sound/core/timer.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Timers abstract layer
   4  *  Copyright (c) by Jaroslav Kysela <[email protected]>
   5  */
   6
   7 #include <linux/delay.h>
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10 #include <linux/time.h>
  11 #include <linux/mutex.h>
  12 #include <linux/device.h>
  13 #include <linux/module.h>
  14 #include <linux/string.h>
  15 #include <linux/sched/signal.h>
  16 #include <linux/anon_inodes.h>
  17 #include <linux/idr.h>
  18 #include <sound/core.h>
  19 #include <sound/timer.h>
  20 #include <sound/control.h>
  21 #include <sound/info.h>
  22 #include <sound/minors.h>
  23 #include <sound/initval.h>
  24 #include <linux/kmod.h>
  25
  26 /* internal flags */
  27 #define SNDRV_TIMER_IFLG_PAUSED         0x00010000
  28 #define SNDRV_TIMER_IFLG_DEAD           0x00020000
  29
  30 #if IS_ENABLED(CONFIG_SND_HRTIMER)
  31 #define DEFAULT_TIMER_LIMIT 4
  32 #else
  33 #define DEFAULT_TIMER_LIMIT 1
  34 #endif
  35
  36 static int timer_limit = DEFAULT_TIMER_LIMIT;
  37 static int timer_tstamp_monotonic = 1;
  38 MODULE_AUTHOR("Jaroslav Kysela <[email protected]>, Takashi Iwai <[email protected]>");
  39 MODULE_DESCRIPTION("ALSA timer interface");
  40 MODULE_LICENSE("GPL");
  41 module_param(timer_limit, int, 0444);
  42 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
  43 module_param(timer_tstamp_monotonic, int, 0444);
  44 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
  45
  46 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
  47 MODULE_ALIAS("devname:snd/timer");
  48
  49 enum timer_tread_format {
  50         TREAD_FORMAT_NONE = 0,
  51         TREAD_FORMAT_TIME64,
  52         TREAD_FORMAT_TIME32,
  53 };
  54
  55 struct snd_timer_tread32 {
  56         int event;
  57         s32 tstamp_sec;
  58         s32 tstamp_nsec;
  59         unsigned int val;
  60 };
  61
  62 struct snd_timer_tread64 {
  63         int event;
  64         u8 pad1[4];
  65         s64 tstamp_sec;
  66         s64 tstamp_nsec;
  67         unsigned int val;
  68         u8 pad2[4];
  69 };
  70
  71 struct snd_timer_user {
  72         struct snd_timer_instance *timeri;
  73         int tread;              /* enhanced read with timestamps and events */
  74         unsigned long ticks;
  75         unsigned long overrun;
  76         int qhead;
  77         int qtail;
  78         int qused;
  79         int queue_size;
  80         bool disconnected;
  81         struct snd_timer_read *queue;
  82         struct snd_timer_tread64 *tqueue;
  83         spinlock_t qlock;
  84         unsigned long last_resolution;
  85         unsigned int filter;
  86         struct timespec64 tstamp;               /* trigger tstamp */
  87         wait_queue_head_t qchange_sleep;
  88         struct snd_fasync *fasync;
  89         struct mutex ioctl_lock;
  90 };
  91
  92 struct snd_timer_status32 {
  93         s32 tstamp_sec;                 /* Timestamp - last update */
  94         s32 tstamp_nsec;
  95         unsigned int resolution;        /* current period resolution in ns */
  96         unsigned int lost;              /* counter of master tick lost */
  97         unsigned int overrun;           /* count of read queue overruns */
  98         unsigned int queue;             /* used queue size */
  99         unsigned char reserved[64];     /* reserved */
 100 };
 101
 102 #define SNDRV_TIMER_IOCTL_STATUS32      _IOR('T', 0x14, struct snd_timer_status32)
 103
 104 struct snd_timer_status64 {
 105         s64 tstamp_sec;                 /* Timestamp - last update */
 106         s64 tstamp_nsec;
 107         unsigned int resolution;        /* current period resolution in ns */
 108         unsigned int lost;              /* counter of master tick lost */
 109         unsigned int overrun;           /* count of read queue overruns */
 110         unsigned int queue;             /* used queue size */
 111         unsigned char reserved[64];     /* reserved */
 112 };
 113
 114 #ifdef CONFIG_SND_UTIMER
 115 #define SNDRV_UTIMERS_MAX_COUNT 128
 116 /* Internal data structure for keeping the state of the userspace-driven timer */
 117 struct snd_utimer {
 118         char *name;
 119         struct snd_timer *timer;
 120         unsigned int id;
 121 };
 122 #endif
 123
 124 #define SNDRV_TIMER_IOCTL_STATUS64      _IOR('T', 0x14, struct snd_timer_status64)
 125
 126 /* list of timers */
 127 static LIST_HEAD(snd_timer_list);
 128
 129 /* list of slave instances */
 130 static LIST_HEAD(snd_timer_slave_list);
 131
 132 /* lock for slave active lists */
 133 static DEFINE_SPINLOCK(slave_active_lock);
 134
 135 #define MAX_SLAVE_INSTANCES     1000
 136 static int num_slaves;
 137
 138 static DEFINE_MUTEX(register_mutex);
 139
 140 static int snd_timer_free(struct snd_timer *timer);
 141 static int snd_timer_dev_free(struct snd_device *device);
 142 static int snd_timer_dev_register(struct snd_device *device);
 143 static int snd_timer_dev_disconnect(struct snd_device *device);
 144
 145 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
 146
 147 /*
 148  * create a timer instance with the given owner string.
 149  */
 150 struct snd_timer_instance *snd_timer_instance_new(const char *owner)
 151 {
 152         struct snd_timer_instance *timeri;
 153
 154         timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
 155         if (timeri == NULL)
 156                 return NULL;
 157         timeri->owner = kstrdup(owner, GFP_KERNEL);
 158         if (! timeri->owner) {
 159                 kfree(timeri);
 160                 return NULL;
 161         }
 162         INIT_LIST_HEAD(&timeri->open_list);
 163         INIT_LIST_HEAD(&timeri->active_list);
 164         INIT_LIST_HEAD(&timeri->ack_list);
 165         INIT_LIST_HEAD(&timeri->slave_list_head);
 166         INIT_LIST_HEAD(&timeri->slave_active_head);
 167
 168         return timeri;
 169 }
 170 EXPORT_SYMBOL(snd_timer_instance_new);
 171
 172 void snd_timer_instance_free(struct snd_timer_instance *timeri)
 173 {
 174         if (timeri) {
 175                 if (timeri->private_free)
 176                         timeri->private_free(timeri);
 177                 kfree(timeri->owner);
 178                 kfree(timeri);
 179         }
 180 }
 181 EXPORT_SYMBOL(snd_timer_instance_free);
 182
 183 /*
 184  * find a timer instance from the given timer id
 185  */
 186 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
 187 {
 188         struct snd_timer *timer;
 189
 190         list_for_each_entry(timer, &snd_timer_list, device_list) {
 191                 if (timer->tmr_class != tid->dev_class)
 192                         continue;
 193                 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
 194                      timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
 195                     (timer->card == NULL ||
 196                      timer->card->number != tid->card))
 197                         continue;
 198                 if (timer->tmr_device != tid->device)
 199                         continue;
 200                 if (timer->tmr_subdevice != tid->subdevice)
 201                         continue;
 202                 return timer;
 203         }
 204         return NULL;
 205 }
 206
 207 #ifdef CONFIG_MODULES
 208
 209 static void snd_timer_request(struct snd_timer_id *tid)
 210 {
 211         switch (tid->dev_class) {
 212         case SNDRV_TIMER_CLASS_GLOBAL:
 213                 if (tid->device < timer_limit)
 214                         request_module("snd-timer-%i", tid->device);
 215                 break;
 216         case SNDRV_TIMER_CLASS_CARD:
 217         case SNDRV_TIMER_CLASS_PCM:
 218                 if (tid->card < snd_ecards_limit)
 219                         request_module("snd-card-%i", tid->card);
 220                 break;
 221         default:
 222                 break;
 223         }
 224 }
 225
 226 #endif
 227
 228 /* move the slave if it belongs to the master; return 1 if match */
 229 static int check_matching_master_slave(struct snd_timer_instance *master,
 230                                        struct snd_timer_instance *slave)
 231 {
 232         if (slave->slave_class != master->slave_class ||
 233             slave->slave_id != master->slave_id)
 234                 return 0;
 235         if (master->timer->num_instances >= master->timer->max_instances)
 236                 return -EBUSY;
 237         list_move_tail(&slave->open_list, &master->slave_list_head);
 238         master->timer->num_instances++;
 239         guard(spinlock_irq)(&slave_active_lock);
 240         guard(spinlock)(&master->timer->lock);
 241         slave->master = master;
 242         slave->timer = master->timer;
 243         if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
 244                 list_add_tail(&slave->active_list, &master->slave_active_head);
 245         return 1;
 246 }
 247
 248 /*
 249  * look for a master instance matching with the slave id of the given slave.
 250  * when found, relink the open_link of the slave.
 251  *
 252  * call this with register_mutex down.
 253  */
 254 static int snd_timer_check_slave(struct snd_timer_instance *slave)
 255 {
 256         struct snd_timer *timer;
 257         struct snd_timer_instance *master;
 258         int err = 0;
 259
 260         /* FIXME: it's really dumb to look up all entries.. */
 261         list_for_each_entry(timer, &snd_timer_list, device_list) {
 262                 list_for_each_entry(master, &timer->open_list_head, open_list) {
 263                         err = check_matching_master_slave(master, slave);
 264                         if (err != 0) /* match found or error */
 265                                 goto out;
 266                 }
 267         }
 268  out:
 269         return err < 0 ? err : 0;
 270 }
 271
 272 /*
 273  * look for slave instances matching with the slave id of the given master.
 274  * when found, relink the open_link of slaves.
 275  *
 276  * call this with register_mutex down.
 277  */
 278 static int snd_timer_check_master(struct snd_timer_instance *master)
 279 {
 280         struct snd_timer_instance *slave, *tmp;
 281         int err = 0;
 282
 283         /* check all pending slaves */
 284         list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
 285                 err = check_matching_master_slave(master, slave);
 286                 if (err < 0)
 287                         break;
 288         }
 289         return err < 0 ? err : 0;
 290 }
 291
 292 static void snd_timer_close_locked(struct snd_timer_instance *timeri,
 293                                    struct device **card_devp_to_put);
 294
 295 /*
 296  * open a timer instance
 297  * when opening a master, the slave id must be here given.
 298  */
 299 int snd_timer_open(struct snd_timer_instance *timeri,
 300                    struct snd_timer_id *tid,
 301                    unsigned int slave_id)
 302 {
 303         struct snd_timer *timer;
 304         struct device *card_dev_to_put = NULL;
 305         int err;
 306
 307         mutex_lock(&register_mutex);
 308         if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
 309                 /* open a slave instance */
 310                 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
 311                     tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
 312                         pr_debug("ALSA: timer: invalid slave class %i\n",
 313                                  tid->dev_sclass);
 314                         err = -EINVAL;
 315                         goto unlock;
 316                 }
 317                 if (num_slaves >= MAX_SLAVE_INSTANCES) {
 318                         err = -EBUSY;
 319                         goto unlock;
 320                 }
 321                 timeri->slave_class = tid->dev_sclass;
 322                 timeri->slave_id = tid->device;
 323                 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 324                 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
 325                 num_slaves++;
 326                 err = snd_timer_check_slave(timeri);
 327                 goto list_added;
 328         }
 329
 330         /* open a master instance */
 331         timer = snd_timer_find(tid);
 332 #ifdef CONFIG_MODULES
 333         if (!timer) {
 334                 mutex_unlock(&register_mutex);
 335                 snd_timer_request(tid);
 336                 mutex_lock(&register_mutex);
 337                 timer = snd_timer_find(tid);
 338         }
 339 #endif
 340         if (!timer) {
 341                 err = -ENODEV;
 342                 goto unlock;
 343         }
 344         if (!list_empty(&timer->open_list_head)) {
 345                 struct snd_timer_instance *t =
 346                         list_entry(timer->open_list_head.next,
 347                                     struct snd_timer_instance, open_list);
 348                 if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
 349                         err = -EBUSY;
 350                         goto unlock;
 351                 }
 352         }
 353         if (timer->num_instances >= timer->max_instances) {
 354                 err = -EBUSY;
 355                 goto unlock;
 356         }
 357         if (!try_module_get(timer->module)) {
 358                 err = -EBUSY;
 359                 goto unlock;
 360         }
 361         /* take a card refcount for safe disconnection */
 362         if (timer->card) {
 363                 get_device(&timer->card->card_dev);
 364                 card_dev_to_put = &timer->card->card_dev;
 365         }
 366
 367         if (list_empty(&timer->open_list_head) && timer->hw.open) {
 368                 err = timer->hw.open(timer);
 369                 if (err) {
 370                         module_put(timer->module);
 371                         goto unlock;
 372                 }
 373         }
 374
 375         timeri->timer = timer;
 376         timeri->slave_class = tid->dev_sclass;
 377         timeri->slave_id = slave_id;
 378
 379         list_add_tail(&timeri->open_list, &timer->open_list_head);
 380         timer->num_instances++;
 381         err = snd_timer_check_master(timeri);
 382 list_added:
 383         if (err < 0)
 384                 snd_timer_close_locked(timeri, &card_dev_to_put);
 385
 386  unlock:
 387         mutex_unlock(&register_mutex);
 388         /* put_device() is called after unlock for avoiding deadlock */
 389         if (err < 0 && card_dev_to_put)
 390                 put_device(card_dev_to_put);
 391         return err;
 392 }
 393 EXPORT_SYMBOL(snd_timer_open);
 394
 395 /* remove slave links, called from snd_timer_close_locked() below */
 396 static void remove_slave_links(struct snd_timer_instance *timeri,
 397                                struct snd_timer *timer)
 398 {
 399         struct snd_timer_instance *slave, *tmp;
 400
 401         guard(spinlock_irq)(&slave_active_lock);
 402         guard(spinlock)(&timer->lock);
 403         timeri->timer = NULL;
 404         list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head, open_list) {
 405                 list_move_tail(&slave->open_list, &snd_timer_slave_list);
 406                 timer->num_instances--;
 407                 slave->master = NULL;
 408                 slave->timer = NULL;
 409                 list_del_init(&slave->ack_list);
 410                 list_del_init(&slave->active_list);
 411         }
 412 }
 413
 414 /*
 415  * close a timer instance
 416  * call this with register_mutex down.
 417  */
 418 static void snd_timer_close_locked(struct snd_timer_instance *timeri,
 419                                    struct device **card_devp_to_put)
 420 {
 421         struct snd_timer *timer = timeri->timer;
 422
 423         if (timer) {
 424                 guard(spinlock_irq)(&timer->lock);
 425                 timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
 426         }
 427
 428         if (!list_empty(&timeri->open_list)) {
 429                 list_del_init(&timeri->open_list);
 430                 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 431                         num_slaves--;
 432         }
 433
 434         /* force to stop the timer */
 435         snd_timer_stop(timeri);
 436
 437         if (timer) {
 438                 timer->num_instances--;
 439                 /* wait, until the active callback is finished */
 440                 spin_lock_irq(&timer->lock);
 441                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 442                         spin_unlock_irq(&timer->lock);
 443                         udelay(10);
 444                         spin_lock_irq(&timer->lock);
 445                 }
 446                 spin_unlock_irq(&timer->lock);
 447
 448                 remove_slave_links(timeri, timer);
 449
 450                 /* slave doesn't need to release timer resources below */
 451                 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 452                         timer = NULL;
 453         }
 454
 455         if (timer) {
 456                 if (list_empty(&timer->open_list_head) && timer->hw.close)
 457                         timer->hw.close(timer);
 458                 /* release a card refcount for safe disconnection */
 459                 if (timer->card)
 460                         *card_devp_to_put = &timer->card->card_dev;
 461                 module_put(timer->module);
 462         }
 463 }
 464
 465 /*
 466  * close a timer instance
 467  */
 468 void snd_timer_close(struct snd_timer_instance *timeri)
 469 {
 470         struct device *card_dev_to_put = NULL;
 471
 472         if (snd_BUG_ON(!timeri))
 473                 return;
 474
 475         scoped_guard(mutex, &register_mutex)
 476                 snd_timer_close_locked(timeri, &card_dev_to_put);
 477         /* put_device() is called after unlock for avoiding deadlock */
 478         if (card_dev_to_put)
 479                 put_device(card_dev_to_put);
 480 }
 481 EXPORT_SYMBOL(snd_timer_close);
 482
 483 static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
 484 {
 485         if (timer->hw.c_resolution)
 486                 return timer->hw.c_resolution(timer);
 487         else
 488                 return timer->hw.resolution;
 489 }
 490
 491 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
 492 {
 493         struct snd_timer * timer;
 494         unsigned long ret = 0;
 495
 496         if (timeri == NULL)
 497                 return 0;
 498         timer = timeri->timer;
 499         if (timer) {
 500                 guard(spinlock_irqsave)(&timer->lock);
 501                 ret = snd_timer_hw_resolution(timer);
 502         }
 503         return ret;
 504 }
 505 EXPORT_SYMBOL(snd_timer_resolution);
 506
 507 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 508 {
 509         struct snd_timer *timer = ti->timer;
 510         unsigned long resolution = 0;
 511         struct snd_timer_instance *ts;
 512         struct timespec64 tstamp;
 513
 514         if (timer_tstamp_monotonic)
 515                 ktime_get_ts64(&tstamp);
 516         else
 517                 ktime_get_real_ts64(&tstamp);
 518         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
 519                        event > SNDRV_TIMER_EVENT_PAUSE))
 520                 return;
 521         if (timer &&
 522             (event == SNDRV_TIMER_EVENT_START ||
 523              event == SNDRV_TIMER_EVENT_CONTINUE))
 524                 resolution = snd_timer_hw_resolution(timer);
 525         if (ti->ccallback)
 526                 ti->ccallback(ti, event, &tstamp, resolution);
 527         if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
 528                 return;
 529         if (timer == NULL)
 530                 return;
 531         if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 532                 return;
 533         event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
 534         list_for_each_entry(ts, &ti->slave_active_head, active_list)
 535                 if (ts->ccallback)
 536                         ts->ccallback(ts, event, &tstamp, resolution);
 537 }
 538
 539 /* start/continue a master timer */
 540 static int snd_timer_start1(struct snd_timer_instance *timeri,
 541                             bool start, unsigned long ticks)
 542 {
 543         struct snd_timer *timer;
 544         int result;
 545
 546         timer = timeri->timer;
 547         if (!timer)
 548                 return -EINVAL;
 549
 550         guard(spinlock_irqsave)(&timer->lock);
 551         if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
 552                 return -EINVAL;
 553         if (timer->card && timer->card->shutdown)
 554                 return -ENODEV;
 555         if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
 556                              SNDRV_TIMER_IFLG_START))
 557                 return -EBUSY;
 558
 559         /* check the actual time for the start tick;
 560          * bail out as error if it's way too low (< 100us)
 561          */
 562         if (start && !(timer->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
 563                 if ((u64)snd_timer_hw_resolution(timer) * ticks < 100000)
 564                         return -EINVAL;
 565         }
 566
 567         if (start)
 568                 timeri->ticks = timeri->cticks = ticks;
 569         else if (!timeri->cticks)
 570                 timeri->cticks = 1;
 571         timeri->pticks = 0;
 572
 573         list_move_tail(&timeri->active_list, &timer->active_list_head);
 574         if (timer->running) {
 575                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 576                         goto __start_now;
 577                 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
 578                 timeri->flags |= SNDRV_TIMER_IFLG_START;
 579                 result = 1; /* delayed start */
 580         } else {
 581                 if (start)
 582                         timer->sticks = ticks;
 583                 timer->hw.start(timer);
 584               __start_now:
 585                 timer->running++;
 586                 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 587                 result = 0;
 588         }
 589         snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 590                           SNDRV_TIMER_EVENT_CONTINUE);
 591         return result;
 592 }
 593
 594 /* start/continue a slave timer */
 595 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
 596                                  bool start)
 597 {
 598         guard(spinlock_irqsave)(&slave_active_lock);
 599         if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
 600                 return -EINVAL;
 601         if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING)
 602                 return -EBUSY;
 603         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 604         if (timeri->master && timeri->timer) {
 605                 guard(spinlock)(&timeri->timer->lock);
 606                 list_add_tail(&timeri->active_list,
 607                               &timeri->master->slave_active_head);
 608                 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 609                                   SNDRV_TIMER_EVENT_CONTINUE);
 610         }
 611         return 1; /* delayed start */
 612 }
 613
 614 /* stop/pause a master timer */
 615 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
 616 {
 617         struct snd_timer *timer;
 618
 619         timer = timeri->timer;
 620         if (!timer)
 621                 return -EINVAL;
 622         guard(spinlock_irqsave)(&timer->lock);
 623         list_del_init(&timeri->ack_list);
 624         list_del_init(&timeri->active_list);
 625         if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
 626                                SNDRV_TIMER_IFLG_START)))
 627                 return -EBUSY;
 628         if (timer->card && timer->card->shutdown)
 629                 return 0;
 630         if (stop) {
 631                 timeri->cticks = timeri->ticks;
 632                 timeri->pticks = 0;
 633         }
 634         if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
 635             !(--timer->running)) {
 636                 timer->hw.stop(timer);
 637                 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
 638                         timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 639                         snd_timer_reschedule(timer, 0);
 640                         if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
 641                                 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 642                                 timer->hw.start(timer);
 643                         }
 644                 }
 645         }
 646         timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
 647         if (stop)
 648                 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
 649         else
 650                 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
 651         snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 652                           SNDRV_TIMER_EVENT_PAUSE);
 653         return 0;
 654 }
 655
 656 /* stop/pause a slave timer */
 657 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
 658 {
 659         bool running;
 660
 661         guard(spinlock_irqsave)(&slave_active_lock);
 662         running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
 663         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 664         if (timeri->timer) {
 665                 guard(spinlock)(&timeri->timer->lock);
 666                 list_del_init(&timeri->ack_list);
 667                 list_del_init(&timeri->active_list);
 668                 if (running)
 669                         snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 670                                           SNDRV_TIMER_EVENT_PAUSE);
 671         }
 672         return running ? 0 : -EBUSY;
 673 }
 674
 675 /*
 676  *  start the timer instance
 677  */
 678 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
 679 {
 680         if (timeri == NULL || ticks < 1)
 681                 return -EINVAL;
 682         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 683                 return snd_timer_start_slave(timeri, true);
 684         else
 685                 return snd_timer_start1(timeri, true, ticks);
 686 }
 687 EXPORT_SYMBOL(snd_timer_start);
 688
 689 /*
 690  * stop the timer instance.
 691  *
 692  * do not call this from the timer callback!
 693  */
 694 int snd_timer_stop(struct snd_timer_instance *timeri)
 695 {
 696         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 697                 return snd_timer_stop_slave(timeri, true);
 698         else
 699                 return snd_timer_stop1(timeri, true);
 700 }
 701 EXPORT_SYMBOL(snd_timer_stop);
 702
 703 /*
 704  * start again..  the tick is kept.
 705  */
 706 int snd_timer_continue(struct snd_timer_instance *timeri)
 707 {
 708         /* timer can continue only after pause */
 709         if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
 710                 return -EINVAL;
 711
 712         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 713                 return snd_timer_start_slave(timeri, false);
 714         else
 715                 return snd_timer_start1(timeri, false, 0);
 716 }
 717 EXPORT_SYMBOL(snd_timer_continue);
 718
 719 /*
 720  * pause.. remember the ticks left
 721  */
 722 int snd_timer_pause(struct snd_timer_instance * timeri)
 723 {
 724         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 725                 return snd_timer_stop_slave(timeri, false);
 726         else
 727                 return snd_timer_stop1(timeri, false);
 728 }
 729 EXPORT_SYMBOL(snd_timer_pause);
 730
 731 /*
 732  * reschedule the timer
 733  *
 734  * start pending instances and check the scheduling ticks.
 735  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
 736  */
 737 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
 738 {
 739         struct snd_timer_instance *ti;
 740         unsigned long ticks = ~0UL;
 741
 742         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 743                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
 744                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
 745                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
 746                         timer->running++;
 747                 }
 748                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
 749                         if (ticks > ti->cticks)
 750                                 ticks = ti->cticks;
 751                 }
 752         }
 753         if (ticks == ~0UL) {
 754                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 755                 return;
 756         }
 757         if (ticks > timer->hw.ticks)
 758                 ticks = timer->hw.ticks;
 759         if (ticks_left != ticks)
 760                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 761         timer->sticks = ticks;
 762 }
 763
 764 /* call callbacks in timer ack list */
 765 static void snd_timer_process_callbacks(struct snd_timer *timer,
 766                                         struct list_head *head)
 767 {
 768         struct snd_timer_instance *ti;
 769         unsigned long resolution, ticks;
 770
 771         while (!list_empty(head)) {
 772                 ti = list_first_entry(head, struct snd_timer_instance,
 773                                       ack_list);
 774
 775                 /* remove from ack_list and make empty */
 776                 list_del_init(&ti->ack_list);
 777
 778                 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
 779                         ticks = ti->pticks;
 780                         ti->pticks = 0;
 781                         resolution = ti->resolution;
 782                         ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 783                         spin_unlock(&timer->lock);
 784                         if (ti->callback)
 785                                 ti->callback(ti, resolution, ticks);
 786                         spin_lock(&timer->lock);
 787                         ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 788                 }
 789         }
 790 }
 791
 792 /* clear pending instances from ack list */
 793 static void snd_timer_clear_callbacks(struct snd_timer *timer,
 794                                       struct list_head *head)
 795 {
 796         guard(spinlock_irqsave)(&timer->lock);
 797         while (!list_empty(head))
 798                 list_del_init(head->next);
 799 }
 800
 801 /*
 802  * timer work
 803  *
 804  */
 805 static void snd_timer_work(struct work_struct *work)
 806 {
 807         struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
 808
 809         if (timer->card && timer->card->shutdown) {
 810                 snd_timer_clear_callbacks(timer, &timer->sack_list_head);
 811                 return;
 812         }
 813
 814         guard(spinlock_irqsave)(&timer->lock);
 815         snd_timer_process_callbacks(timer, &timer->sack_list_head);
 816 }
 817
 818 /*
 819  * timer interrupt
 820  *
 821  * ticks_left is usually equal to timer->sticks.
 822  *
 823  */
 824 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 825 {
 826         struct snd_timer_instance *ti, *ts, *tmp;
 827         unsigned long resolution;
 828         struct list_head *ack_list_head;
 829
 830         if (timer == NULL)
 831                 return;
 832
 833         if (timer->card && timer->card->shutdown) {
 834                 snd_timer_clear_callbacks(timer, &timer->ack_list_head);
 835                 return;
 836         }
 837
 838         guard(spinlock_irqsave)(&timer->lock);
 839
 840         /* remember the current resolution */
 841         resolution = snd_timer_hw_resolution(timer);
 842
 843         /* loop for all active instances
 844          * Here we cannot use list_for_each_entry because the active_list of a
 845          * processed instance is relinked to done_list_head before the callback
 846          * is called.
 847          */
 848         list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
 849                                  active_list) {
 850                 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
 851                         continue;
 852                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
 853                         continue;
 854                 ti->pticks += ticks_left;
 855                 ti->resolution = resolution;
 856                 if (ti->cticks < ticks_left)
 857                         ti->cticks = 0;
 858                 else
 859                         ti->cticks -= ticks_left;
 860                 if (ti->cticks) /* not expired */
 861                         continue;
 862                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
 863                         ti->cticks = ti->ticks;
 864                 } else {
 865                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 866                         --timer->running;
 867                         list_del_init(&ti->active_list);
 868                 }
 869                 if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
 870                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
 871                         ack_list_head = &timer->ack_list_head;
 872                 else
 873                         ack_list_head = &timer->sack_list_head;
 874                 if (list_empty(&ti->ack_list))
 875                         list_add_tail(&ti->ack_list, ack_list_head);
 876                 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
 877                         ts->pticks = ti->pticks;
 878                         ts->resolution = resolution;
 879                         if (list_empty(&ts->ack_list))
 880                                 list_add_tail(&ts->ack_list, ack_list_head);
 881                 }
 882         }
 883         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
 884                 snd_timer_reschedule(timer, timer->sticks);
 885         if (timer->running) {
 886                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
 887                         timer->hw.stop(timer);
 888                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 889                 }
 890                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
 891                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
 892                         /* restart timer */
 893                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 894                         timer->hw.start(timer);
 895                 }
 896         } else {
 897                 timer->hw.stop(timer);
 898         }
 899
 900         /* now process all fast callbacks */
 901         snd_timer_process_callbacks(timer, &timer->ack_list_head);
 902
 903         /* do we have any slow callbacks? */
 904         if (!list_empty(&timer->sack_list_head))
 905                 queue_work(system_highpri_wq, &timer->task_work);
 906 }
 907 EXPORT_SYMBOL(snd_timer_interrupt);
 908
 909 /*
 910
 911  */
 912
 913 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 914                   struct snd_timer **rtimer)
 915 {
 916         struct snd_timer *timer;
 917         int err;
 918         static const struct snd_device_ops ops = {
 919                 .dev_free = snd_timer_dev_free,
 920                 .dev_register = snd_timer_dev_register,
 921                 .dev_disconnect = snd_timer_dev_disconnect,
 922         };
 923
 924         if (snd_BUG_ON(!tid))
 925                 return -EINVAL;
 926         if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
 927             tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
 928                 if (WARN_ON(!card))
 929                         return -EINVAL;
 930         }
 931         if (rtimer)
 932                 *rtimer = NULL;
 933         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
 934         if (!timer)
 935                 return -ENOMEM;
 936         timer->tmr_class = tid->dev_class;
 937         timer->card = card;
 938         timer->tmr_device = tid->device;
 939         timer->tmr_subdevice = tid->subdevice;
 940         if (id)
 941                 strscpy(timer->id, id, sizeof(timer->id));
 942         timer->sticks = 1;
 943         INIT_LIST_HEAD(&timer->device_list);
 944         INIT_LIST_HEAD(&timer->open_list_head);
 945         INIT_LIST_HEAD(&timer->active_list_head);
 946         INIT_LIST_HEAD(&timer->ack_list_head);
 947         INIT_LIST_HEAD(&timer->sack_list_head);
 948         spin_lock_init(&timer->lock);
 949         INIT_WORK(&timer->task_work, snd_timer_work);
 950         timer->max_instances = 1000; /* default limit per timer */
 951         if (card != NULL) {
 952                 timer->module = card->module;
 953                 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
 954                 if (err < 0) {
 955                         snd_timer_free(timer);
 956                         return err;
 957                 }
 958         }
 959         if (rtimer)
 960                 *rtimer = timer;
 961         return 0;
 962 }
 963 EXPORT_SYMBOL(snd_timer_new);
 964
 965 static int snd_timer_free(struct snd_timer *timer)
 966 {
 967         if (!timer)
 968                 return 0;
 969
 970         guard(mutex)(&register_mutex);
 971         if (! list_empty(&timer->open_list_head)) {
 972                 struct list_head *p, *n;
 973                 struct snd_timer_instance *ti;
 974                 pr_warn("ALSA: timer %p is busy?\n", timer);
 975                 list_for_each_safe(p, n, &timer->open_list_head) {
 976                         list_del_init(p);
 977                         ti = list_entry(p, struct snd_timer_instance, open_list);
 978                         ti->timer = NULL;
 979                 }
 980         }
 981         list_del(&timer->device_list);
 982
 983         if (timer->private_free)
 984                 timer->private_free(timer);
 985         kfree(timer);
 986         return 0;
 987 }
 988
 989 static int snd_timer_dev_free(struct snd_device *device)
 990 {
 991         struct snd_timer *timer = device->device_data;
 992         return snd_timer_free(timer);
 993 }
 994
 995 static int snd_timer_dev_register(struct snd_device *dev)
 996 {
 997         struct snd_timer *timer = dev->device_data;
 998         struct snd_timer *timer1;
 999
1000         if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
1001                 return -ENXIO;
1002         if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
1003             !timer->hw.resolution && timer->hw.c_resolution == NULL)
1004                 return -EINVAL;
1005
1006         guard(mutex)(&register_mutex);
1007         list_for_each_entry(timer1, &snd_timer_list, device_list) {
1008                 if (timer1->tmr_class > timer->tmr_class)
1009                         break;
1010                 if (timer1->tmr_class < timer->tmr_class)
1011                         continue;
1012                 if (timer1->card && timer->card) {
1013                         if (timer1->card->number > timer->card->number)
1014                                 break;
1015                         if (timer1->card->number < timer->card->number)
1016                                 continue;
1017                 }
1018                 if (timer1->tmr_device > timer->tmr_device)
1019                         break;
1020                 if (timer1->tmr_device < timer->tmr_device)
1021                         continue;
1022                 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1023                         break;
1024                 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1025                         continue;
1026                 /* conflicts.. */
1027                 return -EBUSY;
1028         }
1029         list_add_tail(&timer->device_list, &timer1->device_list);
1030         return 0;
1031 }
1032
1033 static int snd_timer_dev_disconnect(struct snd_device *device)
1034 {
1035         struct snd_timer *timer = device->device_data;
1036         struct snd_timer_instance *ti;
1037
1038         guard(mutex)(&register_mutex);
1039         list_del_init(&timer->device_list);
1040         /* wake up pending sleepers */
1041         list_for_each_entry(ti, &timer->open_list_head, open_list) {
1042                 if (ti->disconnect)
1043                         ti->disconnect(ti);
1044         }
1045         return 0;
1046 }
1047
1048 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
1049 {
1050         unsigned long resolution = 0;
1051         struct snd_timer_instance *ti, *ts;
1052
1053         if (timer->card && timer->card->shutdown)
1054                 return;
1055         if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1056                 return;
1057         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1058                        event > SNDRV_TIMER_EVENT_MRESUME))
1059                 return;
1060         guard(spinlock_irqsave)(&timer->lock);
1061         if (event == SNDRV_TIMER_EVENT_MSTART ||
1062             event == SNDRV_TIMER_EVENT_MCONTINUE ||
1063             event == SNDRV_TIMER_EVENT_MRESUME)
1064                 resolution = snd_timer_hw_resolution(timer);
1065         list_for_each_entry(ti, &timer->active_list_head, active_list) {
1066                 if (ti->ccallback)
1067                         ti->ccallback(ti, event, tstamp, resolution);
1068                 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1069                         if (ts->ccallback)
1070                                 ts->ccallback(ts, event, tstamp, resolution);
1071         }
1072 }
1073 EXPORT_SYMBOL(snd_timer_notify);
1074
1075 /*
1076  * exported functions for global timers
1077  */
1078 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1079 {
1080         struct snd_timer_id tid;
1081
1082         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1083         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1084         tid.card = -1;
1085         tid.device = device;
1086         tid.subdevice = 0;
1087         return snd_timer_new(NULL, id, &tid, rtimer);
1088 }
1089 EXPORT_SYMBOL(snd_timer_global_new);
1090
1091 int snd_timer_global_free(struct snd_timer *timer)
1092 {
1093         return snd_timer_free(timer);
1094 }
1095 EXPORT_SYMBOL(snd_timer_global_free);
1096
1097 int snd_timer_global_register(struct snd_timer *timer)
1098 {
1099         struct snd_device dev;
1100
1101         memset(&dev, 0, sizeof(dev));
1102         dev.device_data = timer;
1103         return snd_timer_dev_register(&dev);
1104 }
1105 EXPORT_SYMBOL(snd_timer_global_register);
1106
1107 /*
1108  *  System timer
1109  */
1110
1111 struct snd_timer_system_private {
1112         struct timer_list tlist;
1113         struct snd_timer *snd_timer;
1114         unsigned long last_expires;
1115         unsigned long last_jiffies;
1116         unsigned long correction;
1117 };
1118
1119 static void snd_timer_s_function(struct timer_list *t)
1120 {
1121         struct snd_timer_system_private *priv = from_timer(priv, t,
1122                                                                 tlist);
1123         struct snd_timer *timer = priv->snd_timer;
1124         unsigned long jiff = jiffies;
1125         if (time_after(jiff, priv->last_expires))
1126                 priv->correction += (long)jiff - (long)priv->last_expires;
1127         snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1128 }
1129
1130 static int snd_timer_s_start(struct snd_timer * timer)
1131 {
1132         struct snd_timer_system_private *priv;
1133         unsigned long njiff;
1134
1135         priv = (struct snd_timer_system_private *) timer->private_data;
1136         njiff = (priv->last_jiffies = jiffies);
1137         if (priv->correction > timer->sticks - 1) {
1138                 priv->correction -= timer->sticks - 1;
1139                 njiff++;
1140         } else {
1141                 njiff += timer->sticks - priv->correction;
1142                 priv->correction = 0;
1143         }
1144         priv->last_expires = njiff;
1145         mod_timer(&priv->tlist, njiff);
1146         return 0;
1147 }
1148
1149 static int snd_timer_s_stop(struct snd_timer * timer)
1150 {
1151         struct snd_timer_system_private *priv;
1152         unsigned long jiff;
1153
1154         priv = (struct snd_timer_system_private *) timer->private_data;
1155         del_timer(&priv->tlist);
1156         jiff = jiffies;
1157         if (time_before(jiff, priv->last_expires))
1158                 timer->sticks = priv->last_expires - jiff;
1159         else
1160                 timer->sticks = 1;
1161         priv->correction = 0;
1162         return 0;
1163 }
1164
1165 static int snd_timer_s_close(struct snd_timer *timer)
1166 {
1167         struct snd_timer_system_private *priv;
1168
1169         priv = (struct snd_timer_system_private *)timer->private_data;
1170         del_timer_sync(&priv->tlist);
1171         return 0;
1172 }
1173
1174 static const struct snd_timer_hardware snd_timer_system =
1175 {
1176         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
1177         .resolution =   NSEC_PER_SEC / HZ,
1178         .ticks =        10000000L,
1179         .close =        snd_timer_s_close,
1180         .start =        snd_timer_s_start,
1181         .stop =         snd_timer_s_stop
1182 };
1183
1184 static void snd_timer_free_system(struct snd_timer *timer)
1185 {
1186         kfree(timer->private_data);
1187 }
1188
1189 static int snd_timer_register_system(void)
1190 {
1191         struct snd_timer *timer;
1192         struct snd_timer_system_private *priv;
1193         int err;
1194
1195         err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1196         if (err < 0)
1197                 return err;
1198         strcpy(timer->name, "system timer");
1199         timer->hw = snd_timer_system;
1200         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1201         if (priv == NULL) {
1202                 snd_timer_free(timer);
1203                 return -ENOMEM;
1204         }
1205         priv->snd_timer = timer;
1206         timer_setup(&priv->tlist, snd_timer_s_function, 0);
1207         timer->private_data = priv;
1208         timer->private_free = snd_timer_free_system;
1209         return snd_timer_global_register(timer);
1210 }
1211
1212 #ifdef CONFIG_SND_PROC_FS
1213 /*
1214  *  Info interface
1215  */
1216
1217 static void snd_timer_proc_read(struct snd_info_entry *entry,
1218                                 struct snd_info_buffer *buffer)
1219 {
1220         struct snd_timer *timer;
1221         struct snd_timer_instance *ti;
1222         unsigned long resolution;
1223
1224         guard(mutex)(&register_mutex);
1225         list_for_each_entry(timer, &snd_timer_list, device_list) {
1226                 if (timer->card && timer->card->shutdown)
1227                         continue;
1228                 switch (timer->tmr_class) {
1229                 case SNDRV_TIMER_CLASS_GLOBAL:
1230                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1231                         break;
1232                 case SNDRV_TIMER_CLASS_CARD:
1233                         snd_iprintf(buffer, "C%i-%i: ",
1234                                     timer->card->number, timer->tmr_device);
1235                         break;
1236                 case SNDRV_TIMER_CLASS_PCM:
1237                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1238                                     timer->tmr_device, timer->tmr_subdevice);
1239                         break;
1240                 default:
1241                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1242                                     timer->card ? timer->card->number : -1,
1243                                     timer->tmr_device, timer->tmr_subdevice);
1244                 }
1245                 snd_iprintf(buffer, "%s :", timer->name);
1246                 scoped_guard(spinlock_irq, &timer->lock)
1247                         resolution = snd_timer_hw_resolution(timer);
1248                 if (resolution)
1249                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1250                                     resolution / 1000,
1251                                     resolution % 1000,
1252                                     timer->hw.ticks);
1253                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1254                         snd_iprintf(buffer, " SLAVE");
1255                 snd_iprintf(buffer, "\n");
1256                 list_for_each_entry(ti, &timer->open_list_head, open_list)
1257                         snd_iprintf(buffer, "  Client %s : %s\n",
1258                                     ti->owner ? ti->owner : "unknown",
1259                                     (ti->flags & (SNDRV_TIMER_IFLG_START |
1260                                                   SNDRV_TIMER_IFLG_RUNNING))
1261                                     ? "running" : "stopped");
1262         }
1263 }
1264
1265 static struct snd_info_entry *snd_timer_proc_entry;
1266
1267 static void __init snd_timer_proc_init(void)
1268 {
1269         struct snd_info_entry *entry;
1270
1271         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1272         if (entry != NULL) {
1273                 entry->c.text.read = snd_timer_proc_read;
1274                 if (snd_info_register(entry) < 0) {
1275                         snd_info_free_entry(entry);
1276                         entry = NULL;
1277                 }
1278         }
1279         snd_timer_proc_entry = entry;
1280 }
1281
1282 static void __exit snd_timer_proc_done(void)
1283 {
1284         snd_info_free_entry(snd_timer_proc_entry);
1285 }
1286 #else /* !CONFIG_SND_PROC_FS */
1287 #define snd_timer_proc_init()
1288 #define snd_timer_proc_done()
1289 #endif
1290
1291 /*
1292  *  USER SPACE interface
1293  */
1294
1295 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1296                                      unsigned long resolution,
1297                                      unsigned long ticks)
1298 {
1299         struct snd_timer_user *tu = timeri->callback_data;
1300         struct snd_timer_read *r;
1301         int prev;
1302
1303         guard(spinlock)(&tu->qlock);
1304         if (tu->qused > 0) {
1305                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1306                 r = &tu->queue[prev];
1307                 if (r->resolution == resolution) {
1308                         r->ticks += ticks;
1309                         goto __wake;
1310                 }
1311         }
1312         if (tu->qused >= tu->queue_size) {
1313                 tu->overrun++;
1314         } else {
1315                 r = &tu->queue[tu->qtail++];
1316                 tu->qtail %= tu->queue_size;
1317                 r->resolution = resolution;
1318                 r->ticks = ticks;
1319                 tu->qused++;
1320         }
1321       __wake:
1322         snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1323         wake_up(&tu->qchange_sleep);
1324 }
1325
1326 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1327                                             struct snd_timer_tread64 *tread)
1328 {
1329         if (tu->qused >= tu->queue_size) {
1330                 tu->overrun++;
1331         } else {
1332                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1333                 tu->qtail %= tu->queue_size;
1334                 tu->qused++;
1335         }
1336 }
1337
1338 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1339                                      int event,
1340                                      struct timespec64 *tstamp,
1341                                      unsigned long resolution)
1342 {
1343         struct snd_timer_user *tu = timeri->callback_data;
1344         struct snd_timer_tread64 r1;
1345
1346         if (event >= SNDRV_TIMER_EVENT_START &&
1347             event <= SNDRV_TIMER_EVENT_PAUSE)
1348                 tu->tstamp = *tstamp;
1349         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1350                 return;
1351         memset(&r1, 0, sizeof(r1));
1352         r1.event = event;
1353         r1.tstamp_sec = tstamp->tv_sec;
1354         r1.tstamp_nsec = tstamp->tv_nsec;
1355         r1.val = resolution;
1356         scoped_guard(spinlock_irqsave, &tu->qlock)
1357                 snd_timer_user_append_to_tqueue(tu, &r1);
1358         snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1359         wake_up(&tu->qchange_sleep);
1360 }
1361
1362 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1363 {
1364         struct snd_timer_user *tu = timeri->callback_data;
1365
1366         tu->disconnected = true;
1367         wake_up(&tu->qchange_sleep);
1368 }
1369
1370 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1371                                       unsigned long resolution,
1372                                       unsigned long ticks)
1373 {
1374         struct snd_timer_user *tu = timeri->callback_data;
1375         struct snd_timer_tread64 *r, r1;
1376         struct timespec64 tstamp;
1377         int prev, append = 0;
1378
1379         memset(&r1, 0, sizeof(r1));
1380         memset(&tstamp, 0, sizeof(tstamp));
1381         scoped_guard(spinlock, &tu->qlock) {
1382                 if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1383                                    (1 << SNDRV_TIMER_EVENT_TICK))) == 0)
1384                         return;
1385                 if (tu->last_resolution != resolution || ticks > 0) {
1386                         if (timer_tstamp_monotonic)
1387                                 ktime_get_ts64(&tstamp);
1388                         else
1389                                 ktime_get_real_ts64(&tstamp);
1390                 }
1391                 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1392                     tu->last_resolution != resolution) {
1393                         r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1394                         r1.tstamp_sec = tstamp.tv_sec;
1395                         r1.tstamp_nsec = tstamp.tv_nsec;
1396                         r1.val = resolution;
1397                         snd_timer_user_append_to_tqueue(tu, &r1);
1398                         tu->last_resolution = resolution;
1399                         append++;
1400                 }
1401                 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1402                         break;
1403                 if (ticks == 0)
1404                         break;
1405                 if (tu->qused > 0) {
1406                         prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1407                         r = &tu->tqueue[prev];
1408                         if (r->event == SNDRV_TIMER_EVENT_TICK) {
1409                                 r->tstamp_sec = tstamp.tv_sec;
1410                                 r->tstamp_nsec = tstamp.tv_nsec;
1411                                 r->val += ticks;
1412                                 append++;
1413                                 break;
1414                         }
1415                 }
1416                 r1.event = SNDRV_TIMER_EVENT_TICK;
1417                 r1.tstamp_sec = tstamp.tv_sec;
1418                 r1.tstamp_nsec = tstamp.tv_nsec;
1419                 r1.val = ticks;
1420                 snd_timer_user_append_to_tqueue(tu, &r1);
1421                 append++;
1422         }
1423         if (append == 0)
1424                 return;
1425         snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1426         wake_up(&tu->qchange_sleep);
1427 }
1428
1429 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1430 {
1431         struct snd_timer_read *queue = NULL;
1432         struct snd_timer_tread64 *tqueue = NULL;
1433
1434         if (tu->tread) {
1435                 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1436                 if (!tqueue)
1437                         return -ENOMEM;
1438         } else {
1439                 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1440                 if (!queue)
1441                         return -ENOMEM;
1442         }
1443
1444         guard(spinlock_irq)(&tu->qlock);
1445         kfree(tu->queue);
1446         kfree(tu->tqueue);
1447         tu->queue_size = size;
1448         tu->queue = queue;
1449         tu->tqueue = tqueue;
1450         tu->qhead = tu->qtail = tu->qused = 0;
1451
1452         return 0;
1453 }
1454
1455 static int snd_timer_user_open(struct inode *inode, struct file *file)
1456 {
1457         struct snd_timer_user *tu;
1458         int err;
1459
1460         err = stream_open(inode, file);
1461         if (err < 0)
1462                 return err;
1463
1464         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1465         if (tu == NULL)
1466                 return -ENOMEM;
1467         spin_lock_init(&tu->qlock);
1468         init_waitqueue_head(&tu->qchange_sleep);
1469         mutex_init(&tu->ioctl_lock);
1470         tu->ticks = 1;
1471         if (realloc_user_queue(tu, 128) < 0) {
1472                 kfree(tu);
1473                 return -ENOMEM;
1474         }
1475         file->private_data = tu;
1476         return 0;
1477 }
1478
1479 static int snd_timer_user_release(struct inode *inode, struct file *file)
1480 {
1481         struct snd_timer_user *tu;
1482
1483         if (file->private_data) {
1484                 tu = file->private_data;
1485                 file->private_data = NULL;
1486                 scoped_guard(mutex, &tu->ioctl_lock) {
1487                         if (tu->timeri) {
1488                                 snd_timer_close(tu->timeri);
1489                                 snd_timer_instance_free(tu->timeri);
1490                         }
1491                 }
1492                 snd_fasync_free(tu->fasync);
1493                 kfree(tu->queue);
1494                 kfree(tu->tqueue);
1495                 kfree(tu);
1496         }
1497         return 0;
1498 }
1499
1500 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1501 {
1502         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1503         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1504         id->card = -1;
1505         id->device = -1;
1506         id->subdevice = -1;
1507 }
1508
1509 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1510 {
1511         id->dev_class = timer->tmr_class;
1512         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1513         id->card = timer->card ? timer->card->number : -1;
1514         id->device = timer->tmr_device;
1515         id->subdevice = timer->tmr_subdevice;
1516 }
1517
1518 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1519 {
1520         struct snd_timer_id id;
1521         struct snd_timer *timer;
1522         struct list_head *p;
1523
1524         if (copy_from_user(&id, _tid, sizeof(id)))
1525                 return -EFAULT;
1526         guard(mutex)(&register_mutex);
1527         if (id.dev_class < 0) {         /* first item */
1528                 if (list_empty(&snd_timer_list))
1529                         snd_timer_user_zero_id(&id);
1530                 else {
1531                         timer = list_entry(snd_timer_list.next,
1532                                            struct snd_timer, device_list);
1533                         snd_timer_user_copy_id(&id, timer);
1534                 }
1535         } else {
1536                 switch (id.dev_class) {
1537                 case SNDRV_TIMER_CLASS_GLOBAL:
1538                         id.device = id.device < 0 ? 0 : id.device + 1;
1539                         list_for_each(p, &snd_timer_list) {
1540                                 timer = list_entry(p, struct snd_timer, device_list);
1541                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1542                                         snd_timer_user_copy_id(&id, timer);
1543                                         break;
1544                                 }
1545                                 if (timer->tmr_device >= id.device) {
1546                                         snd_timer_user_copy_id(&id, timer);
1547                                         break;
1548                                 }
1549                         }
1550                         if (p == &snd_timer_list)
1551                                 snd_timer_user_zero_id(&id);
1552                         break;
1553                 case SNDRV_TIMER_CLASS_CARD:
1554                 case SNDRV_TIMER_CLASS_PCM:
1555                         if (id.card < 0) {
1556                                 id.card = 0;
1557                         } else {
1558                                 if (id.device < 0) {
1559                                         id.device = 0;
1560                                 } else {
1561                                         if (id.subdevice < 0)
1562                                                 id.subdevice = 0;
1563                                         else if (id.subdevice < INT_MAX)
1564                                                 id.subdevice++;
1565                                 }
1566                         }
1567                         list_for_each(p, &snd_timer_list) {
1568                                 timer = list_entry(p, struct snd_timer, device_list);
1569                                 if (timer->tmr_class > id.dev_class) {
1570                                         snd_timer_user_copy_id(&id, timer);
1571                                         break;
1572                                 }
1573                                 if (timer->tmr_class < id.dev_class)
1574                                         continue;
1575                                 if (timer->card->number > id.card) {
1576                                         snd_timer_user_copy_id(&id, timer);
1577                                         break;
1578                                 }
1579                                 if (timer->card->number < id.card)
1580                                         continue;
1581                                 if (timer->tmr_device > id.device) {
1582                                         snd_timer_user_copy_id(&id, timer);
1583                                         break;
1584                                 }
1585                                 if (timer->tmr_device < id.device)
1586                                         continue;
1587                                 if (timer->tmr_subdevice > id.subdevice) {
1588                                         snd_timer_user_copy_id(&id, timer);
1589                                         break;
1590                                 }
1591                                 if (timer->tmr_subdevice < id.subdevice)
1592                                         continue;
1593                                 snd_timer_user_copy_id(&id, timer);
1594                                 break;
1595                         }
1596                         if (p == &snd_timer_list)
1597                                 snd_timer_user_zero_id(&id);
1598                         break;
1599                 default:
1600                         snd_timer_user_zero_id(&id);
1601                 }
1602         }
1603         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1604                 return -EFAULT;
1605         return 0;
1606 }
1607
1608 static int snd_timer_user_ginfo(struct file *file,
1609                                 struct snd_timer_ginfo __user *_ginfo)
1610 {
1611         struct snd_timer_ginfo *ginfo __free(kfree) = NULL;
1612         struct snd_timer_id tid;
1613         struct snd_timer *t;
1614         struct list_head *p;
1615
1616         ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1617         if (IS_ERR(ginfo))
1618                 return PTR_ERR(ginfo);
1619
1620         tid = ginfo->tid;
1621         memset(ginfo, 0, sizeof(*ginfo));
1622         ginfo->tid = tid;
1623         guard(mutex)(&register_mutex);
1624         t = snd_timer_find(&tid);
1625         if (!t)
1626                 return -ENODEV;
1627         ginfo->card = t->card ? t->card->number : -1;
1628         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1629                 ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1630         strscpy(ginfo->id, t->id, sizeof(ginfo->id));
1631         strscpy(ginfo->name, t->name, sizeof(ginfo->name));
1632         scoped_guard(spinlock_irq, &t->lock)
1633                 ginfo->resolution = snd_timer_hw_resolution(t);
1634         if (t->hw.resolution_min > 0) {
1635                 ginfo->resolution_min = t->hw.resolution_min;
1636                 ginfo->resolution_max = t->hw.resolution_max;
1637         }
1638         list_for_each(p, &t->open_list_head) {
1639                 ginfo->clients++;
1640         }
1641         if (copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1642                 return -EFAULT;
1643         return 0;
1644 }
1645
1646 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1647 {
1648         struct snd_timer *t;
1649
1650         guard(mutex)(&register_mutex);
1651         t = snd_timer_find(&gparams->tid);
1652         if (!t)
1653                 return -ENODEV;
1654         if (!list_empty(&t->open_list_head))
1655                 return -EBUSY;
1656         if (!t->hw.set_period)
1657                 return -ENOSYS;
1658         return t->hw.set_period(t, gparams->period_num, gparams->period_den);
1659 }
1660
1661 static int snd_timer_user_gparams(struct file *file,
1662                                   struct snd_timer_gparams __user *_gparams)
1663 {
1664         struct snd_timer_gparams gparams;
1665
1666         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1667                 return -EFAULT;
1668         return timer_set_gparams(&gparams);
1669 }
1670
1671 static int snd_timer_user_gstatus(struct file *file,
1672                                   struct snd_timer_gstatus __user *_gstatus)
1673 {
1674         struct snd_timer_gstatus gstatus;
1675         struct snd_timer_id tid;
1676         struct snd_timer *t;
1677         int err = 0;
1678
1679         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1680                 return -EFAULT;
1681         tid = gstatus.tid;
1682         memset(&gstatus, 0, sizeof(gstatus));
1683         gstatus.tid = tid;
1684         guard(mutex)(&register_mutex);
1685         t = snd_timer_find(&tid);
1686         if (t != NULL) {
1687                 guard(spinlock_irq)(&t->lock);
1688                 gstatus.resolution = snd_timer_hw_resolution(t);
1689                 if (t->hw.precise_resolution) {
1690                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1691                                                  &gstatus.resolution_den);
1692                 } else {
1693                         gstatus.resolution_num = gstatus.resolution;
1694                         gstatus.resolution_den = 1000000000uL;
1695                 }
1696         } else {
1697                 err = -ENODEV;
1698         }
1699         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1700                 err = -EFAULT;
1701         return err;
1702 }
1703
1704 static int snd_timer_user_tselect(struct file *file,
1705                                   struct snd_timer_select __user *_tselect)
1706 {
1707         struct snd_timer_user *tu;
1708         struct snd_timer_select tselect;
1709         char str[32];
1710         int err = 0;
1711
1712         tu = file->private_data;
1713         if (tu->timeri) {
1714                 snd_timer_close(tu->timeri);
1715                 snd_timer_instance_free(tu->timeri);
1716                 tu->timeri = NULL;
1717         }
1718         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1719                 err = -EFAULT;
1720                 goto __err;
1721         }
1722         sprintf(str, "application %i", current->pid);
1723         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1724                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1725         tu->timeri = snd_timer_instance_new(str);
1726         if (!tu->timeri) {
1727                 err = -ENOMEM;
1728                 goto __err;
1729         }
1730
1731         tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1732         tu->timeri->callback = tu->tread
1733                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1734         tu->timeri->ccallback = snd_timer_user_ccallback;
1735         tu->timeri->callback_data = (void *)tu;
1736         tu->timeri->disconnect = snd_timer_user_disconnect;
1737
1738         err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1739         if (err < 0) {
1740                 snd_timer_instance_free(tu->timeri);
1741                 tu->timeri = NULL;
1742         }
1743
1744       __err:
1745         return err;
1746 }
1747
1748 static int snd_timer_user_info(struct file *file,
1749                                struct snd_timer_info __user *_info)
1750 {
1751         struct snd_timer_user *tu;
1752         struct snd_timer_info *info __free(kfree) = NULL;
1753         struct snd_timer *t;
1754
1755         tu = file->private_data;
1756         if (!tu->timeri)
1757                 return -EBADFD;
1758         t = tu->timeri->timer;
1759         if (!t)
1760                 return -EBADFD;
1761
1762         info = kzalloc(sizeof(*info), GFP_KERNEL);
1763         if (! info)
1764                 return -ENOMEM;
1765         info->card = t->card ? t->card->number : -1;
1766         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1767                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1768         strscpy(info->id, t->id, sizeof(info->id));
1769         strscpy(info->name, t->name, sizeof(info->name));
1770         scoped_guard(spinlock_irq, &t->lock)
1771                 info->resolution = snd_timer_hw_resolution(t);
1772         if (copy_to_user(_info, info, sizeof(*_info)))
1773                 return -EFAULT;
1774         return 0;
1775 }
1776
1777 static int snd_timer_user_params(struct file *file,
1778                                  struct snd_timer_params __user *_params)
1779 {
1780         struct snd_timer_user *tu;
1781         struct snd_timer_params params;
1782         struct snd_timer *t;
1783         int err;
1784
1785         tu = file->private_data;
1786         if (!tu->timeri)
1787                 return -EBADFD;
1788         t = tu->timeri->timer;
1789         if (!t)
1790                 return -EBADFD;
1791         if (copy_from_user(&params, _params, sizeof(params)))
1792                 return -EFAULT;
1793         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1794                 u64 resolution;
1795
1796                 if (params.ticks < 1) {
1797                         err = -EINVAL;
1798                         goto _end;
1799                 }
1800
1801                 /* Don't allow resolution less than 1ms */
1802                 resolution = snd_timer_resolution(tu->timeri);
1803                 resolution *= params.ticks;
1804                 if (resolution < 1000000) {
1805                         err = -EINVAL;
1806                         goto _end;
1807                 }
1808         }
1809         if (params.queue_size > 0 &&
1810             (params.queue_size < 32 || params.queue_size > 1024)) {
1811                 err = -EINVAL;
1812                 goto _end;
1813         }
1814         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1815                               (1<<SNDRV_TIMER_EVENT_TICK)|
1816                               (1<<SNDRV_TIMER_EVENT_START)|
1817                               (1<<SNDRV_TIMER_EVENT_STOP)|
1818                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1819                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1820                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1821                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1822                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1823                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1824                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1825                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1826                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1827                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1828                 err = -EINVAL;
1829                 goto _end;
1830         }
1831         snd_timer_stop(tu->timeri);
1832         scoped_guard(spinlock_irq, &t->lock) {
1833                 tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1834                                        SNDRV_TIMER_IFLG_EXCLUSIVE|
1835                                        SNDRV_TIMER_IFLG_EARLY_EVENT);
1836                 if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1837                         tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1838                 if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1839                         tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1840                 if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1841                         tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1842         }
1843         if (params.queue_size > 0 &&
1844             (unsigned int)tu->queue_size != params.queue_size) {
1845                 err = realloc_user_queue(tu, params.queue_size);
1846                 if (err < 0)
1847                         goto _end;
1848         }
1849         scoped_guard(spinlock_irq, &tu->qlock) {
1850                 tu->qhead = tu->qtail = tu->qused = 0;
1851                 if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1852                         if (tu->tread) {
1853                                 struct snd_timer_tread64 tread;
1854
1855                                 memset(&tread, 0, sizeof(tread));
1856                                 tread.event = SNDRV_TIMER_EVENT_EARLY;
1857                                 tread.tstamp_sec = 0;
1858                                 tread.tstamp_nsec = 0;
1859                                 tread.val = 0;
1860                                 snd_timer_user_append_to_tqueue(tu, &tread);
1861                         } else {
1862                                 struct snd_timer_read *r = &tu->queue[0];
1863
1864                                 r->resolution = 0;
1865                                 r->ticks = 0;
1866                                 tu->qused++;
1867                                 tu->qtail++;
1868                         }
1869                 }
1870                 tu->filter = params.filter;
1871                 tu->ticks = params.ticks;
1872         }
1873         err = 0;
1874  _end:
1875         if (copy_to_user(_params, &params, sizeof(params)))
1876                 return -EFAULT;
1877         return err;
1878 }
1879
1880 static int snd_timer_user_status32(struct file *file,
1881                                    struct snd_timer_status32 __user *_status)
1882  {
1883         struct snd_timer_user *tu;
1884         struct snd_timer_status32 status;
1885
1886         tu = file->private_data;
1887         if (!tu->timeri)
1888                 return -EBADFD;
1889         memset(&status, 0, sizeof(status));
1890         status.tstamp_sec = tu->tstamp.tv_sec;
1891         status.tstamp_nsec = tu->tstamp.tv_nsec;
1892         status.resolution = snd_timer_resolution(tu->timeri);
1893         status.lost = tu->timeri->lost;
1894         status.overrun = tu->overrun;
1895         scoped_guard(spinlock_irq, &tu->qlock)
1896                 status.queue = tu->qused;
1897         if (copy_to_user(_status, &status, sizeof(status)))
1898                 return -EFAULT;
1899         return 0;
1900 }
1901
1902 static int snd_timer_user_status64(struct file *file,
1903                                    struct snd_timer_status64 __user *_status)
1904 {
1905         struct snd_timer_user *tu;
1906         struct snd_timer_status64 status;
1907
1908         tu = file->private_data;
1909         if (!tu->timeri)
1910                 return -EBADFD;
1911         memset(&status, 0, sizeof(status));
1912         status.tstamp_sec = tu->tstamp.tv_sec;
1913         status.tstamp_nsec = tu->tstamp.tv_nsec;
1914         status.resolution = snd_timer_resolution(tu->timeri);
1915         status.lost = tu->timeri->lost;
1916         status.overrun = tu->overrun;
1917         scoped_guard(spinlock_irq, &tu->qlock)
1918                 status.queue = tu->qused;
1919         if (copy_to_user(_status, &status, sizeof(status)))
1920                 return -EFAULT;
1921         return 0;
1922 }
1923
1924 static int snd_timer_user_start(struct file *file)
1925 {
1926         int err;
1927         struct snd_timer_user *tu;
1928
1929         tu = file->private_data;
1930         if (!tu->timeri)
1931                 return -EBADFD;
1932         snd_timer_stop(tu->timeri);
1933         tu->timeri->lost = 0;
1934         tu->last_resolution = 0;
1935         err = snd_timer_start(tu->timeri, tu->ticks);
1936         if (err < 0)
1937                 return err;
1938         return 0;
1939 }
1940
1941 static int snd_timer_user_stop(struct file *file)
1942 {
1943         int err;
1944         struct snd_timer_user *tu;
1945
1946         tu = file->private_data;
1947         if (!tu->timeri)
1948                 return -EBADFD;
1949         err = snd_timer_stop(tu->timeri);
1950         if (err < 0)
1951                 return err;
1952         return 0;
1953 }
1954
1955 static int snd_timer_user_continue(struct file *file)
1956 {
1957         int err;
1958         struct snd_timer_user *tu;
1959
1960         tu = file->private_data;
1961         if (!tu->timeri)
1962                 return -EBADFD;
1963         /* start timer instead of continue if it's not used before */
1964         if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
1965                 return snd_timer_user_start(file);
1966         tu->timeri->lost = 0;
1967         err = snd_timer_continue(tu->timeri);
1968         if (err < 0)
1969                 return err;
1970         return 0;
1971 }
1972
1973 static int snd_timer_user_pause(struct file *file)
1974 {
1975         int err;
1976         struct snd_timer_user *tu;
1977
1978         tu = file->private_data;
1979         if (!tu->timeri)
1980                 return -EBADFD;
1981         err = snd_timer_pause(tu->timeri);
1982         if (err < 0)
1983                 return err;
1984         return 0;
1985 }
1986
1987 static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
1988                                 unsigned int cmd, bool compat)
1989 {
1990         int __user *p = argp;
1991         int xarg, old_tread;
1992
1993         if (tu->timeri) /* too late */
1994                 return -EBUSY;
1995         if (get_user(xarg, p))
1996                 return -EFAULT;
1997
1998         old_tread = tu->tread;
1999
2000         if (!xarg)
2001                 tu->tread = TREAD_FORMAT_NONE;
2002         else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2003                  (IS_ENABLED(CONFIG_64BIT) && !compat))
2004                 tu->tread = TREAD_FORMAT_TIME64;
2005         else
2006                 tu->tread = TREAD_FORMAT_TIME32;
2007
2008         if (tu->tread != old_tread &&
2009             realloc_user_queue(tu, tu->queue_size) < 0) {
2010                 tu->tread = old_tread;
2011                 return -ENOMEM;
2012         }
2013
2014         return 0;
2015 }
2016
2017 enum {
2018         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2019         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2020         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2021         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2022 };
2023
2024 #ifdef CONFIG_SND_UTIMER
2025 /*
2026  * Since userspace-driven timers are passed to userspace, we need to have an identifier
2027  * which will allow us to use them (basically, the subdevice number of udriven timer).
2028  */
2029 static DEFINE_IDA(snd_utimer_ids);
2030
2031 static void snd_utimer_put_id(struct snd_utimer *utimer)
2032 {
2033         int timer_id = utimer->id;
2034
2035         snd_BUG_ON(timer_id < 0 || timer_id >= SNDRV_UTIMERS_MAX_COUNT);
2036         ida_free(&snd_utimer_ids, timer_id);
2037 }
2038
2039 static int snd_utimer_take_id(void)
2040 {
2041         return ida_alloc_max(&snd_utimer_ids, SNDRV_UTIMERS_MAX_COUNT - 1, GFP_KERNEL);
2042 }
2043
2044 static void snd_utimer_free(struct snd_utimer *utimer)
2045 {
2046         snd_timer_free(utimer->timer);
2047         snd_utimer_put_id(utimer);
2048         kfree(utimer->name);
2049         kfree(utimer);
2050 }
2051
2052 static int snd_utimer_release(struct inode *inode, struct file *file)
2053 {
2054         struct snd_utimer *utimer = (struct snd_utimer *)file->private_data;
2055
2056         snd_utimer_free(utimer);
2057         return 0;
2058 }
2059
2060 static int snd_utimer_trigger(struct file *file)
2061 {
2062         struct snd_utimer *utimer = (struct snd_utimer *)file->private_data;
2063
2064         snd_timer_interrupt(utimer->timer, utimer->timer->sticks);
2065         return 0;
2066 }
2067
2068 static long snd_utimer_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
2069 {
2070         switch (ioctl) {
2071         case SNDRV_TIMER_IOCTL_TRIGGER:
2072                 return snd_utimer_trigger(file);
2073         }
2074
2075         return -ENOTTY;
2076 }
2077
2078 static const struct file_operations snd_utimer_fops = {
2079         .llseek = noop_llseek,
2080         .release = snd_utimer_release,
2081         .unlocked_ioctl = snd_utimer_ioctl,
2082 };
2083
2084 static int snd_utimer_start(struct snd_timer *t)
2085 {
2086         return 0;
2087 }
2088
2089 static int snd_utimer_stop(struct snd_timer *t)
2090 {
2091         return 0;
2092 }
2093
2094 static int snd_utimer_open(struct snd_timer *t)
2095 {
2096         return 0;
2097 }
2098
2099 static int snd_utimer_close(struct snd_timer *t)
2100 {
2101         return 0;
2102 }
2103
2104 static const struct snd_timer_hardware timer_hw = {
2105         .flags = SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_WORK,
2106         .open = snd_utimer_open,
2107         .close = snd_utimer_close,
2108         .start = snd_utimer_start,
2109         .stop = snd_utimer_stop,
2110 };
2111
2112 static int snd_utimer_create(struct snd_timer_uinfo *utimer_info,
2113                              struct snd_utimer **r_utimer)
2114 {
2115         struct snd_utimer *utimer;
2116         struct snd_timer *timer;
2117         struct snd_timer_id tid;
2118         int utimer_id;
2119         int err = 0;
2120
2121         if (!utimer_info || utimer_info->resolution == 0)
2122                 return -EINVAL;
2123
2124         utimer = kzalloc(sizeof(*utimer), GFP_KERNEL);
2125         if (!utimer)
2126                 return -ENOMEM;
2127
2128         /* We hold the ioctl lock here so we won't get a race condition when allocating id */
2129         utimer_id = snd_utimer_take_id();
2130         if (utimer_id < 0) {
2131                 err = utimer_id;
2132                 goto err_take_id;
2133         }
2134
2135         utimer->name = kasprintf(GFP_KERNEL, "snd-utimer%d", utimer_id);
2136         if (!utimer->name) {
2137                 err = -ENOMEM;
2138                 goto err_get_name;
2139         }
2140
2141         utimer->id = utimer_id;
2142
2143         tid.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
2144         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
2145         tid.card = -1;
2146         tid.device = SNDRV_TIMER_GLOBAL_UDRIVEN;
2147         tid.subdevice = utimer_id;
2148
2149         err = snd_timer_new(NULL, utimer->name, &tid, &timer);
2150         if (err < 0) {
2151                 pr_err("Can't create userspace-driven timer\n");
2152                 goto err_timer_new;
2153         }
2154
2155         timer->module = THIS_MODULE;
2156         timer->hw = timer_hw;
2157         timer->hw.resolution = utimer_info->resolution;
2158         timer->hw.ticks = 1;
2159         timer->max_instances = MAX_SLAVE_INSTANCES;
2160
2161         utimer->timer = timer;
2162
2163         err = snd_timer_global_register(timer);
2164         if (err < 0) {
2165                 pr_err("Can't register a userspace-driven timer\n");
2166                 goto err_timer_reg;
2167         }
2168
2169         *r_utimer = utimer;
2170         return 0;
2171
2172 err_timer_reg:
2173         snd_timer_free(timer);
2174 err_timer_new:
2175         kfree(utimer->name);
2176 err_get_name:
2177         snd_utimer_put_id(utimer);
2178 err_take_id:
2179         kfree(utimer);
2180
2181         return err;
2182 }
2183
2184 static int snd_utimer_ioctl_create(struct file *file,
2185                                    struct snd_timer_uinfo __user *_utimer_info)
2186 {
2187         struct snd_utimer *utimer;
2188         struct snd_timer_uinfo *utimer_info __free(kfree) = NULL;
2189         int err, timer_fd;
2190
2191         utimer_info = memdup_user(_utimer_info, sizeof(*utimer_info));
2192         if (IS_ERR(utimer_info))
2193                 return PTR_ERR(utimer_info);
2194
2195         err = snd_utimer_create(utimer_info, &utimer);
2196         if (err < 0)
2197                 return err;
2198
2199         utimer_info->id = utimer->id;
2200
2201         timer_fd = anon_inode_getfd(utimer->name, &snd_utimer_fops, utimer, O_RDWR | O_CLOEXEC);
2202         if (timer_fd < 0) {
2203                 snd_utimer_free(utimer);
2204                 return timer_fd;
2205         }
2206
2207         utimer_info->fd = timer_fd;
2208
2209         err = copy_to_user(_utimer_info, utimer_info, sizeof(*utimer_info));
2210         if (err) {
2211                 /*
2212                  * "Leak" the fd, as there is nothing we can do about it.
2213                  * It might have been closed already since anon_inode_getfd
2214                  * makes it available for userspace.
2215                  *
2216                  * We have to rely on the process exit path to do any
2217                  * necessary cleanup (e.g. releasing the file).
2218                  */
2219                 return -EFAULT;
2220         }
2221
2222         return 0;
2223 }
2224
2225 #else
2226
2227 static int snd_utimer_ioctl_create(struct file *file,
2228                                    struct snd_timer_uinfo __user *_utimer_info)
2229 {
2230         return -ENOTTY;
2231 }
2232
2233 #endif
2234
2235 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2236                                  unsigned long arg, bool compat)
2237 {
2238         struct snd_timer_user *tu;
2239         void __user *argp = (void __user *)arg;
2240         int __user *p = argp;
2241
2242         tu = file->private_data;
2243         switch (cmd) {
2244         case SNDRV_TIMER_IOCTL_PVERSION:
2245                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2246         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2247                 return snd_timer_user_next_device(argp);
2248         case SNDRV_TIMER_IOCTL_TREAD_OLD:
2249         case SNDRV_TIMER_IOCTL_TREAD64:
2250                 return snd_timer_user_tread(argp, tu, cmd, compat);
2251         case SNDRV_TIMER_IOCTL_GINFO:
2252                 return snd_timer_user_ginfo(file, argp);
2253         case SNDRV_TIMER_IOCTL_GPARAMS:
2254                 return snd_timer_user_gparams(file, argp);
2255         case SNDRV_TIMER_IOCTL_GSTATUS:
2256                 return snd_timer_user_gstatus(file, argp);
2257         case SNDRV_TIMER_IOCTL_SELECT:
2258                 return snd_timer_user_tselect(file, argp);
2259         case SNDRV_TIMER_IOCTL_INFO:
2260                 return snd_timer_user_info(file, argp);
2261         case SNDRV_TIMER_IOCTL_PARAMS:
2262                 return snd_timer_user_params(file, argp);
2263         case SNDRV_TIMER_IOCTL_STATUS32:
2264                 return snd_timer_user_status32(file, argp);
2265         case SNDRV_TIMER_IOCTL_STATUS64:
2266                 return snd_timer_user_status64(file, argp);
2267         case SNDRV_TIMER_IOCTL_START:
2268         case SNDRV_TIMER_IOCTL_START_OLD:
2269                 return snd_timer_user_start(file);
2270         case SNDRV_TIMER_IOCTL_STOP:
2271         case SNDRV_TIMER_IOCTL_STOP_OLD:
2272                 return snd_timer_user_stop(file);
2273         case SNDRV_TIMER_IOCTL_CONTINUE:
2274         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2275                 return snd_timer_user_continue(file);
2276         case SNDRV_TIMER_IOCTL_PAUSE:
2277         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2278                 return snd_timer_user_pause(file);
2279         case SNDRV_TIMER_IOCTL_CREATE:
2280                 return snd_utimer_ioctl_create(file, argp);
2281         }
2282         return -ENOTTY;
2283 }
2284
2285 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2286                                  unsigned long arg)
2287 {
2288         struct snd_timer_user *tu = file->private_data;
2289
2290         guard(mutex)(&tu->ioctl_lock);
2291         return __snd_timer_user_ioctl(file, cmd, arg, false);
2292 }
2293
2294 static int snd_timer_user_fasync(int fd, struct file * file, int on)
2295 {
2296         struct snd_timer_user *tu;
2297
2298         tu = file->private_data;
2299         return snd_fasync_helper(fd, file, on, &tu->fasync);
2300 }
2301
2302 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2303                                    size_t count, loff_t *offset)
2304 {
2305         struct snd_timer_tread64 *tread;
2306         struct snd_timer_tread32 tread32;
2307         struct snd_timer_user *tu;
2308         long result = 0, unit;
2309         int qhead;
2310         int err = 0;
2311
2312         tu = file->private_data;
2313         switch (tu->tread) {
2314         case TREAD_FORMAT_TIME64:
2315                 unit = sizeof(struct snd_timer_tread64);
2316                 break;
2317         case TREAD_FORMAT_TIME32:
2318                 unit = sizeof(struct snd_timer_tread32);
2319                 break;
2320         case TREAD_FORMAT_NONE:
2321                 unit = sizeof(struct snd_timer_read);
2322                 break;
2323         default:
2324                 WARN_ONCE(1, "Corrupt snd_timer_user\n");
2325                 return -ENOTSUPP;
2326         }
2327
2328         mutex_lock(&tu->ioctl_lock);
2329         spin_lock_irq(&tu->qlock);
2330         while ((long)count - result >= unit) {
2331                 while (!tu->qused) {
2332                         wait_queue_entry_t wait;
2333
2334                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2335                                 err = -EAGAIN;
2336                                 goto _error;
2337                         }
2338
2339                         set_current_state(TASK_INTERRUPTIBLE);
2340                         init_waitqueue_entry(&wait, current);
2341                         add_wait_queue(&tu->qchange_sleep, &wait);
2342
2343                         spin_unlock_irq(&tu->qlock);
2344                         mutex_unlock(&tu->ioctl_lock);
2345                         schedule();
2346                         mutex_lock(&tu->ioctl_lock);
2347                         spin_lock_irq(&tu->qlock);
2348
2349                         remove_wait_queue(&tu->qchange_sleep, &wait);
2350
2351                         if (tu->disconnected) {
2352                                 err = -ENODEV;
2353                                 goto _error;
2354                         }
2355                         if (signal_pending(current)) {
2356                                 err = -ERESTARTSYS;
2357                                 goto _error;
2358                         }
2359                 }
2360
2361                 qhead = tu->qhead++;
2362                 tu->qhead %= tu->queue_size;
2363                 tu->qused--;
2364                 spin_unlock_irq(&tu->qlock);
2365
2366                 tread = &tu->tqueue[qhead];
2367
2368                 switch (tu->tread) {
2369                 case TREAD_FORMAT_TIME64:
2370                         if (copy_to_user(buffer, tread,
2371                                          sizeof(struct snd_timer_tread64)))
2372                                 err = -EFAULT;
2373                         break;
2374                 case TREAD_FORMAT_TIME32:
2375                         memset(&tread32, 0, sizeof(tread32));
2376                         tread32 = (struct snd_timer_tread32) {
2377                                 .event = tread->event,
2378                                 .tstamp_sec = tread->tstamp_sec,
2379                                 .tstamp_nsec = tread->tstamp_nsec,
2380                                 .val = tread->val,
2381                         };
2382
2383                         if (copy_to_user(buffer, &tread32, sizeof(tread32)))
2384                                 err = -EFAULT;
2385                         break;
2386                 case TREAD_FORMAT_NONE:
2387                         if (copy_to_user(buffer, &tu->queue[qhead],
2388                                          sizeof(struct snd_timer_read)))
2389                                 err = -EFAULT;
2390                         break;
2391                 default:
2392                         err = -ENOTSUPP;
2393                         break;
2394                 }
2395
2396                 spin_lock_irq(&tu->qlock);
2397                 if (err < 0)
2398                         goto _error;
2399                 result += unit;
2400                 buffer += unit;
2401         }
2402  _error:
2403         spin_unlock_irq(&tu->qlock);
2404         mutex_unlock(&tu->ioctl_lock);
2405         return result > 0 ? result : err;
2406 }
2407
2408 static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2409 {
2410         __poll_t mask;
2411         struct snd_timer_user *tu;
2412
2413         tu = file->private_data;
2414
2415         poll_wait(file, &tu->qchange_sleep, wait);
2416
2417         mask = 0;
2418         guard(spinlock_irq)(&tu->qlock);
2419         if (tu->qused)
2420                 mask |= EPOLLIN | EPOLLRDNORM;
2421         if (tu->disconnected)
2422                 mask |= EPOLLERR;
2423
2424         return mask;
2425 }
2426
2427 #ifdef CONFIG_COMPAT
2428 #include "timer_compat.c"
2429 #else
2430 #define snd_timer_user_ioctl_compat     NULL
2431 #endif
2432
2433 static const struct file_operations snd_timer_f_ops =
2434 {
2435         .owner =        THIS_MODULE,
2436         .read =         snd_timer_user_read,
2437         .open =         snd_timer_user_open,
2438         .release =      snd_timer_user_release,
2439         .poll =         snd_timer_user_poll,
2440         .unlocked_ioctl =       snd_timer_user_ioctl,
2441         .compat_ioctl = snd_timer_user_ioctl_compat,
2442         .fasync =       snd_timer_user_fasync,
2443 };
2444
2445 /* unregister the system timer */
2446 static void snd_timer_free_all(void)
2447 {
2448         struct snd_timer *timer, *n;
2449
2450         list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2451                 snd_timer_free(timer);
2452 }
2453
2454 static struct device *timer_dev;
2455
2456 /*
2457  *  ENTRY functions
2458  */
2459
2460 static int __init alsa_timer_init(void)
2461 {
2462         int err;
2463
2464         err = snd_device_alloc(&timer_dev, NULL);
2465         if (err < 0)
2466                 return err;
2467         dev_set_name(timer_dev, "timer");
2468
2469 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2470         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2471                               "system timer");
2472 #endif
2473
2474         err = snd_timer_register_system();
2475         if (err < 0) {
2476                 pr_err("ALSA: unable to register system timer (%i)\n", err);
2477                 goto put_timer;
2478         }
2479
2480         err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2481                                   &snd_timer_f_ops, NULL, timer_dev);
2482         if (err < 0) {
2483                 pr_err("ALSA: unable to register timer device (%i)\n", err);
2484                 snd_timer_free_all();
2485                 goto put_timer;
2486         }
2487
2488         snd_timer_proc_init();
2489         return 0;
2490
2491 put_timer:
2492         put_device(timer_dev);
2493         return err;
2494 }
2495
2496 static void __exit alsa_timer_exit(void)
2497 {
2498         snd_unregister_device(timer_dev);
2499         snd_timer_free_all();
2500         put_device(timer_dev);
2501         snd_timer_proc_done();
2502 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2503         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2504 #endif
2505 }
2506
2507 module_init(alsa_timer_init)
2508 module_exit(alsa_timer_exit)