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 extern wait_queue_func_t default_wake_function; 80 81 #define DEFINE_WAIT_FUNC(name, function) \ 82 wait_queue_t name = { \ 83 .private = current, \ 84 .func = function, \ 85 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 86 } 87 88 #define DEFINE_WAIT(name) \ 89 DEFINE_WAIT_FUNC(name, autoremove_wake_function) 90 91 #define DECLARE_WAITQUEUE(name, task) \ 92 wait_queue_t name = { \ 93 .private = task, \ 94 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 95 } 96 97 #define DECLARE_WAIT_QUEUE_HEAD(name) \ 98 wait_queue_head_t name = { \ 99 .task_list = LINUX_LIST_HEAD_INIT(name.task_list), \ 100 }; \ 101 MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF) 102 103 #define init_waitqueue_head(wqh) do { \ 104 mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \ 105 NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \ 106 INIT_LIST_HEAD(&(wqh)->task_list); \ 107 } while (0) 108 109 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool); 110 111 #define wake_up(wqh) \ 112 linux_wake_up(wqh, TASK_NORMAL, 1, false) 113 #define wake_up_all(wqh) \ 114 linux_wake_up(wqh, TASK_NORMAL, 0, false) 115 #define wake_up_locked(wqh) \ 116 linux_wake_up(wqh, TASK_NORMAL, 1, true) 117 #define wake_up_all_locked(wqh) \ 118 linux_wake_up(wqh, TASK_NORMAL, 0, true) 119 #define wake_up_interruptible(wqh) \ 120 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false) 121 #define wake_up_interruptible_all(wqh) \ 122 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false) 123 124 int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int, 125 unsigned int, spinlock_t *); 126 127 /* 128 * Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if 129 * cond is true after timeout, remaining jiffies (> 0) if cond is true before 130 * timeout. 131 */ 132 #define __wait_event_common(wqh, cond, timeout, state, lock) ({ \ 133 DEFINE_WAIT(__wq); \ 134 const int __timeout = ((int)(timeout)) < 1 ? 1 : (timeout); \ 135 int __start = ticks; \ 136 int __ret = 0; \ 137 \ 138 for (;;) { \ 139 linux_prepare_to_wait(&(wqh), &__wq, state); \ 140 if (cond) \ 141 break; \ 142 __ret = linux_wait_event_common(&(wqh), &__wq, \ 143 __timeout, state, lock); \ 144 if (__ret != 0) \ 145 break; \ 146 } \ 147 linux_finish_wait(&(wqh), &__wq); \ 148 if (__timeout != MAX_SCHEDULE_TIMEOUT) { \ 149 if (__ret == -EWOULDBLOCK) \ 150 __ret = !!(cond); \ 151 else if (__ret != -ERESTARTSYS) { \ 152 __ret = __timeout + __start - ticks; \ 153 /* range check return value */ \ 154 if (__ret < 1) \ 155 __ret = 1; \ 156 else if (__ret > __timeout) \ 157 __ret = __timeout; \ 158 } \ 159 } \ 160 __ret; \ 161 }) 162 163 #define wait_event(wqh, cond) do { \ 164 (void) __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 165 TASK_UNINTERRUPTIBLE, NULL); \ 166 } while (0) 167 168 #define wait_event_timeout(wqh, cond, timeout) ({ \ 169 __wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \ 170 NULL); \ 171 }) 172 173 #define wait_event_interruptible(wqh, cond) ({ \ 174 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 175 TASK_INTERRUPTIBLE, NULL); \ 176 }) 177 178 #define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \ 179 __wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \ 180 NULL); \ 181 }) 182 183 /* 184 * Wait queue is already locked. 185 */ 186 #define wait_event_interruptible_locked(wqh, cond) ({ \ 187 int __ret; \ 188 \ 189 spin_unlock(&(wqh).lock); \ 190 __ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 191 TASK_INTERRUPTIBLE, NULL); \ 192 spin_lock(&(wqh).lock); \ 193 __ret; \ 194 }) 195 196 /* 197 * Hold the (locked) spinlock when testing the cond. 198 */ 199 #define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \ 200 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 201 TASK_INTERRUPTIBLE, &(lock)); \ 202 }) 203 204 static inline void 205 __add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 206 { 207 list_add(&wq->task_list, &wqh->task_list); 208 } 209 210 static inline void 211 add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 212 { 213 214 spin_lock(&wqh->lock); 215 __add_wait_queue(wqh, wq); 216 spin_unlock(&wqh->lock); 217 } 218 219 static inline void 220 __add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq) 221 { 222 list_add_tail(&wq->task_list, &wqh->task_list); 223 } 224 225 static inline void 226 __remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 227 { 228 list_del(&wq->task_list); 229 } 230 231 static inline void 232 remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 233 { 234 235 spin_lock(&wqh->lock); 236 __remove_wait_queue(wqh, wq); 237 spin_unlock(&wqh->lock); 238 } 239 240 bool linux_waitqueue_active(wait_queue_head_t *); 241 242 #define waitqueue_active(wqh) linux_waitqueue_active(wqh) 243 244 void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int); 245 void linux_finish_wait(wait_queue_head_t *, wait_queue_t *); 246 247 #define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state) 248 #define finish_wait(wqh, wq) linux_finish_wait(wqh, wq) 249 250 void linux_wake_up_bit(void *, int); 251 int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int); 252 void linux_wake_up_atomic_t(atomic_t *); 253 int linux_wait_on_atomic_t(atomic_t *, unsigned int); 254 255 #define wake_up_bit(word, bit) linux_wake_up_bit(word, bit) 256 #define wait_on_bit(word, bit, state) \ 257 linux_wait_on_bit_timeout(word, bit, state, MAX_SCHEDULE_TIMEOUT) 258 #define wait_on_bit_timeout(word, bit, state, timeout) \ 259 linux_wait_on_bit_timeout(word, bit, state, timeout) 260 #define wake_up_atomic_t(a) linux_wake_up_atomic_t(a) 261 /* 262 * All existing callers have a cb that just schedule()s. To avoid adding 263 * complexity, just emulate that internally. The prototype is different so that 264 * callers must be manually modified; a cb that does something other than call 265 * schedule() will require special treatment. 266 */ 267 #define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state) 268 269 struct task_struct; 270 bool linux_wake_up_state(struct task_struct *, unsigned int); 271 272 #define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL) 273 #define wake_up_state(task, state) linux_wake_up_state(task, state) 274 275 #endif /* _LINUX_WAIT_H_ */ 276