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