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