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_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_wake_up(wait_queue_head_t *wqh, unsigned int state, int nr, bool locked) 192 { 193 wait_queue_t *pos, *next; 194 195 if (!locked) 196 spin_lock(&wqh->lock); 197 list_for_each_entry_safe(pos, next, &wqh->task_list, task_list) { 198 if (pos->func == NULL) { 199 if (wake_up_task(pos->private, state) != 0 && --nr == 0) 200 break; 201 } else { 202 if (pos->func(pos, state, 0, NULL) != 0 && --nr == 0) 203 break; 204 } 205 } 206 if (!locked) 207 spin_unlock(&wqh->lock); 208 } 209 210 void 211 linux_prepare_to_wait(wait_queue_head_t *wqh, wait_queue_t *wq, int state) 212 { 213 214 spin_lock(&wqh->lock); 215 if (list_empty(&wq->task_list)) 216 __add_wait_queue(wqh, wq); 217 set_task_state(current, state); 218 spin_unlock(&wqh->lock); 219 } 220 221 void 222 linux_finish_wait(wait_queue_head_t *wqh, wait_queue_t *wq) 223 { 224 225 spin_lock(&wqh->lock); 226 set_task_state(current, TASK_RUNNING); 227 if (!list_empty(&wq->task_list)) { 228 __remove_wait_queue(wqh, wq); 229 INIT_LIST_HEAD(&wq->task_list); 230 } 231 spin_unlock(&wqh->lock); 232 } 233 234 bool 235 linux_waitqueue_active(wait_queue_head_t *wqh) 236 { 237 bool ret; 238 239 spin_lock(&wqh->lock); 240 ret = !list_empty(&wqh->task_list); 241 spin_unlock(&wqh->lock); 242 return (ret); 243 } 244 245 int 246 linux_wait_event_common(wait_queue_head_t *wqh, wait_queue_t *wq, int timeout, 247 unsigned int state, spinlock_t *lock) 248 { 249 struct task_struct *task; 250 int ret; 251 252 if (lock != NULL) 253 spin_unlock_irq(lock); 254 255 /* range check timeout */ 256 if (timeout < 1) 257 timeout = 1; 258 else if (timeout == MAX_SCHEDULE_TIMEOUT) 259 timeout = 0; 260 261 task = current; 262 263 /* 264 * Our wait queue entry is on the stack - make sure it doesn't 265 * get swapped out while we sleep. 266 */ 267 PHOLD(task->task_thread->td_proc); 268 sleepq_lock(task); 269 if (atomic_read(&task->state) != TASK_WAKING) { 270 ret = linux_add_to_sleepqueue(task, task, "wevent", timeout, 271 state); 272 } else { 273 sleepq_release(task); 274 ret = 0; 275 } 276 PRELE(task->task_thread->td_proc); 277 278 if (lock != NULL) 279 spin_lock_irq(lock); 280 return (ret); 281 } 282 283 int 284 linux_schedule_timeout(int timeout) 285 { 286 struct task_struct *task; 287 int ret; 288 int state; 289 int remainder; 290 291 task = current; 292 293 /* range check timeout */ 294 if (timeout < 1) 295 timeout = 1; 296 else if (timeout == MAX_SCHEDULE_TIMEOUT) 297 timeout = 0; 298 299 remainder = ticks + timeout; 300 301 sleepq_lock(task); 302 state = atomic_read(&task->state); 303 if (state != TASK_WAKING) { 304 ret = linux_add_to_sleepqueue(task, task, "sched", timeout, 305 state); 306 } else { 307 sleepq_release(task); 308 ret = 0; 309 } 310 set_task_state(task, TASK_RUNNING); 311 312 if (timeout == 0) 313 return (MAX_SCHEDULE_TIMEOUT); 314 315 /* range check return value */ 316 remainder -= ticks; 317 318 /* range check return value */ 319 if (ret == -ERESTARTSYS && remainder < 1) 320 remainder = 1; 321 else if (remainder < 0) 322 remainder = 0; 323 else if (remainder > timeout) 324 remainder = timeout; 325 return (remainder); 326 } 327 328 static void 329 wake_up_sleepers(void *wchan) 330 { 331 int wakeup_swapper; 332 333 sleepq_lock(wchan); 334 wakeup_swapper = sleepq_signal(wchan, SLEEPQ_SLEEP, 0, 0); 335 sleepq_release(wchan); 336 if (wakeup_swapper) 337 kick_proc0(); 338 } 339 340 #define bit_to_wchan(word, bit) ((void *)(((uintptr_t)(word) << 6) | (bit))) 341 342 void 343 linux_wake_up_bit(void *word, int bit) 344 { 345 346 wake_up_sleepers(bit_to_wchan(word, bit)); 347 } 348 349 int 350 linux_wait_on_bit_timeout(unsigned long *word, int bit, unsigned int state, 351 int timeout) 352 { 353 struct task_struct *task; 354 void *wchan; 355 int ret; 356 357 /* range check timeout */ 358 if (timeout < 1) 359 timeout = 1; 360 else if (timeout == MAX_SCHEDULE_TIMEOUT) 361 timeout = 0; 362 363 task = current; 364 wchan = bit_to_wchan(word, bit); 365 for (;;) { 366 sleepq_lock(wchan); 367 if ((*word & (1 << bit)) == 0) { 368 sleepq_release(wchan); 369 ret = 0; 370 break; 371 } 372 set_task_state(task, state); 373 ret = linux_add_to_sleepqueue(wchan, task, "wbit", timeout, 374 state); 375 if (ret != 0) 376 break; 377 } 378 set_task_state(task, TASK_RUNNING); 379 380 return (ret); 381 } 382 383 void 384 linux_wake_up_atomic_t(atomic_t *a) 385 { 386 387 wake_up_sleepers(a); 388 } 389 390 int 391 linux_wait_on_atomic_t(atomic_t *a, unsigned int state) 392 { 393 struct task_struct *task; 394 void *wchan; 395 int ret; 396 397 task = current; 398 wchan = a; 399 for (;;) { 400 sleepq_lock(wchan); 401 if (atomic_read(a) == 0) { 402 sleepq_release(wchan); 403 ret = 0; 404 break; 405 } 406 set_task_state(task, state); 407 ret = linux_add_to_sleepqueue(wchan, task, "watomic", 0, state); 408 if (ret != 0) 409 break; 410 } 411 set_task_state(task, TASK_RUNNING); 412 413 return (ret); 414 } 415 416 bool 417 linux_wake_up_state(struct task_struct *task, unsigned int state) 418 { 419 420 return (wake_up_task(task, state) != 0); 421 } 422