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