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
31 #ifndef _LINUXKPI_LINUX_WAIT_H_
32 #define _LINUXKPI_LINUX_WAIT_H_
33
34 #include <linux/compiler.h>
35 #include <linux/list.h>
36 #include <linux/spinlock.h>
37 #include <linux/sched.h>
38
39 #include <asm/atomic.h>
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43
44 #define SKIP_SLEEP() (SCHEDULER_STOPPED() || kdb_active)
45
46 #define might_sleep() \
47 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "might_sleep()")
48
49 #define might_sleep_if(cond) do { \
50 if (cond) { might_sleep(); } \
51 } while (0)
52
53 struct wait_queue;
54 struct wait_queue_head;
55
56 #define wait_queue_entry wait_queue
57
58 typedef struct wait_queue wait_queue_t;
59 typedef struct wait_queue_entry wait_queue_entry_t;
60 typedef struct wait_queue_head wait_queue_head_t;
61
62 typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *);
63
64 /*
65 * Many API consumers directly reference these fields and those of
66 * wait_queue_head.
67 */
68 struct wait_queue {
69 unsigned int flags; /* always 0 */
70 void *private;
71 wait_queue_func_t *func;
72 union {
73 struct list_head task_list; /* < v4.13 */
74 struct list_head entry; /* >= v4.13 */
75 };
76 };
77
78 struct wait_queue_head {
79 spinlock_t lock;
80 union {
81 struct list_head task_list; /* < v4.13 */
82 struct list_head head; /* >= v4.13 */
83 };
84 };
85
86 /*
87 * This function is referenced by at least one DRM driver, so it may not be
88 * renamed and furthermore must be the default wait queue callback.
89 */
90 extern wait_queue_func_t autoremove_wake_function;
91 extern wait_queue_func_t default_wake_function;
92
93 #define DEFINE_WAIT_FUNC(name, function) \
94 wait_queue_t name = { \
95 .private = current, \
96 .func = function, \
97 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
98 }
99
100 #define DEFINE_WAIT(name) \
101 DEFINE_WAIT_FUNC(name, autoremove_wake_function)
102
103 #define DECLARE_WAITQUEUE(name, task) \
104 wait_queue_t name = { \
105 .private = task, \
106 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
107 }
108
109 #define DECLARE_WAIT_QUEUE_HEAD(name) \
110 wait_queue_head_t name = { \
111 .task_list = LINUX_LIST_HEAD_INIT(name.task_list), \
112 }; \
113 MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF)
114
115 #define init_waitqueue_head(wqh) do { \
116 mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \
117 NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \
118 INIT_LIST_HEAD(&(wqh)->task_list); \
119 } while (0)
120
121 #define __init_waitqueue_head(wqh, name, lk) init_waitqueue_head(wqh)
122
123 void linux_init_wait_entry(wait_queue_t *, int);
124 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool);
125
126 #define init_wait_entry(wq, flags) \
127 linux_init_wait_entry(wq, flags)
128 #define wake_up(wqh) \
129 linux_wake_up(wqh, TASK_NORMAL, 1, false)
130 #define wake_up_all(wqh) \
131 linux_wake_up(wqh, TASK_NORMAL, 0, false)
132 #define wake_up_locked(wqh) \
133 linux_wake_up(wqh, TASK_NORMAL, 1, true)
134 #define wake_up_all_locked(wqh) \
135 linux_wake_up(wqh, TASK_NORMAL, 0, true)
136 #define wake_up_interruptible(wqh) \
137 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false)
138 #define wake_up_interruptible_all(wqh) \
139 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false)
140
141 int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int,
142 unsigned int, spinlock_t *);
143
144 /*
145 * Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if
146 * cond is true after timeout, remaining jiffies (> 0) if cond is true before
147 * timeout.
148 */
149 #define __wait_event_common(wqh, cond, timeout, state, lock) ({ \
150 DEFINE_WAIT(__wq); \
151 const int __timeout = ((int)(timeout)) < 1 ? 1 : (timeout); \
152 int __start = ticks; \
153 int __ret = 0; \
154 \
155 for (;;) { \
156 linux_prepare_to_wait(&(wqh), &__wq, state); \
157 if (cond) \
158 break; \
159 __ret = linux_wait_event_common(&(wqh), &__wq, \
160 __timeout, state, lock); \
161 if (__ret != 0) \
162 break; \
163 } \
164 linux_finish_wait(&(wqh), &__wq); \
165 if (__timeout != MAX_SCHEDULE_TIMEOUT) { \
166 if (__ret == -EWOULDBLOCK) \
167 __ret = !!(cond); \
168 else if (__ret != -ERESTARTSYS) { \
169 __ret = __timeout + __start - ticks; \
170 /* range check return value */ \
171 if (__ret < 1) \
172 __ret = 1; \
173 else if (__ret > __timeout) \
174 __ret = __timeout; \
175 } \
176 } \
177 __ret; \
178 })
179
180 #define wait_event(wqh, cond) do { \
181 (void) __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
182 TASK_UNINTERRUPTIBLE, NULL); \
183 } while (0)
184
185 #define wait_event_timeout(wqh, cond, timeout) ({ \
186 __wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \
187 NULL); \
188 })
189
190 #define wait_event_killable(wqh, cond) ({ \
191 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
192 TASK_INTERRUPTIBLE, NULL); \
193 })
194
195 #define wait_event_interruptible(wqh, cond) ({ \
196 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
197 TASK_INTERRUPTIBLE, NULL); \
198 })
199
200 #define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \
201 __wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \
202 NULL); \
203 })
204
205 /*
206 * Wait queue is already locked.
207 */
208 #define wait_event_interruptible_locked(wqh, cond) ({ \
209 int __ret; \
210 \
211 spin_unlock(&(wqh).lock); \
212 __ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
213 TASK_INTERRUPTIBLE, NULL); \
214 spin_lock(&(wqh).lock); \
215 __ret; \
216 })
217
218 /*
219 * The passed spinlock is held when testing the condition.
220 */
221 #define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \
222 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
223 TASK_INTERRUPTIBLE, &(lock)); \
224 })
225
226 /*
227 * The passed spinlock is held when testing the condition.
228 */
229 #define wait_event_lock_irq(wqh, cond, lock) ({ \
230 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
231 TASK_UNINTERRUPTIBLE, &(lock)); \
232 })
233
234 static inline void
__add_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)235 __add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
236 {
237 list_add(&wq->task_list, &wqh->task_list);
238 }
239
240 static inline void
add_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)241 add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
242 {
243
244 spin_lock(&wqh->lock);
245 __add_wait_queue(wqh, wq);
246 spin_unlock(&wqh->lock);
247 }
248
249 static inline void
__add_wait_queue_tail(wait_queue_head_t * wqh,wait_queue_t * wq)250 __add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq)
251 {
252 list_add_tail(&wq->task_list, &wqh->task_list);
253 }
254
255 static inline void
__add_wait_queue_entry_tail(wait_queue_head_t * wqh,wait_queue_entry_t * wq)256 __add_wait_queue_entry_tail(wait_queue_head_t *wqh, wait_queue_entry_t *wq)
257 {
258 list_add_tail(&wq->entry, &wqh->head);
259 }
260
261 static inline void
__remove_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)262 __remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
263 {
264 list_del(&wq->task_list);
265 }
266
267 static inline void
remove_wait_queue(wait_queue_head_t * wqh,wait_queue_t * wq)268 remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
269 {
270
271 spin_lock(&wqh->lock);
272 __remove_wait_queue(wqh, wq);
273 spin_unlock(&wqh->lock);
274 }
275
276 bool linux_waitqueue_active(wait_queue_head_t *);
277
278 #define waitqueue_active(wqh) linux_waitqueue_active(wqh)
279
280 void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int);
281 void linux_finish_wait(wait_queue_head_t *, wait_queue_t *);
282
283 #define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state)
284 #define finish_wait(wqh, wq) linux_finish_wait(wqh, wq)
285
286 void linux_wake_up_bit(void *, int);
287 int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int);
288 void linux_wake_up_atomic_t(atomic_t *);
289 int linux_wait_on_atomic_t(atomic_t *, unsigned int);
290
291 #define wake_up_bit(word, bit) linux_wake_up_bit(word, bit)
292 #define wait_on_bit(word, bit, state) \
293 linux_wait_on_bit_timeout(word, bit, state, MAX_SCHEDULE_TIMEOUT)
294 #define wait_on_bit_timeout(word, bit, state, timeout) \
295 linux_wait_on_bit_timeout(word, bit, state, timeout)
296 #define wake_up_atomic_t(a) linux_wake_up_atomic_t(a)
297 /*
298 * All existing callers have a cb that just schedule()s. To avoid adding
299 * complexity, just emulate that internally. The prototype is different so that
300 * callers must be manually modified; a cb that does something other than call
301 * schedule() will require special treatment.
302 */
303 #define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state)
304
305 struct task_struct;
306 bool linux_wake_up_state(struct task_struct *, unsigned int);
307
308 #define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL)
309 #define wake_up_state(task, state) linux_wake_up_state(task, state)
310
311 #endif /* _LINUXKPI_LINUX_WAIT_H_ */
312