Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Initialization routines
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/module.h>
10#include <linux/device.h>
11#include <linux/file.h>
12#include <linux/slab.h>
13#include <linux/time.h>
14#include <linux/ctype.h>
15#include <linux/pm.h>
16#include <linux/debugfs.h>
17#include <linux/completion.h>
18#include <linux/interrupt.h>
19
20#include <sound/core.h>
21#include <sound/control.h>
22#include <sound/info.h>
23
24/* monitor files for graceful shutdown (hotplug) */
25struct snd_monitor_file {
26 struct file *file;
27 const struct file_operations *disconnected_f_op;
28 struct list_head shutdown_list; /* still need to shutdown */
29 struct list_head list; /* link of monitor files */
30};
31
32static DEFINE_SPINLOCK(shutdown_lock);
33static LIST_HEAD(shutdown_files);
34
35static const struct file_operations snd_shutdown_f_ops;
36
37/* locked for registering/using */
38static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39static struct snd_card *snd_cards[SNDRV_CARDS];
40
41static DEFINE_MUTEX(snd_card_mutex);
42
43static char *slots[SNDRV_CARDS];
44module_param_array(slots, charp, NULL, 0444);
45MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
46
47/* return non-zero if the given index is reserved for the given
48 * module via slots option
49 */
50static int module_slot_match(struct module *module, int idx)
51{
52 int match = 1;
53#ifdef MODULE
54 const char *s1, *s2;
55
56 if (!module || !*module->name || !slots[idx])
57 return 0;
58
59 s1 = module->name;
60 s2 = slots[idx];
61 if (*s2 == '!') {
62 match = 0; /* negative match */
63 s2++;
64 }
65 /* compare module name strings
66 * hyphens are handled as equivalent with underscore
67 */
68 for (;;) {
69 char c1 = *s1++;
70 char c2 = *s2++;
71 if (c1 == '-')
72 c1 = '_';
73 if (c2 == '-')
74 c2 = '_';
75 if (c1 != c2)
76 return !match;
77 if (!c1)
78 break;
79 }
80#endif /* MODULE */
81 return match;
82}
83
84#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
85int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
87#endif
88
89static int check_empty_slot(struct module *module, int slot)
90{
91 return !slots[slot] || !*slots[slot];
92}
93
94/* return an empty slot number (>= 0) found in the given bitmask @mask.
95 * @mask == -1 == 0xffffffff means: take any free slot up to 32
96 * when no slot is available, return the original @mask as is.
97 */
98static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
99 struct module *module)
100{
101 int slot;
102
103 for (slot = 0; slot < SNDRV_CARDS; slot++) {
104 if (slot < 32 && !(mask & (1U << slot)))
105 continue;
106 if (!test_bit(slot, snd_cards_lock)) {
107 if (check(module, slot))
108 return slot; /* found */
109 }
110 }
111 return mask; /* unchanged */
112}
113
114/* the default release callback set in snd_device_initialize() below;
115 * this is just NOP for now, as almost all jobs are already done in
116 * dev_free callback of snd_device chain instead.
117 */
118static void default_release(struct device *dev)
119{
120}
121
122/**
123 * snd_device_initialize - Initialize struct device for sound devices
124 * @dev: device to initialize
125 * @card: card to assign, optional
126 */
127void snd_device_initialize(struct device *dev, struct snd_card *card)
128{
129 device_initialize(dev);
130 if (card)
131 dev->parent = &card->card_dev;
132 dev->class = sound_class;
133 dev->release = default_release;
134}
135EXPORT_SYMBOL_GPL(snd_device_initialize);
136
137static int snd_card_init(struct snd_card *card, struct device *parent,
138 int idx, const char *xid, struct module *module,
139 size_t extra_size);
140static int snd_card_do_free(struct snd_card *card);
141static const struct attribute_group card_dev_attr_group;
142
143static void release_card_device(struct device *dev)
144{
145 snd_card_do_free(dev_to_snd_card(dev));
146}
147
148/**
149 * snd_card_new - create and initialize a soundcard structure
150 * @parent: the parent device object
151 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
152 * @xid: card identification (ASCII string)
153 * @module: top level module for locking
154 * @extra_size: allocate this extra size after the main soundcard structure
155 * @card_ret: the pointer to store the created card instance
156 *
157 * The function allocates snd_card instance via kzalloc with the given
158 * space for the driver to use freely. The allocated struct is stored
159 * in the given card_ret pointer.
160 *
161 * Return: Zero if successful or a negative error code.
162 */
163int snd_card_new(struct device *parent, int idx, const char *xid,
164 struct module *module, int extra_size,
165 struct snd_card **card_ret)
166{
167 struct snd_card *card;
168 int err;
169
170 if (snd_BUG_ON(!card_ret))
171 return -EINVAL;
172 *card_ret = NULL;
173
174 if (extra_size < 0)
175 extra_size = 0;
176 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
177 if (!card)
178 return -ENOMEM;
179
180 err = snd_card_init(card, parent, idx, xid, module, extra_size);
181 if (err < 0)
182 return err; /* card is freed by error handler */
183
184 *card_ret = card;
185 return 0;
186}
187EXPORT_SYMBOL(snd_card_new);
188
189static void __snd_card_release(struct device *dev, void *data)
190{
191 snd_card_free(data);
192}
193
194/**
195 * snd_devm_card_new - managed snd_card object creation
196 * @parent: the parent device object
197 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
198 * @xid: card identification (ASCII string)
199 * @module: top level module for locking
200 * @extra_size: allocate this extra size after the main soundcard structure
201 * @card_ret: the pointer to store the created card instance
202 *
203 * This function works like snd_card_new() but manages the allocated resource
204 * via devres, i.e. you don't need to free explicitly.
205 *
206 * When a snd_card object is created with this function and registered via
207 * snd_card_register(), the very first devres action to call snd_card_free()
208 * is added automatically. In that way, the resource disconnection is assured
209 * at first, then released in the expected order.
210 *
211 * If an error happens at the probe before snd_card_register() is called and
212 * there have been other devres resources, you'd need to free the card manually
213 * via snd_card_free() call in the error; otherwise it may lead to UAF due to
214 * devres call orders. You can use snd_card_free_on_error() helper for
215 * handling it more easily.
216 *
217 * Return: zero if successful, or a negative error code
218 */
219int snd_devm_card_new(struct device *parent, int idx, const char *xid,
220 struct module *module, size_t extra_size,
221 struct snd_card **card_ret)
222{
223 struct snd_card *card;
224 int err;
225
226 *card_ret = NULL;
227 card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
228 GFP_KERNEL);
229 if (!card)
230 return -ENOMEM;
231 card->managed = true;
232 err = snd_card_init(card, parent, idx, xid, module, extra_size);
233 if (err < 0) {
234 devres_free(card); /* in managed mode, we need to free manually */
235 return err;
236 }
237
238 devres_add(parent, card);
239 *card_ret = card;
240 return 0;
241}
242EXPORT_SYMBOL_GPL(snd_devm_card_new);
243
244/**
245 * snd_card_free_on_error - a small helper for handling devm probe errors
246 * @dev: the managed device object
247 * @ret: the return code from the probe callback
248 *
249 * This function handles the explicit snd_card_free() call at the error from
250 * the probe callback. It's just a small helper for simplifying the error
251 * handling with the managed devices.
252 *
253 * Return: zero if successful, or a negative error code
254 */
255int snd_card_free_on_error(struct device *dev, int ret)
256{
257 struct snd_card *card;
258
259 if (!ret)
260 return 0;
261 card = devres_find(dev, __snd_card_release, NULL, NULL);
262 if (card)
263 snd_card_free(card);
264 return ret;
265}
266EXPORT_SYMBOL_GPL(snd_card_free_on_error);
267
268static int snd_card_init(struct snd_card *card, struct device *parent,
269 int idx, const char *xid, struct module *module,
270 size_t extra_size)
271{
272 int err;
273#ifdef CONFIG_SND_DEBUG
274 char name[8];
275#endif
276
277 if (extra_size > 0)
278 card->private_data = (char *)card + sizeof(struct snd_card);
279 if (xid)
280 strscpy(card->id, xid, sizeof(card->id));
281 err = 0;
282 mutex_lock(&snd_card_mutex);
283 if (idx < 0) /* first check the matching module-name slot */
284 idx = get_slot_from_bitmask(idx, module_slot_match, module);
285 if (idx < 0) /* if not matched, assign an empty slot */
286 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
287 if (idx < 0)
288 err = -ENODEV;
289 else if (idx < snd_ecards_limit) {
290 if (test_bit(idx, snd_cards_lock))
291 err = -EBUSY; /* invalid */
292 } else if (idx >= SNDRV_CARDS)
293 err = -ENODEV;
294 if (err < 0) {
295 mutex_unlock(&snd_card_mutex);
296 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
297 idx, snd_ecards_limit - 1, err);
298 if (!card->managed)
299 kfree(card); /* manually free here, as no destructor called */
300 return err;
301 }
302 set_bit(idx, snd_cards_lock); /* lock it */
303 if (idx >= snd_ecards_limit)
304 snd_ecards_limit = idx + 1; /* increase the limit */
305 mutex_unlock(&snd_card_mutex);
306 card->dev = parent;
307 card->number = idx;
308#ifdef MODULE
309 WARN_ON(!module);
310 card->module = module;
311#endif
312 INIT_LIST_HEAD(&card->devices);
313 init_rwsem(&card->controls_rwsem);
314 rwlock_init(&card->ctl_files_rwlock);
315 INIT_LIST_HEAD(&card->controls);
316 INIT_LIST_HEAD(&card->ctl_files);
317#ifdef CONFIG_SND_CTL_FAST_LOOKUP
318 xa_init(&card->ctl_numids);
319 xa_init(&card->ctl_hash);
320#endif
321 spin_lock_init(&card->files_lock);
322 INIT_LIST_HEAD(&card->files_list);
323 mutex_init(&card->memory_mutex);
324#ifdef CONFIG_PM
325 init_waitqueue_head(&card->power_sleep);
326 init_waitqueue_head(&card->power_ref_sleep);
327 atomic_set(&card->power_ref, 0);
328#endif
329 init_waitqueue_head(&card->remove_sleep);
330 card->sync_irq = -1;
331
332 device_initialize(&card->card_dev);
333 card->card_dev.parent = parent;
334 card->card_dev.class = sound_class;
335 card->card_dev.release = release_card_device;
336 card->card_dev.groups = card->dev_groups;
337 card->dev_groups[0] = &card_dev_attr_group;
338 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
339 if (err < 0)
340 goto __error;
341
342 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
343 dev_driver_string(card->dev), dev_name(&card->card_dev));
344
345 /* the control interface cannot be accessed from the user space until */
346 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
347 err = snd_ctl_create(card);
348 if (err < 0) {
349 dev_err(parent, "unable to register control minors\n");
350 goto __error;
351 }
352 err = snd_info_card_create(card);
353 if (err < 0) {
354 dev_err(parent, "unable to create card info\n");
355 goto __error_ctl;
356 }
357
358#ifdef CONFIG_SND_DEBUG
359 sprintf(name, "card%d", idx);
360 card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
361#endif
362 return 0;
363
364 __error_ctl:
365 snd_device_free_all(card);
366 __error:
367 put_device(&card->card_dev);
368 return err;
369}
370
371/**
372 * snd_card_ref - Get the card object from the index
373 * @idx: the card index
374 *
375 * Returns a card object corresponding to the given index or NULL if not found.
376 * Release the object via snd_card_unref().
377 *
378 * Return: a card object or NULL
379 */
380struct snd_card *snd_card_ref(int idx)
381{
382 struct snd_card *card;
383
384 mutex_lock(&snd_card_mutex);
385 card = snd_cards[idx];
386 if (card)
387 get_device(&card->card_dev);
388 mutex_unlock(&snd_card_mutex);
389 return card;
390}
391EXPORT_SYMBOL_GPL(snd_card_ref);
392
393/* return non-zero if a card is already locked */
394int snd_card_locked(int card)
395{
396 int locked;
397
398 mutex_lock(&snd_card_mutex);
399 locked = test_bit(card, snd_cards_lock);
400 mutex_unlock(&snd_card_mutex);
401 return locked;
402}
403
404static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
405{
406 return -ENODEV;
407}
408
409static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
410 size_t count, loff_t *offset)
411{
412 return -ENODEV;
413}
414
415static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
416 size_t count, loff_t *offset)
417{
418 return -ENODEV;
419}
420
421static int snd_disconnect_release(struct inode *inode, struct file *file)
422{
423 struct snd_monitor_file *df = NULL, *_df;
424
425 spin_lock(&shutdown_lock);
426 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
427 if (_df->file == file) {
428 df = _df;
429 list_del_init(&df->shutdown_list);
430 break;
431 }
432 }
433 spin_unlock(&shutdown_lock);
434
435 if (likely(df)) {
436 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
437 df->disconnected_f_op->fasync(-1, file, 0);
438 return df->disconnected_f_op->release(inode, file);
439 }
440
441 panic("%s(%p, %p) failed!", __func__, inode, file);
442}
443
444static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
445{
446 return EPOLLERR | EPOLLNVAL;
447}
448
449static long snd_disconnect_ioctl(struct file *file,
450 unsigned int cmd, unsigned long arg)
451{
452 return -ENODEV;
453}
454
455static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
456{
457 return -ENODEV;
458}
459
460static int snd_disconnect_fasync(int fd, struct file *file, int on)
461{
462 return -ENODEV;
463}
464
465static const struct file_operations snd_shutdown_f_ops =
466{
467 .owner = THIS_MODULE,
468 .llseek = snd_disconnect_llseek,
469 .read = snd_disconnect_read,
470 .write = snd_disconnect_write,
471 .release = snd_disconnect_release,
472 .poll = snd_disconnect_poll,
473 .unlocked_ioctl = snd_disconnect_ioctl,
474#ifdef CONFIG_COMPAT
475 .compat_ioctl = snd_disconnect_ioctl,
476#endif
477 .mmap = snd_disconnect_mmap,
478 .fasync = snd_disconnect_fasync
479};
480
481/**
482 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
483 * @card: soundcard structure
484 *
485 * Disconnects all APIs from the file-operations (user space).
486 *
487 * Return: Zero, otherwise a negative error code.
488 *
489 * Note: The current implementation replaces all active file->f_op with special
490 * dummy file operations (they do nothing except release).
491 */
492int snd_card_disconnect(struct snd_card *card)
493{
494 struct snd_monitor_file *mfile;
495
496 if (!card)
497 return -EINVAL;
498
499 spin_lock(&card->files_lock);
500 if (card->shutdown) {
501 spin_unlock(&card->files_lock);
502 return 0;
503 }
504 card->shutdown = 1;
505
506 /* replace file->f_op with special dummy operations */
507 list_for_each_entry(mfile, &card->files_list, list) {
508 /* it's critical part, use endless loop */
509 /* we have no room to fail */
510 mfile->disconnected_f_op = mfile->file->f_op;
511
512 spin_lock(&shutdown_lock);
513 list_add(&mfile->shutdown_list, &shutdown_files);
514 spin_unlock(&shutdown_lock);
515
516 mfile->file->f_op = &snd_shutdown_f_ops;
517 fops_get(mfile->file->f_op);
518 }
519 spin_unlock(&card->files_lock);
520
521 /* notify all connected devices about disconnection */
522 /* at this point, they cannot respond to any calls except release() */
523
524#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
525 if (snd_mixer_oss_notify_callback)
526 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
527#endif
528
529 /* notify all devices that we are disconnected */
530 snd_device_disconnect_all(card);
531
532 if (card->sync_irq > 0)
533 synchronize_irq(card->sync_irq);
534
535 snd_info_card_disconnect(card);
536 if (card->registered) {
537 device_del(&card->card_dev);
538 card->registered = false;
539 }
540
541 /* disable fops (user space) operations for ALSA API */
542 mutex_lock(&snd_card_mutex);
543 snd_cards[card->number] = NULL;
544 clear_bit(card->number, snd_cards_lock);
545 mutex_unlock(&snd_card_mutex);
546
547#ifdef CONFIG_PM
548 wake_up(&card->power_sleep);
549 snd_power_sync_ref(card);
550#endif
551 return 0;
552}
553EXPORT_SYMBOL(snd_card_disconnect);
554
555/**
556 * snd_card_disconnect_sync - disconnect card and wait until files get closed
557 * @card: card object to disconnect
558 *
559 * This calls snd_card_disconnect() for disconnecting all belonging components
560 * and waits until all pending files get closed.
561 * It assures that all accesses from user-space finished so that the driver
562 * can release its resources gracefully.
563 */
564void snd_card_disconnect_sync(struct snd_card *card)
565{
566 int err;
567
568 err = snd_card_disconnect(card);
569 if (err < 0) {
570 dev_err(card->dev,
571 "snd_card_disconnect error (%d), skipping sync\n",
572 err);
573 return;
574 }
575
576 spin_lock_irq(&card->files_lock);
577 wait_event_lock_irq(card->remove_sleep,
578 list_empty(&card->files_list),
579 card->files_lock);
580 spin_unlock_irq(&card->files_lock);
581}
582EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
583
584static int snd_card_do_free(struct snd_card *card)
585{
586 card->releasing = true;
587#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
588 if (snd_mixer_oss_notify_callback)
589 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
590#endif
591 snd_device_free_all(card);
592 if (card->private_free)
593 card->private_free(card);
594 if (snd_info_card_free(card) < 0) {
595 dev_warn(card->dev, "unable to free card info\n");
596 /* Not fatal error */
597 }
598#ifdef CONFIG_SND_DEBUG
599 debugfs_remove(card->debugfs_root);
600 card->debugfs_root = NULL;
601#endif
602 if (card->release_completion)
603 complete(card->release_completion);
604 if (!card->managed)
605 kfree(card);
606 return 0;
607}
608
609/**
610 * snd_card_free_when_closed - Disconnect the card, free it later eventually
611 * @card: soundcard structure
612 *
613 * Unlike snd_card_free(), this function doesn't try to release the card
614 * resource immediately, but tries to disconnect at first. When the card
615 * is still in use, the function returns before freeing the resources.
616 * The card resources will be freed when the refcount gets to zero.
617 *
618 * Return: zero if successful, or a negative error code
619 */
620int snd_card_free_when_closed(struct snd_card *card)
621{
622 int ret = snd_card_disconnect(card);
623 if (ret)
624 return ret;
625 put_device(&card->card_dev);
626 return 0;
627}
628EXPORT_SYMBOL(snd_card_free_when_closed);
629
630/**
631 * snd_card_free - frees given soundcard structure
632 * @card: soundcard structure
633 *
634 * This function releases the soundcard structure and the all assigned
635 * devices automatically. That is, you don't have to release the devices
636 * by yourself.
637 *
638 * This function waits until the all resources are properly released.
639 *
640 * Return: Zero. Frees all associated devices and frees the control
641 * interface associated to given soundcard.
642 */
643int snd_card_free(struct snd_card *card)
644{
645 DECLARE_COMPLETION_ONSTACK(released);
646 int ret;
647
648 /* The call of snd_card_free() is allowed from various code paths;
649 * a manual call from the driver and the call via devres_free, and
650 * we need to avoid double-free. Moreover, the release via devres
651 * may call snd_card_free() twice due to its nature, we need to have
652 * the check here at the beginning.
653 */
654 if (card->releasing)
655 return 0;
656
657 card->release_completion = &released;
658 ret = snd_card_free_when_closed(card);
659 if (ret)
660 return ret;
661 /* wait, until all devices are ready for the free operation */
662 wait_for_completion(&released);
663
664 return 0;
665}
666EXPORT_SYMBOL(snd_card_free);
667
668/* retrieve the last word of shortname or longname */
669static const char *retrieve_id_from_card_name(const char *name)
670{
671 const char *spos = name;
672
673 while (*name) {
674 if (isspace(*name) && isalnum(name[1]))
675 spos = name + 1;
676 name++;
677 }
678 return spos;
679}
680
681/* return true if the given id string doesn't conflict any other card ids */
682static bool card_id_ok(struct snd_card *card, const char *id)
683{
684 int i;
685 if (!snd_info_check_reserved_words(id))
686 return false;
687 for (i = 0; i < snd_ecards_limit; i++) {
688 if (snd_cards[i] && snd_cards[i] != card &&
689 !strcmp(snd_cards[i]->id, id))
690 return false;
691 }
692 return true;
693}
694
695/* copy to card->id only with valid letters from nid */
696static void copy_valid_id_string(struct snd_card *card, const char *src,
697 const char *nid)
698{
699 char *id = card->id;
700
701 while (*nid && !isalnum(*nid))
702 nid++;
703 if (isdigit(*nid))
704 *id++ = isalpha(*src) ? *src : 'D';
705 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
706 if (isalnum(*nid))
707 *id++ = *nid;
708 nid++;
709 }
710 *id = 0;
711}
712
713/* Set card->id from the given string
714 * If the string conflicts with other ids, add a suffix to make it unique.
715 */
716static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
717 const char *nid)
718{
719 int len, loops;
720 bool is_default = false;
721 char *id;
722
723 copy_valid_id_string(card, src, nid);
724 id = card->id;
725
726 again:
727 /* use "Default" for obviously invalid strings
728 * ("card" conflicts with proc directories)
729 */
730 if (!*id || !strncmp(id, "card", 4)) {
731 strcpy(id, "Default");
732 is_default = true;
733 }
734
735 len = strlen(id);
736 for (loops = 0; loops < SNDRV_CARDS; loops++) {
737 char *spos;
738 char sfxstr[5]; /* "_012" */
739 int sfxlen;
740
741 if (card_id_ok(card, id))
742 return; /* OK */
743
744 /* Add _XYZ suffix */
745 sprintf(sfxstr, "_%X", loops + 1);
746 sfxlen = strlen(sfxstr);
747 if (len + sfxlen >= sizeof(card->id))
748 spos = id + sizeof(card->id) - sfxlen - 1;
749 else
750 spos = id + len;
751 strcpy(spos, sfxstr);
752 }
753 /* fallback to the default id */
754 if (!is_default) {
755 *id = 0;
756 goto again;
757 }
758 /* last resort... */
759 dev_err(card->dev, "unable to set card id (%s)\n", id);
760 if (card->proc_root->name)
761 strscpy(card->id, card->proc_root->name, sizeof(card->id));
762}
763
764/**
765 * snd_card_set_id - set card identification name
766 * @card: soundcard structure
767 * @nid: new identification string
768 *
769 * This function sets the card identification and checks for name
770 * collisions.
771 */
772void snd_card_set_id(struct snd_card *card, const char *nid)
773{
774 /* check if user specified own card->id */
775 if (card->id[0] != '\0')
776 return;
777 mutex_lock(&snd_card_mutex);
778 snd_card_set_id_no_lock(card, nid, nid);
779 mutex_unlock(&snd_card_mutex);
780}
781EXPORT_SYMBOL(snd_card_set_id);
782
783static ssize_t id_show(struct device *dev,
784 struct device_attribute *attr, char *buf)
785{
786 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
787 return sysfs_emit(buf, "%s\n", card->id);
788}
789
790static ssize_t id_store(struct device *dev, struct device_attribute *attr,
791 const char *buf, size_t count)
792{
793 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
794 char buf1[sizeof(card->id)];
795 size_t copy = count > sizeof(card->id) - 1 ?
796 sizeof(card->id) - 1 : count;
797 size_t idx;
798 int c;
799
800 for (idx = 0; idx < copy; idx++) {
801 c = buf[idx];
802 if (!isalnum(c) && c != '_' && c != '-')
803 return -EINVAL;
804 }
805 memcpy(buf1, buf, copy);
806 buf1[copy] = '\0';
807 mutex_lock(&snd_card_mutex);
808 if (!card_id_ok(NULL, buf1)) {
809 mutex_unlock(&snd_card_mutex);
810 return -EEXIST;
811 }
812 strcpy(card->id, buf1);
813 snd_info_card_id_change(card);
814 mutex_unlock(&snd_card_mutex);
815
816 return count;
817}
818
819static DEVICE_ATTR_RW(id);
820
821static ssize_t number_show(struct device *dev,
822 struct device_attribute *attr, char *buf)
823{
824 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
825 return sysfs_emit(buf, "%i\n", card->number);
826}
827
828static DEVICE_ATTR_RO(number);
829
830static struct attribute *card_dev_attrs[] = {
831 &dev_attr_id.attr,
832 &dev_attr_number.attr,
833 NULL
834};
835
836static const struct attribute_group card_dev_attr_group = {
837 .attrs = card_dev_attrs,
838};
839
840/**
841 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
842 * @card: card instance
843 * @group: attribute group to append
844 *
845 * Return: zero if successful, or a negative error code
846 */
847int snd_card_add_dev_attr(struct snd_card *card,
848 const struct attribute_group *group)
849{
850 int i;
851
852 /* loop for (arraysize-1) here to keep NULL at the last entry */
853 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
854 if (!card->dev_groups[i]) {
855 card->dev_groups[i] = group;
856 return 0;
857 }
858 }
859
860 dev_err(card->dev, "Too many groups assigned\n");
861 return -ENOSPC;
862}
863EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
864
865static void trigger_card_free(void *data)
866{
867 snd_card_free(data);
868}
869
870/**
871 * snd_card_register - register the soundcard
872 * @card: soundcard structure
873 *
874 * This function registers all the devices assigned to the soundcard.
875 * Until calling this, the ALSA control interface is blocked from the
876 * external accesses. Thus, you should call this function at the end
877 * of the initialization of the card.
878 *
879 * Return: Zero otherwise a negative error code if the registration failed.
880 */
881int snd_card_register(struct snd_card *card)
882{
883 int err;
884
885 if (snd_BUG_ON(!card))
886 return -EINVAL;
887
888 if (!card->registered) {
889 err = device_add(&card->card_dev);
890 if (err < 0)
891 return err;
892 card->registered = true;
893 } else {
894 if (card->managed)
895 devm_remove_action(card->dev, trigger_card_free, card);
896 }
897
898 if (card->managed) {
899 err = devm_add_action(card->dev, trigger_card_free, card);
900 if (err < 0)
901 return err;
902 }
903
904 err = snd_device_register_all(card);
905 if (err < 0)
906 return err;
907 mutex_lock(&snd_card_mutex);
908 if (snd_cards[card->number]) {
909 /* already registered */
910 mutex_unlock(&snd_card_mutex);
911 return snd_info_card_register(card); /* register pending info */
912 }
913 if (*card->id) {
914 /* make a unique id name from the given string */
915 char tmpid[sizeof(card->id)];
916 memcpy(tmpid, card->id, sizeof(card->id));
917 snd_card_set_id_no_lock(card, tmpid, tmpid);
918 } else {
919 /* create an id from either shortname or longname */
920 const char *src;
921 src = *card->shortname ? card->shortname : card->longname;
922 snd_card_set_id_no_lock(card, src,
923 retrieve_id_from_card_name(src));
924 }
925 snd_cards[card->number] = card;
926 mutex_unlock(&snd_card_mutex);
927 err = snd_info_card_register(card);
928 if (err < 0)
929 return err;
930
931#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
932 if (snd_mixer_oss_notify_callback)
933 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
934#endif
935 return 0;
936}
937EXPORT_SYMBOL(snd_card_register);
938
939#ifdef CONFIG_SND_PROC_FS
940static void snd_card_info_read(struct snd_info_entry *entry,
941 struct snd_info_buffer *buffer)
942{
943 int idx, count;
944 struct snd_card *card;
945
946 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
947 mutex_lock(&snd_card_mutex);
948 card = snd_cards[idx];
949 if (card) {
950 count++;
951 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
952 idx,
953 card->id,
954 card->driver,
955 card->shortname);
956 snd_iprintf(buffer, " %s\n",
957 card->longname);
958 }
959 mutex_unlock(&snd_card_mutex);
960 }
961 if (!count)
962 snd_iprintf(buffer, "--- no soundcards ---\n");
963}
964
965#ifdef CONFIG_SND_OSSEMUL
966void snd_card_info_read_oss(struct snd_info_buffer *buffer)
967{
968 int idx, count;
969 struct snd_card *card;
970
971 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
972 mutex_lock(&snd_card_mutex);
973 card = snd_cards[idx];
974 if (card) {
975 count++;
976 snd_iprintf(buffer, "%s\n", card->longname);
977 }
978 mutex_unlock(&snd_card_mutex);
979 }
980 if (!count) {
981 snd_iprintf(buffer, "--- no soundcards ---\n");
982 }
983}
984
985#endif
986
987#ifdef MODULE
988static void snd_card_module_info_read(struct snd_info_entry *entry,
989 struct snd_info_buffer *buffer)
990{
991 int idx;
992 struct snd_card *card;
993
994 for (idx = 0; idx < SNDRV_CARDS; idx++) {
995 mutex_lock(&snd_card_mutex);
996 card = snd_cards[idx];
997 if (card)
998 snd_iprintf(buffer, "%2i %s\n",
999 idx, card->module->name);
1000 mutex_unlock(&snd_card_mutex);
1001 }
1002}
1003#endif
1004
1005int __init snd_card_info_init(void)
1006{
1007 struct snd_info_entry *entry;
1008
1009 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
1010 if (! entry)
1011 return -ENOMEM;
1012 entry->c.text.read = snd_card_info_read;
1013 if (snd_info_register(entry) < 0)
1014 return -ENOMEM; /* freed in error path */
1015
1016#ifdef MODULE
1017 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1018 if (!entry)
1019 return -ENOMEM;
1020 entry->c.text.read = snd_card_module_info_read;
1021 if (snd_info_register(entry) < 0)
1022 return -ENOMEM; /* freed in error path */
1023#endif
1024
1025 return 0;
1026}
1027#endif /* CONFIG_SND_PROC_FS */
1028
1029/**
1030 * snd_component_add - add a component string
1031 * @card: soundcard structure
1032 * @component: the component id string
1033 *
1034 * This function adds the component id string to the supported list.
1035 * The component can be referred from the alsa-lib.
1036 *
1037 * Return: Zero otherwise a negative error code.
1038 */
1039
1040int snd_component_add(struct snd_card *card, const char *component)
1041{
1042 char *ptr;
1043 int len = strlen(component);
1044
1045 ptr = strstr(card->components, component);
1046 if (ptr != NULL) {
1047 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1048 return 1;
1049 }
1050 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1051 snd_BUG();
1052 return -ENOMEM;
1053 }
1054 if (card->components[0] != '\0')
1055 strcat(card->components, " ");
1056 strcat(card->components, component);
1057 return 0;
1058}
1059EXPORT_SYMBOL(snd_component_add);
1060
1061/**
1062 * snd_card_file_add - add the file to the file list of the card
1063 * @card: soundcard structure
1064 * @file: file pointer
1065 *
1066 * This function adds the file to the file linked-list of the card.
1067 * This linked-list is used to keep tracking the connection state,
1068 * and to avoid the release of busy resources by hotplug.
1069 *
1070 * Return: zero or a negative error code.
1071 */
1072int snd_card_file_add(struct snd_card *card, struct file *file)
1073{
1074 struct snd_monitor_file *mfile;
1075
1076 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1077 if (mfile == NULL)
1078 return -ENOMEM;
1079 mfile->file = file;
1080 mfile->disconnected_f_op = NULL;
1081 INIT_LIST_HEAD(&mfile->shutdown_list);
1082 spin_lock(&card->files_lock);
1083 if (card->shutdown) {
1084 spin_unlock(&card->files_lock);
1085 kfree(mfile);
1086 return -ENODEV;
1087 }
1088 list_add(&mfile->list, &card->files_list);
1089 get_device(&card->card_dev);
1090 spin_unlock(&card->files_lock);
1091 return 0;
1092}
1093EXPORT_SYMBOL(snd_card_file_add);
1094
1095/**
1096 * snd_card_file_remove - remove the file from the file list
1097 * @card: soundcard structure
1098 * @file: file pointer
1099 *
1100 * This function removes the file formerly added to the card via
1101 * snd_card_file_add() function.
1102 * If all files are removed and snd_card_free_when_closed() was
1103 * called beforehand, it processes the pending release of
1104 * resources.
1105 *
1106 * Return: Zero or a negative error code.
1107 */
1108int snd_card_file_remove(struct snd_card *card, struct file *file)
1109{
1110 struct snd_monitor_file *mfile, *found = NULL;
1111
1112 spin_lock(&card->files_lock);
1113 list_for_each_entry(mfile, &card->files_list, list) {
1114 if (mfile->file == file) {
1115 list_del(&mfile->list);
1116 spin_lock(&shutdown_lock);
1117 list_del(&mfile->shutdown_list);
1118 spin_unlock(&shutdown_lock);
1119 if (mfile->disconnected_f_op)
1120 fops_put(mfile->disconnected_f_op);
1121 found = mfile;
1122 break;
1123 }
1124 }
1125 if (list_empty(&card->files_list))
1126 wake_up_all(&card->remove_sleep);
1127 spin_unlock(&card->files_lock);
1128 if (!found) {
1129 dev_err(card->dev, "card file remove problem (%p)\n", file);
1130 return -ENOENT;
1131 }
1132 kfree(found);
1133 put_device(&card->card_dev);
1134 return 0;
1135}
1136EXPORT_SYMBOL(snd_card_file_remove);
1137
1138#ifdef CONFIG_PM
1139/**
1140 * snd_power_ref_and_wait - wait until the card gets powered up
1141 * @card: soundcard structure
1142 *
1143 * Take the power_ref reference count of the given card, and
1144 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1145 * The refcount is down again while sleeping until power-up, hence this
1146 * function can be used for syncing the floating control ops accesses,
1147 * typically around calling control ops.
1148 *
1149 * The caller needs to pull down the refcount via snd_power_unref() later
1150 * no matter whether the error is returned from this function or not.
1151 *
1152 * Return: Zero if successful, or a negative error code.
1153 */
1154int snd_power_ref_and_wait(struct snd_card *card)
1155{
1156 snd_power_ref(card);
1157 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1158 return 0;
1159 wait_event_cmd(card->power_sleep,
1160 card->shutdown ||
1161 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1162 snd_power_unref(card), snd_power_ref(card));
1163 return card->shutdown ? -ENODEV : 0;
1164}
1165EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1166
1167/**
1168 * snd_power_wait - wait until the card gets powered up (old form)
1169 * @card: soundcard structure
1170 *
1171 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1172 *
1173 * Return: Zero if successful, or a negative error code.
1174 */
1175int snd_power_wait(struct snd_card *card)
1176{
1177 int ret;
1178
1179 ret = snd_power_ref_and_wait(card);
1180 snd_power_unref(card);
1181 return ret;
1182}
1183EXPORT_SYMBOL(snd_power_wait);
1184#endif /* CONFIG_PM */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Initialization routines
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/module.h>
10#include <linux/device.h>
11#include <linux/file.h>
12#include <linux/slab.h>
13#include <linux/time.h>
14#include <linux/ctype.h>
15#include <linux/pm.h>
16#include <linux/debugfs.h>
17#include <linux/completion.h>
18#include <linux/interrupt.h>
19
20#include <sound/core.h>
21#include <sound/control.h>
22#include <sound/info.h>
23
24/* monitor files for graceful shutdown (hotplug) */
25struct snd_monitor_file {
26 struct file *file;
27 const struct file_operations *disconnected_f_op;
28 struct list_head shutdown_list; /* still need to shutdown */
29 struct list_head list; /* link of monitor files */
30};
31
32static DEFINE_SPINLOCK(shutdown_lock);
33static LIST_HEAD(shutdown_files);
34
35static const struct file_operations snd_shutdown_f_ops;
36
37/* locked for registering/using */
38static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39static struct snd_card *snd_cards[SNDRV_CARDS];
40
41static DEFINE_MUTEX(snd_card_mutex);
42
43static char *slots[SNDRV_CARDS];
44module_param_array(slots, charp, NULL, 0444);
45MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
46
47/* return non-zero if the given index is reserved for the given
48 * module via slots option
49 */
50static int module_slot_match(struct module *module, int idx)
51{
52 int match = 1;
53#ifdef MODULE
54 const char *s1, *s2;
55
56 if (!module || !*module->name || !slots[idx])
57 return 0;
58
59 s1 = module->name;
60 s2 = slots[idx];
61 if (*s2 == '!') {
62 match = 0; /* negative match */
63 s2++;
64 }
65 /* compare module name strings
66 * hyphens are handled as equivalent with underscore
67 */
68 for (;;) {
69 char c1 = *s1++;
70 char c2 = *s2++;
71 if (c1 == '-')
72 c1 = '_';
73 if (c2 == '-')
74 c2 = '_';
75 if (c1 != c2)
76 return !match;
77 if (!c1)
78 break;
79 }
80#endif /* MODULE */
81 return match;
82}
83
84#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
85int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
87#endif
88
89static int check_empty_slot(struct module *module, int slot)
90{
91 return !slots[slot] || !*slots[slot];
92}
93
94/* return an empty slot number (>= 0) found in the given bitmask @mask.
95 * @mask == -1 == 0xffffffff means: take any free slot up to 32
96 * when no slot is available, return the original @mask as is.
97 */
98static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
99 struct module *module)
100{
101 int slot;
102
103 for (slot = 0; slot < SNDRV_CARDS; slot++) {
104 if (slot < 32 && !(mask & (1U << slot)))
105 continue;
106 if (!test_bit(slot, snd_cards_lock)) {
107 if (check(module, slot))
108 return slot; /* found */
109 }
110 }
111 return mask; /* unchanged */
112}
113
114/* the default release callback set in snd_device_initialize() below;
115 * this is just NOP for now, as almost all jobs are already done in
116 * dev_free callback of snd_device chain instead.
117 */
118static void default_release(struct device *dev)
119{
120}
121
122/**
123 * snd_device_initialize - Initialize struct device for sound devices
124 * @dev: device to initialize
125 * @card: card to assign, optional
126 */
127void snd_device_initialize(struct device *dev, struct snd_card *card)
128{
129 device_initialize(dev);
130 if (card)
131 dev->parent = &card->card_dev;
132 dev->class = sound_class;
133 dev->release = default_release;
134}
135EXPORT_SYMBOL_GPL(snd_device_initialize);
136
137static int snd_card_do_free(struct snd_card *card);
138static const struct attribute_group card_dev_attr_group;
139
140static void release_card_device(struct device *dev)
141{
142 snd_card_do_free(dev_to_snd_card(dev));
143}
144
145/**
146 * snd_card_new - create and initialize a soundcard structure
147 * @parent: the parent device object
148 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
149 * @xid: card identification (ASCII string)
150 * @module: top level module for locking
151 * @extra_size: allocate this extra size after the main soundcard structure
152 * @card_ret: the pointer to store the created card instance
153 *
154 * The function allocates snd_card instance via kzalloc with the given
155 * space for the driver to use freely. The allocated struct is stored
156 * in the given card_ret pointer.
157 *
158 * Return: Zero if successful or a negative error code.
159 */
160int snd_card_new(struct device *parent, int idx, const char *xid,
161 struct module *module, int extra_size,
162 struct snd_card **card_ret)
163{
164 struct snd_card *card;
165 int err;
166#ifdef CONFIG_SND_DEBUG
167 char name[8];
168#endif
169
170 if (snd_BUG_ON(!card_ret))
171 return -EINVAL;
172 *card_ret = NULL;
173
174 if (extra_size < 0)
175 extra_size = 0;
176 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
177 if (!card)
178 return -ENOMEM;
179 if (extra_size > 0)
180 card->private_data = (char *)card + sizeof(struct snd_card);
181 if (xid)
182 strscpy(card->id, xid, sizeof(card->id));
183 err = 0;
184 mutex_lock(&snd_card_mutex);
185 if (idx < 0) /* first check the matching module-name slot */
186 idx = get_slot_from_bitmask(idx, module_slot_match, module);
187 if (idx < 0) /* if not matched, assign an empty slot */
188 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
189 if (idx < 0)
190 err = -ENODEV;
191 else if (idx < snd_ecards_limit) {
192 if (test_bit(idx, snd_cards_lock))
193 err = -EBUSY; /* invalid */
194 } else if (idx >= SNDRV_CARDS)
195 err = -ENODEV;
196 if (err < 0) {
197 mutex_unlock(&snd_card_mutex);
198 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
199 idx, snd_ecards_limit - 1, err);
200 kfree(card);
201 return err;
202 }
203 set_bit(idx, snd_cards_lock); /* lock it */
204 if (idx >= snd_ecards_limit)
205 snd_ecards_limit = idx + 1; /* increase the limit */
206 mutex_unlock(&snd_card_mutex);
207 card->dev = parent;
208 card->number = idx;
209#ifdef MODULE
210 WARN_ON(!module);
211 card->module = module;
212#endif
213 INIT_LIST_HEAD(&card->devices);
214 init_rwsem(&card->controls_rwsem);
215 rwlock_init(&card->ctl_files_rwlock);
216 INIT_LIST_HEAD(&card->controls);
217 INIT_LIST_HEAD(&card->ctl_files);
218 spin_lock_init(&card->files_lock);
219 INIT_LIST_HEAD(&card->files_list);
220 mutex_init(&card->memory_mutex);
221#ifdef CONFIG_PM
222 init_waitqueue_head(&card->power_sleep);
223 init_waitqueue_head(&card->power_ref_sleep);
224 atomic_set(&card->power_ref, 0);
225#endif
226 init_waitqueue_head(&card->remove_sleep);
227 card->sync_irq = -1;
228
229 device_initialize(&card->card_dev);
230 card->card_dev.parent = parent;
231 card->card_dev.class = sound_class;
232 card->card_dev.release = release_card_device;
233 card->card_dev.groups = card->dev_groups;
234 card->dev_groups[0] = &card_dev_attr_group;
235 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
236 if (err < 0)
237 goto __error;
238
239 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
240 dev_driver_string(card->dev), dev_name(&card->card_dev));
241
242 /* the control interface cannot be accessed from the user space until */
243 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
244 err = snd_ctl_create(card);
245 if (err < 0) {
246 dev_err(parent, "unable to register control minors\n");
247 goto __error;
248 }
249 err = snd_info_card_create(card);
250 if (err < 0) {
251 dev_err(parent, "unable to create card info\n");
252 goto __error_ctl;
253 }
254
255#ifdef CONFIG_SND_DEBUG
256 sprintf(name, "card%d", idx);
257 card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
258#endif
259
260 *card_ret = card;
261 return 0;
262
263 __error_ctl:
264 snd_device_free_all(card);
265 __error:
266 put_device(&card->card_dev);
267 return err;
268}
269EXPORT_SYMBOL(snd_card_new);
270
271/**
272 * snd_card_ref - Get the card object from the index
273 * @idx: the card index
274 *
275 * Returns a card object corresponding to the given index or NULL if not found.
276 * Release the object via snd_card_unref().
277 */
278struct snd_card *snd_card_ref(int idx)
279{
280 struct snd_card *card;
281
282 mutex_lock(&snd_card_mutex);
283 card = snd_cards[idx];
284 if (card)
285 get_device(&card->card_dev);
286 mutex_unlock(&snd_card_mutex);
287 return card;
288}
289EXPORT_SYMBOL_GPL(snd_card_ref);
290
291/* return non-zero if a card is already locked */
292int snd_card_locked(int card)
293{
294 int locked;
295
296 mutex_lock(&snd_card_mutex);
297 locked = test_bit(card, snd_cards_lock);
298 mutex_unlock(&snd_card_mutex);
299 return locked;
300}
301
302static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
303{
304 return -ENODEV;
305}
306
307static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
308 size_t count, loff_t *offset)
309{
310 return -ENODEV;
311}
312
313static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
314 size_t count, loff_t *offset)
315{
316 return -ENODEV;
317}
318
319static int snd_disconnect_release(struct inode *inode, struct file *file)
320{
321 struct snd_monitor_file *df = NULL, *_df;
322
323 spin_lock(&shutdown_lock);
324 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
325 if (_df->file == file) {
326 df = _df;
327 list_del_init(&df->shutdown_list);
328 break;
329 }
330 }
331 spin_unlock(&shutdown_lock);
332
333 if (likely(df)) {
334 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
335 df->disconnected_f_op->fasync(-1, file, 0);
336 return df->disconnected_f_op->release(inode, file);
337 }
338
339 panic("%s(%p, %p) failed!", __func__, inode, file);
340}
341
342static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
343{
344 return EPOLLERR | EPOLLNVAL;
345}
346
347static long snd_disconnect_ioctl(struct file *file,
348 unsigned int cmd, unsigned long arg)
349{
350 return -ENODEV;
351}
352
353static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
354{
355 return -ENODEV;
356}
357
358static int snd_disconnect_fasync(int fd, struct file *file, int on)
359{
360 return -ENODEV;
361}
362
363static const struct file_operations snd_shutdown_f_ops =
364{
365 .owner = THIS_MODULE,
366 .llseek = snd_disconnect_llseek,
367 .read = snd_disconnect_read,
368 .write = snd_disconnect_write,
369 .release = snd_disconnect_release,
370 .poll = snd_disconnect_poll,
371 .unlocked_ioctl = snd_disconnect_ioctl,
372#ifdef CONFIG_COMPAT
373 .compat_ioctl = snd_disconnect_ioctl,
374#endif
375 .mmap = snd_disconnect_mmap,
376 .fasync = snd_disconnect_fasync
377};
378
379/**
380 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
381 * @card: soundcard structure
382 *
383 * Disconnects all APIs from the file-operations (user space).
384 *
385 * Return: Zero, otherwise a negative error code.
386 *
387 * Note: The current implementation replaces all active file->f_op with special
388 * dummy file operations (they do nothing except release).
389 */
390int snd_card_disconnect(struct snd_card *card)
391{
392 struct snd_monitor_file *mfile;
393
394 if (!card)
395 return -EINVAL;
396
397 spin_lock(&card->files_lock);
398 if (card->shutdown) {
399 spin_unlock(&card->files_lock);
400 return 0;
401 }
402 card->shutdown = 1;
403
404 /* replace file->f_op with special dummy operations */
405 list_for_each_entry(mfile, &card->files_list, list) {
406 /* it's critical part, use endless loop */
407 /* we have no room to fail */
408 mfile->disconnected_f_op = mfile->file->f_op;
409
410 spin_lock(&shutdown_lock);
411 list_add(&mfile->shutdown_list, &shutdown_files);
412 spin_unlock(&shutdown_lock);
413
414 mfile->file->f_op = &snd_shutdown_f_ops;
415 fops_get(mfile->file->f_op);
416 }
417 spin_unlock(&card->files_lock);
418
419 /* notify all connected devices about disconnection */
420 /* at this point, they cannot respond to any calls except release() */
421
422#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
423 if (snd_mixer_oss_notify_callback)
424 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
425#endif
426
427 /* notify all devices that we are disconnected */
428 snd_device_disconnect_all(card);
429
430 if (card->sync_irq > 0)
431 synchronize_irq(card->sync_irq);
432
433 snd_info_card_disconnect(card);
434 if (card->registered) {
435 device_del(&card->card_dev);
436 card->registered = false;
437 }
438
439 /* disable fops (user space) operations for ALSA API */
440 mutex_lock(&snd_card_mutex);
441 snd_cards[card->number] = NULL;
442 clear_bit(card->number, snd_cards_lock);
443 mutex_unlock(&snd_card_mutex);
444
445#ifdef CONFIG_PM
446 wake_up(&card->power_sleep);
447 snd_power_sync_ref(card);
448#endif
449 return 0;
450}
451EXPORT_SYMBOL(snd_card_disconnect);
452
453/**
454 * snd_card_disconnect_sync - disconnect card and wait until files get closed
455 * @card: card object to disconnect
456 *
457 * This calls snd_card_disconnect() for disconnecting all belonging components
458 * and waits until all pending files get closed.
459 * It assures that all accesses from user-space finished so that the driver
460 * can release its resources gracefully.
461 */
462void snd_card_disconnect_sync(struct snd_card *card)
463{
464 int err;
465
466 err = snd_card_disconnect(card);
467 if (err < 0) {
468 dev_err(card->dev,
469 "snd_card_disconnect error (%d), skipping sync\n",
470 err);
471 return;
472 }
473
474 spin_lock_irq(&card->files_lock);
475 wait_event_lock_irq(card->remove_sleep,
476 list_empty(&card->files_list),
477 card->files_lock);
478 spin_unlock_irq(&card->files_lock);
479}
480EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
481
482static int snd_card_do_free(struct snd_card *card)
483{
484#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
485 if (snd_mixer_oss_notify_callback)
486 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
487#endif
488 snd_device_free_all(card);
489 if (card->private_free)
490 card->private_free(card);
491 if (snd_info_card_free(card) < 0) {
492 dev_warn(card->dev, "unable to free card info\n");
493 /* Not fatal error */
494 }
495#ifdef CONFIG_SND_DEBUG
496 debugfs_remove(card->debugfs_root);
497 card->debugfs_root = NULL;
498#endif
499 if (card->release_completion)
500 complete(card->release_completion);
501 kfree(card);
502 return 0;
503}
504
505/**
506 * snd_card_free_when_closed - Disconnect the card, free it later eventually
507 * @card: soundcard structure
508 *
509 * Unlike snd_card_free(), this function doesn't try to release the card
510 * resource immediately, but tries to disconnect at first. When the card
511 * is still in use, the function returns before freeing the resources.
512 * The card resources will be freed when the refcount gets to zero.
513 */
514int snd_card_free_when_closed(struct snd_card *card)
515{
516 int ret = snd_card_disconnect(card);
517 if (ret)
518 return ret;
519 put_device(&card->card_dev);
520 return 0;
521}
522EXPORT_SYMBOL(snd_card_free_when_closed);
523
524/**
525 * snd_card_free - frees given soundcard structure
526 * @card: soundcard structure
527 *
528 * This function releases the soundcard structure and the all assigned
529 * devices automatically. That is, you don't have to release the devices
530 * by yourself.
531 *
532 * This function waits until the all resources are properly released.
533 *
534 * Return: Zero. Frees all associated devices and frees the control
535 * interface associated to given soundcard.
536 */
537int snd_card_free(struct snd_card *card)
538{
539 DECLARE_COMPLETION_ONSTACK(released);
540 int ret;
541
542 card->release_completion = &released;
543 ret = snd_card_free_when_closed(card);
544 if (ret)
545 return ret;
546 /* wait, until all devices are ready for the free operation */
547 wait_for_completion(&released);
548
549 return 0;
550}
551EXPORT_SYMBOL(snd_card_free);
552
553/* retrieve the last word of shortname or longname */
554static const char *retrieve_id_from_card_name(const char *name)
555{
556 const char *spos = name;
557
558 while (*name) {
559 if (isspace(*name) && isalnum(name[1]))
560 spos = name + 1;
561 name++;
562 }
563 return spos;
564}
565
566/* return true if the given id string doesn't conflict any other card ids */
567static bool card_id_ok(struct snd_card *card, const char *id)
568{
569 int i;
570 if (!snd_info_check_reserved_words(id))
571 return false;
572 for (i = 0; i < snd_ecards_limit; i++) {
573 if (snd_cards[i] && snd_cards[i] != card &&
574 !strcmp(snd_cards[i]->id, id))
575 return false;
576 }
577 return true;
578}
579
580/* copy to card->id only with valid letters from nid */
581static void copy_valid_id_string(struct snd_card *card, const char *src,
582 const char *nid)
583{
584 char *id = card->id;
585
586 while (*nid && !isalnum(*nid))
587 nid++;
588 if (isdigit(*nid))
589 *id++ = isalpha(*src) ? *src : 'D';
590 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
591 if (isalnum(*nid))
592 *id++ = *nid;
593 nid++;
594 }
595 *id = 0;
596}
597
598/* Set card->id from the given string
599 * If the string conflicts with other ids, add a suffix to make it unique.
600 */
601static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
602 const char *nid)
603{
604 int len, loops;
605 bool is_default = false;
606 char *id;
607
608 copy_valid_id_string(card, src, nid);
609 id = card->id;
610
611 again:
612 /* use "Default" for obviously invalid strings
613 * ("card" conflicts with proc directories)
614 */
615 if (!*id || !strncmp(id, "card", 4)) {
616 strcpy(id, "Default");
617 is_default = true;
618 }
619
620 len = strlen(id);
621 for (loops = 0; loops < SNDRV_CARDS; loops++) {
622 char *spos;
623 char sfxstr[5]; /* "_012" */
624 int sfxlen;
625
626 if (card_id_ok(card, id))
627 return; /* OK */
628
629 /* Add _XYZ suffix */
630 sprintf(sfxstr, "_%X", loops + 1);
631 sfxlen = strlen(sfxstr);
632 if (len + sfxlen >= sizeof(card->id))
633 spos = id + sizeof(card->id) - sfxlen - 1;
634 else
635 spos = id + len;
636 strcpy(spos, sfxstr);
637 }
638 /* fallback to the default id */
639 if (!is_default) {
640 *id = 0;
641 goto again;
642 }
643 /* last resort... */
644 dev_err(card->dev, "unable to set card id (%s)\n", id);
645 if (card->proc_root->name)
646 strscpy(card->id, card->proc_root->name, sizeof(card->id));
647}
648
649/**
650 * snd_card_set_id - set card identification name
651 * @card: soundcard structure
652 * @nid: new identification string
653 *
654 * This function sets the card identification and checks for name
655 * collisions.
656 */
657void snd_card_set_id(struct snd_card *card, const char *nid)
658{
659 /* check if user specified own card->id */
660 if (card->id[0] != '\0')
661 return;
662 mutex_lock(&snd_card_mutex);
663 snd_card_set_id_no_lock(card, nid, nid);
664 mutex_unlock(&snd_card_mutex);
665}
666EXPORT_SYMBOL(snd_card_set_id);
667
668static ssize_t id_show(struct device *dev,
669 struct device_attribute *attr, char *buf)
670{
671 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
672 return scnprintf(buf, PAGE_SIZE, "%s\n", card->id);
673}
674
675static ssize_t id_store(struct device *dev, struct device_attribute *attr,
676 const char *buf, size_t count)
677{
678 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
679 char buf1[sizeof(card->id)];
680 size_t copy = count > sizeof(card->id) - 1 ?
681 sizeof(card->id) - 1 : count;
682 size_t idx;
683 int c;
684
685 for (idx = 0; idx < copy; idx++) {
686 c = buf[idx];
687 if (!isalnum(c) && c != '_' && c != '-')
688 return -EINVAL;
689 }
690 memcpy(buf1, buf, copy);
691 buf1[copy] = '\0';
692 mutex_lock(&snd_card_mutex);
693 if (!card_id_ok(NULL, buf1)) {
694 mutex_unlock(&snd_card_mutex);
695 return -EEXIST;
696 }
697 strcpy(card->id, buf1);
698 snd_info_card_id_change(card);
699 mutex_unlock(&snd_card_mutex);
700
701 return count;
702}
703
704static DEVICE_ATTR_RW(id);
705
706static ssize_t number_show(struct device *dev,
707 struct device_attribute *attr, char *buf)
708{
709 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
710 return scnprintf(buf, PAGE_SIZE, "%i\n", card->number);
711}
712
713static DEVICE_ATTR_RO(number);
714
715static struct attribute *card_dev_attrs[] = {
716 &dev_attr_id.attr,
717 &dev_attr_number.attr,
718 NULL
719};
720
721static const struct attribute_group card_dev_attr_group = {
722 .attrs = card_dev_attrs,
723};
724
725/**
726 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
727 * @card: card instance
728 * @group: attribute group to append
729 */
730int snd_card_add_dev_attr(struct snd_card *card,
731 const struct attribute_group *group)
732{
733 int i;
734
735 /* loop for (arraysize-1) here to keep NULL at the last entry */
736 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
737 if (!card->dev_groups[i]) {
738 card->dev_groups[i] = group;
739 return 0;
740 }
741 }
742
743 dev_err(card->dev, "Too many groups assigned\n");
744 return -ENOSPC;
745}
746EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
747
748/**
749 * snd_card_register - register the soundcard
750 * @card: soundcard structure
751 *
752 * This function registers all the devices assigned to the soundcard.
753 * Until calling this, the ALSA control interface is blocked from the
754 * external accesses. Thus, you should call this function at the end
755 * of the initialization of the card.
756 *
757 * Return: Zero otherwise a negative error code if the registration failed.
758 */
759int snd_card_register(struct snd_card *card)
760{
761 int err;
762
763 if (snd_BUG_ON(!card))
764 return -EINVAL;
765
766 if (!card->registered) {
767 err = device_add(&card->card_dev);
768 if (err < 0)
769 return err;
770 card->registered = true;
771 }
772
773 err = snd_device_register_all(card);
774 if (err < 0)
775 return err;
776 mutex_lock(&snd_card_mutex);
777 if (snd_cards[card->number]) {
778 /* already registered */
779 mutex_unlock(&snd_card_mutex);
780 return snd_info_card_register(card); /* register pending info */
781 }
782 if (*card->id) {
783 /* make a unique id name from the given string */
784 char tmpid[sizeof(card->id)];
785 memcpy(tmpid, card->id, sizeof(card->id));
786 snd_card_set_id_no_lock(card, tmpid, tmpid);
787 } else {
788 /* create an id from either shortname or longname */
789 const char *src;
790 src = *card->shortname ? card->shortname : card->longname;
791 snd_card_set_id_no_lock(card, src,
792 retrieve_id_from_card_name(src));
793 }
794 snd_cards[card->number] = card;
795 mutex_unlock(&snd_card_mutex);
796 err = snd_info_card_register(card);
797 if (err < 0)
798 return err;
799
800#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
801 if (snd_mixer_oss_notify_callback)
802 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
803#endif
804 return 0;
805}
806EXPORT_SYMBOL(snd_card_register);
807
808#ifdef CONFIG_SND_PROC_FS
809static void snd_card_info_read(struct snd_info_entry *entry,
810 struct snd_info_buffer *buffer)
811{
812 int idx, count;
813 struct snd_card *card;
814
815 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
816 mutex_lock(&snd_card_mutex);
817 card = snd_cards[idx];
818 if (card) {
819 count++;
820 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
821 idx,
822 card->id,
823 card->driver,
824 card->shortname);
825 snd_iprintf(buffer, " %s\n",
826 card->longname);
827 }
828 mutex_unlock(&snd_card_mutex);
829 }
830 if (!count)
831 snd_iprintf(buffer, "--- no soundcards ---\n");
832}
833
834#ifdef CONFIG_SND_OSSEMUL
835void snd_card_info_read_oss(struct snd_info_buffer *buffer)
836{
837 int idx, count;
838 struct snd_card *card;
839
840 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
841 mutex_lock(&snd_card_mutex);
842 card = snd_cards[idx];
843 if (card) {
844 count++;
845 snd_iprintf(buffer, "%s\n", card->longname);
846 }
847 mutex_unlock(&snd_card_mutex);
848 }
849 if (!count) {
850 snd_iprintf(buffer, "--- no soundcards ---\n");
851 }
852}
853
854#endif
855
856#ifdef MODULE
857static void snd_card_module_info_read(struct snd_info_entry *entry,
858 struct snd_info_buffer *buffer)
859{
860 int idx;
861 struct snd_card *card;
862
863 for (idx = 0; idx < SNDRV_CARDS; idx++) {
864 mutex_lock(&snd_card_mutex);
865 card = snd_cards[idx];
866 if (card)
867 snd_iprintf(buffer, "%2i %s\n",
868 idx, card->module->name);
869 mutex_unlock(&snd_card_mutex);
870 }
871}
872#endif
873
874int __init snd_card_info_init(void)
875{
876 struct snd_info_entry *entry;
877
878 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
879 if (! entry)
880 return -ENOMEM;
881 entry->c.text.read = snd_card_info_read;
882 if (snd_info_register(entry) < 0)
883 return -ENOMEM; /* freed in error path */
884
885#ifdef MODULE
886 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
887 if (!entry)
888 return -ENOMEM;
889 entry->c.text.read = snd_card_module_info_read;
890 if (snd_info_register(entry) < 0)
891 return -ENOMEM; /* freed in error path */
892#endif
893
894 return 0;
895}
896#endif /* CONFIG_SND_PROC_FS */
897
898/**
899 * snd_component_add - add a component string
900 * @card: soundcard structure
901 * @component: the component id string
902 *
903 * This function adds the component id string to the supported list.
904 * The component can be referred from the alsa-lib.
905 *
906 * Return: Zero otherwise a negative error code.
907 */
908
909int snd_component_add(struct snd_card *card, const char *component)
910{
911 char *ptr;
912 int len = strlen(component);
913
914 ptr = strstr(card->components, component);
915 if (ptr != NULL) {
916 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
917 return 1;
918 }
919 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
920 snd_BUG();
921 return -ENOMEM;
922 }
923 if (card->components[0] != '\0')
924 strcat(card->components, " ");
925 strcat(card->components, component);
926 return 0;
927}
928EXPORT_SYMBOL(snd_component_add);
929
930/**
931 * snd_card_file_add - add the file to the file list of the card
932 * @card: soundcard structure
933 * @file: file pointer
934 *
935 * This function adds the file to the file linked-list of the card.
936 * This linked-list is used to keep tracking the connection state,
937 * and to avoid the release of busy resources by hotplug.
938 *
939 * Return: zero or a negative error code.
940 */
941int snd_card_file_add(struct snd_card *card, struct file *file)
942{
943 struct snd_monitor_file *mfile;
944
945 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
946 if (mfile == NULL)
947 return -ENOMEM;
948 mfile->file = file;
949 mfile->disconnected_f_op = NULL;
950 INIT_LIST_HEAD(&mfile->shutdown_list);
951 spin_lock(&card->files_lock);
952 if (card->shutdown) {
953 spin_unlock(&card->files_lock);
954 kfree(mfile);
955 return -ENODEV;
956 }
957 list_add(&mfile->list, &card->files_list);
958 get_device(&card->card_dev);
959 spin_unlock(&card->files_lock);
960 return 0;
961}
962EXPORT_SYMBOL(snd_card_file_add);
963
964/**
965 * snd_card_file_remove - remove the file from the file list
966 * @card: soundcard structure
967 * @file: file pointer
968 *
969 * This function removes the file formerly added to the card via
970 * snd_card_file_add() function.
971 * If all files are removed and snd_card_free_when_closed() was
972 * called beforehand, it processes the pending release of
973 * resources.
974 *
975 * Return: Zero or a negative error code.
976 */
977int snd_card_file_remove(struct snd_card *card, struct file *file)
978{
979 struct snd_monitor_file *mfile, *found = NULL;
980
981 spin_lock(&card->files_lock);
982 list_for_each_entry(mfile, &card->files_list, list) {
983 if (mfile->file == file) {
984 list_del(&mfile->list);
985 spin_lock(&shutdown_lock);
986 list_del(&mfile->shutdown_list);
987 spin_unlock(&shutdown_lock);
988 if (mfile->disconnected_f_op)
989 fops_put(mfile->disconnected_f_op);
990 found = mfile;
991 break;
992 }
993 }
994 if (list_empty(&card->files_list))
995 wake_up_all(&card->remove_sleep);
996 spin_unlock(&card->files_lock);
997 if (!found) {
998 dev_err(card->dev, "card file remove problem (%p)\n", file);
999 return -ENOENT;
1000 }
1001 kfree(found);
1002 put_device(&card->card_dev);
1003 return 0;
1004}
1005EXPORT_SYMBOL(snd_card_file_remove);
1006
1007#ifdef CONFIG_PM
1008/**
1009 * snd_power_ref_and_wait - wait until the card gets powered up
1010 * @card: soundcard structure
1011 *
1012 * Take the power_ref reference count of the given card, and
1013 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1014 * The refcount is down again while sleeping until power-up, hence this
1015 * function can be used for syncing the floating control ops accesses,
1016 * typically around calling control ops.
1017 *
1018 * The caller needs to pull down the refcount via snd_power_unref() later
1019 * no matter whether the error is returned from this function or not.
1020 *
1021 * Return: Zero if successful, or a negative error code.
1022 */
1023int snd_power_ref_and_wait(struct snd_card *card)
1024{
1025 wait_queue_entry_t wait;
1026 int result = 0;
1027
1028 snd_power_ref(card);
1029 /* fastpath */
1030 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1031 return 0;
1032 init_waitqueue_entry(&wait, current);
1033 add_wait_queue(&card->power_sleep, &wait);
1034 while (1) {
1035 if (card->shutdown) {
1036 result = -ENODEV;
1037 break;
1038 }
1039 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1040 break;
1041 snd_power_unref(card);
1042 set_current_state(TASK_UNINTERRUPTIBLE);
1043 schedule_timeout(30 * HZ);
1044 snd_power_ref(card);
1045 }
1046 remove_wait_queue(&card->power_sleep, &wait);
1047 return result;
1048}
1049EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1050
1051/**
1052 * snd_power_wait - wait until the card gets powered up (old form)
1053 * @card: soundcard structure
1054 *
1055 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1056 *
1057 * Return: Zero if successful, or a negative error code.
1058 */
1059int snd_power_wait(struct snd_card *card)
1060{
1061 int ret;
1062
1063 ret = snd_power_ref_and_wait(card);
1064 snd_power_unref(card);
1065 return ret;
1066}
1067EXPORT_SYMBOL(snd_power_wait);
1068#endif /* CONFIG_PM */