sys/compat/linuxkpi/common/include/linux/wait.h

   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 _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
 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
 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
 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
 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
 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
 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_ */