sound/core/timer.c

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