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1/*
2 * Initialization routines
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/init.h>
23#include <linux/sched.h>
24#include <linux/module.h>
25#include <linux/device.h>
26#include <linux/file.h>
27#include <linux/slab.h>
28#include <linux/time.h>
29#include <linux/ctype.h>
30#include <linux/pm.h>
31#include <linux/completion.h>
32
33#include <sound/core.h>
34#include <sound/control.h>
35#include <sound/info.h>
36
37/* monitor files for graceful shutdown (hotplug) */
38struct snd_monitor_file {
39 struct file *file;
40 const struct file_operations *disconnected_f_op;
41 struct list_head shutdown_list; /* still need to shutdown */
42 struct list_head list; /* link of monitor files */
43};
44
45static DEFINE_SPINLOCK(shutdown_lock);
46static LIST_HEAD(shutdown_files);
47
48static const struct file_operations snd_shutdown_f_ops;
49
50/* locked for registering/using */
51static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
52struct snd_card *snd_cards[SNDRV_CARDS];
53EXPORT_SYMBOL(snd_cards);
54
55static DEFINE_MUTEX(snd_card_mutex);
56
57static char *slots[SNDRV_CARDS];
58module_param_array(slots, charp, NULL, 0444);
59MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
60
61/* return non-zero if the given index is reserved for the given
62 * module via slots option
63 */
64static int module_slot_match(struct module *module, int idx)
65{
66 int match = 1;
67#ifdef MODULE
68 const char *s1, *s2;
69
70 if (!module || !*module->name || !slots[idx])
71 return 0;
72
73 s1 = module->name;
74 s2 = slots[idx];
75 if (*s2 == '!') {
76 match = 0; /* negative match */
77 s2++;
78 }
79 /* compare module name strings
80 * hyphens are handled as equivalent with underscore
81 */
82 for (;;) {
83 char c1 = *s1++;
84 char c2 = *s2++;
85 if (c1 == '-')
86 c1 = '_';
87 if (c2 == '-')
88 c2 = '_';
89 if (c1 != c2)
90 return !match;
91 if (!c1)
92 break;
93 }
94#endif /* MODULE */
95 return match;
96}
97
98#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
99int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
100EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
101#endif
102
103#ifdef CONFIG_PROC_FS
104static void snd_card_id_read(struct snd_info_entry *entry,
105 struct snd_info_buffer *buffer)
106{
107 snd_iprintf(buffer, "%s\n", entry->card->id);
108}
109
110static inline int init_info_for_card(struct snd_card *card)
111{
112 int err;
113 struct snd_info_entry *entry;
114
115 if ((err = snd_info_card_register(card)) < 0) {
116 dev_dbg(card->dev, "unable to create card info\n");
117 return err;
118 }
119 if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
120 dev_dbg(card->dev, "unable to create card entry\n");
121 return err;
122 }
123 entry->c.text.read = snd_card_id_read;
124 if (snd_info_register(entry) < 0) {
125 snd_info_free_entry(entry);
126 entry = NULL;
127 }
128 card->proc_id = entry;
129 return 0;
130}
131#else /* !CONFIG_PROC_FS */
132#define init_info_for_card(card)
133#endif
134
135static int check_empty_slot(struct module *module, int slot)
136{
137 return !slots[slot] || !*slots[slot];
138}
139
140/* return an empty slot number (>= 0) found in the given bitmask @mask.
141 * @mask == -1 == 0xffffffff means: take any free slot up to 32
142 * when no slot is available, return the original @mask as is.
143 */
144static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
145 struct module *module)
146{
147 int slot;
148
149 for (slot = 0; slot < SNDRV_CARDS; slot++) {
150 if (slot < 32 && !(mask & (1U << slot)))
151 continue;
152 if (!test_bit(slot, snd_cards_lock)) {
153 if (check(module, slot))
154 return slot; /* found */
155 }
156 }
157 return mask; /* unchanged */
158}
159
160static int snd_card_do_free(struct snd_card *card);
161static const struct attribute_group *card_dev_attr_groups[];
162
163static void release_card_device(struct device *dev)
164{
165 snd_card_do_free(dev_to_snd_card(dev));
166}
167
168/**
169 * snd_card_new - create and initialize a soundcard structure
170 * @parent: the parent device object
171 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
172 * @xid: card identification (ASCII string)
173 * @module: top level module for locking
174 * @extra_size: allocate this extra size after the main soundcard structure
175 * @card_ret: the pointer to store the created card instance
176 *
177 * Creates and initializes a soundcard structure.
178 *
179 * The function allocates snd_card instance via kzalloc with the given
180 * space for the driver to use freely. The allocated struct is stored
181 * in the given card_ret pointer.
182 *
183 * Return: Zero if successful or a negative error code.
184 */
185int snd_card_new(struct device *parent, int idx, const char *xid,
186 struct module *module, int extra_size,
187 struct snd_card **card_ret)
188{
189 struct snd_card *card;
190 int err;
191
192 if (snd_BUG_ON(!card_ret))
193 return -EINVAL;
194 *card_ret = NULL;
195
196 if (extra_size < 0)
197 extra_size = 0;
198 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
199 if (!card)
200 return -ENOMEM;
201 if (extra_size > 0)
202 card->private_data = (char *)card + sizeof(struct snd_card);
203 if (xid)
204 strlcpy(card->id, xid, sizeof(card->id));
205 err = 0;
206 mutex_lock(&snd_card_mutex);
207 if (idx < 0) /* first check the matching module-name slot */
208 idx = get_slot_from_bitmask(idx, module_slot_match, module);
209 if (idx < 0) /* if not matched, assign an empty slot */
210 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
211 if (idx < 0)
212 err = -ENODEV;
213 else if (idx < snd_ecards_limit) {
214 if (test_bit(idx, snd_cards_lock))
215 err = -EBUSY; /* invalid */
216 } else if (idx >= SNDRV_CARDS)
217 err = -ENODEV;
218 if (err < 0) {
219 mutex_unlock(&snd_card_mutex);
220 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
221 idx, snd_ecards_limit - 1, err);
222 kfree(card);
223 return err;
224 }
225 set_bit(idx, snd_cards_lock); /* lock it */
226 if (idx >= snd_ecards_limit)
227 snd_ecards_limit = idx + 1; /* increase the limit */
228 mutex_unlock(&snd_card_mutex);
229 card->dev = parent;
230 card->number = idx;
231 card->module = module;
232 INIT_LIST_HEAD(&card->devices);
233 init_rwsem(&card->controls_rwsem);
234 rwlock_init(&card->ctl_files_rwlock);
235 INIT_LIST_HEAD(&card->controls);
236 INIT_LIST_HEAD(&card->ctl_files);
237 spin_lock_init(&card->files_lock);
238 INIT_LIST_HEAD(&card->files_list);
239#ifdef CONFIG_PM
240 mutex_init(&card->power_lock);
241 init_waitqueue_head(&card->power_sleep);
242#endif
243
244 device_initialize(&card->card_dev);
245 card->card_dev.parent = parent;
246 card->card_dev.class = sound_class;
247 card->card_dev.release = release_card_device;
248 card->card_dev.groups = card_dev_attr_groups;
249 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
250 if (err < 0)
251 goto __error;
252
253 /* the control interface cannot be accessed from the user space until */
254 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
255 err = snd_ctl_create(card);
256 if (err < 0) {
257 dev_err(parent, "unable to register control minors\n");
258 goto __error;
259 }
260 err = snd_info_card_create(card);
261 if (err < 0) {
262 dev_err(parent, "unable to create card info\n");
263 goto __error_ctl;
264 }
265 *card_ret = card;
266 return 0;
267
268 __error_ctl:
269 snd_device_free_all(card);
270 __error:
271 put_device(&card->card_dev);
272 return err;
273}
274EXPORT_SYMBOL(snd_card_new);
275
276/* return non-zero if a card is already locked */
277int snd_card_locked(int card)
278{
279 int locked;
280
281 mutex_lock(&snd_card_mutex);
282 locked = test_bit(card, snd_cards_lock);
283 mutex_unlock(&snd_card_mutex);
284 return locked;
285}
286
287static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
288{
289 return -ENODEV;
290}
291
292static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
293 size_t count, loff_t *offset)
294{
295 return -ENODEV;
296}
297
298static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
299 size_t count, loff_t *offset)
300{
301 return -ENODEV;
302}
303
304static int snd_disconnect_release(struct inode *inode, struct file *file)
305{
306 struct snd_monitor_file *df = NULL, *_df;
307
308 spin_lock(&shutdown_lock);
309 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
310 if (_df->file == file) {
311 df = _df;
312 list_del_init(&df->shutdown_list);
313 break;
314 }
315 }
316 spin_unlock(&shutdown_lock);
317
318 if (likely(df)) {
319 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
320 df->disconnected_f_op->fasync(-1, file, 0);
321 return df->disconnected_f_op->release(inode, file);
322 }
323
324 panic("%s(%p, %p) failed!", __func__, inode, file);
325}
326
327static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
328{
329 return POLLERR | POLLNVAL;
330}
331
332static long snd_disconnect_ioctl(struct file *file,
333 unsigned int cmd, unsigned long arg)
334{
335 return -ENODEV;
336}
337
338static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
339{
340 return -ENODEV;
341}
342
343static int snd_disconnect_fasync(int fd, struct file *file, int on)
344{
345 return -ENODEV;
346}
347
348static const struct file_operations snd_shutdown_f_ops =
349{
350 .owner = THIS_MODULE,
351 .llseek = snd_disconnect_llseek,
352 .read = snd_disconnect_read,
353 .write = snd_disconnect_write,
354 .release = snd_disconnect_release,
355 .poll = snd_disconnect_poll,
356 .unlocked_ioctl = snd_disconnect_ioctl,
357#ifdef CONFIG_COMPAT
358 .compat_ioctl = snd_disconnect_ioctl,
359#endif
360 .mmap = snd_disconnect_mmap,
361 .fasync = snd_disconnect_fasync
362};
363
364/**
365 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
366 * @card: soundcard structure
367 *
368 * Disconnects all APIs from the file-operations (user space).
369 *
370 * Return: Zero, otherwise a negative error code.
371 *
372 * Note: The current implementation replaces all active file->f_op with special
373 * dummy file operations (they do nothing except release).
374 */
375int snd_card_disconnect(struct snd_card *card)
376{
377 struct snd_monitor_file *mfile;
378 int err;
379
380 if (!card)
381 return -EINVAL;
382
383 spin_lock(&card->files_lock);
384 if (card->shutdown) {
385 spin_unlock(&card->files_lock);
386 return 0;
387 }
388 card->shutdown = 1;
389 spin_unlock(&card->files_lock);
390
391 /* phase 1: disable fops (user space) operations for ALSA API */
392 mutex_lock(&snd_card_mutex);
393 snd_cards[card->number] = NULL;
394 clear_bit(card->number, snd_cards_lock);
395 mutex_unlock(&snd_card_mutex);
396
397 /* phase 2: replace file->f_op with special dummy operations */
398
399 spin_lock(&card->files_lock);
400 list_for_each_entry(mfile, &card->files_list, list) {
401 /* it's critical part, use endless loop */
402 /* we have no room to fail */
403 mfile->disconnected_f_op = mfile->file->f_op;
404
405 spin_lock(&shutdown_lock);
406 list_add(&mfile->shutdown_list, &shutdown_files);
407 spin_unlock(&shutdown_lock);
408
409 mfile->file->f_op = &snd_shutdown_f_ops;
410 fops_get(mfile->file->f_op);
411 }
412 spin_unlock(&card->files_lock);
413
414 /* phase 3: notify all connected devices about disconnection */
415 /* at this point, they cannot respond to any calls except release() */
416
417#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
418 if (snd_mixer_oss_notify_callback)
419 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
420#endif
421
422 /* notify all devices that we are disconnected */
423 err = snd_device_disconnect_all(card);
424 if (err < 0)
425 dev_err(card->dev, "not all devices for card %i can be disconnected\n", card->number);
426
427 snd_info_card_disconnect(card);
428 if (card->registered) {
429 device_del(&card->card_dev);
430 card->registered = false;
431 }
432#ifdef CONFIG_PM
433 wake_up(&card->power_sleep);
434#endif
435 return 0;
436}
437
438EXPORT_SYMBOL(snd_card_disconnect);
439
440/**
441 * snd_card_free - frees given soundcard structure
442 * @card: soundcard structure
443 *
444 * This function releases the soundcard structure and the all assigned
445 * devices automatically. That is, you don't have to release the devices
446 * by yourself.
447 *
448 * Return: Zero. Frees all associated devices and frees the control
449 * interface associated to given soundcard.
450 */
451static int snd_card_do_free(struct snd_card *card)
452{
453#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
454 if (snd_mixer_oss_notify_callback)
455 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
456#endif
457 snd_device_free_all(card);
458 if (card->private_free)
459 card->private_free(card);
460 snd_info_free_entry(card->proc_id);
461 if (snd_info_card_free(card) < 0) {
462 dev_warn(card->dev, "unable to free card info\n");
463 /* Not fatal error */
464 }
465 if (card->release_completion)
466 complete(card->release_completion);
467 kfree(card);
468 return 0;
469}
470
471int snd_card_free_when_closed(struct snd_card *card)
472{
473 int ret = snd_card_disconnect(card);
474 if (ret)
475 return ret;
476 put_device(&card->card_dev);
477 return 0;
478}
479EXPORT_SYMBOL(snd_card_free_when_closed);
480
481int snd_card_free(struct snd_card *card)
482{
483 struct completion released;
484 int ret;
485
486 init_completion(&released);
487 card->release_completion = &released;
488 ret = snd_card_free_when_closed(card);
489 if (ret)
490 return ret;
491 /* wait, until all devices are ready for the free operation */
492 wait_for_completion(&released);
493 return 0;
494}
495EXPORT_SYMBOL(snd_card_free);
496
497/* retrieve the last word of shortname or longname */
498static const char *retrieve_id_from_card_name(const char *name)
499{
500 const char *spos = name;
501
502 while (*name) {
503 if (isspace(*name) && isalnum(name[1]))
504 spos = name + 1;
505 name++;
506 }
507 return spos;
508}
509
510/* return true if the given id string doesn't conflict any other card ids */
511static bool card_id_ok(struct snd_card *card, const char *id)
512{
513 int i;
514 if (!snd_info_check_reserved_words(id))
515 return false;
516 for (i = 0; i < snd_ecards_limit; i++) {
517 if (snd_cards[i] && snd_cards[i] != card &&
518 !strcmp(snd_cards[i]->id, id))
519 return false;
520 }
521 return true;
522}
523
524/* copy to card->id only with valid letters from nid */
525static void copy_valid_id_string(struct snd_card *card, const char *src,
526 const char *nid)
527{
528 char *id = card->id;
529
530 while (*nid && !isalnum(*nid))
531 nid++;
532 if (isdigit(*nid))
533 *id++ = isalpha(*src) ? *src : 'D';
534 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
535 if (isalnum(*nid))
536 *id++ = *nid;
537 nid++;
538 }
539 *id = 0;
540}
541
542/* Set card->id from the given string
543 * If the string conflicts with other ids, add a suffix to make it unique.
544 */
545static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
546 const char *nid)
547{
548 int len, loops;
549 bool is_default = false;
550 char *id;
551
552 copy_valid_id_string(card, src, nid);
553 id = card->id;
554
555 again:
556 /* use "Default" for obviously invalid strings
557 * ("card" conflicts with proc directories)
558 */
559 if (!*id || !strncmp(id, "card", 4)) {
560 strcpy(id, "Default");
561 is_default = true;
562 }
563
564 len = strlen(id);
565 for (loops = 0; loops < SNDRV_CARDS; loops++) {
566 char *spos;
567 char sfxstr[5]; /* "_012" */
568 int sfxlen;
569
570 if (card_id_ok(card, id))
571 return; /* OK */
572
573 /* Add _XYZ suffix */
574 sprintf(sfxstr, "_%X", loops + 1);
575 sfxlen = strlen(sfxstr);
576 if (len + sfxlen >= sizeof(card->id))
577 spos = id + sizeof(card->id) - sfxlen - 1;
578 else
579 spos = id + len;
580 strcpy(spos, sfxstr);
581 }
582 /* fallback to the default id */
583 if (!is_default) {
584 *id = 0;
585 goto again;
586 }
587 /* last resort... */
588 dev_err(card->dev, "unable to set card id (%s)\n", id);
589 if (card->proc_root->name)
590 strlcpy(card->id, card->proc_root->name, sizeof(card->id));
591}
592
593/**
594 * snd_card_set_id - set card identification name
595 * @card: soundcard structure
596 * @nid: new identification string
597 *
598 * This function sets the card identification and checks for name
599 * collisions.
600 */
601void snd_card_set_id(struct snd_card *card, const char *nid)
602{
603 /* check if user specified own card->id */
604 if (card->id[0] != '\0')
605 return;
606 mutex_lock(&snd_card_mutex);
607 snd_card_set_id_no_lock(card, nid, nid);
608 mutex_unlock(&snd_card_mutex);
609}
610EXPORT_SYMBOL(snd_card_set_id);
611
612static ssize_t
613card_id_show_attr(struct device *dev,
614 struct device_attribute *attr, char *buf)
615{
616 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
617 return snprintf(buf, PAGE_SIZE, "%s\n", card->id);
618}
619
620static ssize_t
621card_id_store_attr(struct device *dev, struct device_attribute *attr,
622 const char *buf, size_t count)
623{
624 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
625 char buf1[sizeof(card->id)];
626 size_t copy = count > sizeof(card->id) - 1 ?
627 sizeof(card->id) - 1 : count;
628 size_t idx;
629 int c;
630
631 for (idx = 0; idx < copy; idx++) {
632 c = buf[idx];
633 if (!isalnum(c) && c != '_' && c != '-')
634 return -EINVAL;
635 }
636 memcpy(buf1, buf, copy);
637 buf1[copy] = '\0';
638 mutex_lock(&snd_card_mutex);
639 if (!card_id_ok(NULL, buf1)) {
640 mutex_unlock(&snd_card_mutex);
641 return -EEXIST;
642 }
643 strcpy(card->id, buf1);
644 snd_info_card_id_change(card);
645 mutex_unlock(&snd_card_mutex);
646
647 return count;
648}
649
650static DEVICE_ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
651
652static ssize_t
653card_number_show_attr(struct device *dev,
654 struct device_attribute *attr, char *buf)
655{
656 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
657 return snprintf(buf, PAGE_SIZE, "%i\n", card->number);
658}
659
660static DEVICE_ATTR(number, S_IRUGO, card_number_show_attr, NULL);
661
662static struct attribute *card_dev_attrs[] = {
663 &dev_attr_id.attr,
664 &dev_attr_number.attr,
665 NULL
666};
667
668static struct attribute_group card_dev_attr_group = {
669 .attrs = card_dev_attrs,
670};
671
672static const struct attribute_group *card_dev_attr_groups[] = {
673 &card_dev_attr_group,
674 NULL
675};
676
677/**
678 * snd_card_register - register the soundcard
679 * @card: soundcard structure
680 *
681 * This function registers all the devices assigned to the soundcard.
682 * Until calling this, the ALSA control interface is blocked from the
683 * external accesses. Thus, you should call this function at the end
684 * of the initialization of the card.
685 *
686 * Return: Zero otherwise a negative error code if the registration failed.
687 */
688int snd_card_register(struct snd_card *card)
689{
690 int err;
691
692 if (snd_BUG_ON(!card))
693 return -EINVAL;
694
695 if (!card->registered) {
696 err = device_add(&card->card_dev);
697 if (err < 0)
698 return err;
699 card->registered = true;
700 }
701
702 if ((err = snd_device_register_all(card)) < 0)
703 return err;
704 mutex_lock(&snd_card_mutex);
705 if (snd_cards[card->number]) {
706 /* already registered */
707 mutex_unlock(&snd_card_mutex);
708 return 0;
709 }
710 if (*card->id) {
711 /* make a unique id name from the given string */
712 char tmpid[sizeof(card->id)];
713 memcpy(tmpid, card->id, sizeof(card->id));
714 snd_card_set_id_no_lock(card, tmpid, tmpid);
715 } else {
716 /* create an id from either shortname or longname */
717 const char *src;
718 src = *card->shortname ? card->shortname : card->longname;
719 snd_card_set_id_no_lock(card, src,
720 retrieve_id_from_card_name(src));
721 }
722 snd_cards[card->number] = card;
723 mutex_unlock(&snd_card_mutex);
724 init_info_for_card(card);
725#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
726 if (snd_mixer_oss_notify_callback)
727 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
728#endif
729 return 0;
730}
731
732EXPORT_SYMBOL(snd_card_register);
733
734#ifdef CONFIG_PROC_FS
735static struct snd_info_entry *snd_card_info_entry;
736
737static void snd_card_info_read(struct snd_info_entry *entry,
738 struct snd_info_buffer *buffer)
739{
740 int idx, count;
741 struct snd_card *card;
742
743 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
744 mutex_lock(&snd_card_mutex);
745 if ((card = snd_cards[idx]) != NULL) {
746 count++;
747 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
748 idx,
749 card->id,
750 card->driver,
751 card->shortname);
752 snd_iprintf(buffer, " %s\n",
753 card->longname);
754 }
755 mutex_unlock(&snd_card_mutex);
756 }
757 if (!count)
758 snd_iprintf(buffer, "--- no soundcards ---\n");
759}
760
761#ifdef CONFIG_SND_OSSEMUL
762
763void snd_card_info_read_oss(struct snd_info_buffer *buffer)
764{
765 int idx, count;
766 struct snd_card *card;
767
768 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
769 mutex_lock(&snd_card_mutex);
770 if ((card = snd_cards[idx]) != NULL) {
771 count++;
772 snd_iprintf(buffer, "%s\n", card->longname);
773 }
774 mutex_unlock(&snd_card_mutex);
775 }
776 if (!count) {
777 snd_iprintf(buffer, "--- no soundcards ---\n");
778 }
779}
780
781#endif
782
783#ifdef MODULE
784static struct snd_info_entry *snd_card_module_info_entry;
785static void snd_card_module_info_read(struct snd_info_entry *entry,
786 struct snd_info_buffer *buffer)
787{
788 int idx;
789 struct snd_card *card;
790
791 for (idx = 0; idx < SNDRV_CARDS; idx++) {
792 mutex_lock(&snd_card_mutex);
793 if ((card = snd_cards[idx]) != NULL)
794 snd_iprintf(buffer, "%2i %s\n",
795 idx, card->module->name);
796 mutex_unlock(&snd_card_mutex);
797 }
798}
799#endif
800
801int __init snd_card_info_init(void)
802{
803 struct snd_info_entry *entry;
804
805 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
806 if (! entry)
807 return -ENOMEM;
808 entry->c.text.read = snd_card_info_read;
809 if (snd_info_register(entry) < 0) {
810 snd_info_free_entry(entry);
811 return -ENOMEM;
812 }
813 snd_card_info_entry = entry;
814
815#ifdef MODULE
816 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
817 if (entry) {
818 entry->c.text.read = snd_card_module_info_read;
819 if (snd_info_register(entry) < 0)
820 snd_info_free_entry(entry);
821 else
822 snd_card_module_info_entry = entry;
823 }
824#endif
825
826 return 0;
827}
828
829int __exit snd_card_info_done(void)
830{
831 snd_info_free_entry(snd_card_info_entry);
832#ifdef MODULE
833 snd_info_free_entry(snd_card_module_info_entry);
834#endif
835 return 0;
836}
837
838#endif /* CONFIG_PROC_FS */
839
840/**
841 * snd_component_add - add a component string
842 * @card: soundcard structure
843 * @component: the component id string
844 *
845 * This function adds the component id string to the supported list.
846 * The component can be referred from the alsa-lib.
847 *
848 * Return: Zero otherwise a negative error code.
849 */
850
851int snd_component_add(struct snd_card *card, const char *component)
852{
853 char *ptr;
854 int len = strlen(component);
855
856 ptr = strstr(card->components, component);
857 if (ptr != NULL) {
858 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
859 return 1;
860 }
861 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
862 snd_BUG();
863 return -ENOMEM;
864 }
865 if (card->components[0] != '\0')
866 strcat(card->components, " ");
867 strcat(card->components, component);
868 return 0;
869}
870
871EXPORT_SYMBOL(snd_component_add);
872
873/**
874 * snd_card_file_add - add the file to the file list of the card
875 * @card: soundcard structure
876 * @file: file pointer
877 *
878 * This function adds the file to the file linked-list of the card.
879 * This linked-list is used to keep tracking the connection state,
880 * and to avoid the release of busy resources by hotplug.
881 *
882 * Return: zero or a negative error code.
883 */
884int snd_card_file_add(struct snd_card *card, struct file *file)
885{
886 struct snd_monitor_file *mfile;
887
888 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
889 if (mfile == NULL)
890 return -ENOMEM;
891 mfile->file = file;
892 mfile->disconnected_f_op = NULL;
893 INIT_LIST_HEAD(&mfile->shutdown_list);
894 spin_lock(&card->files_lock);
895 if (card->shutdown) {
896 spin_unlock(&card->files_lock);
897 kfree(mfile);
898 return -ENODEV;
899 }
900 list_add(&mfile->list, &card->files_list);
901 get_device(&card->card_dev);
902 spin_unlock(&card->files_lock);
903 return 0;
904}
905
906EXPORT_SYMBOL(snd_card_file_add);
907
908/**
909 * snd_card_file_remove - remove the file from the file list
910 * @card: soundcard structure
911 * @file: file pointer
912 *
913 * This function removes the file formerly added to the card via
914 * snd_card_file_add() function.
915 * If all files are removed and snd_card_free_when_closed() was
916 * called beforehand, it processes the pending release of
917 * resources.
918 *
919 * Return: Zero or a negative error code.
920 */
921int snd_card_file_remove(struct snd_card *card, struct file *file)
922{
923 struct snd_monitor_file *mfile, *found = NULL;
924
925 spin_lock(&card->files_lock);
926 list_for_each_entry(mfile, &card->files_list, list) {
927 if (mfile->file == file) {
928 list_del(&mfile->list);
929 spin_lock(&shutdown_lock);
930 list_del(&mfile->shutdown_list);
931 spin_unlock(&shutdown_lock);
932 if (mfile->disconnected_f_op)
933 fops_put(mfile->disconnected_f_op);
934 found = mfile;
935 break;
936 }
937 }
938 spin_unlock(&card->files_lock);
939 if (!found) {
940 dev_err(card->dev, "card file remove problem (%p)\n", file);
941 return -ENOENT;
942 }
943 kfree(found);
944 put_device(&card->card_dev);
945 return 0;
946}
947
948EXPORT_SYMBOL(snd_card_file_remove);
949
950#ifdef CONFIG_PM
951/**
952 * snd_power_wait - wait until the power-state is changed.
953 * @card: soundcard structure
954 * @power_state: expected power state
955 *
956 * Waits until the power-state is changed.
957 *
958 * Return: Zero if successful, or a negative error code.
959 *
960 * Note: the power lock must be active before call.
961 */
962int snd_power_wait(struct snd_card *card, unsigned int power_state)
963{
964 wait_queue_t wait;
965 int result = 0;
966
967 /* fastpath */
968 if (snd_power_get_state(card) == power_state)
969 return 0;
970 init_waitqueue_entry(&wait, current);
971 add_wait_queue(&card->power_sleep, &wait);
972 while (1) {
973 if (card->shutdown) {
974 result = -ENODEV;
975 break;
976 }
977 if (snd_power_get_state(card) == power_state)
978 break;
979 set_current_state(TASK_UNINTERRUPTIBLE);
980 snd_power_unlock(card);
981 schedule_timeout(30 * HZ);
982 snd_power_lock(card);
983 }
984 remove_wait_queue(&card->power_sleep, &wait);
985 return result;
986}
987
988EXPORT_SYMBOL(snd_power_wait);
989#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 */