1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
6 * Copyright (c) 2017 Mark Johnston <[email protected]>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice unmodified, this list of conditions, and the following
14 * 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * $FreeBSD$
31 */
32
33 #ifndef _LINUX_WAIT_H_
34 #define _LINUX_WAIT_H_
35
36 #include <linux/compiler.h>
37 #include <linux/list.h>
38 #include <linux/spinlock.h>
39
40 #include <asm/atomic.h>
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44
45 #define SKIP_SLEEP() (SCHEDULER_STOPPED() || kdb_active)
46
47 #define might_sleep() \
48 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "might_sleep()")
49
50 #define might_sleep_if(cond) do { \
51 if (cond) { might_sleep(); } \
52 } while (0)
53
54 struct wait_queue;
55 struct wait_queue_head;
56
57 #define wait_queue_entry wait_queue
58
59 typedef struct wait_queue wait_queue_t;
60 typedef struct wait_queue_entry wait_queue_entry_t;
61 typedef struct wait_queue_head wait_queue_head_t;
62
63 typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *);
64
65 /*
66 * Many API consumers directly reference these fields and those of
67 * wait_queue_head.
68 */
69 struct wait_queue {
70 unsigned int flags; /* always 0 */
71 void *private;
72 wait_queue_func_t *func;
73 union {
74 struct list_head task_list; /* < v4.13 */
75 struct list_head entry; /* >= v4.13 */
76 };
77 };
78
79 struct wait_queue_head {
80 spinlock_t lock;
81 union {
82 struct list_head task_list; /* < v4.13 */
83 struct list_head head; /* >= v4.13 */
84 };
85 };
86
87 /*
88 * This function is referenced by at least one DRM driver, so it may not be
89 * renamed and furthermore must be the default wait queue callback.
90 */
91 extern wait_queue_func_t autoremove_wake_function;
92 extern wait_queue_func_t default_wake_function;
93
94 #define DEFINE_WAIT_FUNC(name, function) \
95 wait_queue_t name = { \
96 .private = current, \
97 .func = function, \
98 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
99 }
100
101 #define DEFINE_WAIT(name) \
102 DEFINE_WAIT_FUNC(name, autoremove_wake_function)
103
104 #define DECLARE_WAITQUEUE(name, task) \
105 wait_queue_t name = { \
106 .private = task, \
107 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
108 }
109
110 #define DECLARE_WAIT_QUEUE_HEAD(name) \
111 wait_queue_head_t name = { \
112 .task_list = LINUX_LIST_HEAD_INIT(name.task_list), \
113 }; \
114 MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF)
115
116 #define init_waitqueue_head(wqh) do { \
117 mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \
118 NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \
119 INIT_LIST_HEAD(&(wqh)->task_list); \
120 } while (0)
121
122 void linux_init_wait_entry(wait_queue_t *, int);
123 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool);
124
125 #define init_wait_entry(wq, flags) \
126 linux_init_wait_entry(wq, flags)
127 #define wake_up(wqh) \
128 linux_wake_up(wqh, TASK_NORMAL, 1, false)
129 #define wake_up_all(wqh) \
130 linux_wake_up(wqh, TASK_NORMAL, 0, false)
131 #define wake_up_locked(wqh) \
132 linux_wake_up(wqh, TASK_NORMAL, 1, true)
133 #define wake_up_all_locked(wqh) \
134 linux_wake_up(wqh, TASK_NORMAL, 0, true)
135 #define wake_up_interruptible(wqh) \
136 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false)
137 #define wake_up_interruptible_all(wqh) \
138 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false)
139
140 int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int,
141 unsigned int, spinlock_t *);
142
143 /*
144 * Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if
145 * cond is true after timeout, remaining jiffies (> 0) if cond is true before
146 * timeout.
147 */
148 #define __wait_event_common(wqh, cond, timeout, state, lock) ({ \
149 DEFINE_WAIT(__wq); \
150 const int __timeout = ((int)(timeout)) < 1 ? 1 : (timeout); \
151 int __start = ticks; \
152 int __ret = 0; \
153 \
154 for (;;) { \
155 linux_prepare_to_wait(&(wqh), &__wq, state); \
156 if (cond) \
157 break; \
158 __ret = linux_wait_event_common(&(wqh), &__wq, \
159 __timeout, state, lock); \
160 if (__ret != 0) \
161 break; \
162 } \
163 linux_finish_wait(&(wqh), &__wq); \
164 if (__timeout != MAX_SCHEDULE_TIMEOUT) { \
165 if (__ret == -EWOULDBLOCK) \
166 __ret = !!(cond); \
167 else if (__ret != -ERESTARTSYS) { \
168 __ret = __timeout + __start - ticks; \
169 /* range check return value */ \
170 if (__ret < 1) \
171 __ret = 1; \
172 else if (__ret > __timeout) \
173 __ret = __timeout; \
174 } \
175 } \
176 __ret; \
177 })
178
179 #define wait_event(wqh, cond) do { \
180 (void) __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
181 TASK_UNINTERRUPTIBLE, NULL); \
182 } while (0)
183
184 #define wait_event_timeout(wqh, cond, timeout) ({ \
185 __wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \
186 NULL); \
187 })
188
189 #define wait_event_killable(wqh, cond) ({ \
190 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
191 TASK_INTERRUPTIBLE, NULL); \
192 })
193
194 #define wait_event_interruptible(wqh, cond) ({ \
195 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
196 TASK_INTERRUPTIBLE, NULL); \
197 })
198
199 #define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \
200 __wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \
201 NULL); \
202 })
203
204 /*
205 * Wait queue is already locked.
206 */
207 #define wait_event_interruptible_locked(wqh, cond) ({ \
208 int __ret; \
209 \
210 spin_unlock(&(wqh).lock); \
211 __ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
212 TASK_INTERRUPTIBLE, NULL); \
213 spin_lock(&(wqh).lock); \
214 __ret; \
215 })
216
217 /*
218 * The passed spinlock is held when testing the condition.
219 */
220 #define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \
221 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
222 TASK_INTERRUPTIBLE, &(lock)); \
223 })
224
225 /*
226 * The passed spinlock is held when testing the condition.
227 */
228 #define wait_event_lock_irq(wqh, cond, lock) ({ \
229 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
230 TASK_UNINTERRUPTIBLE, &(lock)); \
231 })
232
233 static inline void
__add_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)234 __add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
235 {
236 list_add(&wq->task_list, &wqh->task_list);
237 }
238
239 static inline void
add_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)240 add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
241 {
242
243 spin_lock(&wqh->lock);
244 __add_wait_queue(wqh, wq);
245 spin_unlock(&wqh->lock);
246 }
247
248 static inline void
__add_wait_queue_tail(wait_queue_head_t * wqh,wait_queue_t * wq)249 __add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq)
250 {
251 list_add_tail(&wq->task_list, &wqh->task_list);
252 }
253
254 static inline void
__add_wait_queue_entry_tail(wait_queue_head_t * wqh,wait_queue_entry_t * wq)255 __add_wait_queue_entry_tail(wait_queue_head_t *wqh, wait_queue_entry_t *wq)
256 {
257 list_add_tail(&wq->entry, &wqh->head);
258 }
259
260 static inline void
__remove_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)261 __remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
262 {
263 list_del(&wq->task_list);
264 }
265
266 static inline void
remove_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)267 remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
268 {
269
270 spin_lock(&wqh->lock);
271 __remove_wait_queue(wqh, wq);
272 spin_unlock(&wqh->lock);
273 }
274
275 bool linux_waitqueue_active(wait_queue_head_t *);
276
277 #define waitqueue_active(wqh) linux_waitqueue_active(wqh)
278
279 void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int);
280 void linux_finish_wait(wait_queue_head_t *, wait_queue_t *);
281
282 #define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state)
283 #define finish_wait(wqh, wq) linux_finish_wait(wqh, wq)
284
285 void linux_wake_up_bit(void *, int);
286 int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int);
287 void linux_wake_up_atomic_t(atomic_t *);
288 int linux_wait_on_atomic_t(atomic_t *, unsigned int);
289
290 #define wake_up_bit(word, bit) linux_wake_up_bit(word, bit)
291 #define wait_on_bit(word, bit, state) \
292 linux_wait_on_bit_timeout(word, bit, state, MAX_SCHEDULE_TIMEOUT)
293 #define wait_on_bit_timeout(word, bit, state, timeout) \
294 linux_wait_on_bit_timeout(word, bit, state, timeout)
295 #define wake_up_atomic_t(a) linux_wake_up_atomic_t(a)
296 /*
297 * All existing callers have a cb that just schedule()s. To avoid adding
298 * complexity, just emulate that internally. The prototype is different so that
299 * callers must be manually modified; a cb that does something other than call
300 * schedule() will require special treatment.
301 */
302 #define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state)
303
304 struct task_struct;
305 bool linux_wake_up_state(struct task_struct *, unsigned int);
306
307 #define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL)
308 #define wake_up_state(task, state) linux_wake_up_state(task, state)
309
310 #endif /* _LINUX_WAIT_H_ */
311