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 <markj@FreeBSD.org>
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 _LINUXKPI_LINUX_WAIT_H_
34 #define _LINUXKPI_LINUX_WAIT_H_
35
36 #include <linux/compiler.h>
37 #include <linux/list.h>
38 #include <linux/spinlock.h>
39 #include <linux/sched.h>
40
41 #include <asm/atomic.h>
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45
46 #define SKIP_SLEEP() (SCHEDULER_STOPPED() || kdb_active)
47
48 #define might_sleep() \
49 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "might_sleep()")
50
51 #define might_sleep_if(cond) do { \
52 if (cond) { might_sleep(); } \
53 } while (0)
54
55 struct wait_queue;
56 struct wait_queue_head;
57
58 #define wait_queue_entry wait_queue
59
60 typedef struct wait_queue wait_queue_t;
61 typedef struct wait_queue_entry wait_queue_entry_t;
62 typedef struct wait_queue_head wait_queue_head_t;
63
64 typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *);
65
66 /*
67 * Many API consumers directly reference these fields and those of
68 * wait_queue_head.
69 */
70 struct wait_queue {
71 unsigned int flags; /* always 0 */
72 void *private;
73 wait_queue_func_t *func;
74 union {
75 struct list_head task_list; /* < v4.13 */
76 struct list_head entry; /* >= v4.13 */
77 };
78 };
79
80 struct wait_queue_head {
81 spinlock_t lock;
82 union {
83 struct list_head task_list; /* < v4.13 */
84 struct list_head head; /* >= v4.13 */
85 };
86 };
87
88 /*
89 * This function is referenced by at least one DRM driver, so it may not be
90 * renamed and furthermore must be the default wait queue callback.
91 */
92 extern wait_queue_func_t autoremove_wake_function;
93 extern wait_queue_func_t default_wake_function;
94
95 #define DEFINE_WAIT_FUNC(name, function) \
96 wait_queue_t name = { \
97 .private = current, \
98 .func = function, \
99 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
100 }
101
102 #define DEFINE_WAIT(name) \
103 DEFINE_WAIT_FUNC(name, autoremove_wake_function)
104
105 #define DECLARE_WAITQUEUE(name, task) \
106 wait_queue_t name = { \
107 .private = task, \
108 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
109 }
110
111 #define DECLARE_WAIT_QUEUE_HEAD(name) \
112 wait_queue_head_t name = { \
113 .task_list = LINUX_LIST_HEAD_INIT(name.task_list), \
114 }; \
115 MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF)
116
117 #define init_waitqueue_head(wqh) do { \
118 mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \
119 NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \
120 INIT_LIST_HEAD(&(wqh)->task_list); \
121 } while (0)
122
123 #define __init_waitqueue_head(wqh, name, lk) init_waitqueue_head(wqh)
124
125 void linux_init_wait_entry(wait_queue_t *, int);
126 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool);
127
128 #define init_wait_entry(wq, flags) \
129 linux_init_wait_entry(wq, flags)
130 #define wake_up(wqh) \
131 linux_wake_up(wqh, TASK_NORMAL, 1, false)
132 #define wake_up_all(wqh) \
133 linux_wake_up(wqh, TASK_NORMAL, 0, false)
134 #define wake_up_locked(wqh) \
135 linux_wake_up(wqh, TASK_NORMAL, 1, true)
136 #define wake_up_all_locked(wqh) \
137 linux_wake_up(wqh, TASK_NORMAL, 0, true)
138 #define wake_up_interruptible(wqh) \
139 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false)
140 #define wake_up_interruptible_all(wqh) \
141 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false)
142
143 int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int,
144 unsigned int, spinlock_t *);
145
146 /*
147 * Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if
148 * cond is true after timeout, remaining jiffies (> 0) if cond is true before
149 * timeout.
150 */
151 #define __wait_event_common(wqh, cond, timeout, state, lock) ({ \
152 DEFINE_WAIT(__wq); \
153 const int __timeout = ((int)(timeout)) < 1 ? 1 : (timeout); \
154 int __start = ticks; \
155 int __ret = 0; \
156 \
157 for (;;) { \
158 linux_prepare_to_wait(&(wqh), &__wq, state); \
159 if (cond) \
160 break; \
161 __ret = linux_wait_event_common(&(wqh), &__wq, \
162 __timeout, state, lock); \
163 if (__ret != 0) \
164 break; \
165 } \
166 linux_finish_wait(&(wqh), &__wq); \
167 if (__timeout != MAX_SCHEDULE_TIMEOUT) { \
168 if (__ret == -EWOULDBLOCK) \
169 __ret = !!(cond); \
170 else if (__ret != -ERESTARTSYS) { \
171 __ret = __timeout + __start - ticks; \
172 /* range check return value */ \
173 if (__ret < 1) \
174 __ret = 1; \
175 else if (__ret > __timeout) \
176 __ret = __timeout; \
177 } \
178 } \
179 __ret; \
180 })
181
182 #define wait_event(wqh, cond) do { \
183 (void) __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
184 TASK_UNINTERRUPTIBLE, NULL); \
185 } while (0)
186
187 #define wait_event_timeout(wqh, cond, timeout) ({ \
188 __wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \
189 NULL); \
190 })
191
192 #define wait_event_killable(wqh, cond) ({ \
193 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
194 TASK_INTERRUPTIBLE, NULL); \
195 })
196
197 #define wait_event_interruptible(wqh, cond) ({ \
198 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
199 TASK_INTERRUPTIBLE, NULL); \
200 })
201
202 #define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \
203 __wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \
204 NULL); \
205 })
206
207 /*
208 * Wait queue is already locked.
209 */
210 #define wait_event_interruptible_locked(wqh, cond) ({ \
211 int __ret; \
212 \
213 spin_unlock(&(wqh).lock); \
214 __ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
215 TASK_INTERRUPTIBLE, NULL); \
216 spin_lock(&(wqh).lock); \
217 __ret; \
218 })
219
220 /*
221 * The passed spinlock is held when testing the condition.
222 */
223 #define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \
224 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
225 TASK_INTERRUPTIBLE, &(lock)); \
226 })
227
228 /*
229 * The passed spinlock is held when testing the condition.
230 */
231 #define wait_event_lock_irq(wqh, cond, lock) ({ \
232 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
233 TASK_UNINTERRUPTIBLE, &(lock)); \
234 })
235
236 static inline void
237 __add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
238 {
239 list_add(&wq->task_list, &wqh->task_list);
240 }
241
242 static inline void
243 add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
244 {
245
246 spin_lock(&wqh->lock);
247 __add_wait_queue(wqh, wq);
248 spin_unlock(&wqh->lock);
249 }
250
251 static inline void
252 __add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq)
253 {
254 list_add_tail(&wq->task_list, &wqh->task_list);
255 }
256
257 static inline void
258 __add_wait_queue_entry_tail(wait_queue_head_t *wqh, wait_queue_entry_t *wq)
259 {
260 list_add_tail(&wq->entry, &wqh->head);
261 }
262
263 static inline void
264 __remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
265 {
266 list_del(&wq->task_list);
267 }
268
269 static inline void
270 remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
271 {
272
273 spin_lock(&wqh->lock);
274 __remove_wait_queue(wqh, wq);
275 spin_unlock(&wqh->lock);
276 }
277
278 bool linux_waitqueue_active(wait_queue_head_t *);
279
280 #define waitqueue_active(wqh) linux_waitqueue_active(wqh)
281
282 void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int);
283 void linux_finish_wait(wait_queue_head_t *, wait_queue_t *);
284
285 #define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state)
286 #define finish_wait(wqh, wq) linux_finish_wait(wqh, wq)
287
288 void linux_wake_up_bit(void *, int);
289 int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int);
290 void linux_wake_up_atomic_t(atomic_t *);
291 int linux_wait_on_atomic_t(atomic_t *, unsigned int);
292
293 #define wake_up_bit(word, bit) linux_wake_up_bit(word, bit)
294 #define wait_on_bit(word, bit, state) \
295 linux_wait_on_bit_timeout(word, bit, state, MAX_SCHEDULE_TIMEOUT)
296 #define wait_on_bit_timeout(word, bit, state, timeout) \
297 linux_wait_on_bit_timeout(word, bit, state, timeout)
298 #define wake_up_atomic_t(a) linux_wake_up_atomic_t(a)
299 /*
300 * All existing callers have a cb that just schedule()s. To avoid adding
301 * complexity, just emulate that internally. The prototype is different so that
302 * callers must be manually modified; a cb that does something other than call
303 * schedule() will require special treatment.
304 */
305 #define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state)
306
307 struct task_struct;
308 bool linux_wake_up_state(struct task_struct *, unsigned int);
309
310 #define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL)
311 #define wake_up_state(task, state) linux_wake_up_state(task, state)
312
313 #endif /* _LINUXKPI_LINUX_WAIT_H_ */
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