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