(lock);
267 else
268 lock->vt_holder = tfile;
269
270 return ret;
271}
272EXPORT_SYMBOL(ttm_vt_lock);
273
274int ttm_vt_unlock(struct ttm_lock *lock)
275{
276 return ttm_ref_object_base_unref(lock->vt_holder,
277 lock->base.hash.key, TTM_REF_USAGE);
278}
279EXPORT_SYMBOL(ttm_vt_unlock);
280
281void ttm_suspend_unlock(struct ttm_lock *lock)
282{
283 spin_lock(&lock->lock);
284 lock->flags &= ~TTM_SUSPEND_LOCK;
285 wake_up_all(&lock->queue);
286 spin_unlock(&lock->lock);
287}
288EXPORT_SYMBOL(ttm_suspend_unlock);
289
290static bool __ttm_suspend_lock(struct ttm_lock *lock)
291{
292 bool locked = false;
293
294 spin_lock(&lock->lock);
295 if (lock->rw == 0) {
296 lock->flags &= ~TTM_SUSPEND_LOCK_PENDING;
297 lock->flags |= TTM_SUSPEND_LOCK;
298 locked = true;
299 } else {
300 lock->flags |= TTM_SUSPEND_LOCK_PENDING;
301 }
302 spin_unlock(&lock->lock);
303 return locked;
304}
305
306void ttm_suspend_lock(struct ttm_lock *lock)
307{
308 wait_event(lock->queue, __ttm_suspend_lock(lock));
309}
310EXPORT_SYMBOL(ttm_suspend_lock);
1/**************************************************************************
2 *
3 * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27/*
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29 */
30
31#include <drm/ttm/ttm_lock.h>
32#include <drm/ttm/ttm_module.h>
33#include <linux/atomic.h>
34#include <linux/errno.h>
35#include <linux/wait.h>
36#include <linux/sched/signal.h>
37#include <linux/module.h>
38
39#define TTM_WRITE_LOCK_PENDING (1 << 0)
40#define TTM_VT_LOCK_PENDING (1 << 1)
41#define TTM_SUSPEND_LOCK_PENDING (1 << 2)
42#define TTM_VT_LOCK (1 << 3)
43#define TTM_SUSPEND_LOCK (1 << 4)
44
45void ttm_lock_init(struct ttm_lock *lock)
46{
47 spin_lock_init(&lock->lock);
48 init_waitqueue_head(&lock->queue);
49 lock->rw = 0;
50 lock->flags = 0;
51 lock->kill_takers = false;
52 lock->signal = SIGKILL;
53}
54EXPORT_SYMBOL(ttm_lock_init);
55
56void ttm_read_unlock(struct ttm_lock *lock)
57{
58 spin_lock(&lock->lock);
59 if (--lock->rw == 0)
60 wake_up_all(&lock->queue);
61 spin_unlock(&lock->lock);
62}
63EXPORT_SYMBOL(ttm_read_unlock);
64
65static bool __ttm_read_lock(struct ttm_lock *lock)
66{
67 bool locked = false;
68
69 spin_lock(&lock->lock);
70 if (unlikely(lock->kill_takers)) {
71 send_sig(lock->signal, current, 0);
72 spin_unlock(&lock->lock);
73 return false;
74 }
75 if (lock->rw >= 0 && lock->flags == 0) {
76 ++lock->rw;
77 locked = true;
78 }
79 spin_unlock(&lock->lock);
80 return locked;
81}
82
83int ttm_read_lock(struct ttm_lock *lock, bool interruptible)
84{
85 int ret = 0;
86
87 if (interruptible)
88 ret = wait_event_interruptible(lock->queue,
89 __ttm_read_lock(lock));
90 else
91 wait_event(lock->queue, __ttm_read_lock(lock));
92 return ret;
93}
94EXPORT_SYMBOL(ttm_read_lock);
95
96static bool __ttm_read_trylock(struct ttm_lock *lock, bool *locked)
97{
98 bool block = true;
99
100 *locked = false;
101
102 spin_lock(&lock->lock);
103 if (unlikely(lock->kill_takers)) {
104 send_sig(lock->signal, current, 0);
105 spin_unlock(&lock->lock);
106 return false;
107 }
108 if (lock->rw >= 0 && lock->flags == 0) {
109 ++lock->rw;
110 block = false;
111 *locked = true;
112 } else if (lock->flags == 0) {
113 block = false;
114 }
115 spin_unlock(&lock->lock);
116
117 return !block;
118}
119
120int ttm_read_trylock(struct ttm_lock *lock, bool interruptible)
121{
122 int ret = 0;
123 bool locked;
124
125 if (interruptible)
126 ret = wait_event_interruptible
127 (lock->queue, __ttm_read_trylock(lock, &locked));
128 else
129 wait_event(lock->queue, __ttm_read_trylock(lock, &locked));
130
131 if (unlikely(ret != 0)) {
132 BUG_ON(locked);
133 return ret;
134 }
135
136 return (locked) ? 0 : -EBUSY;
137}
138
139void ttm_write_unlock(struct ttm_lock *lock)
140{
141 spin_lock(&lock->lock);
142 lock->rw = 0;
143 wake_up_all(&lock->queue);
144 spin_unlock(&lock->lock);
145}
146EXPORT_SYMBOL(ttm_write_unlock);
147
148static bool __ttm_write_lock(struct ttm_lock *lock)
149{
150 bool locked = false;
151
152 spin_lock(&lock->lock);
153 if (unlikely(lock->kill_takers)) {
154 send_sig(lock->signal, current, 0);
155 spin_unlock(&lock->lock);
156 return false;
157 }
158 if (lock->rw == 0 && ((lock->flags & ~TTM_WRITE_LOCK_PENDING) == 0)) {
159 lock->rw = -1;
160 lock->flags &= ~TTM_WRITE_LOCK_PENDING;
161 locked = true;
162 } else {
163 lock->flags |= TTM_WRITE_LOCK_PENDING;
164 }
165 spin_unlock(&lock->lock);
166 return locked;
167}
168
169int ttm_write_lock(struct ttm_lock *lock, bool interruptible)
170{
171 int ret = 0;
172
173 if (interruptible) {
174 ret = wait_event_interruptible(lock->queue,
175 __ttm_write_lock(lock));
176 if (unlikely(ret != 0)) {
177 spin_lock(&lock->lock);
178 lock->flags &= ~TTM_WRITE_LOCK_PENDING;
179 wake_up_all(&lock->queue);
180 spin_unlock(&lock->lock);
181 }
182 } else
183 wait_event(lock->queue, __ttm_write_lock(lock));
184
185 return ret;
186}
187EXPORT_SYMBOL(ttm_write_lock);
188
189static int __ttm_vt_unlock(struct ttm_lock *lock)
190{
191 int ret = 0;
192
193 spin_lock(&lock->lock);
194 if (unlikely(!(lock->flags & TTM_VT_LOCK)))
195 ret = -EINVAL;
196 lock->flags &= ~TTM_VT_LOCK;
197 wake_up_all(&lock->queue);
198 spin_unlock(&lock->lock);
199
200 return ret;
201}
202
203static void ttm_vt_lock_remove(struct ttm_base_object **p_base)
204{
205 struct ttm_base_object *base = *p_base;
206 struct ttm_lock *lock = container_of(base, struct ttm_lock, base);
207 int ret;
208
209 *p_base = NULL;
210 ret = __ttm_vt_unlock(lock);
211 BUG_ON(ret != 0);
212}
213
214static bool __ttm_vt_lock(struct ttm_lock *lock)
215{
216 bool locked = false;
217
218 spin_lock(&lock->lock);
219 if (lock->rw == 0) {
220 lock->flags &= ~TTM_VT_LOCK_PENDING;
221 lock->flags |= TTM_VT_LOCK;
222 locked = true;
223 } else {
224 lock->flags |= TTM_VT_LOCK_PENDING;
225 }
226 spin_unlock(&lock->lock);
227 return locked;
228}
229
230int ttm_vt_lock(struct ttm_lock *lock,
231 bool interruptible,
232 struct ttm_object_file *tfile)
233{
234 int ret = 0;
235
236 if (interruptible) {
237 ret = wait_event_interruptible(lock->queue,
238 __ttm_vt_lock(lock));
239 if (unlikely(ret != 0)) {
240 spin_lock(&lock->lock);
241 lock->flags &= ~TTM_VT_LOCK_PENDING;
242 wake_up_all(&lock->queue);
243 spin_unlock(&lock->lock);
244 return ret;
245 }
246 } else
247 wait_event(lock->queue, __ttm_vt_lock(lock));
248
249 /*
250 * Add a base-object, the destructor of which will
251 * make sure the lock is released if the client dies
252 * while holding it.
253 */
254
255 ret = ttm_base_object_init(tfile, &lock->base, false,
256 ttm_lock_type, &ttm_vt_lock_remove, NULL);
257 if (ret)
258 (void)__ttm_vt_unlock(lock);
259 else
260 lock->vt_holder = tfile;
261
262 return ret;
263}
264EXPORT_SYMBOL(ttm_vt_lock);
265
266int ttm_vt_unlock(struct ttm_lock *lock)
267{
268 return ttm_ref_object_base_unref(lock->vt_holder,
269 lock->base.hash.key, TTM_REF_USAGE);
270}
271EXPORT_SYMBOL(ttm_vt_unlock);
272
273void ttm_suspend_unlock(struct ttm_lock *lock)
274{
275 spin_lock(&lock->lock);
276 lock->flags &= ~TTM_SUSPEND_LOCK;
277 wake_up_all(&lock->queue);
278 spin_unlock(&lock->lock);
279}
280EXPORT_SYMBOL(ttm_suspend_unlock);
281
282static bool __ttm_suspend_lock(struct ttm_lock *lock)
283{
284 bool locked = false;
285
286 spin_lock(&lock->lock);
287 if (lock->rw == 0) {
288 lock->flags &= ~TTM_SUSPEND_LOCK_PENDING;
289 lock->flags |= TTM_SUSPEND_LOCK;
290 locked = true;
291 } else {
292 lock->flags |= TTM_SUSPEND_LOCK_PENDING;
293 }
294 spin_unlock(&lock->lock);
295 return locked;
296}
297
298void ttm_suspend_lock(struct ttm_lock *lock)
299{
300 wait_event(lock->queue, __ttm_suspend_lock(lock));
301}
302EXPORT_SYMBOL(ttm_suspend_lock);