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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 CONFIG_MODULES
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 /* CONFIG_MODULES */
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_alloc() */
115static void default_release_alloc(struct device *dev)
116{
117 kfree(dev);
118}
119
120/**
121 * snd_device_alloc - Allocate and initialize struct device for sound devices
122 * @dev_p: pointer to store the allocated device
123 * @card: card to assign, optional
124 *
125 * For releasing the allocated device, call put_device().
126 */
127int snd_device_alloc(struct device **dev_p, struct snd_card *card)
128{
129 struct device *dev;
130
131 *dev_p = NULL;
132 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
133 if (!dev)
134 return -ENOMEM;
135 device_initialize(dev);
136 if (card)
137 dev->parent = &card->card_dev;
138 dev->class = &sound_class;
139 dev->release = default_release_alloc;
140 *dev_p = dev;
141 return 0;
142}
143EXPORT_SYMBOL_GPL(snd_device_alloc);
144
145static int snd_card_init(struct snd_card *card, struct device *parent,
146 int idx, const char *xid, struct module *module,
147 size_t extra_size);
148static int snd_card_do_free(struct snd_card *card);
149static const struct attribute_group card_dev_attr_group;
150
151static void release_card_device(struct device *dev)
152{
153 snd_card_do_free(dev_to_snd_card(dev));
154}
155
156/**
157 * snd_card_new - create and initialize a soundcard structure
158 * @parent: the parent device object
159 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
160 * @xid: card identification (ASCII string)
161 * @module: top level module for locking
162 * @extra_size: allocate this extra size after the main soundcard structure
163 * @card_ret: the pointer to store the created card instance
164 *
165 * The function allocates snd_card instance via kzalloc with the given
166 * space for the driver to use freely. The allocated struct is stored
167 * in the given card_ret pointer.
168 *
169 * Return: Zero if successful or a negative error code.
170 */
171int snd_card_new(struct device *parent, int idx, const char *xid,
172 struct module *module, int extra_size,
173 struct snd_card **card_ret)
174{
175 struct snd_card *card;
176 int err;
177
178 if (snd_BUG_ON(!card_ret))
179 return -EINVAL;
180 *card_ret = NULL;
181
182 if (extra_size < 0)
183 extra_size = 0;
184 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
185 if (!card)
186 return -ENOMEM;
187
188 err = snd_card_init(card, parent, idx, xid, module, extra_size);
189 if (err < 0)
190 return err; /* card is freed by error handler */
191
192 *card_ret = card;
193 return 0;
194}
195EXPORT_SYMBOL(snd_card_new);
196
197static void __snd_card_release(struct device *dev, void *data)
198{
199 snd_card_free(data);
200}
201
202/**
203 * snd_devm_card_new - managed snd_card object creation
204 * @parent: the parent device object
205 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
206 * @xid: card identification (ASCII string)
207 * @module: top level module for locking
208 * @extra_size: allocate this extra size after the main soundcard structure
209 * @card_ret: the pointer to store the created card instance
210 *
211 * This function works like snd_card_new() but manages the allocated resource
212 * via devres, i.e. you don't need to free explicitly.
213 *
214 * When a snd_card object is created with this function and registered via
215 * snd_card_register(), the very first devres action to call snd_card_free()
216 * is added automatically. In that way, the resource disconnection is assured
217 * at first, then released in the expected order.
218 *
219 * If an error happens at the probe before snd_card_register() is called and
220 * there have been other devres resources, you'd need to free the card manually
221 * via snd_card_free() call in the error; otherwise it may lead to UAF due to
222 * devres call orders. You can use snd_card_free_on_error() helper for
223 * handling it more easily.
224 *
225 * Return: zero if successful, or a negative error code
226 */
227int snd_devm_card_new(struct device *parent, int idx, const char *xid,
228 struct module *module, size_t extra_size,
229 struct snd_card **card_ret)
230{
231 struct snd_card *card;
232 int err;
233
234 *card_ret = NULL;
235 card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
236 GFP_KERNEL);
237 if (!card)
238 return -ENOMEM;
239 card->managed = true;
240 err = snd_card_init(card, parent, idx, xid, module, extra_size);
241 if (err < 0) {
242 devres_free(card); /* in managed mode, we need to free manually */
243 return err;
244 }
245
246 devres_add(parent, card);
247 *card_ret = card;
248 return 0;
249}
250EXPORT_SYMBOL_GPL(snd_devm_card_new);
251
252/**
253 * snd_card_free_on_error - a small helper for handling devm probe errors
254 * @dev: the managed device object
255 * @ret: the return code from the probe callback
256 *
257 * This function handles the explicit snd_card_free() call at the error from
258 * the probe callback. It's just a small helper for simplifying the error
259 * handling with the managed devices.
260 *
261 * Return: zero if successful, or a negative error code
262 */
263int snd_card_free_on_error(struct device *dev, int ret)
264{
265 struct snd_card *card;
266
267 if (!ret)
268 return 0;
269 card = devres_find(dev, __snd_card_release, NULL, NULL);
270 if (card)
271 snd_card_free(card);
272 return ret;
273}
274EXPORT_SYMBOL_GPL(snd_card_free_on_error);
275
276static int snd_card_init(struct snd_card *card, struct device *parent,
277 int idx, const char *xid, struct module *module,
278 size_t extra_size)
279{
280 int err;
281
282 if (extra_size > 0)
283 card->private_data = (char *)card + sizeof(struct snd_card);
284 if (xid)
285 strscpy(card->id, xid, sizeof(card->id));
286 err = 0;
287 scoped_guard(mutex, &snd_card_mutex) {
288 if (idx < 0) /* first check the matching module-name slot */
289 idx = get_slot_from_bitmask(idx, module_slot_match, module);
290 if (idx < 0) /* if not matched, assign an empty slot */
291 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
292 if (idx < 0)
293 err = -ENODEV;
294 else if (idx < snd_ecards_limit) {
295 if (test_bit(idx, snd_cards_lock))
296 err = -EBUSY; /* invalid */
297 } else if (idx >= SNDRV_CARDS)
298 err = -ENODEV;
299 if (!err) {
300 set_bit(idx, snd_cards_lock); /* lock it */
301 if (idx >= snd_ecards_limit)
302 snd_ecards_limit = idx + 1; /* increase the limit */
303 }
304 }
305 if (err < 0) {
306 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
307 idx, snd_ecards_limit - 1, err);
308 if (!card->managed)
309 kfree(card); /* manually free here, as no destructor called */
310 return err;
311 }
312 card->dev = parent;
313 card->number = idx;
314 WARN_ON(IS_MODULE(CONFIG_SND) && !module);
315 card->module = module;
316 INIT_LIST_HEAD(&card->devices);
317 init_rwsem(&card->controls_rwsem);
318 rwlock_init(&card->controls_rwlock);
319 INIT_LIST_HEAD(&card->controls);
320 INIT_LIST_HEAD(&card->ctl_files);
321#ifdef CONFIG_SND_CTL_FAST_LOOKUP
322 xa_init(&card->ctl_numids);
323 xa_init(&card->ctl_hash);
324#endif
325 spin_lock_init(&card->files_lock);
326 INIT_LIST_HEAD(&card->files_list);
327 mutex_init(&card->memory_mutex);
328#ifdef CONFIG_PM
329 init_waitqueue_head(&card->power_sleep);
330 init_waitqueue_head(&card->power_ref_sleep);
331 atomic_set(&card->power_ref, 0);
332#endif
333 init_waitqueue_head(&card->remove_sleep);
334 card->sync_irq = -1;
335
336 device_initialize(&card->card_dev);
337 card->card_dev.parent = parent;
338 card->card_dev.class = &sound_class;
339 card->card_dev.release = release_card_device;
340 card->card_dev.groups = card->dev_groups;
341 card->dev_groups[0] = &card_dev_attr_group;
342 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
343 if (err < 0)
344 goto __error;
345
346 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
347 dev_driver_string(card->dev), dev_name(&card->card_dev));
348
349 /* the control interface cannot be accessed from the user space until */
350 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
351 err = snd_ctl_create(card);
352 if (err < 0) {
353 dev_err(parent, "unable to register control minors\n");
354 goto __error;
355 }
356 err = snd_info_card_create(card);
357 if (err < 0) {
358 dev_err(parent, "unable to create card info\n");
359 goto __error_ctl;
360 }
361
362#ifdef CONFIG_SND_DEBUG
363 card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev),
364 sound_debugfs_root);
365#endif
366 return 0;
367
368 __error_ctl:
369 snd_device_free_all(card);
370 __error:
371 put_device(&card->card_dev);
372 return err;
373}
374
375/**
376 * snd_card_ref - Get the card object from the index
377 * @idx: the card index
378 *
379 * Returns a card object corresponding to the given index or NULL if not found.
380 * Release the object via snd_card_unref().
381 *
382 * Return: a card object or NULL
383 */
384struct snd_card *snd_card_ref(int idx)
385{
386 struct snd_card *card;
387
388 guard(mutex)(&snd_card_mutex);
389 card = snd_cards[idx];
390 if (card)
391 get_device(&card->card_dev);
392 return card;
393}
394EXPORT_SYMBOL_GPL(snd_card_ref);
395
396/* return non-zero if a card is already locked */
397int snd_card_locked(int card)
398{
399 guard(mutex)(&snd_card_mutex);
400 return test_bit(card, snd_cards_lock);
401}
402
403static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
404{
405 return -ENODEV;
406}
407
408static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
409 size_t count, loff_t *offset)
410{
411 return -ENODEV;
412}
413
414static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
415 size_t count, loff_t *offset)
416{
417 return -ENODEV;
418}
419
420static int snd_disconnect_release(struct inode *inode, struct file *file)
421{
422 struct snd_monitor_file *df = NULL, *_df;
423
424 scoped_guard(spinlock, &shutdown_lock) {
425 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
426 if (_df->file == file) {
427 df = _df;
428 list_del_init(&df->shutdown_list);
429 break;
430 }
431 }
432 }
433
434 if (likely(df)) {
435 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
436 df->disconnected_f_op->fasync(-1, file, 0);
437 return df->disconnected_f_op->release(inode, file);
438 }
439
440 panic("%s(%p, %p) failed!", __func__, inode, file);
441}
442
443static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
444{
445 return EPOLLERR | EPOLLNVAL;
446}
447
448static long snd_disconnect_ioctl(struct file *file,
449 unsigned int cmd, unsigned long arg)
450{
451 return -ENODEV;
452}
453
454static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
455{
456 return -ENODEV;
457}
458
459static int snd_disconnect_fasync(int fd, struct file *file, int on)
460{
461 return -ENODEV;
462}
463
464static const struct file_operations snd_shutdown_f_ops =
465{
466 .owner = THIS_MODULE,
467 .llseek = snd_disconnect_llseek,
468 .read = snd_disconnect_read,
469 .write = snd_disconnect_write,
470 .release = snd_disconnect_release,
471 .poll = snd_disconnect_poll,
472 .unlocked_ioctl = snd_disconnect_ioctl,
473#ifdef CONFIG_COMPAT
474 .compat_ioctl = snd_disconnect_ioctl,
475#endif
476 .mmap = snd_disconnect_mmap,
477 .fasync = snd_disconnect_fasync
478};
479
480/**
481 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
482 * @card: soundcard structure
483 *
484 * Disconnects all APIs from the file-operations (user space).
485 *
486 * Return: Zero, otherwise a negative error code.
487 *
488 * Note: The current implementation replaces all active file->f_op with special
489 * dummy file operations (they do nothing except release).
490 */
491void snd_card_disconnect(struct snd_card *card)
492{
493 struct snd_monitor_file *mfile;
494
495 if (!card)
496 return;
497
498 scoped_guard(spinlock, &card->files_lock) {
499 if (card->shutdown)
500 return;
501 card->shutdown = 1;
502
503 /* replace file->f_op with special dummy operations */
504 list_for_each_entry(mfile, &card->files_list, list) {
505 /* it's critical part, use endless loop */
506 /* we have no room to fail */
507 mfile->disconnected_f_op = mfile->file->f_op;
508
509 scoped_guard(spinlock, &shutdown_lock)
510 list_add(&mfile->shutdown_list, &shutdown_files);
511
512 mfile->file->f_op = &snd_shutdown_f_ops;
513 fops_get(mfile->file->f_op);
514 }
515 }
516
517#ifdef CONFIG_PM
518 /* wake up sleepers here before other callbacks for avoiding potential
519 * deadlocks with other locks (e.g. in kctls);
520 * then this notifies the shutdown and sleepers would abort immediately
521 */
522 wake_up_all(&card->power_sleep);
523#endif
524
525 /* notify all connected devices about disconnection */
526 /* at this point, they cannot respond to any calls except release() */
527
528#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
529 if (snd_mixer_oss_notify_callback)
530 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
531#endif
532
533 /* notify all devices that we are disconnected */
534 snd_device_disconnect_all(card);
535
536 if (card->sync_irq > 0)
537 synchronize_irq(card->sync_irq);
538
539 snd_info_card_disconnect(card);
540#ifdef CONFIG_SND_DEBUG
541 debugfs_remove(card->debugfs_root);
542 card->debugfs_root = NULL;
543#endif
544
545 if (card->registered) {
546 device_del(&card->card_dev);
547 card->registered = false;
548 }
549
550 /* disable fops (user space) operations for ALSA API */
551 scoped_guard(mutex, &snd_card_mutex) {
552 snd_cards[card->number] = NULL;
553 clear_bit(card->number, snd_cards_lock);
554 }
555
556 snd_power_sync_ref(card);
557}
558EXPORT_SYMBOL(snd_card_disconnect);
559
560/**
561 * snd_card_disconnect_sync - disconnect card and wait until files get closed
562 * @card: card object to disconnect
563 *
564 * This calls snd_card_disconnect() for disconnecting all belonging components
565 * and waits until all pending files get closed.
566 * It assures that all accesses from user-space finished so that the driver
567 * can release its resources gracefully.
568 */
569void snd_card_disconnect_sync(struct snd_card *card)
570{
571 snd_card_disconnect(card);
572
573 guard(spinlock_irq)(&card->files_lock);
574 wait_event_lock_irq(card->remove_sleep,
575 list_empty(&card->files_list),
576 card->files_lock);
577}
578EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
579
580static int snd_card_do_free(struct snd_card *card)
581{
582 card->releasing = true;
583#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
584 if (snd_mixer_oss_notify_callback)
585 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
586#endif
587 snd_device_free_all(card);
588 if (card->private_free)
589 card->private_free(card);
590 if (snd_info_card_free(card) < 0) {
591 dev_warn(card->dev, "unable to free card info\n");
592 /* Not fatal error */
593 }
594 if (card->release_completion)
595 complete(card->release_completion);
596 if (!card->managed)
597 kfree(card);
598 return 0;
599}
600
601/**
602 * snd_card_free_when_closed - Disconnect the card, free it later eventually
603 * @card: soundcard structure
604 *
605 * Unlike snd_card_free(), this function doesn't try to release the card
606 * resource immediately, but tries to disconnect at first. When the card
607 * is still in use, the function returns before freeing the resources.
608 * The card resources will be freed when the refcount gets to zero.
609 *
610 * Return: zero if successful, or a negative error code
611 */
612void snd_card_free_when_closed(struct snd_card *card)
613{
614 if (!card)
615 return;
616
617 snd_card_disconnect(card);
618 put_device(&card->card_dev);
619 return;
620}
621EXPORT_SYMBOL(snd_card_free_when_closed);
622
623/**
624 * snd_card_free - frees given soundcard structure
625 * @card: soundcard structure
626 *
627 * This function releases the soundcard structure and the all assigned
628 * devices automatically. That is, you don't have to release the devices
629 * by yourself.
630 *
631 * This function waits until the all resources are properly released.
632 *
633 * Return: Zero. Frees all associated devices and frees the control
634 * interface associated to given soundcard.
635 */
636void snd_card_free(struct snd_card *card)
637{
638 DECLARE_COMPLETION_ONSTACK(released);
639
640 /* The call of snd_card_free() is allowed from various code paths;
641 * a manual call from the driver and the call via devres_free, and
642 * we need to avoid double-free. Moreover, the release via devres
643 * may call snd_card_free() twice due to its nature, we need to have
644 * the check here at the beginning.
645 */
646 if (card->releasing)
647 return;
648
649 card->release_completion = &released;
650 snd_card_free_when_closed(card);
651
652 /* wait, until all devices are ready for the free operation */
653 wait_for_completion(&released);
654}
655EXPORT_SYMBOL(snd_card_free);
656
657/* check, if the character is in the valid ASCII range */
658static inline bool safe_ascii_char(char c)
659{
660 return isascii(c) && isalnum(c);
661}
662
663/* retrieve the last word of shortname or longname */
664static const char *retrieve_id_from_card_name(const char *name)
665{
666 const char *spos = name;
667
668 while (*name) {
669 if (isspace(*name) && safe_ascii_char(name[1]))
670 spos = name + 1;
671 name++;
672 }
673 return spos;
674}
675
676/* return true if the given id string doesn't conflict any other card ids */
677static bool card_id_ok(struct snd_card *card, const char *id)
678{
679 int i;
680 if (!snd_info_check_reserved_words(id))
681 return false;
682 for (i = 0; i < snd_ecards_limit; i++) {
683 if (snd_cards[i] && snd_cards[i] != card &&
684 !strcmp(snd_cards[i]->id, id))
685 return false;
686 }
687 return true;
688}
689
690/* copy to card->id only with valid letters from nid */
691static void copy_valid_id_string(struct snd_card *card, const char *src,
692 const char *nid)
693{
694 char *id = card->id;
695
696 while (*nid && !safe_ascii_char(*nid))
697 nid++;
698 if (isdigit(*nid))
699 *id++ = isalpha(*src) ? *src : 'D';
700 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
701 if (safe_ascii_char(*nid))
702 *id++ = *nid;
703 nid++;
704 }
705 *id = 0;
706}
707
708/* Set card->id from the given string
709 * If the string conflicts with other ids, add a suffix to make it unique.
710 */
711static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
712 const char *nid)
713{
714 int len, loops;
715 bool is_default = false;
716 char *id;
717
718 copy_valid_id_string(card, src, nid);
719 id = card->id;
720
721 again:
722 /* use "Default" for obviously invalid strings
723 * ("card" conflicts with proc directories)
724 */
725 if (!*id || !strncmp(id, "card", 4)) {
726 strcpy(id, "Default");
727 is_default = true;
728 }
729
730 len = strlen(id);
731 for (loops = 0; loops < SNDRV_CARDS; loops++) {
732 char *spos;
733 char sfxstr[5]; /* "_012" */
734 int sfxlen;
735
736 if (card_id_ok(card, id))
737 return; /* OK */
738
739 /* Add _XYZ suffix */
740 sprintf(sfxstr, "_%X", loops + 1);
741 sfxlen = strlen(sfxstr);
742 if (len + sfxlen >= sizeof(card->id))
743 spos = id + sizeof(card->id) - sfxlen - 1;
744 else
745 spos = id + len;
746 strcpy(spos, sfxstr);
747 }
748 /* fallback to the default id */
749 if (!is_default) {
750 *id = 0;
751 goto again;
752 }
753 /* last resort... */
754 dev_err(card->dev, "unable to set card id (%s)\n", id);
755 if (card->proc_root->name)
756 strscpy(card->id, card->proc_root->name, sizeof(card->id));
757}
758
759/**
760 * snd_card_set_id - set card identification name
761 * @card: soundcard structure
762 * @nid: new identification string
763 *
764 * This function sets the card identification and checks for name
765 * collisions.
766 */
767void snd_card_set_id(struct snd_card *card, const char *nid)
768{
769 /* check if user specified own card->id */
770 if (card->id[0] != '\0')
771 return;
772 guard(mutex)(&snd_card_mutex);
773 snd_card_set_id_no_lock(card, nid, nid);
774}
775EXPORT_SYMBOL(snd_card_set_id);
776
777static ssize_t id_show(struct device *dev,
778 struct device_attribute *attr, char *buf)
779{
780 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
781 return sysfs_emit(buf, "%s\n", card->id);
782}
783
784static ssize_t id_store(struct device *dev, struct device_attribute *attr,
785 const char *buf, size_t count)
786{
787 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
788 char buf1[sizeof(card->id)];
789 size_t copy = count > sizeof(card->id) - 1 ?
790 sizeof(card->id) - 1 : count;
791 size_t idx;
792 int c;
793
794 for (idx = 0; idx < copy; idx++) {
795 c = buf[idx];
796 if (!safe_ascii_char(c) && c != '_' && c != '-')
797 return -EINVAL;
798 }
799 memcpy(buf1, buf, copy);
800 buf1[copy] = '\0';
801 guard(mutex)(&snd_card_mutex);
802 if (!card_id_ok(NULL, buf1))
803 return -EEXIST;
804 strcpy(card->id, buf1);
805 snd_info_card_id_change(card);
806
807 return count;
808}
809
810static DEVICE_ATTR_RW(id);
811
812static ssize_t number_show(struct device *dev,
813 struct device_attribute *attr, char *buf)
814{
815 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
816 return sysfs_emit(buf, "%i\n", card->number);
817}
818
819static DEVICE_ATTR_RO(number);
820
821static struct attribute *card_dev_attrs[] = {
822 &dev_attr_id.attr,
823 &dev_attr_number.attr,
824 NULL
825};
826
827static const struct attribute_group card_dev_attr_group = {
828 .attrs = card_dev_attrs,
829};
830
831/**
832 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
833 * @card: card instance
834 * @group: attribute group to append
835 *
836 * Return: zero if successful, or a negative error code
837 */
838int snd_card_add_dev_attr(struct snd_card *card,
839 const struct attribute_group *group)
840{
841 int i;
842
843 /* loop for (arraysize-1) here to keep NULL at the last entry */
844 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
845 if (!card->dev_groups[i]) {
846 card->dev_groups[i] = group;
847 return 0;
848 }
849 }
850
851 dev_err(card->dev, "Too many groups assigned\n");
852 return -ENOSPC;
853}
854EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
855
856static void trigger_card_free(void *data)
857{
858 snd_card_free(data);
859}
860
861/**
862 * snd_card_register - register the soundcard
863 * @card: soundcard structure
864 *
865 * This function registers all the devices assigned to the soundcard.
866 * Until calling this, the ALSA control interface is blocked from the
867 * external accesses. Thus, you should call this function at the end
868 * of the initialization of the card.
869 *
870 * Return: Zero otherwise a negative error code if the registration failed.
871 */
872int snd_card_register(struct snd_card *card)
873{
874 int err;
875
876 if (snd_BUG_ON(!card))
877 return -EINVAL;
878
879 if (!card->registered) {
880 err = device_add(&card->card_dev);
881 if (err < 0)
882 return err;
883 card->registered = true;
884 } else {
885 if (card->managed)
886 devm_remove_action(card->dev, trigger_card_free, card);
887 }
888
889 if (card->managed) {
890 err = devm_add_action(card->dev, trigger_card_free, card);
891 if (err < 0)
892 return err;
893 }
894
895 err = snd_device_register_all(card);
896 if (err < 0)
897 return err;
898 scoped_guard(mutex, &snd_card_mutex) {
899 if (snd_cards[card->number]) {
900 /* already registered */
901 return snd_info_card_register(card); /* register pending info */
902 }
903 if (*card->id) {
904 /* make a unique id name from the given string */
905 char tmpid[sizeof(card->id)];
906
907 memcpy(tmpid, card->id, sizeof(card->id));
908 snd_card_set_id_no_lock(card, tmpid, tmpid);
909 } else {
910 /* create an id from either shortname or longname */
911 const char *src;
912
913 src = *card->shortname ? card->shortname : card->longname;
914 snd_card_set_id_no_lock(card, src,
915 retrieve_id_from_card_name(src));
916 }
917 snd_cards[card->number] = card;
918 }
919 err = snd_info_card_register(card);
920 if (err < 0)
921 return err;
922
923#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
924 if (snd_mixer_oss_notify_callback)
925 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
926#endif
927 return 0;
928}
929EXPORT_SYMBOL(snd_card_register);
930
931#ifdef CONFIG_SND_PROC_FS
932static void snd_card_info_read(struct snd_info_entry *entry,
933 struct snd_info_buffer *buffer)
934{
935 int idx, count;
936 struct snd_card *card;
937
938 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
939 guard(mutex)(&snd_card_mutex);
940 card = snd_cards[idx];
941 if (card) {
942 count++;
943 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
944 idx,
945 card->id,
946 card->driver,
947 card->shortname);
948 snd_iprintf(buffer, " %s\n",
949 card->longname);
950 }
951 }
952 if (!count)
953 snd_iprintf(buffer, "--- no soundcards ---\n");
954}
955
956#ifdef CONFIG_SND_OSSEMUL
957void snd_card_info_read_oss(struct snd_info_buffer *buffer)
958{
959 int idx, count;
960 struct snd_card *card;
961
962 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
963 guard(mutex)(&snd_card_mutex);
964 card = snd_cards[idx];
965 if (card) {
966 count++;
967 snd_iprintf(buffer, "%s\n", card->longname);
968 }
969 }
970 if (!count) {
971 snd_iprintf(buffer, "--- no soundcards ---\n");
972 }
973}
974
975#endif
976
977#ifdef CONFIG_MODULES
978static void snd_card_module_info_read(struct snd_info_entry *entry,
979 struct snd_info_buffer *buffer)
980{
981 int idx;
982 struct snd_card *card;
983
984 for (idx = 0; idx < SNDRV_CARDS; idx++) {
985 guard(mutex)(&snd_card_mutex);
986 card = snd_cards[idx];
987 if (card)
988 snd_iprintf(buffer, "%2i %s\n",
989 idx, card->module->name);
990 }
991}
992#endif
993
994int __init snd_card_info_init(void)
995{
996 struct snd_info_entry *entry;
997
998 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
999 if (! entry)
1000 return -ENOMEM;
1001 entry->c.text.read = snd_card_info_read;
1002 if (snd_info_register(entry) < 0)
1003 return -ENOMEM; /* freed in error path */
1004
1005#ifdef CONFIG_MODULES
1006 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1007 if (!entry)
1008 return -ENOMEM;
1009 entry->c.text.read = snd_card_module_info_read;
1010 if (snd_info_register(entry) < 0)
1011 return -ENOMEM; /* freed in error path */
1012#endif
1013
1014 return 0;
1015}
1016#endif /* CONFIG_SND_PROC_FS */
1017
1018/**
1019 * snd_component_add - add a component string
1020 * @card: soundcard structure
1021 * @component: the component id string
1022 *
1023 * This function adds the component id string to the supported list.
1024 * The component can be referred from the alsa-lib.
1025 *
1026 * Return: Zero otherwise a negative error code.
1027 */
1028
1029int snd_component_add(struct snd_card *card, const char *component)
1030{
1031 char *ptr;
1032 int len = strlen(component);
1033
1034 ptr = strstr(card->components, component);
1035 if (ptr != NULL) {
1036 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1037 return 1;
1038 }
1039 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1040 snd_BUG();
1041 return -ENOMEM;
1042 }
1043 if (card->components[0] != '\0')
1044 strcat(card->components, " ");
1045 strcat(card->components, component);
1046 return 0;
1047}
1048EXPORT_SYMBOL(snd_component_add);
1049
1050/**
1051 * snd_card_file_add - add the file to the file list of the card
1052 * @card: soundcard structure
1053 * @file: file pointer
1054 *
1055 * This function adds the file to the file linked-list of the card.
1056 * This linked-list is used to keep tracking the connection state,
1057 * and to avoid the release of busy resources by hotplug.
1058 *
1059 * Return: zero or a negative error code.
1060 */
1061int snd_card_file_add(struct snd_card *card, struct file *file)
1062{
1063 struct snd_monitor_file *mfile;
1064
1065 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1066 if (mfile == NULL)
1067 return -ENOMEM;
1068 mfile->file = file;
1069 mfile->disconnected_f_op = NULL;
1070 INIT_LIST_HEAD(&mfile->shutdown_list);
1071 guard(spinlock)(&card->files_lock);
1072 if (card->shutdown) {
1073 kfree(mfile);
1074 return -ENODEV;
1075 }
1076 list_add(&mfile->list, &card->files_list);
1077 get_device(&card->card_dev);
1078 return 0;
1079}
1080EXPORT_SYMBOL(snd_card_file_add);
1081
1082/**
1083 * snd_card_file_remove - remove the file from the file list
1084 * @card: soundcard structure
1085 * @file: file pointer
1086 *
1087 * This function removes the file formerly added to the card via
1088 * snd_card_file_add() function.
1089 * If all files are removed and snd_card_free_when_closed() was
1090 * called beforehand, it processes the pending release of
1091 * resources.
1092 *
1093 * Return: Zero or a negative error code.
1094 */
1095int snd_card_file_remove(struct snd_card *card, struct file *file)
1096{
1097 struct snd_monitor_file *mfile, *found = NULL;
1098
1099 scoped_guard(spinlock, &card->files_lock) {
1100 list_for_each_entry(mfile, &card->files_list, list) {
1101 if (mfile->file == file) {
1102 list_del(&mfile->list);
1103 scoped_guard(spinlock, &shutdown_lock)
1104 list_del(&mfile->shutdown_list);
1105 if (mfile->disconnected_f_op)
1106 fops_put(mfile->disconnected_f_op);
1107 found = mfile;
1108 break;
1109 }
1110 }
1111 if (list_empty(&card->files_list))
1112 wake_up_all(&card->remove_sleep);
1113 }
1114 if (!found) {
1115 dev_err(card->dev, "card file remove problem (%p)\n", file);
1116 return -ENOENT;
1117 }
1118 kfree(found);
1119 put_device(&card->card_dev);
1120 return 0;
1121}
1122EXPORT_SYMBOL(snd_card_file_remove);
1123
1124#ifdef CONFIG_PM
1125/**
1126 * snd_power_ref_and_wait - wait until the card gets powered up
1127 * @card: soundcard structure
1128 *
1129 * Take the power_ref reference count of the given card, and
1130 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1131 * The refcount is down again while sleeping until power-up, hence this
1132 * function can be used for syncing the floating control ops accesses,
1133 * typically around calling control ops.
1134 *
1135 * The caller needs to pull down the refcount via snd_power_unref() later
1136 * no matter whether the error is returned from this function or not.
1137 *
1138 * Return: Zero if successful, or a negative error code.
1139 */
1140int snd_power_ref_and_wait(struct snd_card *card)
1141{
1142 snd_power_ref(card);
1143 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1144 return 0;
1145 wait_event_cmd(card->power_sleep,
1146 card->shutdown ||
1147 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1148 snd_power_unref(card), snd_power_ref(card));
1149 return card->shutdown ? -ENODEV : 0;
1150}
1151EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1152
1153/**
1154 * snd_power_wait - wait until the card gets powered up (old form)
1155 * @card: soundcard structure
1156 *
1157 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1158 *
1159 * Return: Zero if successful, or a negative error code.
1160 */
1161int snd_power_wait(struct snd_card *card)
1162{
1163 int ret;
1164
1165 ret = snd_power_ref_and_wait(card);
1166 snd_power_unref(card);
1167 return ret;
1168}
1169EXPORT_SYMBOL(snd_power_wait);
1170#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/completion.h>
17
18#include <sound/core.h>
19#include <sound/control.h>
20#include <sound/info.h>
21
22/* monitor files for graceful shutdown (hotplug) */
23struct snd_monitor_file {
24 struct file *file;
25 const struct file_operations *disconnected_f_op;
26 struct list_head shutdown_list; /* still need to shutdown */
27 struct list_head list; /* link of monitor files */
28};
29
30static DEFINE_SPINLOCK(shutdown_lock);
31static LIST_HEAD(shutdown_files);
32
33static const struct file_operations snd_shutdown_f_ops;
34
35/* locked for registering/using */
36static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
37static struct snd_card *snd_cards[SNDRV_CARDS];
38
39static DEFINE_MUTEX(snd_card_mutex);
40
41static char *slots[SNDRV_CARDS];
42module_param_array(slots, charp, NULL, 0444);
43MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
44
45/* return non-zero if the given index is reserved for the given
46 * module via slots option
47 */
48static int module_slot_match(struct module *module, int idx)
49{
50 int match = 1;
51#ifdef MODULE
52 const char *s1, *s2;
53
54 if (!module || !*module->name || !slots[idx])
55 return 0;
56
57 s1 = module->name;
58 s2 = slots[idx];
59 if (*s2 == '!') {
60 match = 0; /* negative match */
61 s2++;
62 }
63 /* compare module name strings
64 * hyphens are handled as equivalent with underscore
65 */
66 for (;;) {
67 char c1 = *s1++;
68 char c2 = *s2++;
69 if (c1 == '-')
70 c1 = '_';
71 if (c2 == '-')
72 c2 = '_';
73 if (c1 != c2)
74 return !match;
75 if (!c1)
76 break;
77 }
78#endif /* MODULE */
79 return match;
80}
81
82#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
83int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
84EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
85#endif
86
87static int check_empty_slot(struct module *module, int slot)
88{
89 return !slots[slot] || !*slots[slot];
90}
91
92/* return an empty slot number (>= 0) found in the given bitmask @mask.
93 * @mask == -1 == 0xffffffff means: take any free slot up to 32
94 * when no slot is available, return the original @mask as is.
95 */
96static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
97 struct module *module)
98{
99 int slot;
100
101 for (slot = 0; slot < SNDRV_CARDS; slot++) {
102 if (slot < 32 && !(mask & (1U << slot)))
103 continue;
104 if (!test_bit(slot, snd_cards_lock)) {
105 if (check(module, slot))
106 return slot; /* found */
107 }
108 }
109 return mask; /* unchanged */
110}
111
112/* the default release callback set in snd_device_initialize() below;
113 * this is just NOP for now, as almost all jobs are already done in
114 * dev_free callback of snd_device chain instead.
115 */
116static void default_release(struct device *dev)
117{
118}
119
120/**
121 * snd_device_initialize - Initialize struct device for sound devices
122 * @dev: device to initialize
123 * @card: card to assign, optional
124 */
125void snd_device_initialize(struct device *dev, struct snd_card *card)
126{
127 device_initialize(dev);
128 if (card)
129 dev->parent = &card->card_dev;
130 dev->class = sound_class;
131 dev->release = default_release;
132}
133EXPORT_SYMBOL_GPL(snd_device_initialize);
134
135static int snd_card_do_free(struct snd_card *card);
136static const struct attribute_group card_dev_attr_group;
137
138static void release_card_device(struct device *dev)
139{
140 snd_card_do_free(dev_to_snd_card(dev));
141}
142
143/**
144 * snd_card_new - create and initialize a soundcard structure
145 * @parent: the parent device object
146 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
147 * @xid: card identification (ASCII string)
148 * @module: top level module for locking
149 * @extra_size: allocate this extra size after the main soundcard structure
150 * @card_ret: the pointer to store the created card instance
151 *
152 * Creates and initializes a soundcard structure.
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
167 if (snd_BUG_ON(!card_ret))
168 return -EINVAL;
169 *card_ret = NULL;
170
171 if (extra_size < 0)
172 extra_size = 0;
173 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
174 if (!card)
175 return -ENOMEM;
176 if (extra_size > 0)
177 card->private_data = (char *)card + sizeof(struct snd_card);
178 if (xid)
179 strlcpy(card->id, xid, sizeof(card->id));
180 err = 0;
181 mutex_lock(&snd_card_mutex);
182 if (idx < 0) /* first check the matching module-name slot */
183 idx = get_slot_from_bitmask(idx, module_slot_match, module);
184 if (idx < 0) /* if not matched, assign an empty slot */
185 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
186 if (idx < 0)
187 err = -ENODEV;
188 else if (idx < snd_ecards_limit) {
189 if (test_bit(idx, snd_cards_lock))
190 err = -EBUSY; /* invalid */
191 } else if (idx >= SNDRV_CARDS)
192 err = -ENODEV;
193 if (err < 0) {
194 mutex_unlock(&snd_card_mutex);
195 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
196 idx, snd_ecards_limit - 1, err);
197 kfree(card);
198 return err;
199 }
200 set_bit(idx, snd_cards_lock); /* lock it */
201 if (idx >= snd_ecards_limit)
202 snd_ecards_limit = idx + 1; /* increase the limit */
203 mutex_unlock(&snd_card_mutex);
204 card->dev = parent;
205 card->number = idx;
206#ifdef MODULE
207 WARN_ON(!module);
208 card->module = module;
209#endif
210 INIT_LIST_HEAD(&card->devices);
211 init_rwsem(&card->controls_rwsem);
212 rwlock_init(&card->ctl_files_rwlock);
213 INIT_LIST_HEAD(&card->controls);
214 INIT_LIST_HEAD(&card->ctl_files);
215 spin_lock_init(&card->files_lock);
216 INIT_LIST_HEAD(&card->files_list);
217 mutex_init(&card->memory_mutex);
218#ifdef CONFIG_PM
219 init_waitqueue_head(&card->power_sleep);
220#endif
221 init_waitqueue_head(&card->remove_sleep);
222 card->sync_irq = -1;
223
224 device_initialize(&card->card_dev);
225 card->card_dev.parent = parent;
226 card->card_dev.class = sound_class;
227 card->card_dev.release = release_card_device;
228 card->card_dev.groups = card->dev_groups;
229 card->dev_groups[0] = &card_dev_attr_group;
230 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
231 if (err < 0)
232 goto __error;
233
234 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
235 dev_driver_string(card->dev), dev_name(&card->card_dev));
236
237 /* the control interface cannot be accessed from the user space until */
238 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
239 err = snd_ctl_create(card);
240 if (err < 0) {
241 dev_err(parent, "unable to register control minors\n");
242 goto __error;
243 }
244 err = snd_info_card_create(card);
245 if (err < 0) {
246 dev_err(parent, "unable to create card info\n");
247 goto __error_ctl;
248 }
249 *card_ret = card;
250 return 0;
251
252 __error_ctl:
253 snd_device_free_all(card);
254 __error:
255 put_device(&card->card_dev);
256 return err;
257}
258EXPORT_SYMBOL(snd_card_new);
259
260/**
261 * snd_card_ref - Get the card object from the index
262 * @idx: the card index
263 *
264 * Returns a card object corresponding to the given index or NULL if not found.
265 * Release the object via snd_card_unref().
266 */
267struct snd_card *snd_card_ref(int idx)
268{
269 struct snd_card *card;
270
271 mutex_lock(&snd_card_mutex);
272 card = snd_cards[idx];
273 if (card)
274 get_device(&card->card_dev);
275 mutex_unlock(&snd_card_mutex);
276 return card;
277}
278EXPORT_SYMBOL_GPL(snd_card_ref);
279
280/* return non-zero if a card is already locked */
281int snd_card_locked(int card)
282{
283 int locked;
284
285 mutex_lock(&snd_card_mutex);
286 locked = test_bit(card, snd_cards_lock);
287 mutex_unlock(&snd_card_mutex);
288 return locked;
289}
290
291static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
292{
293 return -ENODEV;
294}
295
296static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
297 size_t count, loff_t *offset)
298{
299 return -ENODEV;
300}
301
302static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
303 size_t count, loff_t *offset)
304{
305 return -ENODEV;
306}
307
308static int snd_disconnect_release(struct inode *inode, struct file *file)
309{
310 struct snd_monitor_file *df = NULL, *_df;
311
312 spin_lock(&shutdown_lock);
313 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
314 if (_df->file == file) {
315 df = _df;
316 list_del_init(&df->shutdown_list);
317 break;
318 }
319 }
320 spin_unlock(&shutdown_lock);
321
322 if (likely(df)) {
323 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
324 df->disconnected_f_op->fasync(-1, file, 0);
325 return df->disconnected_f_op->release(inode, file);
326 }
327
328 panic("%s(%p, %p) failed!", __func__, inode, file);
329}
330
331static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
332{
333 return EPOLLERR | EPOLLNVAL;
334}
335
336static long snd_disconnect_ioctl(struct file *file,
337 unsigned int cmd, unsigned long arg)
338{
339 return -ENODEV;
340}
341
342static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
343{
344 return -ENODEV;
345}
346
347static int snd_disconnect_fasync(int fd, struct file *file, int on)
348{
349 return -ENODEV;
350}
351
352static const struct file_operations snd_shutdown_f_ops =
353{
354 .owner = THIS_MODULE,
355 .llseek = snd_disconnect_llseek,
356 .read = snd_disconnect_read,
357 .write = snd_disconnect_write,
358 .release = snd_disconnect_release,
359 .poll = snd_disconnect_poll,
360 .unlocked_ioctl = snd_disconnect_ioctl,
361#ifdef CONFIG_COMPAT
362 .compat_ioctl = snd_disconnect_ioctl,
363#endif
364 .mmap = snd_disconnect_mmap,
365 .fasync = snd_disconnect_fasync
366};
367
368/**
369 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
370 * @card: soundcard structure
371 *
372 * Disconnects all APIs from the file-operations (user space).
373 *
374 * Return: Zero, otherwise a negative error code.
375 *
376 * Note: The current implementation replaces all active file->f_op with special
377 * dummy file operations (they do nothing except release).
378 */
379int snd_card_disconnect(struct snd_card *card)
380{
381 struct snd_monitor_file *mfile;
382
383 if (!card)
384 return -EINVAL;
385
386 spin_lock(&card->files_lock);
387 if (card->shutdown) {
388 spin_unlock(&card->files_lock);
389 return 0;
390 }
391 card->shutdown = 1;
392 spin_unlock(&card->files_lock);
393
394 /* replace file->f_op with special dummy operations */
395 spin_lock(&card->files_lock);
396 list_for_each_entry(mfile, &card->files_list, list) {
397 /* it's critical part, use endless loop */
398 /* we have no room to fail */
399 mfile->disconnected_f_op = mfile->file->f_op;
400
401 spin_lock(&shutdown_lock);
402 list_add(&mfile->shutdown_list, &shutdown_files);
403 spin_unlock(&shutdown_lock);
404
405 mfile->file->f_op = &snd_shutdown_f_ops;
406 fops_get(mfile->file->f_op);
407 }
408 spin_unlock(&card->files_lock);
409
410 /* notify all connected devices about disconnection */
411 /* at this point, they cannot respond to any calls except release() */
412
413#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
414 if (snd_mixer_oss_notify_callback)
415 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
416#endif
417
418 /* notify all devices that we are disconnected */
419 snd_device_disconnect_all(card);
420
421 snd_info_card_disconnect(card);
422 if (card->registered) {
423 device_del(&card->card_dev);
424 card->registered = false;
425 }
426
427 /* disable fops (user space) operations for ALSA API */
428 mutex_lock(&snd_card_mutex);
429 snd_cards[card->number] = NULL;
430 clear_bit(card->number, snd_cards_lock);
431 mutex_unlock(&snd_card_mutex);
432
433#ifdef CONFIG_PM
434 wake_up(&card->power_sleep);
435#endif
436 return 0;
437}
438EXPORT_SYMBOL(snd_card_disconnect);
439
440/**
441 * snd_card_disconnect_sync - disconnect card and wait until files get closed
442 * @card: card object to disconnect
443 *
444 * This calls snd_card_disconnect() for disconnecting all belonging components
445 * and waits until all pending files get closed.
446 * It assures that all accesses from user-space finished so that the driver
447 * can release its resources gracefully.
448 */
449void snd_card_disconnect_sync(struct snd_card *card)
450{
451 int err;
452
453 err = snd_card_disconnect(card);
454 if (err < 0) {
455 dev_err(card->dev,
456 "snd_card_disconnect error (%d), skipping sync\n",
457 err);
458 return;
459 }
460
461 spin_lock_irq(&card->files_lock);
462 wait_event_lock_irq(card->remove_sleep,
463 list_empty(&card->files_list),
464 card->files_lock);
465 spin_unlock_irq(&card->files_lock);
466}
467EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
468
469static int snd_card_do_free(struct snd_card *card)
470{
471#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
472 if (snd_mixer_oss_notify_callback)
473 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
474#endif
475 snd_device_free_all(card);
476 if (card->private_free)
477 card->private_free(card);
478 if (snd_info_card_free(card) < 0) {
479 dev_warn(card->dev, "unable to free card info\n");
480 /* Not fatal error */
481 }
482 if (card->release_completion)
483 complete(card->release_completion);
484 kfree(card);
485 return 0;
486}
487
488/**
489 * snd_card_free_when_closed - Disconnect the card, free it later eventually
490 * @card: soundcard structure
491 *
492 * Unlike snd_card_free(), this function doesn't try to release the card
493 * resource immediately, but tries to disconnect at first. When the card
494 * is still in use, the function returns before freeing the resources.
495 * The card resources will be freed when the refcount gets to zero.
496 */
497int snd_card_free_when_closed(struct snd_card *card)
498{
499 int ret = snd_card_disconnect(card);
500 if (ret)
501 return ret;
502 put_device(&card->card_dev);
503 return 0;
504}
505EXPORT_SYMBOL(snd_card_free_when_closed);
506
507/**
508 * snd_card_free - frees given soundcard structure
509 * @card: soundcard structure
510 *
511 * This function releases the soundcard structure and the all assigned
512 * devices automatically. That is, you don't have to release the devices
513 * by yourself.
514 *
515 * This function waits until the all resources are properly released.
516 *
517 * Return: Zero. Frees all associated devices and frees the control
518 * interface associated to given soundcard.
519 */
520int snd_card_free(struct snd_card *card)
521{
522 struct completion released;
523 int ret;
524
525 init_completion(&released);
526 card->release_completion = &released;
527 ret = snd_card_free_when_closed(card);
528 if (ret)
529 return ret;
530 /* wait, until all devices are ready for the free operation */
531 wait_for_completion(&released);
532 return 0;
533}
534EXPORT_SYMBOL(snd_card_free);
535
536/* retrieve the last word of shortname or longname */
537static const char *retrieve_id_from_card_name(const char *name)
538{
539 const char *spos = name;
540
541 while (*name) {
542 if (isspace(*name) && isalnum(name[1]))
543 spos = name + 1;
544 name++;
545 }
546 return spos;
547}
548
549/* return true if the given id string doesn't conflict any other card ids */
550static bool card_id_ok(struct snd_card *card, const char *id)
551{
552 int i;
553 if (!snd_info_check_reserved_words(id))
554 return false;
555 for (i = 0; i < snd_ecards_limit; i++) {
556 if (snd_cards[i] && snd_cards[i] != card &&
557 !strcmp(snd_cards[i]->id, id))
558 return false;
559 }
560 return true;
561}
562
563/* copy to card->id only with valid letters from nid */
564static void copy_valid_id_string(struct snd_card *card, const char *src,
565 const char *nid)
566{
567 char *id = card->id;
568
569 while (*nid && !isalnum(*nid))
570 nid++;
571 if (isdigit(*nid))
572 *id++ = isalpha(*src) ? *src : 'D';
573 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
574 if (isalnum(*nid))
575 *id++ = *nid;
576 nid++;
577 }
578 *id = 0;
579}
580
581/* Set card->id from the given string
582 * If the string conflicts with other ids, add a suffix to make it unique.
583 */
584static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
585 const char *nid)
586{
587 int len, loops;
588 bool is_default = false;
589 char *id;
590
591 copy_valid_id_string(card, src, nid);
592 id = card->id;
593
594 again:
595 /* use "Default" for obviously invalid strings
596 * ("card" conflicts with proc directories)
597 */
598 if (!*id || !strncmp(id, "card", 4)) {
599 strcpy(id, "Default");
600 is_default = true;
601 }
602
603 len = strlen(id);
604 for (loops = 0; loops < SNDRV_CARDS; loops++) {
605 char *spos;
606 char sfxstr[5]; /* "_012" */
607 int sfxlen;
608
609 if (card_id_ok(card, id))
610 return; /* OK */
611
612 /* Add _XYZ suffix */
613 sprintf(sfxstr, "_%X", loops + 1);
614 sfxlen = strlen(sfxstr);
615 if (len + sfxlen >= sizeof(card->id))
616 spos = id + sizeof(card->id) - sfxlen - 1;
617 else
618 spos = id + len;
619 strcpy(spos, sfxstr);
620 }
621 /* fallback to the default id */
622 if (!is_default) {
623 *id = 0;
624 goto again;
625 }
626 /* last resort... */
627 dev_err(card->dev, "unable to set card id (%s)\n", id);
628 if (card->proc_root->name)
629 strlcpy(card->id, card->proc_root->name, sizeof(card->id));
630}
631
632/**
633 * snd_card_set_id - set card identification name
634 * @card: soundcard structure
635 * @nid: new identification string
636 *
637 * This function sets the card identification and checks for name
638 * collisions.
639 */
640void snd_card_set_id(struct snd_card *card, const char *nid)
641{
642 /* check if user specified own card->id */
643 if (card->id[0] != '\0')
644 return;
645 mutex_lock(&snd_card_mutex);
646 snd_card_set_id_no_lock(card, nid, nid);
647 mutex_unlock(&snd_card_mutex);
648}
649EXPORT_SYMBOL(snd_card_set_id);
650
651static ssize_t
652card_id_show_attr(struct device *dev,
653 struct device_attribute *attr, char *buf)
654{
655 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
656 return scnprintf(buf, PAGE_SIZE, "%s\n", card->id);
657}
658
659static ssize_t
660card_id_store_attr(struct device *dev, struct device_attribute *attr,
661 const char *buf, size_t count)
662{
663 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
664 char buf1[sizeof(card->id)];
665 size_t copy = count > sizeof(card->id) - 1 ?
666 sizeof(card->id) - 1 : count;
667 size_t idx;
668 int c;
669
670 for (idx = 0; idx < copy; idx++) {
671 c = buf[idx];
672 if (!isalnum(c) && c != '_' && c != '-')
673 return -EINVAL;
674 }
675 memcpy(buf1, buf, copy);
676 buf1[copy] = '\0';
677 mutex_lock(&snd_card_mutex);
678 if (!card_id_ok(NULL, buf1)) {
679 mutex_unlock(&snd_card_mutex);
680 return -EEXIST;
681 }
682 strcpy(card->id, buf1);
683 snd_info_card_id_change(card);
684 mutex_unlock(&snd_card_mutex);
685
686 return count;
687}
688
689static DEVICE_ATTR(id, 0644, card_id_show_attr, card_id_store_attr);
690
691static ssize_t
692card_number_show_attr(struct device *dev,
693 struct device_attribute *attr, char *buf)
694{
695 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
696 return scnprintf(buf, PAGE_SIZE, "%i\n", card->number);
697}
698
699static DEVICE_ATTR(number, 0444, card_number_show_attr, NULL);
700
701static struct attribute *card_dev_attrs[] = {
702 &dev_attr_id.attr,
703 &dev_attr_number.attr,
704 NULL
705};
706
707static const struct attribute_group card_dev_attr_group = {
708 .attrs = card_dev_attrs,
709};
710
711/**
712 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
713 * @card: card instance
714 * @group: attribute group to append
715 */
716int snd_card_add_dev_attr(struct snd_card *card,
717 const struct attribute_group *group)
718{
719 int i;
720
721 /* loop for (arraysize-1) here to keep NULL at the last entry */
722 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
723 if (!card->dev_groups[i]) {
724 card->dev_groups[i] = group;
725 return 0;
726 }
727 }
728
729 dev_err(card->dev, "Too many groups assigned\n");
730 return -ENOSPC;
731}
732EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
733
734/**
735 * snd_card_register - register the soundcard
736 * @card: soundcard structure
737 *
738 * This function registers all the devices assigned to the soundcard.
739 * Until calling this, the ALSA control interface is blocked from the
740 * external accesses. Thus, you should call this function at the end
741 * of the initialization of the card.
742 *
743 * Return: Zero otherwise a negative error code if the registration failed.
744 */
745int snd_card_register(struct snd_card *card)
746{
747 int err;
748
749 if (snd_BUG_ON(!card))
750 return -EINVAL;
751
752 if (!card->registered) {
753 err = device_add(&card->card_dev);
754 if (err < 0)
755 return err;
756 card->registered = true;
757 }
758
759 if ((err = snd_device_register_all(card)) < 0)
760 return err;
761 mutex_lock(&snd_card_mutex);
762 if (snd_cards[card->number]) {
763 /* already registered */
764 mutex_unlock(&snd_card_mutex);
765 return snd_info_card_register(card); /* register pending info */
766 }
767 if (*card->id) {
768 /* make a unique id name from the given string */
769 char tmpid[sizeof(card->id)];
770 memcpy(tmpid, card->id, sizeof(card->id));
771 snd_card_set_id_no_lock(card, tmpid, tmpid);
772 } else {
773 /* create an id from either shortname or longname */
774 const char *src;
775 src = *card->shortname ? card->shortname : card->longname;
776 snd_card_set_id_no_lock(card, src,
777 retrieve_id_from_card_name(src));
778 }
779 snd_cards[card->number] = card;
780 mutex_unlock(&snd_card_mutex);
781 err = snd_info_card_register(card);
782 if (err < 0)
783 return err;
784
785#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
786 if (snd_mixer_oss_notify_callback)
787 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
788#endif
789 return 0;
790}
791EXPORT_SYMBOL(snd_card_register);
792
793#ifdef CONFIG_SND_PROC_FS
794static void snd_card_info_read(struct snd_info_entry *entry,
795 struct snd_info_buffer *buffer)
796{
797 int idx, count;
798 struct snd_card *card;
799
800 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
801 mutex_lock(&snd_card_mutex);
802 if ((card = snd_cards[idx]) != NULL) {
803 count++;
804 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
805 idx,
806 card->id,
807 card->driver,
808 card->shortname);
809 snd_iprintf(buffer, " %s\n",
810 card->longname);
811 }
812 mutex_unlock(&snd_card_mutex);
813 }
814 if (!count)
815 snd_iprintf(buffer, "--- no soundcards ---\n");
816}
817
818#ifdef CONFIG_SND_OSSEMUL
819void snd_card_info_read_oss(struct snd_info_buffer *buffer)
820{
821 int idx, count;
822 struct snd_card *card;
823
824 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
825 mutex_lock(&snd_card_mutex);
826 if ((card = snd_cards[idx]) != NULL) {
827 count++;
828 snd_iprintf(buffer, "%s\n", card->longname);
829 }
830 mutex_unlock(&snd_card_mutex);
831 }
832 if (!count) {
833 snd_iprintf(buffer, "--- no soundcards ---\n");
834 }
835}
836
837#endif
838
839#ifdef MODULE
840static void snd_card_module_info_read(struct snd_info_entry *entry,
841 struct snd_info_buffer *buffer)
842{
843 int idx;
844 struct snd_card *card;
845
846 for (idx = 0; idx < SNDRV_CARDS; idx++) {
847 mutex_lock(&snd_card_mutex);
848 if ((card = snd_cards[idx]) != NULL)
849 snd_iprintf(buffer, "%2i %s\n",
850 idx, card->module->name);
851 mutex_unlock(&snd_card_mutex);
852 }
853}
854#endif
855
856int __init snd_card_info_init(void)
857{
858 struct snd_info_entry *entry;
859
860 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
861 if (! entry)
862 return -ENOMEM;
863 entry->c.text.read = snd_card_info_read;
864 if (snd_info_register(entry) < 0)
865 return -ENOMEM; /* freed in error path */
866
867#ifdef MODULE
868 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
869 if (!entry)
870 return -ENOMEM;
871 entry->c.text.read = snd_card_module_info_read;
872 if (snd_info_register(entry) < 0)
873 return -ENOMEM; /* freed in error path */
874#endif
875
876 return 0;
877}
878#endif /* CONFIG_SND_PROC_FS */
879
880/**
881 * snd_component_add - add a component string
882 * @card: soundcard structure
883 * @component: the component id string
884 *
885 * This function adds the component id string to the supported list.
886 * The component can be referred from the alsa-lib.
887 *
888 * Return: Zero otherwise a negative error code.
889 */
890
891int snd_component_add(struct snd_card *card, const char *component)
892{
893 char *ptr;
894 int len = strlen(component);
895
896 ptr = strstr(card->components, component);
897 if (ptr != NULL) {
898 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
899 return 1;
900 }
901 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
902 snd_BUG();
903 return -ENOMEM;
904 }
905 if (card->components[0] != '\0')
906 strcat(card->components, " ");
907 strcat(card->components, component);
908 return 0;
909}
910EXPORT_SYMBOL(snd_component_add);
911
912/**
913 * snd_card_file_add - add the file to the file list of the card
914 * @card: soundcard structure
915 * @file: file pointer
916 *
917 * This function adds the file to the file linked-list of the card.
918 * This linked-list is used to keep tracking the connection state,
919 * and to avoid the release of busy resources by hotplug.
920 *
921 * Return: zero or a negative error code.
922 */
923int snd_card_file_add(struct snd_card *card, struct file *file)
924{
925 struct snd_monitor_file *mfile;
926
927 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
928 if (mfile == NULL)
929 return -ENOMEM;
930 mfile->file = file;
931 mfile->disconnected_f_op = NULL;
932 INIT_LIST_HEAD(&mfile->shutdown_list);
933 spin_lock(&card->files_lock);
934 if (card->shutdown) {
935 spin_unlock(&card->files_lock);
936 kfree(mfile);
937 return -ENODEV;
938 }
939 list_add(&mfile->list, &card->files_list);
940 get_device(&card->card_dev);
941 spin_unlock(&card->files_lock);
942 return 0;
943}
944EXPORT_SYMBOL(snd_card_file_add);
945
946/**
947 * snd_card_file_remove - remove the file from the file list
948 * @card: soundcard structure
949 * @file: file pointer
950 *
951 * This function removes the file formerly added to the card via
952 * snd_card_file_add() function.
953 * If all files are removed and snd_card_free_when_closed() was
954 * called beforehand, it processes the pending release of
955 * resources.
956 *
957 * Return: Zero or a negative error code.
958 */
959int snd_card_file_remove(struct snd_card *card, struct file *file)
960{
961 struct snd_monitor_file *mfile, *found = NULL;
962
963 spin_lock(&card->files_lock);
964 list_for_each_entry(mfile, &card->files_list, list) {
965 if (mfile->file == file) {
966 list_del(&mfile->list);
967 spin_lock(&shutdown_lock);
968 list_del(&mfile->shutdown_list);
969 spin_unlock(&shutdown_lock);
970 if (mfile->disconnected_f_op)
971 fops_put(mfile->disconnected_f_op);
972 found = mfile;
973 break;
974 }
975 }
976 if (list_empty(&card->files_list))
977 wake_up_all(&card->remove_sleep);
978 spin_unlock(&card->files_lock);
979 if (!found) {
980 dev_err(card->dev, "card file remove problem (%p)\n", file);
981 return -ENOENT;
982 }
983 kfree(found);
984 put_device(&card->card_dev);
985 return 0;
986}
987EXPORT_SYMBOL(snd_card_file_remove);
988
989#ifdef CONFIG_PM
990/**
991 * snd_power_wait - wait until the power-state is changed.
992 * @card: soundcard structure
993 * @power_state: expected power state
994 *
995 * Waits until the power-state is changed.
996 *
997 * Return: Zero if successful, or a negative error code.
998 */
999int snd_power_wait(struct snd_card *card, unsigned int power_state)
1000{
1001 wait_queue_entry_t wait;
1002 int result = 0;
1003
1004 /* fastpath */
1005 if (snd_power_get_state(card) == power_state)
1006 return 0;
1007 init_waitqueue_entry(&wait, current);
1008 add_wait_queue(&card->power_sleep, &wait);
1009 while (1) {
1010 if (card->shutdown) {
1011 result = -ENODEV;
1012 break;
1013 }
1014 if (snd_power_get_state(card) == power_state)
1015 break;
1016 set_current_state(TASK_UNINTERRUPTIBLE);
1017 schedule_timeout(30 * HZ);
1018 }
1019 remove_wait_queue(&card->power_sleep, &wait);
1020 return result;
1021}
1022EXPORT_SYMBOL(snd_power_wait);
1023#endif /* CONFIG_PM */