1 /*- 2 * Copyright (c) 2017 Mark Johnston <markj@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conds 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conds, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conds and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/proc.h> 33 #include <sys/signalvar.h> 34 #include <sys/sleepqueue.h> 35 36 #include <linux/delay.h> 37 #include <linux/errno.h> 38 #include <linux/kernel.h> 39 #include <linux/list.h> 40 #include <linux/sched.h> 41 #include <linux/spinlock.h> 42 #include <linux/wait.h> 43 44 static int 45 linux_add_to_sleepqueue(void *wchan, struct task_struct *task, 46 const char *wmesg, int timeout, int state) 47 { 48 int flags, ret; 49 50 MPASS((state & ~(TASK_PARKED | TASK_NORMAL)) == 0); 51 52 flags = SLEEPQ_SLEEP | ((state & TASK_INTERRUPTIBLE) != 0 ? 53 SLEEPQ_INTERRUPTIBLE : 0); 54 55 sleepq_add(wchan, NULL, wmesg, flags, 0); 56 if (timeout != 0) 57 sleepq_set_timeout(wchan, timeout); 58 59 DROP_GIANT(); 60 if ((state & TASK_INTERRUPTIBLE) != 0) { 61 if (timeout == 0) 62 ret = -sleepq_wait_sig(wchan, 0); 63 else 64 ret = -sleepq_timedwait_sig(wchan, 0); 65 } else { 66 if (timeout == 0) { 67 sleepq_wait(wchan, 0); 68 ret = 0; 69 } else 70 ret = -sleepq_timedwait(wchan, 0); 71 } 72 PICKUP_GIANT(); 73 74 /* filter return value */ 75 if (ret != 0 && ret != -EWOULDBLOCK) { 76 linux_schedule_save_interrupt_value(task, ret); 77 ret = -ERESTARTSYS; 78 } 79 return (ret); 80 } 81 82 unsigned int 83 linux_msleep_interruptible(unsigned int ms) 84 { 85 int ret; 86 87 /* guard against invalid values */ 88 if (ms == 0) 89 ms = 1; 90 ret = -pause_sbt("lnxsleep", mstosbt(ms), 0, C_HARDCLOCK | C_CATCH); 91 92 switch (ret) { 93 case -EWOULDBLOCK: 94 return (0); 95 default: 96 linux_schedule_save_interrupt_value(current, ret); 97 return (ms); 98 } 99 } 100 101 static int 102 wake_up_task(struct task_struct *task, unsigned int state) 103 { 104 int ret, wakeup_swapper; 105 106 ret = wakeup_swapper = 0; 107 sleepq_lock(task); 108 if ((atomic_read(&task->state) & state) != 0) { 109 set_task_state(task, TASK_WAKING); 110 wakeup_swapper = sleepq_signal(task, SLEEPQ_SLEEP, 0, 0); 111 ret = 1; 112 } 113 sleepq_release(task); 114 if (wakeup_swapper) 115 kick_proc0(); 116 return (ret); 117 } 118 119 bool 120 linux_signal_pending(struct task_struct *task) 121 { 122 struct thread *td; 123 sigset_t pending; 124 125 td = task->task_thread; 126 PROC_LOCK(td->td_proc); 127 pending = td->td_siglist; 128 SIGSETOR(pending, td->td_proc->p_siglist); 129 SIGSETNAND(pending, td->td_sigmask); 130 PROC_UNLOCK(td->td_proc); 131 return (!SIGISEMPTY(pending)); 132 } 133 134 bool 135 linux_fatal_signal_pending(struct task_struct *task) 136 { 137 struct thread *td; 138 bool ret; 139 140 td = task->task_thread; 141 PROC_LOCK(td->td_proc); 142 ret = SIGISMEMBER(td->td_siglist, SIGKILL) || 143 SIGISMEMBER(td->td_proc->p_siglist, SIGKILL); 144 PROC_UNLOCK(td->td_proc); 145 return (ret); 146 } 147 148 bool 149 linux_signal_pending_state(long state, struct task_struct *task) 150 { 151 152 MPASS((state & ~TASK_NORMAL) == 0); 153 154 if ((state & TASK_INTERRUPTIBLE) == 0) 155 return (false); 156 return (linux_signal_pending(task)); 157 } 158 159 void 160 linux_send_sig(int signo, struct task_struct *task) 161 { 162 struct thread *td; 163 164 td = task->task_thread; 165 PROC_LOCK(td->td_proc); 166 tdsignal(td, signo); 167 PROC_UNLOCK(td->td_proc); 168 } 169 170 int 171 autoremove_wake_function(wait_queue_t *wq, unsigned int state, int flags, 172 void *key __unused) 173 { 174 struct task_struct *task; 175 int ret; 176 177 task = wq->private; 178 if ((ret = wake_up_task(task, state)) != 0) 179 list_del_init(&wq->task_list); 180 return (ret); 181 } 182 183 int 184 default_wake_function(wait_queue_t *wq, unsigned int state, int flags, 185 void *key __unused) 186 { 187 return (wake_up_task(wq->private, state)); 188 } 189 190 void 191 linux_init_wait_entry(wait_queue_t *wq, int flags) 192 { 193 194 memset(wq, 0, sizeof(*wq)); 195 wq->flags = flags; 196 wq->private = current; 197 wq->func = autoremove_wake_function; 198 INIT_LIST_HEAD(&wq->task_list); 199 } 200 201 void 202 linux_wake_up(wait_queue_head_t *wqh, unsigned int state, int nr, bool locked) 203 { 204 wait_queue_t *pos, *next; 205 206 if (!locked) 207 spin_lock(&wqh->lock); 208 list_for_each_entry_safe(pos, next, &wqh->task_list, task_list) { 209 if (pos->func == NULL) { 210 if (wake_up_task(pos->private, state) != 0 && --nr == 0) 211 break; 212 } else { 213 if (pos->func(pos, state, 0, NULL) != 0 && --nr == 0) 214 break; 215 } 216 } 217 if (!locked) 218 spin_unlock(&wqh->lock); 219 } 220 221 void 222 linux_prepare_to_wait(wait_queue_head_t *wqh, wait_queue_t *wq, int state) 223 { 224 225 spin_lock(&wqh->lock); 226 if (list_empty(&wq->task_list)) 227 __add_wait_queue(wqh, wq); 228 set_task_state(current, state); 229 spin_unlock(&wqh->lock); 230 } 231 232 void 233 linux_finish_wait(wait_queue_head_t *wqh, wait_queue_t *wq) 234 { 235 236 spin_lock(&wqh->lock); 237 set_task_state(current, TASK_RUNNING); 238 if (!list_empty(&wq->task_list)) { 239 __remove_wait_queue(wqh, wq); 240 INIT_LIST_HEAD(&wq->task_list); 241 } 242 spin_unlock(&wqh->lock); 243 } 244 245 bool 246 linux_waitqueue_active(wait_queue_head_t *wqh) 247 { 248 bool ret; 249 250 spin_lock(&wqh->lock); 251 ret = !list_empty(&wqh->task_list); 252 spin_unlock(&wqh->lock); 253 return (ret); 254 } 255 256 int 257 linux_wait_event_common(wait_queue_head_t *wqh, wait_queue_t *wq, int timeout, 258 unsigned int state, spinlock_t *lock) 259 { 260 struct task_struct *task; 261 int ret; 262 263 if (lock != NULL) 264 spin_unlock_irq(lock); 265 266 /* range check timeout */ 267 if (timeout < 1) 268 timeout = 1; 269 else if (timeout == MAX_SCHEDULE_TIMEOUT) 270 timeout = 0; 271 272 task = current; 273 274 /* 275 * Our wait queue entry is on the stack - make sure it doesn't 276 * get swapped out while we sleep. 277 */ 278 PHOLD(task->task_thread->td_proc); 279 sleepq_lock(task); 280 if (atomic_read(&task->state) != TASK_WAKING) { 281 ret = linux_add_to_sleepqueue(task, task, "wevent", timeout, 282 state); 283 } else { 284 sleepq_release(task); 285 ret = 0; 286 } 287 PRELE(task->task_thread->td_proc); 288 289 if (lock != NULL) 290 spin_lock_irq(lock); 291 return (ret); 292 } 293 294 int 295 linux_schedule_timeout(int timeout) 296 { 297 struct task_struct *task; 298 int ret; 299 int state; 300 int remainder; 301 302 task = current; 303 304 /* range check timeout */ 305 if (timeout < 1) 306 timeout = 1; 307 else if (timeout == MAX_SCHEDULE_TIMEOUT) 308 timeout = 0; 309 310 remainder = ticks + timeout; 311 312 sleepq_lock(task); 313 state = atomic_read(&task->state); 314 if (state != TASK_WAKING) { 315 ret = linux_add_to_sleepqueue(task, task, "sched", timeout, 316 state); 317 } else { 318 sleepq_release(task); 319 ret = 0; 320 } 321 set_task_state(task, TASK_RUNNING); 322 323 if (timeout == 0) 324 return (MAX_SCHEDULE_TIMEOUT); 325 326 /* range check return value */ 327 remainder -= ticks; 328 329 /* range check return value */ 330 if (ret == -ERESTARTSYS && remainder < 1) 331 remainder = 1; 332 else if (remainder < 0) 333 remainder = 0; 334 else if (remainder > timeout) 335 remainder = timeout; 336 return (remainder); 337 } 338 339 static void 340 wake_up_sleepers(void *wchan) 341 { 342 int wakeup_swapper; 343 344 sleepq_lock(wchan); 345 wakeup_swapper = sleepq_signal(wchan, SLEEPQ_SLEEP, 0, 0); 346 sleepq_release(wchan); 347 if (wakeup_swapper) 348 kick_proc0(); 349 } 350 351 #define bit_to_wchan(word, bit) ((void *)(((uintptr_t)(word) << 6) | (bit))) 352 353 void 354 linux_wake_up_bit(void *word, int bit) 355 { 356 357 wake_up_sleepers(bit_to_wchan(word, bit)); 358 } 359 360 int 361 linux_wait_on_bit_timeout(unsigned long *word, int bit, unsigned int state, 362 int timeout) 363 { 364 struct task_struct *task; 365 void *wchan; 366 int ret; 367 368 /* range check timeout */ 369 if (timeout < 1) 370 timeout = 1; 371 else if (timeout == MAX_SCHEDULE_TIMEOUT) 372 timeout = 0; 373 374 task = current; 375 wchan = bit_to_wchan(word, bit); 376 for (;;) { 377 sleepq_lock(wchan); 378 if ((*word & (1 << bit)) == 0) { 379 sleepq_release(wchan); 380 ret = 0; 381 break; 382 } 383 set_task_state(task, state); 384 ret = linux_add_to_sleepqueue(wchan, task, "wbit", timeout, 385 state); 386 if (ret != 0) 387 break; 388 } 389 set_task_state(task, TASK_RUNNING); 390 391 return (ret); 392 } 393 394 void 395 linux_wake_up_atomic_t(atomic_t *a) 396 { 397 398 wake_up_sleepers(a); 399 } 400 401 int 402 linux_wait_on_atomic_t(atomic_t *a, unsigned int state) 403 { 404 struct task_struct *task; 405 void *wchan; 406 int ret; 407 408 task = current; 409 wchan = a; 410 for (;;) { 411 sleepq_lock(wchan); 412 if (atomic_read(a) == 0) { 413 sleepq_release(wchan); 414 ret = 0; 415 break; 416 } 417 set_task_state(task, state); 418 ret = linux_add_to_sleepqueue(wchan, task, "watomic", 0, state); 419 if (ret != 0) 420 break; 421 } 422 set_task_state(task, TASK_RUNNING); 423 424 return (ret); 425 } 426 427 bool 428 linux_wake_up_state(struct task_struct *task, unsigned int state) 429 { 430 431 return (wake_up_task(task, state) != 0); 432 } 433