sound/core/timer.c

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