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) */
25 struct 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
32 static DEFINE_SPINLOCK(shutdown_lock);
33 static LIST_HEAD(shutdown_files);
34
35 static const struct file_operations snd_shutdown_f_ops;
36
37 /* locked for registering/using */
38 static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39 static struct snd_card *snd_cards[SNDRV_CARDS];
40
41 static DEFINE_MUTEX(snd_card_mutex);
42
43 static char *slots[SNDRV_CARDS];
44 module_param_array(slots, charp, NULL, 0444);
45 MODULE_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 */
module_slot_match(struct module * module,int idx)50 static 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)
85 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
87 #endif
88
check_empty_slot(struct module * module,int slot)89 static 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 */
get_slot_from_bitmask(int mask,int (* check)(struct module *,int),struct module * module)98 static 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() */
default_release_alloc(struct device * dev)115 static 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 */
snd_device_alloc(struct device ** dev_p,struct snd_card * card)127 int 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 }
143 EXPORT_SYMBOL_GPL(snd_device_alloc);
144
145 static 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);
148 static int snd_card_do_free(struct snd_card *card);
149 static const struct attribute_group card_dev_attr_group;
150
release_card_device(struct device * dev)151 static 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 */
snd_card_new(struct device * parent,int idx,const char * xid,struct module * module,int extra_size,struct snd_card ** card_ret)171 int 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 }
195 EXPORT_SYMBOL(snd_card_new);
196
__snd_card_release(struct device * dev,void * data)197 static 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 */
snd_devm_card_new(struct device * parent,int idx,const char * xid,struct module * module,size_t extra_size,struct snd_card ** card_ret)227 int 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 }
250 EXPORT_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 */
snd_card_free_on_error(struct device * dev,int ret)263 int 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 }
274 EXPORT_SYMBOL_GPL(snd_card_free_on_error);
275
snd_card_init(struct snd_card * card,struct device * parent,int idx,const char * xid,struct module * module,size_t extra_size)276 static 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 mutex_lock(&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 < 0) {
300 mutex_unlock(&snd_card_mutex);
301 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
302 idx, snd_ecards_limit - 1, err);
303 if (!card->managed)
304 kfree(card); /* manually free here, as no destructor called */
305 return err;
306 }
307 set_bit(idx, snd_cards_lock); /* lock it */
308 if (idx >= snd_ecards_limit)
309 snd_ecards_limit = idx + 1; /* increase the limit */
310 mutex_unlock(&snd_card_mutex);
311 card->dev = parent;
312 card->number = idx;
313 #ifdef MODULE
314 WARN_ON(!module);
315 #endif
316 card->module = module;
317 INIT_LIST_HEAD(&card->devices);
318 init_rwsem(&card->controls_rwsem);
319 rwlock_init(&card->ctl_files_rwlock);
320 INIT_LIST_HEAD(&card->controls);
321 INIT_LIST_HEAD(&card->ctl_files);
322 #ifdef CONFIG_SND_CTL_FAST_LOOKUP
323 xa_init(&card->ctl_numids);
324 xa_init(&card->ctl_hash);
325 #endif
326 spin_lock_init(&card->files_lock);
327 INIT_LIST_HEAD(&card->files_list);
328 mutex_init(&card->memory_mutex);
329 #ifdef CONFIG_PM
330 init_waitqueue_head(&card->power_sleep);
331 init_waitqueue_head(&card->power_ref_sleep);
332 atomic_set(&card->power_ref, 0);
333 #endif
334 init_waitqueue_head(&card->remove_sleep);
335 card->sync_irq = -1;
336
337 device_initialize(&card->card_dev);
338 card->card_dev.parent = parent;
339 card->card_dev.class = &sound_class;
340 card->card_dev.release = release_card_device;
341 card->card_dev.groups = card->dev_groups;
342 card->dev_groups[0] = &card_dev_attr_group;
343 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
344 if (err < 0)
345 goto __error;
346
347 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
348 dev_driver_string(card->dev), dev_name(&card->card_dev));
349
350 /* the control interface cannot be accessed from the user space until */
351 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
352 err = snd_ctl_create(card);
353 if (err < 0) {
354 dev_err(parent, "unable to register control minors\n");
355 goto __error;
356 }
357 err = snd_info_card_create(card);
358 if (err < 0) {
359 dev_err(parent, "unable to create card info\n");
360 goto __error_ctl;
361 }
362
363 #ifdef CONFIG_SND_DEBUG
364 card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev),
365 sound_debugfs_root);
366 #endif
367 return 0;
368
369 __error_ctl:
370 snd_device_free_all(card);
371 __error:
372 put_device(&card->card_dev);
373 return err;
374 }
375
376 /**
377 * snd_card_ref - Get the card object from the index
378 * @idx: the card index
379 *
380 * Returns a card object corresponding to the given index or NULL if not found.
381 * Release the object via snd_card_unref().
382 *
383 * Return: a card object or NULL
384 */
snd_card_ref(int idx)385 struct snd_card *snd_card_ref(int idx)
386 {
387 struct snd_card *card;
388
389 mutex_lock(&snd_card_mutex);
390 card = snd_cards[idx];
391 if (card)
392 get_device(&card->card_dev);
393 mutex_unlock(&snd_card_mutex);
394 return card;
395 }
396 EXPORT_SYMBOL_GPL(snd_card_ref);
397
398 /* return non-zero if a card is already locked */
snd_card_locked(int card)399 int snd_card_locked(int card)
400 {
401 int locked;
402
403 mutex_lock(&snd_card_mutex);
404 locked = test_bit(card, snd_cards_lock);
405 mutex_unlock(&snd_card_mutex);
406 return locked;
407 }
408
snd_disconnect_llseek(struct file * file,loff_t offset,int orig)409 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
410 {
411 return -ENODEV;
412 }
413
snd_disconnect_read(struct file * file,char __user * buf,size_t count,loff_t * offset)414 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
415 size_t count, loff_t *offset)
416 {
417 return -ENODEV;
418 }
419
snd_disconnect_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)420 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
421 size_t count, loff_t *offset)
422 {
423 return -ENODEV;
424 }
425
snd_disconnect_release(struct inode * inode,struct file * file)426 static int snd_disconnect_release(struct inode *inode, struct file *file)
427 {
428 struct snd_monitor_file *df = NULL, *_df;
429
430 spin_lock(&shutdown_lock);
431 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
432 if (_df->file == file) {
433 df = _df;
434 list_del_init(&df->shutdown_list);
435 break;
436 }
437 }
438 spin_unlock(&shutdown_lock);
439
440 if (likely(df)) {
441 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
442 df->disconnected_f_op->fasync(-1, file, 0);
443 return df->disconnected_f_op->release(inode, file);
444 }
445
446 panic("%s(%p, %p) failed!", __func__, inode, file);
447 }
448
snd_disconnect_poll(struct file * file,poll_table * wait)449 static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
450 {
451 return EPOLLERR | EPOLLNVAL;
452 }
453
snd_disconnect_ioctl(struct file * file,unsigned int cmd,unsigned long arg)454 static long snd_disconnect_ioctl(struct file *file,
455 unsigned int cmd, unsigned long arg)
456 {
457 return -ENODEV;
458 }
459
snd_disconnect_mmap(struct file * file,struct vm_area_struct * vma)460 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
461 {
462 return -ENODEV;
463 }
464
snd_disconnect_fasync(int fd,struct file * file,int on)465 static int snd_disconnect_fasync(int fd, struct file *file, int on)
466 {
467 return -ENODEV;
468 }
469
470 static const struct file_operations snd_shutdown_f_ops =
471 {
472 .owner = THIS_MODULE,
473 .llseek = snd_disconnect_llseek,
474 .read = snd_disconnect_read,
475 .write = snd_disconnect_write,
476 .release = snd_disconnect_release,
477 .poll = snd_disconnect_poll,
478 .unlocked_ioctl = snd_disconnect_ioctl,
479 #ifdef CONFIG_COMPAT
480 .compat_ioctl = snd_disconnect_ioctl,
481 #endif
482 .mmap = snd_disconnect_mmap,
483 .fasync = snd_disconnect_fasync
484 };
485
486 /**
487 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
488 * @card: soundcard structure
489 *
490 * Disconnects all APIs from the file-operations (user space).
491 *
492 * Return: Zero, otherwise a negative error code.
493 *
494 * Note: The current implementation replaces all active file->f_op with special
495 * dummy file operations (they do nothing except release).
496 */
snd_card_disconnect(struct snd_card * card)497 void snd_card_disconnect(struct snd_card *card)
498 {
499 struct snd_monitor_file *mfile;
500
501 if (!card)
502 return;
503
504 spin_lock(&card->files_lock);
505 if (card->shutdown) {
506 spin_unlock(&card->files_lock);
507 return;
508 }
509 card->shutdown = 1;
510
511 /* replace file->f_op with special dummy operations */
512 list_for_each_entry(mfile, &card->files_list, list) {
513 /* it's critical part, use endless loop */
514 /* we have no room to fail */
515 mfile->disconnected_f_op = mfile->file->f_op;
516
517 spin_lock(&shutdown_lock);
518 list_add(&mfile->shutdown_list, &shutdown_files);
519 spin_unlock(&shutdown_lock);
520
521 mfile->file->f_op = &snd_shutdown_f_ops;
522 fops_get(mfile->file->f_op);
523 }
524 spin_unlock(&card->files_lock);
525
526 #ifdef CONFIG_PM
527 /* wake up sleepers here before other callbacks for avoiding potential
528 * deadlocks with other locks (e.g. in kctls);
529 * then this notifies the shutdown and sleepers would abort immediately
530 */
531 wake_up_all(&card->power_sleep);
532 #endif
533
534 /* notify all connected devices about disconnection */
535 /* at this point, they cannot respond to any calls except release() */
536
537 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
538 if (snd_mixer_oss_notify_callback)
539 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
540 #endif
541
542 /* notify all devices that we are disconnected */
543 snd_device_disconnect_all(card);
544
545 if (card->sync_irq > 0)
546 synchronize_irq(card->sync_irq);
547
548 snd_info_card_disconnect(card);
549 #ifdef CONFIG_SND_DEBUG
550 debugfs_remove(card->debugfs_root);
551 card->debugfs_root = NULL;
552 #endif
553
554 if (card->registered) {
555 device_del(&card->card_dev);
556 card->registered = false;
557 }
558
559 /* disable fops (user space) operations for ALSA API */
560 mutex_lock(&snd_card_mutex);
561 snd_cards[card->number] = NULL;
562 clear_bit(card->number, snd_cards_lock);
563 mutex_unlock(&snd_card_mutex);
564
565 #ifdef CONFIG_PM
566 snd_power_sync_ref(card);
567 #endif
568 }
569 EXPORT_SYMBOL(snd_card_disconnect);
570
571 /**
572 * snd_card_disconnect_sync - disconnect card and wait until files get closed
573 * @card: card object to disconnect
574 *
575 * This calls snd_card_disconnect() for disconnecting all belonging components
576 * and waits until all pending files get closed.
577 * It assures that all accesses from user-space finished so that the driver
578 * can release its resources gracefully.
579 */
snd_card_disconnect_sync(struct snd_card * card)580 void snd_card_disconnect_sync(struct snd_card *card)
581 {
582 snd_card_disconnect(card);
583
584 spin_lock_irq(&card->files_lock);
585 wait_event_lock_irq(card->remove_sleep,
586 list_empty(&card->files_list),
587 card->files_lock);
588 spin_unlock_irq(&card->files_lock);
589 }
590 EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
591
snd_card_do_free(struct snd_card * card)592 static int snd_card_do_free(struct snd_card *card)
593 {
594 card->releasing = true;
595 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
596 if (snd_mixer_oss_notify_callback)
597 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
598 #endif
599 snd_device_free_all(card);
600 if (card->private_free)
601 card->private_free(card);
602 if (snd_info_card_free(card) < 0) {
603 dev_warn(card->dev, "unable to free card info\n");
604 /* Not fatal error */
605 }
606 if (card->release_completion)
607 complete(card->release_completion);
608 if (!card->managed)
609 kfree(card);
610 return 0;
611 }
612
613 /**
614 * snd_card_free_when_closed - Disconnect the card, free it later eventually
615 * @card: soundcard structure
616 *
617 * Unlike snd_card_free(), this function doesn't try to release the card
618 * resource immediately, but tries to disconnect at first. When the card
619 * is still in use, the function returns before freeing the resources.
620 * The card resources will be freed when the refcount gets to zero.
621 *
622 * Return: zero if successful, or a negative error code
623 */
snd_card_free_when_closed(struct snd_card * card)624 void snd_card_free_when_closed(struct snd_card *card)
625 {
626 if (!card)
627 return;
628
629 snd_card_disconnect(card);
630 put_device(&card->card_dev);
631 return;
632 }
633 EXPORT_SYMBOL(snd_card_free_when_closed);
634
635 /**
636 * snd_card_free - frees given soundcard structure
637 * @card: soundcard structure
638 *
639 * This function releases the soundcard structure and the all assigned
640 * devices automatically. That is, you don't have to release the devices
641 * by yourself.
642 *
643 * This function waits until the all resources are properly released.
644 *
645 * Return: Zero. Frees all associated devices and frees the control
646 * interface associated to given soundcard.
647 */
snd_card_free(struct snd_card * card)648 void snd_card_free(struct snd_card *card)
649 {
650 DECLARE_COMPLETION_ONSTACK(released);
651
652 /* The call of snd_card_free() is allowed from various code paths;
653 * a manual call from the driver and the call via devres_free, and
654 * we need to avoid double-free. Moreover, the release via devres
655 * may call snd_card_free() twice due to its nature, we need to have
656 * the check here at the beginning.
657 */
658 if (card->releasing)
659 return;
660
661 card->release_completion = &released;
662 snd_card_free_when_closed(card);
663
664 /* wait, until all devices are ready for the free operation */
665 wait_for_completion(&released);
666 }
667 EXPORT_SYMBOL(snd_card_free);
668
669 /* retrieve the last word of shortname or longname */
retrieve_id_from_card_name(const char * name)670 static const char *retrieve_id_from_card_name(const char *name)
671 {
672 const char *spos = name;
673
674 while (*name) {
675 if (isspace(*name) && isalnum(name[1]))
676 spos = name + 1;
677 name++;
678 }
679 return spos;
680 }
681
682 /* return true if the given id string doesn't conflict any other card ids */
card_id_ok(struct snd_card * card,const char * id)683 static bool card_id_ok(struct snd_card *card, const char *id)
684 {
685 int i;
686 if (!snd_info_check_reserved_words(id))
687 return false;
688 for (i = 0; i < snd_ecards_limit; i++) {
689 if (snd_cards[i] && snd_cards[i] != card &&
690 !strcmp(snd_cards[i]->id, id))
691 return false;
692 }
693 return true;
694 }
695
696 /* copy to card->id only with valid letters from nid */
copy_valid_id_string(struct snd_card * card,const char * src,const char * nid)697 static void copy_valid_id_string(struct snd_card *card, const char *src,
698 const char *nid)
699 {
700 char *id = card->id;
701
702 while (*nid && !isalnum(*nid))
703 nid++;
704 if (isdigit(*nid))
705 *id++ = isalpha(*src) ? *src : 'D';
706 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
707 if (isalnum(*nid))
708 *id++ = *nid;
709 nid++;
710 }
711 *id = 0;
712 }
713
714 /* Set card->id from the given string
715 * If the string conflicts with other ids, add a suffix to make it unique.
716 */
snd_card_set_id_no_lock(struct snd_card * card,const char * src,const char * nid)717 static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
718 const char *nid)
719 {
720 int len, loops;
721 bool is_default = false;
722 char *id;
723
724 copy_valid_id_string(card, src, nid);
725 id = card->id;
726
727 again:
728 /* use "Default" for obviously invalid strings
729 * ("card" conflicts with proc directories)
730 */
731 if (!*id || !strncmp(id, "card", 4)) {
732 strcpy(id, "Default");
733 is_default = true;
734 }
735
736 len = strlen(id);
737 for (loops = 0; loops < SNDRV_CARDS; loops++) {
738 char *spos;
739 char sfxstr[5]; /* "_012" */
740 int sfxlen;
741
742 if (card_id_ok(card, id))
743 return; /* OK */
744
745 /* Add _XYZ suffix */
746 sprintf(sfxstr, "_%X", loops + 1);
747 sfxlen = strlen(sfxstr);
748 if (len + sfxlen >= sizeof(card->id))
749 spos = id + sizeof(card->id) - sfxlen - 1;
750 else
751 spos = id + len;
752 strcpy(spos, sfxstr);
753 }
754 /* fallback to the default id */
755 if (!is_default) {
756 *id = 0;
757 goto again;
758 }
759 /* last resort... */
760 dev_err(card->dev, "unable to set card id (%s)\n", id);
761 if (card->proc_root->name)
762 strscpy(card->id, card->proc_root->name, sizeof(card->id));
763 }
764
765 /**
766 * snd_card_set_id - set card identification name
767 * @card: soundcard structure
768 * @nid: new identification string
769 *
770 * This function sets the card identification and checks for name
771 * collisions.
772 */
snd_card_set_id(struct snd_card * card,const char * nid)773 void snd_card_set_id(struct snd_card *card, const char *nid)
774 {
775 /* check if user specified own card->id */
776 if (card->id[0] != '\0')
777 return;
778 mutex_lock(&snd_card_mutex);
779 snd_card_set_id_no_lock(card, nid, nid);
780 mutex_unlock(&snd_card_mutex);
781 }
782 EXPORT_SYMBOL(snd_card_set_id);
783
id_show(struct device * dev,struct device_attribute * attr,char * buf)784 static ssize_t id_show(struct device *dev,
785 struct device_attribute *attr, char *buf)
786 {
787 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
788 return sysfs_emit(buf, "%s\n", card->id);
789 }
790
id_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)791 static ssize_t id_store(struct device *dev, struct device_attribute *attr,
792 const char *buf, size_t count)
793 {
794 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
795 char buf1[sizeof(card->id)];
796 size_t copy = count > sizeof(card->id) - 1 ?
797 sizeof(card->id) - 1 : count;
798 size_t idx;
799 int c;
800
801 for (idx = 0; idx < copy; idx++) {
802 c = buf[idx];
803 if (!isalnum(c) && c != '_' && c != '-')
804 return -EINVAL;
805 }
806 memcpy(buf1, buf, copy);
807 buf1[copy] = '\0';
808 mutex_lock(&snd_card_mutex);
809 if (!card_id_ok(NULL, buf1)) {
810 mutex_unlock(&snd_card_mutex);
811 return -EEXIST;
812 }
813 strcpy(card->id, buf1);
814 snd_info_card_id_change(card);
815 mutex_unlock(&snd_card_mutex);
816
817 return count;
818 }
819
820 static DEVICE_ATTR_RW(id);
821
number_show(struct device * dev,struct device_attribute * attr,char * buf)822 static ssize_t number_show(struct device *dev,
823 struct device_attribute *attr, char *buf)
824 {
825 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
826 return sysfs_emit(buf, "%i\n", card->number);
827 }
828
829 static DEVICE_ATTR_RO(number);
830
831 static struct attribute *card_dev_attrs[] = {
832 &dev_attr_id.attr,
833 &dev_attr_number.attr,
834 NULL
835 };
836
837 static const struct attribute_group card_dev_attr_group = {
838 .attrs = card_dev_attrs,
839 };
840
841 /**
842 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
843 * @card: card instance
844 * @group: attribute group to append
845 *
846 * Return: zero if successful, or a negative error code
847 */
snd_card_add_dev_attr(struct snd_card * card,const struct attribute_group * group)848 int snd_card_add_dev_attr(struct snd_card *card,
849 const struct attribute_group *group)
850 {
851 int i;
852
853 /* loop for (arraysize-1) here to keep NULL at the last entry */
854 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
855 if (!card->dev_groups[i]) {
856 card->dev_groups[i] = group;
857 return 0;
858 }
859 }
860
861 dev_err(card->dev, "Too many groups assigned\n");
862 return -ENOSPC;
863 }
864 EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
865
trigger_card_free(void * data)866 static void trigger_card_free(void *data)
867 {
868 snd_card_free(data);
869 }
870
871 /**
872 * snd_card_register - register the soundcard
873 * @card: soundcard structure
874 *
875 * This function registers all the devices assigned to the soundcard.
876 * Until calling this, the ALSA control interface is blocked from the
877 * external accesses. Thus, you should call this function at the end
878 * of the initialization of the card.
879 *
880 * Return: Zero otherwise a negative error code if the registration failed.
881 */
snd_card_register(struct snd_card * card)882 int snd_card_register(struct snd_card *card)
883 {
884 int err;
885
886 if (snd_BUG_ON(!card))
887 return -EINVAL;
888
889 if (!card->registered) {
890 err = device_add(&card->card_dev);
891 if (err < 0)
892 return err;
893 card->registered = true;
894 } else {
895 if (card->managed)
896 devm_remove_action(card->dev, trigger_card_free, card);
897 }
898
899 if (card->managed) {
900 err = devm_add_action(card->dev, trigger_card_free, card);
901 if (err < 0)
902 return err;
903 }
904
905 err = snd_device_register_all(card);
906 if (err < 0)
907 return err;
908 mutex_lock(&snd_card_mutex);
909 if (snd_cards[card->number]) {
910 /* already registered */
911 mutex_unlock(&snd_card_mutex);
912 return snd_info_card_register(card); /* register pending info */
913 }
914 if (*card->id) {
915 /* make a unique id name from the given string */
916 char tmpid[sizeof(card->id)];
917 memcpy(tmpid, card->id, sizeof(card->id));
918 snd_card_set_id_no_lock(card, tmpid, tmpid);
919 } else {
920 /* create an id from either shortname or longname */
921 const char *src;
922 src = *card->shortname ? card->shortname : card->longname;
923 snd_card_set_id_no_lock(card, src,
924 retrieve_id_from_card_name(src));
925 }
926 snd_cards[card->number] = card;
927 mutex_unlock(&snd_card_mutex);
928 err = snd_info_card_register(card);
929 if (err < 0)
930 return err;
931
932 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
933 if (snd_mixer_oss_notify_callback)
934 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
935 #endif
936 return 0;
937 }
938 EXPORT_SYMBOL(snd_card_register);
939
940 #ifdef CONFIG_SND_PROC_FS
snd_card_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)941 static void snd_card_info_read(struct snd_info_entry *entry,
942 struct snd_info_buffer *buffer)
943 {
944 int idx, count;
945 struct snd_card *card;
946
947 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
948 mutex_lock(&snd_card_mutex);
949 card = snd_cards[idx];
950 if (card) {
951 count++;
952 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
953 idx,
954 card->id,
955 card->driver,
956 card->shortname);
957 snd_iprintf(buffer, " %s\n",
958 card->longname);
959 }
960 mutex_unlock(&snd_card_mutex);
961 }
962 if (!count)
963 snd_iprintf(buffer, "--- no soundcards ---\n");
964 }
965
966 #ifdef CONFIG_SND_OSSEMUL
snd_card_info_read_oss(struct snd_info_buffer * buffer)967 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
968 {
969 int idx, count;
970 struct snd_card *card;
971
972 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
973 mutex_lock(&snd_card_mutex);
974 card = snd_cards[idx];
975 if (card) {
976 count++;
977 snd_iprintf(buffer, "%s\n", card->longname);
978 }
979 mutex_unlock(&snd_card_mutex);
980 }
981 if (!count) {
982 snd_iprintf(buffer, "--- no soundcards ---\n");
983 }
984 }
985
986 #endif
987
988 #ifdef MODULE
snd_card_module_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)989 static void snd_card_module_info_read(struct snd_info_entry *entry,
990 struct snd_info_buffer *buffer)
991 {
992 int idx;
993 struct snd_card *card;
994
995 for (idx = 0; idx < SNDRV_CARDS; idx++) {
996 mutex_lock(&snd_card_mutex);
997 card = snd_cards[idx];
998 if (card)
999 snd_iprintf(buffer, "%2i %s\n",
1000 idx, card->module->name);
1001 mutex_unlock(&snd_card_mutex);
1002 }
1003 }
1004 #endif
1005
snd_card_info_init(void)1006 int __init snd_card_info_init(void)
1007 {
1008 struct snd_info_entry *entry;
1009
1010 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
1011 if (! entry)
1012 return -ENOMEM;
1013 entry->c.text.read = snd_card_info_read;
1014 if (snd_info_register(entry) < 0)
1015 return -ENOMEM; /* freed in error path */
1016
1017 #ifdef MODULE
1018 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1019 if (!entry)
1020 return -ENOMEM;
1021 entry->c.text.read = snd_card_module_info_read;
1022 if (snd_info_register(entry) < 0)
1023 return -ENOMEM; /* freed in error path */
1024 #endif
1025
1026 return 0;
1027 }
1028 #endif /* CONFIG_SND_PROC_FS */
1029
1030 /**
1031 * snd_component_add - add a component string
1032 * @card: soundcard structure
1033 * @component: the component id string
1034 *
1035 * This function adds the component id string to the supported list.
1036 * The component can be referred from the alsa-lib.
1037 *
1038 * Return: Zero otherwise a negative error code.
1039 */
1040
snd_component_add(struct snd_card * card,const char * component)1041 int snd_component_add(struct snd_card *card, const char *component)
1042 {
1043 char *ptr;
1044 int len = strlen(component);
1045
1046 ptr = strstr(card->components, component);
1047 if (ptr != NULL) {
1048 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1049 return 1;
1050 }
1051 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1052 snd_BUG();
1053 return -ENOMEM;
1054 }
1055 if (card->components[0] != '\0')
1056 strcat(card->components, " ");
1057 strcat(card->components, component);
1058 return 0;
1059 }
1060 EXPORT_SYMBOL(snd_component_add);
1061
1062 /**
1063 * snd_card_file_add - add the file to the file list of the card
1064 * @card: soundcard structure
1065 * @file: file pointer
1066 *
1067 * This function adds the file to the file linked-list of the card.
1068 * This linked-list is used to keep tracking the connection state,
1069 * and to avoid the release of busy resources by hotplug.
1070 *
1071 * Return: zero or a negative error code.
1072 */
snd_card_file_add(struct snd_card * card,struct file * file)1073 int snd_card_file_add(struct snd_card *card, struct file *file)
1074 {
1075 struct snd_monitor_file *mfile;
1076
1077 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1078 if (mfile == NULL)
1079 return -ENOMEM;
1080 mfile->file = file;
1081 mfile->disconnected_f_op = NULL;
1082 INIT_LIST_HEAD(&mfile->shutdown_list);
1083 spin_lock(&card->files_lock);
1084 if (card->shutdown) {
1085 spin_unlock(&card->files_lock);
1086 kfree(mfile);
1087 return -ENODEV;
1088 }
1089 list_add(&mfile->list, &card->files_list);
1090 get_device(&card->card_dev);
1091 spin_unlock(&card->files_lock);
1092 return 0;
1093 }
1094 EXPORT_SYMBOL(snd_card_file_add);
1095
1096 /**
1097 * snd_card_file_remove - remove the file from the file list
1098 * @card: soundcard structure
1099 * @file: file pointer
1100 *
1101 * This function removes the file formerly added to the card via
1102 * snd_card_file_add() function.
1103 * If all files are removed and snd_card_free_when_closed() was
1104 * called beforehand, it processes the pending release of
1105 * resources.
1106 *
1107 * Return: Zero or a negative error code.
1108 */
snd_card_file_remove(struct snd_card * card,struct file * file)1109 int snd_card_file_remove(struct snd_card *card, struct file *file)
1110 {
1111 struct snd_monitor_file *mfile, *found = NULL;
1112
1113 spin_lock(&card->files_lock);
1114 list_for_each_entry(mfile, &card->files_list, list) {
1115 if (mfile->file == file) {
1116 list_del(&mfile->list);
1117 spin_lock(&shutdown_lock);
1118 list_del(&mfile->shutdown_list);
1119 spin_unlock(&shutdown_lock);
1120 if (mfile->disconnected_f_op)
1121 fops_put(mfile->disconnected_f_op);
1122 found = mfile;
1123 break;
1124 }
1125 }
1126 if (list_empty(&card->files_list))
1127 wake_up_all(&card->remove_sleep);
1128 spin_unlock(&card->files_lock);
1129 if (!found) {
1130 dev_err(card->dev, "card file remove problem (%p)\n", file);
1131 return -ENOENT;
1132 }
1133 kfree(found);
1134 put_device(&card->card_dev);
1135 return 0;
1136 }
1137 EXPORT_SYMBOL(snd_card_file_remove);
1138
1139 #ifdef CONFIG_PM
1140 /**
1141 * snd_power_ref_and_wait - wait until the card gets powered up
1142 * @card: soundcard structure
1143 *
1144 * Take the power_ref reference count of the given card, and
1145 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1146 * The refcount is down again while sleeping until power-up, hence this
1147 * function can be used for syncing the floating control ops accesses,
1148 * typically around calling control ops.
1149 *
1150 * The caller needs to pull down the refcount via snd_power_unref() later
1151 * no matter whether the error is returned from this function or not.
1152 *
1153 * Return: Zero if successful, or a negative error code.
1154 */
snd_power_ref_and_wait(struct snd_card * card)1155 int snd_power_ref_and_wait(struct snd_card *card)
1156 {
1157 snd_power_ref(card);
1158 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1159 return 0;
1160 wait_event_cmd(card->power_sleep,
1161 card->shutdown ||
1162 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1163 snd_power_unref(card), snd_power_ref(card));
1164 return card->shutdown ? -ENODEV : 0;
1165 }
1166 EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1167
1168 /**
1169 * snd_power_wait - wait until the card gets powered up (old form)
1170 * @card: soundcard structure
1171 *
1172 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1173 *
1174 * Return: Zero if successful, or a negative error code.
1175 */
snd_power_wait(struct snd_card * card)1176 int snd_power_wait(struct snd_card *card)
1177 {
1178 int ret;
1179
1180 ret = snd_power_ref_and_wait(card);
1181 snd_power_unref(card);
1182 return ret;
1183 }
1184 EXPORT_SYMBOL(snd_power_wait);
1185 #endif /* CONFIG_PM */
1186