| 1 | /* $NetBSD: linux_work.c,v 1.1 2016/02/24 22:04:15 skrll Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2013 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Taylor R. Campbell. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | #include <sys/cdefs.h> |
| 33 | __KERNEL_RCSID(0, "$NetBSD: linux_work.c,v 1.1 2016/02/24 22:04:15 skrll Exp $" ); |
| 34 | |
| 35 | #include <sys/types.h> |
| 36 | #include <sys/param.h> |
| 37 | #include <sys/atomic.h> |
| 38 | #include <sys/callout.h> |
| 39 | #include <sys/condvar.h> |
| 40 | #include <sys/errno.h> |
| 41 | #include <sys/intr.h> |
| 42 | #include <sys/kmem.h> |
| 43 | #include <sys/mutex.h> |
| 44 | #include <sys/queue.h> |
| 45 | #include <sys/systm.h> |
| 46 | #include <sys/workqueue.h> |
| 47 | #include <sys/cpu.h> |
| 48 | |
| 49 | #include <machine/lock.h> |
| 50 | |
| 51 | #include <linux/workqueue.h> |
| 52 | |
| 53 | /* XXX Kludge until we sync with HEAD. */ |
| 54 | #if DIAGNOSTIC |
| 55 | #define __diagused |
| 56 | #else |
| 57 | #define __diagused __unused |
| 58 | #endif |
| 59 | |
| 60 | struct workqueue_struct { |
| 61 | struct workqueue *wq_workqueue; |
| 62 | |
| 63 | /* XXX The following should all be per-CPU. */ |
| 64 | kmutex_t wq_lock; |
| 65 | |
| 66 | /* |
| 67 | * Condvar for when any state related to this workqueue |
| 68 | * changes. XXX Could split this into multiple condvars for |
| 69 | * different purposes, but whatever... |
| 70 | */ |
| 71 | kcondvar_t wq_cv; |
| 72 | |
| 73 | TAILQ_HEAD(, delayed_work) wq_delayed; |
| 74 | struct work_struct *wq_current_work; |
| 75 | }; |
| 76 | |
| 77 | static void linux_work_lock_init(struct work_struct *); |
| 78 | static void linux_work_lock(struct work_struct *); |
| 79 | static void linux_work_unlock(struct work_struct *); |
| 80 | static bool linux_work_locked(struct work_struct *) __diagused; |
| 81 | |
| 82 | static void linux_wq_barrier(struct work_struct *); |
| 83 | |
| 84 | static void linux_wait_for_cancelled_work(struct work_struct *); |
| 85 | static void linux_wait_for_invoked_work(struct work_struct *); |
| 86 | static void linux_worker(struct work *, void *); |
| 87 | |
| 88 | static void linux_cancel_delayed_work_callout(struct delayed_work *, bool); |
| 89 | static void linux_wait_for_delayed_cancelled_work(struct delayed_work *); |
| 90 | static void linux_worker_intr(void *); |
| 91 | |
| 92 | struct workqueue_struct *system_wq; |
| 93 | |
| 94 | int |
| 95 | linux_workqueue_init(void) |
| 96 | { |
| 97 | |
| 98 | system_wq = alloc_ordered_workqueue("lnxsyswq" , 0); |
| 99 | if (system_wq == NULL) |
| 100 | return ENOMEM; |
| 101 | |
| 102 | return 0; |
| 103 | } |
| 104 | |
| 105 | void |
| 106 | linux_workqueue_fini(void) |
| 107 | { |
| 108 | destroy_workqueue(system_wq); |
| 109 | system_wq = NULL; |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * Workqueues |
| 114 | */ |
| 115 | |
| 116 | struct workqueue_struct * |
| 117 | alloc_ordered_workqueue(const char *name, int linux_flags) |
| 118 | { |
| 119 | struct workqueue_struct *wq; |
| 120 | int flags = WQ_MPSAFE; |
| 121 | int error; |
| 122 | |
| 123 | KASSERT(linux_flags == 0); |
| 124 | |
| 125 | wq = kmem_alloc(sizeof(*wq), KM_SLEEP); |
| 126 | error = workqueue_create(&wq->wq_workqueue, name, &linux_worker, |
| 127 | wq, PRI_NONE, IPL_VM, flags); |
| 128 | if (error) { |
| 129 | kmem_free(wq, sizeof(*wq)); |
| 130 | return NULL; |
| 131 | } |
| 132 | |
| 133 | mutex_init(&wq->wq_lock, MUTEX_DEFAULT, IPL_VM); |
| 134 | cv_init(&wq->wq_cv, name); |
| 135 | TAILQ_INIT(&wq->wq_delayed); |
| 136 | wq->wq_current_work = NULL; |
| 137 | |
| 138 | return wq; |
| 139 | } |
| 140 | |
| 141 | void |
| 142 | destroy_workqueue(struct workqueue_struct *wq) |
| 143 | { |
| 144 | |
| 145 | /* |
| 146 | * Cancel all delayed work. |
| 147 | */ |
| 148 | for (;;) { |
| 149 | struct delayed_work *dw; |
| 150 | |
| 151 | mutex_enter(&wq->wq_lock); |
| 152 | if (TAILQ_EMPTY(&wq->wq_delayed)) { |
| 153 | dw = NULL; |
| 154 | } else { |
| 155 | dw = TAILQ_FIRST(&wq->wq_delayed); |
| 156 | TAILQ_REMOVE(&wq->wq_delayed, dw, dw_entry); |
| 157 | } |
| 158 | mutex_exit(&wq->wq_lock); |
| 159 | |
| 160 | if (dw == NULL) |
| 161 | break; |
| 162 | |
| 163 | cancel_delayed_work_sync(dw); |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * workqueue_destroy empties the queue; we need not wait for |
| 168 | * completion explicitly. However, we can't destroy the |
| 169 | * condvar or mutex until this is done. |
| 170 | */ |
| 171 | workqueue_destroy(wq->wq_workqueue); |
| 172 | KASSERT(wq->wq_current_work == NULL); |
| 173 | wq->wq_workqueue = NULL; |
| 174 | |
| 175 | cv_destroy(&wq->wq_cv); |
| 176 | mutex_destroy(&wq->wq_lock); |
| 177 | |
| 178 | kmem_free(wq, sizeof(*wq)); |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * Flush |
| 183 | * |
| 184 | * Note: This doesn't cancel or wait for delayed work. This seems to |
| 185 | * match what Linux does (or, doesn't do). |
| 186 | */ |
| 187 | |
| 188 | void |
| 189 | flush_scheduled_work(void) |
| 190 | { |
| 191 | flush_workqueue(system_wq); |
| 192 | } |
| 193 | |
| 194 | struct wq_flush_work { |
| 195 | struct work_struct wqfw_work; |
| 196 | struct wq_flush *wqfw_flush; |
| 197 | }; |
| 198 | |
| 199 | struct wq_flush { |
| 200 | kmutex_t wqf_lock; |
| 201 | kcondvar_t wqf_cv; |
| 202 | unsigned int wqf_n; |
| 203 | }; |
| 204 | |
| 205 | void |
| 206 | flush_work(struct work_struct *work) |
| 207 | { |
| 208 | struct workqueue_struct *const wq = work->w_wq; |
| 209 | |
| 210 | if (wq != NULL) |
| 211 | flush_workqueue(wq); |
| 212 | } |
| 213 | |
| 214 | void |
| 215 | flush_workqueue(struct workqueue_struct *wq) |
| 216 | { |
| 217 | static const struct wq_flush zero_wqf; |
| 218 | struct wq_flush wqf = zero_wqf; |
| 219 | |
| 220 | mutex_init(&wqf.wqf_lock, MUTEX_DEFAULT, IPL_NONE); |
| 221 | cv_init(&wqf.wqf_cv, "lnxwflsh" ); |
| 222 | |
| 223 | if (1) { |
| 224 | struct wq_flush_work *const wqfw = kmem_zalloc(sizeof(*wqfw), |
| 225 | KM_SLEEP); |
| 226 | |
| 227 | wqf.wqf_n = 1; |
| 228 | wqfw->wqfw_flush = &wqf; |
| 229 | INIT_WORK(&wqfw->wqfw_work, &linux_wq_barrier); |
| 230 | wqfw->wqfw_work.w_wq = wq; |
| 231 | wqfw->wqfw_work.w_state = WORK_PENDING; |
| 232 | workqueue_enqueue(wq->wq_workqueue, &wqfw->wqfw_work.w_wk, |
| 233 | NULL); |
| 234 | } else { |
| 235 | struct cpu_info *ci; |
| 236 | CPU_INFO_ITERATOR cii; |
| 237 | struct wq_flush_work *wqfw; |
| 238 | |
| 239 | panic("per-CPU Linux workqueues don't work yet!" ); |
| 240 | |
| 241 | wqf.wqf_n = 0; |
| 242 | for (CPU_INFO_FOREACH(cii, ci)) { |
| 243 | wqfw = kmem_zalloc(sizeof(*wqfw), KM_SLEEP); |
| 244 | mutex_enter(&wqf.wqf_lock); |
| 245 | wqf.wqf_n++; |
| 246 | mutex_exit(&wqf.wqf_lock); |
| 247 | wqfw->wqfw_flush = &wqf; |
| 248 | INIT_WORK(&wqfw->wqfw_work, &linux_wq_barrier); |
| 249 | wqfw->wqfw_work.w_state = WORK_PENDING; |
| 250 | wqfw->wqfw_work.w_wq = wq; |
| 251 | workqueue_enqueue(wq->wq_workqueue, |
| 252 | &wqfw->wqfw_work.w_wk, ci); |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | mutex_enter(&wqf.wqf_lock); |
| 257 | while (0 < wqf.wqf_n) |
| 258 | cv_wait(&wqf.wqf_cv, &wqf.wqf_lock); |
| 259 | mutex_exit(&wqf.wqf_lock); |
| 260 | |
| 261 | cv_destroy(&wqf.wqf_cv); |
| 262 | mutex_destroy(&wqf.wqf_lock); |
| 263 | } |
| 264 | |
| 265 | static void |
| 266 | linux_wq_barrier(struct work_struct *work) |
| 267 | { |
| 268 | struct wq_flush_work *const wqfw = container_of(work, |
| 269 | struct wq_flush_work, wqfw_work); |
| 270 | struct wq_flush *const wqf = wqfw->wqfw_flush; |
| 271 | |
| 272 | mutex_enter(&wqf->wqf_lock); |
| 273 | if (--wqf->wqf_n == 0) |
| 274 | cv_broadcast(&wqf->wqf_cv); |
| 275 | mutex_exit(&wqf->wqf_lock); |
| 276 | |
| 277 | kmem_free(wqfw, sizeof(*wqfw)); |
| 278 | } |
| 279 | |
| 280 | /* |
| 281 | * Work locking |
| 282 | * |
| 283 | * We use __cpu_simple_lock(9) rather than mutex(9) because Linux code |
| 284 | * does not destroy work, so there is nowhere to call mutex_destroy. |
| 285 | * |
| 286 | * XXX This is getting out of hand... Really, work items shouldn't |
| 287 | * have locks in them at all; instead the workqueues should. |
| 288 | */ |
| 289 | |
| 290 | static void |
| 291 | linux_work_lock_init(struct work_struct *work) |
| 292 | { |
| 293 | |
| 294 | __cpu_simple_lock_init(&work->w_lock); |
| 295 | } |
| 296 | |
| 297 | static void |
| 298 | linux_work_lock(struct work_struct *work) |
| 299 | { |
| 300 | struct cpu_info *ci; |
| 301 | int cnt, s; |
| 302 | |
| 303 | /* XXX Copypasta of MUTEX_SPIN_SPLRAISE. */ |
| 304 | s = splvm(); |
| 305 | ci = curcpu(); |
| 306 | cnt = ci->ci_mtx_count--; |
| 307 | __insn_barrier(); |
| 308 | if (cnt == 0) |
| 309 | ci->ci_mtx_oldspl = s; |
| 310 | |
| 311 | __cpu_simple_lock(&work->w_lock); |
| 312 | } |
| 313 | |
| 314 | static void |
| 315 | linux_work_unlock(struct work_struct *work) |
| 316 | { |
| 317 | struct cpu_info *ci; |
| 318 | int s; |
| 319 | |
| 320 | __cpu_simple_unlock(&work->w_lock); |
| 321 | |
| 322 | /* XXX Copypasta of MUTEX_SPIN_SPLRESTORE. */ |
| 323 | ci = curcpu(); |
| 324 | s = ci->ci_mtx_oldspl; |
| 325 | __insn_barrier(); |
| 326 | if (++ci->ci_mtx_count == 0) |
| 327 | splx(s); |
| 328 | } |
| 329 | |
| 330 | static bool __diagused |
| 331 | linux_work_locked(struct work_struct *work) |
| 332 | { |
| 333 | return __SIMPLELOCK_LOCKED_P(&work->w_lock); |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * Work |
| 338 | */ |
| 339 | |
| 340 | void |
| 341 | INIT_WORK(struct work_struct *work, void (*fn)(struct work_struct *)) |
| 342 | { |
| 343 | |
| 344 | linux_work_lock_init(work); |
| 345 | work->w_state = WORK_IDLE; |
| 346 | work->w_wq = NULL; |
| 347 | work->w_fn = fn; |
| 348 | } |
| 349 | |
| 350 | bool |
| 351 | schedule_work(struct work_struct *work) |
| 352 | { |
| 353 | return queue_work(system_wq, work); |
| 354 | } |
| 355 | |
| 356 | bool |
| 357 | queue_work(struct workqueue_struct *wq, struct work_struct *work) |
| 358 | { |
| 359 | /* True if we put it on the queue, false if it was already there. */ |
| 360 | bool newly_queued; |
| 361 | |
| 362 | KASSERT(wq != NULL); |
| 363 | |
| 364 | linux_work_lock(work); |
| 365 | switch (work->w_state) { |
| 366 | case WORK_IDLE: |
| 367 | case WORK_INVOKED: |
| 368 | work->w_state = WORK_PENDING; |
| 369 | work->w_wq = wq; |
| 370 | workqueue_enqueue(wq->wq_workqueue, &work->w_wk, NULL); |
| 371 | newly_queued = true; |
| 372 | break; |
| 373 | |
| 374 | case WORK_DELAYED: |
| 375 | panic("queue_work(delayed work %p)" , work); |
| 376 | break; |
| 377 | |
| 378 | case WORK_PENDING: |
| 379 | KASSERT(work->w_wq == wq); |
| 380 | newly_queued = false; |
| 381 | break; |
| 382 | |
| 383 | case WORK_CANCELLED: |
| 384 | newly_queued = false; |
| 385 | break; |
| 386 | |
| 387 | case WORK_DELAYED_CANCELLED: |
| 388 | panic("queue_work(delayed work %p)" , work); |
| 389 | break; |
| 390 | |
| 391 | default: |
| 392 | panic("work %p in bad state: %d" , work, (int)work->w_state); |
| 393 | break; |
| 394 | } |
| 395 | linux_work_unlock(work); |
| 396 | |
| 397 | return newly_queued; |
| 398 | } |
| 399 | |
| 400 | bool |
| 401 | cancel_work_sync(struct work_struct *work) |
| 402 | { |
| 403 | bool cancelled_p = false; |
| 404 | |
| 405 | linux_work_lock(work); |
| 406 | switch (work->w_state) { |
| 407 | case WORK_IDLE: /* Nothing to do. */ |
| 408 | break; |
| 409 | |
| 410 | case WORK_DELAYED: |
| 411 | panic("cancel_work_sync(delayed work %p)" , work); |
| 412 | break; |
| 413 | |
| 414 | case WORK_PENDING: |
| 415 | work->w_state = WORK_CANCELLED; |
| 416 | linux_wait_for_cancelled_work(work); |
| 417 | cancelled_p = true; |
| 418 | break; |
| 419 | |
| 420 | case WORK_INVOKED: |
| 421 | linux_wait_for_invoked_work(work); |
| 422 | break; |
| 423 | |
| 424 | case WORK_CANCELLED: /* Already done. */ |
| 425 | break; |
| 426 | |
| 427 | case WORK_DELAYED_CANCELLED: |
| 428 | panic("cancel_work_sync(delayed work %p)" , work); |
| 429 | break; |
| 430 | |
| 431 | default: |
| 432 | panic("work %p in bad state: %d" , work, (int)work->w_state); |
| 433 | break; |
| 434 | } |
| 435 | linux_work_unlock(work); |
| 436 | |
| 437 | return cancelled_p; |
| 438 | } |
| 439 | |
| 440 | static void |
| 441 | linux_wait_for_cancelled_work(struct work_struct *work) |
| 442 | { |
| 443 | struct workqueue_struct *wq; |
| 444 | |
| 445 | KASSERT(linux_work_locked(work)); |
| 446 | KASSERT(work->w_state == WORK_CANCELLED); |
| 447 | |
| 448 | wq = work->w_wq; |
| 449 | do { |
| 450 | mutex_enter(&wq->wq_lock); |
| 451 | linux_work_unlock(work); |
| 452 | cv_wait(&wq->wq_cv, &wq->wq_lock); |
| 453 | mutex_exit(&wq->wq_lock); |
| 454 | linux_work_lock(work); |
| 455 | } while ((work->w_state == WORK_CANCELLED) && (work->w_wq == wq)); |
| 456 | } |
| 457 | |
| 458 | static void |
| 459 | linux_wait_for_invoked_work(struct work_struct *work) |
| 460 | { |
| 461 | struct workqueue_struct *wq; |
| 462 | |
| 463 | KASSERT(linux_work_locked(work)); |
| 464 | KASSERT(work->w_state == WORK_INVOKED); |
| 465 | |
| 466 | wq = work->w_wq; |
| 467 | mutex_enter(&wq->wq_lock); |
| 468 | linux_work_unlock(work); |
| 469 | while (wq->wq_current_work == work) |
| 470 | cv_wait(&wq->wq_cv, &wq->wq_lock); |
| 471 | mutex_exit(&wq->wq_lock); |
| 472 | |
| 473 | linux_work_lock(work); /* XXX needless relock */ |
| 474 | } |
| 475 | |
| 476 | static void |
| 477 | linux_worker(struct work *wk, void *arg) |
| 478 | { |
| 479 | struct work_struct *const work = container_of(wk, struct work_struct, |
| 480 | w_wk); |
| 481 | struct workqueue_struct *const wq = arg; |
| 482 | |
| 483 | linux_work_lock(work); |
| 484 | switch (work->w_state) { |
| 485 | case WORK_IDLE: |
| 486 | panic("idle work %p got queued: %p" , work, wq); |
| 487 | break; |
| 488 | |
| 489 | case WORK_DELAYED: |
| 490 | panic("delayed work %p got queued: %p" , work, wq); |
| 491 | break; |
| 492 | |
| 493 | case WORK_PENDING: |
| 494 | KASSERT(work->w_wq == wq); |
| 495 | |
| 496 | /* Get ready to invoke this one. */ |
| 497 | mutex_enter(&wq->wq_lock); |
| 498 | work->w_state = WORK_INVOKED; |
| 499 | KASSERT(wq->wq_current_work == NULL); |
| 500 | wq->wq_current_work = work; |
| 501 | mutex_exit(&wq->wq_lock); |
| 502 | |
| 503 | /* Unlock it and do it. Can't use work after this. */ |
| 504 | linux_work_unlock(work); |
| 505 | (*work->w_fn)(work); |
| 506 | |
| 507 | /* All done. Notify anyone waiting for completion. */ |
| 508 | mutex_enter(&wq->wq_lock); |
| 509 | KASSERT(wq->wq_current_work == work); |
| 510 | wq->wq_current_work = NULL; |
| 511 | cv_broadcast(&wq->wq_cv); |
| 512 | mutex_exit(&wq->wq_lock); |
| 513 | return; |
| 514 | |
| 515 | case WORK_INVOKED: |
| 516 | panic("invoked work %p got requeued: %p" , work, wq); |
| 517 | break; |
| 518 | |
| 519 | case WORK_CANCELLED: |
| 520 | KASSERT(work->w_wq == wq); |
| 521 | |
| 522 | /* Return to idle; notify anyone waiting for cancellation. */ |
| 523 | mutex_enter(&wq->wq_lock); |
| 524 | work->w_state = WORK_IDLE; |
| 525 | work->w_wq = NULL; |
| 526 | cv_broadcast(&wq->wq_cv); |
| 527 | mutex_exit(&wq->wq_lock); |
| 528 | break; |
| 529 | |
| 530 | case WORK_DELAYED_CANCELLED: |
| 531 | panic("cancelled delayed work %p got uqeued: %p" , work, wq); |
| 532 | break; |
| 533 | |
| 534 | default: |
| 535 | panic("work %p in bad state: %d" , work, (int)work->w_state); |
| 536 | break; |
| 537 | } |
| 538 | linux_work_unlock(work); |
| 539 | } |
| 540 | |
| 541 | /* |
| 542 | * Delayed work |
| 543 | */ |
| 544 | |
| 545 | void |
| 546 | INIT_DELAYED_WORK(struct delayed_work *dw, void (*fn)(struct work_struct *)) |
| 547 | { |
| 548 | INIT_WORK(&dw->work, fn); |
| 549 | } |
| 550 | |
| 551 | bool |
| 552 | schedule_delayed_work(struct delayed_work *dw, unsigned long ticks) |
| 553 | { |
| 554 | return queue_delayed_work(system_wq, dw, ticks); |
| 555 | } |
| 556 | |
| 557 | bool |
| 558 | queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *dw, |
| 559 | unsigned long ticks) |
| 560 | { |
| 561 | bool newly_queued; |
| 562 | |
| 563 | KASSERT(wq != NULL); |
| 564 | |
| 565 | linux_work_lock(&dw->work); |
| 566 | switch (dw->work.w_state) { |
| 567 | case WORK_IDLE: |
| 568 | case WORK_INVOKED: |
| 569 | if (ticks == 0) { |
| 570 | /* Skip the delay and queue it now. */ |
| 571 | dw->work.w_state = WORK_PENDING; |
| 572 | dw->work.w_wq = wq; |
| 573 | workqueue_enqueue(wq->wq_workqueue, &dw->work.w_wk, |
| 574 | NULL); |
| 575 | } else { |
| 576 | callout_init(&dw->dw_callout, CALLOUT_MPSAFE); |
| 577 | callout_reset(&dw->dw_callout, ticks, |
| 578 | &linux_worker_intr, dw); |
| 579 | dw->work.w_state = WORK_DELAYED; |
| 580 | dw->work.w_wq = wq; |
| 581 | mutex_enter(&wq->wq_lock); |
| 582 | TAILQ_INSERT_HEAD(&wq->wq_delayed, dw, dw_entry); |
| 583 | mutex_exit(&wq->wq_lock); |
| 584 | } |
| 585 | newly_queued = true; |
| 586 | break; |
| 587 | |
| 588 | case WORK_DELAYED: |
| 589 | /* |
| 590 | * Timer is already ticking. Leave it to time out |
| 591 | * whenever it was going to time out, as Linux does -- |
| 592 | * neither speed it up nor postpone it. |
| 593 | */ |
| 594 | newly_queued = false; |
| 595 | break; |
| 596 | |
| 597 | case WORK_PENDING: |
| 598 | KASSERT(dw->work.w_wq == wq); |
| 599 | newly_queued = false; |
| 600 | break; |
| 601 | |
| 602 | case WORK_CANCELLED: |
| 603 | case WORK_DELAYED_CANCELLED: |
| 604 | /* XXX Wait for cancellation and then queue? */ |
| 605 | newly_queued = false; |
| 606 | break; |
| 607 | |
| 608 | default: |
| 609 | panic("delayed work %p in bad state: %d" , dw, |
| 610 | (int)dw->work.w_state); |
| 611 | break; |
| 612 | } |
| 613 | linux_work_unlock(&dw->work); |
| 614 | |
| 615 | return newly_queued; |
| 616 | } |
| 617 | |
| 618 | bool |
| 619 | mod_delayed_work(struct workqueue_struct *wq, struct delayed_work *dw, |
| 620 | unsigned long ticks) |
| 621 | { |
| 622 | bool timer_modified; |
| 623 | |
| 624 | KASSERT(wq != NULL); |
| 625 | |
| 626 | linux_work_lock(&dw->work); |
| 627 | switch (dw->work.w_state) { |
| 628 | case WORK_IDLE: |
| 629 | case WORK_INVOKED: |
| 630 | if (ticks == 0) { |
| 631 | /* Skip the delay and queue it now. */ |
| 632 | dw->work.w_state = WORK_PENDING; |
| 633 | dw->work.w_wq = wq; |
| 634 | workqueue_enqueue(wq->wq_workqueue, &dw->work.w_wk, |
| 635 | NULL); |
| 636 | } else { |
| 637 | callout_init(&dw->dw_callout, CALLOUT_MPSAFE); |
| 638 | callout_reset(&dw->dw_callout, ticks, |
| 639 | &linux_worker_intr, dw); |
| 640 | dw->work.w_state = WORK_DELAYED; |
| 641 | dw->work.w_wq = wq; |
| 642 | mutex_enter(&wq->wq_lock); |
| 643 | TAILQ_INSERT_HEAD(&wq->wq_delayed, dw, dw_entry); |
| 644 | mutex_exit(&wq->wq_lock); |
| 645 | } |
| 646 | timer_modified = false; |
| 647 | break; |
| 648 | |
| 649 | case WORK_DELAYED: |
| 650 | /* |
| 651 | * Timer is already ticking. Reschedule it. |
| 652 | */ |
| 653 | callout_schedule(&dw->dw_callout, ticks); |
| 654 | timer_modified = true; |
| 655 | break; |
| 656 | |
| 657 | case WORK_PENDING: |
| 658 | KASSERT(dw->work.w_wq == wq); |
| 659 | timer_modified = false; |
| 660 | break; |
| 661 | |
| 662 | case WORK_CANCELLED: |
| 663 | case WORK_DELAYED_CANCELLED: |
| 664 | /* XXX Wait for cancellation and then queue? */ |
| 665 | timer_modified = false; |
| 666 | break; |
| 667 | |
| 668 | default: |
| 669 | panic("delayed work %p in bad state: %d" , dw, |
| 670 | (int)dw->work.w_state); |
| 671 | break; |
| 672 | } |
| 673 | linux_work_unlock(&dw->work); |
| 674 | |
| 675 | return timer_modified; |
| 676 | } |
| 677 | |
| 678 | bool |
| 679 | cancel_delayed_work(struct delayed_work *dw) |
| 680 | { |
| 681 | bool cancelled_p = false; |
| 682 | |
| 683 | linux_work_lock(&dw->work); |
| 684 | switch (dw->work.w_state) { |
| 685 | case WORK_IDLE: /* Nothing to do. */ |
| 686 | break; |
| 687 | |
| 688 | case WORK_DELAYED: |
| 689 | dw->work.w_state = WORK_DELAYED_CANCELLED; |
| 690 | linux_cancel_delayed_work_callout(dw, false); |
| 691 | cancelled_p = true; |
| 692 | break; |
| 693 | |
| 694 | case WORK_PENDING: |
| 695 | dw->work.w_state = WORK_CANCELLED; |
| 696 | cancelled_p = true; |
| 697 | break; |
| 698 | |
| 699 | case WORK_INVOKED: /* Don't wait! */ |
| 700 | break; |
| 701 | |
| 702 | case WORK_CANCELLED: /* Already done. */ |
| 703 | case WORK_DELAYED_CANCELLED: |
| 704 | break; |
| 705 | |
| 706 | default: |
| 707 | panic("delayed work %p in bad state: %d" , dw, |
| 708 | (int)dw->work.w_state); |
| 709 | break; |
| 710 | } |
| 711 | linux_work_unlock(&dw->work); |
| 712 | |
| 713 | return cancelled_p; |
| 714 | } |
| 715 | |
| 716 | bool |
| 717 | cancel_delayed_work_sync(struct delayed_work *dw) |
| 718 | { |
| 719 | bool cancelled_p = false; |
| 720 | |
| 721 | linux_work_lock(&dw->work); |
| 722 | switch (dw->work.w_state) { |
| 723 | case WORK_IDLE: /* Nothing to do. */ |
| 724 | break; |
| 725 | |
| 726 | case WORK_DELAYED: |
| 727 | dw->work.w_state = WORK_DELAYED_CANCELLED; |
| 728 | linux_cancel_delayed_work_callout(dw, true); |
| 729 | cancelled_p = true; |
| 730 | break; |
| 731 | |
| 732 | case WORK_PENDING: |
| 733 | dw->work.w_state = WORK_CANCELLED; |
| 734 | linux_wait_for_cancelled_work(&dw->work); |
| 735 | cancelled_p = true; |
| 736 | break; |
| 737 | |
| 738 | case WORK_INVOKED: |
| 739 | linux_wait_for_invoked_work(&dw->work); |
| 740 | break; |
| 741 | |
| 742 | case WORK_CANCELLED: /* Already done. */ |
| 743 | break; |
| 744 | |
| 745 | case WORK_DELAYED_CANCELLED: |
| 746 | linux_wait_for_delayed_cancelled_work(dw); |
| 747 | break; |
| 748 | |
| 749 | default: |
| 750 | panic("delayed work %p in bad state: %d" , dw, |
| 751 | (int)dw->work.w_state); |
| 752 | break; |
| 753 | } |
| 754 | linux_work_unlock(&dw->work); |
| 755 | |
| 756 | return cancelled_p; |
| 757 | } |
| 758 | |
| 759 | static void |
| 760 | linux_cancel_delayed_work_callout(struct delayed_work *dw, bool wait) |
| 761 | { |
| 762 | bool fired_p; |
| 763 | |
| 764 | KASSERT(linux_work_locked(&dw->work)); |
| 765 | KASSERT(dw->work.w_state == WORK_DELAYED_CANCELLED); |
| 766 | |
| 767 | if (wait) { |
| 768 | /* |
| 769 | * We unlock, halt, and then relock, rather than |
| 770 | * passing an interlock to callout_halt, for two |
| 771 | * reasons: |
| 772 | * |
| 773 | * (1) The work lock is not a mutex(9), so we can't use it. |
| 774 | * (2) The WORK_DELAYED_CANCELLED state serves as an interlock. |
| 775 | */ |
| 776 | linux_work_unlock(&dw->work); |
| 777 | fired_p = callout_halt(&dw->dw_callout, NULL); |
| 778 | linux_work_lock(&dw->work); |
| 779 | } else { |
| 780 | fired_p = callout_stop(&dw->dw_callout); |
| 781 | } |
| 782 | |
| 783 | /* |
| 784 | * fired_p means we didn't cancel the callout, so it must have |
| 785 | * already begun and will clean up after itself. |
| 786 | * |
| 787 | * !fired_p means we cancelled it so we have to clean up after |
| 788 | * it. Nobody else should have changed the state in that case. |
| 789 | */ |
| 790 | if (!fired_p) { |
| 791 | struct workqueue_struct *wq; |
| 792 | |
| 793 | KASSERT(linux_work_locked(&dw->work)); |
| 794 | KASSERT(dw->work.w_state == WORK_DELAYED_CANCELLED); |
| 795 | |
| 796 | wq = dw->work.w_wq; |
| 797 | mutex_enter(&wq->wq_lock); |
| 798 | TAILQ_REMOVE(&wq->wq_delayed, dw, dw_entry); |
| 799 | callout_destroy(&dw->dw_callout); |
| 800 | dw->work.w_state = WORK_IDLE; |
| 801 | dw->work.w_wq = NULL; |
| 802 | cv_broadcast(&wq->wq_cv); |
| 803 | mutex_exit(&wq->wq_lock); |
| 804 | } |
| 805 | } |
| 806 | |
| 807 | static void |
| 808 | linux_wait_for_delayed_cancelled_work(struct delayed_work *dw) |
| 809 | { |
| 810 | struct workqueue_struct *wq; |
| 811 | |
| 812 | KASSERT(linux_work_locked(&dw->work)); |
| 813 | KASSERT(dw->work.w_state == WORK_DELAYED_CANCELLED); |
| 814 | |
| 815 | wq = dw->work.w_wq; |
| 816 | do { |
| 817 | mutex_enter(&wq->wq_lock); |
| 818 | linux_work_unlock(&dw->work); |
| 819 | cv_wait(&wq->wq_cv, &wq->wq_lock); |
| 820 | mutex_exit(&wq->wq_lock); |
| 821 | linux_work_lock(&dw->work); |
| 822 | } while ((dw->work.w_state == WORK_DELAYED_CANCELLED) && |
| 823 | (dw->work.w_wq == wq)); |
| 824 | } |
| 825 | |
| 826 | static void |
| 827 | linux_worker_intr(void *arg) |
| 828 | { |
| 829 | struct delayed_work *dw = arg; |
| 830 | struct workqueue_struct *wq; |
| 831 | |
| 832 | linux_work_lock(&dw->work); |
| 833 | |
| 834 | KASSERT((dw->work.w_state == WORK_DELAYED) || |
| 835 | (dw->work.w_state == WORK_DELAYED_CANCELLED)); |
| 836 | |
| 837 | wq = dw->work.w_wq; |
| 838 | mutex_enter(&wq->wq_lock); |
| 839 | |
| 840 | /* Queue the work, or return it to idle and alert any cancellers. */ |
| 841 | if (__predict_true(dw->work.w_state == WORK_DELAYED)) { |
| 842 | dw->work.w_state = WORK_PENDING; |
| 843 | workqueue_enqueue(dw->work.w_wq->wq_workqueue, &dw->work.w_wk, |
| 844 | NULL); |
| 845 | } else { |
| 846 | KASSERT(dw->work.w_state == WORK_DELAYED_CANCELLED); |
| 847 | dw->work.w_state = WORK_IDLE; |
| 848 | dw->work.w_wq = NULL; |
| 849 | cv_broadcast(&wq->wq_cv); |
| 850 | } |
| 851 | |
| 852 | /* Either way, the callout is done. */ |
| 853 | TAILQ_REMOVE(&wq->wq_delayed, dw, dw_entry); |
| 854 | callout_destroy(&dw->dw_callout); |
| 855 | |
| 856 | mutex_exit(&wq->wq_lock); |
| 857 | linux_work_unlock(&dw->work); |
| 858 | } |
| 859 | |