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 | */ |
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 | |
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 | */ |
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() */ |
115 | static void default_release_alloc(struct device *dev) |
116 | { |
117 | kfree(objp: 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 | */ |
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(size: 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 ); |
148 | static int snd_card_do_free(struct snd_card *card); |
149 | static const struct attribute_group card_dev_attr_group; |
150 | |
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 | */ |
171 | int snd_card_new(struct device *parent, int idx, const char *xid, |
172 | struct module *module, int , |
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(size: 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 | |
197 | static void __snd_card_release(struct device *dev, void *data) |
198 | { |
199 | snd_card_free(card: 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 | */ |
227 | int snd_devm_card_new(struct device *parent, int idx, const char *xid, |
228 | struct module *module, size_t , |
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(res: card); /* in managed mode, we need to free manually */ |
243 | return err; |
244 | } |
245 | |
246 | devres_add(dev: parent, res: 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 | */ |
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, release: __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 | |
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 ) |
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(mask: idx, check: module_slot_match, module); |
290 | if (idx < 0) /* if not matched, assign an empty slot */ |
291 | idx = get_slot_from_bitmask(mask: idx, check: 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(nr: idx, addr: 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(objp: 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 | card->module = module; |
317 | #endif |
318 | INIT_LIST_HEAD(list: &card->devices); |
319 | init_rwsem(&card->controls_rwsem); |
320 | rwlock_init(&card->ctl_files_rwlock); |
321 | INIT_LIST_HEAD(list: &card->controls); |
322 | INIT_LIST_HEAD(list: &card->ctl_files); |
323 | #ifdef CONFIG_SND_CTL_FAST_LOOKUP |
324 | xa_init(xa: &card->ctl_numids); |
325 | xa_init(xa: &card->ctl_hash); |
326 | #endif |
327 | spin_lock_init(&card->files_lock); |
328 | INIT_LIST_HEAD(list: &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(v: &card->power_ref, i: 0); |
334 | #endif |
335 | init_waitqueue_head(&card->remove_sleep); |
336 | card->sync_irq = -1; |
337 | |
338 | device_initialize(dev: &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(kobj: &card->card_dev.kobj, name: "card%d" , idx); |
345 | if (err < 0) |
346 | goto __error; |
347 | |
348 | snprintf(buf: card->irq_descr, size: sizeof(card->irq_descr), fmt: "%s:%s" , |
349 | dev_driver_string(dev: card->dev), dev_name(dev: &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(name: dev_name(dev: &card->card_dev), |
366 | parent: sound_debugfs_root); |
367 | #endif |
368 | return 0; |
369 | |
370 | __error_ctl: |
371 | snd_device_free_all(card); |
372 | __error: |
373 | put_device(dev: &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 | */ |
386 | struct snd_card *snd_card_ref(int idx) |
387 | { |
388 | struct snd_card *card; |
389 | |
390 | guard(mutex)(T: &snd_card_mutex); |
391 | card = snd_cards[idx]; |
392 | if (card) |
393 | get_device(dev: &card->card_dev); |
394 | return card; |
395 | } |
396 | EXPORT_SYMBOL_GPL(snd_card_ref); |
397 | |
398 | /* return non-zero if a card is already locked */ |
399 | int snd_card_locked(int card) |
400 | { |
401 | guard(mutex)(T: &snd_card_mutex); |
402 | return test_bit(card, snd_cards_lock); |
403 | } |
404 | |
405 | static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig) |
406 | { |
407 | return -ENODEV; |
408 | } |
409 | |
410 | static ssize_t snd_disconnect_read(struct file *file, char __user *buf, |
411 | size_t count, loff_t *offset) |
412 | { |
413 | return -ENODEV; |
414 | } |
415 | |
416 | static 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 | |
422 | static 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(entry: &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(fmt: "%s(%p, %p) failed!" , __func__, inode, file); |
443 | } |
444 | |
445 | static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait) |
446 | { |
447 | return EPOLLERR | EPOLLNVAL; |
448 | } |
449 | |
450 | static long snd_disconnect_ioctl(struct file *file, |
451 | unsigned int cmd, unsigned long arg) |
452 | { |
453 | return -ENODEV; |
454 | } |
455 | |
456 | static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma) |
457 | { |
458 | return -ENODEV; |
459 | } |
460 | |
461 | static int snd_disconnect_fasync(int fd, struct file *file, int on) |
462 | { |
463 | return -ENODEV; |
464 | } |
465 | |
466 | static 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 | */ |
493 | void 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(new: &mfile->shutdown_list, head: &shutdown_files); |
513 | |
514 | mfile->file->f_op = &snd_shutdown_f_ops; |
515 | fops_get(mfile->file->f_op); |
516 | } |
517 | } |
518 | |
519 | /* notify all connected devices about disconnection */ |
520 | /* at this point, they cannot respond to any calls except release() */ |
521 | |
522 | #if IS_ENABLED(CONFIG_SND_MIXER_OSS) |
523 | if (snd_mixer_oss_notify_callback) |
524 | snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT); |
525 | #endif |
526 | |
527 | /* notify all devices that we are disconnected */ |
528 | snd_device_disconnect_all(card); |
529 | |
530 | if (card->sync_irq > 0) |
531 | synchronize_irq(irq: card->sync_irq); |
532 | |
533 | snd_info_card_disconnect(card); |
534 | if (card->registered) { |
535 | device_del(dev: &card->card_dev); |
536 | card->registered = false; |
537 | } |
538 | |
539 | /* disable fops (user space) operations for ALSA API */ |
540 | scoped_guard(mutex, &snd_card_mutex) { |
541 | snd_cards[card->number] = NULL; |
542 | clear_bit(nr: card->number, addr: snd_cards_lock); |
543 | } |
544 | |
545 | #ifdef CONFIG_PM |
546 | wake_up(&card->power_sleep); |
547 | snd_power_sync_ref(card); |
548 | #endif |
549 | } |
550 | EXPORT_SYMBOL(snd_card_disconnect); |
551 | |
552 | /** |
553 | * snd_card_disconnect_sync - disconnect card and wait until files get closed |
554 | * @card: card object to disconnect |
555 | * |
556 | * This calls snd_card_disconnect() for disconnecting all belonging components |
557 | * and waits until all pending files get closed. |
558 | * It assures that all accesses from user-space finished so that the driver |
559 | * can release its resources gracefully. |
560 | */ |
561 | void snd_card_disconnect_sync(struct snd_card *card) |
562 | { |
563 | snd_card_disconnect(card); |
564 | |
565 | guard(spinlock_irq)(l: &card->files_lock); |
566 | wait_event_lock_irq(card->remove_sleep, |
567 | list_empty(&card->files_list), |
568 | card->files_lock); |
569 | } |
570 | EXPORT_SYMBOL_GPL(snd_card_disconnect_sync); |
571 | |
572 | static int snd_card_do_free(struct snd_card *card) |
573 | { |
574 | card->releasing = true; |
575 | #if IS_ENABLED(CONFIG_SND_MIXER_OSS) |
576 | if (snd_mixer_oss_notify_callback) |
577 | snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE); |
578 | #endif |
579 | snd_device_free_all(card); |
580 | if (card->private_free) |
581 | card->private_free(card); |
582 | if (snd_info_card_free(card) < 0) { |
583 | dev_warn(card->dev, "unable to free card info\n" ); |
584 | /* Not fatal error */ |
585 | } |
586 | #ifdef CONFIG_SND_DEBUG |
587 | debugfs_remove(dentry: card->debugfs_root); |
588 | card->debugfs_root = NULL; |
589 | #endif |
590 | if (card->release_completion) |
591 | complete(card->release_completion); |
592 | if (!card->managed) |
593 | kfree(objp: card); |
594 | return 0; |
595 | } |
596 | |
597 | /** |
598 | * snd_card_free_when_closed - Disconnect the card, free it later eventually |
599 | * @card: soundcard structure |
600 | * |
601 | * Unlike snd_card_free(), this function doesn't try to release the card |
602 | * resource immediately, but tries to disconnect at first. When the card |
603 | * is still in use, the function returns before freeing the resources. |
604 | * The card resources will be freed when the refcount gets to zero. |
605 | * |
606 | * Return: zero if successful, or a negative error code |
607 | */ |
608 | void snd_card_free_when_closed(struct snd_card *card) |
609 | { |
610 | if (!card) |
611 | return; |
612 | |
613 | snd_card_disconnect(card); |
614 | put_device(dev: &card->card_dev); |
615 | return; |
616 | } |
617 | EXPORT_SYMBOL(snd_card_free_when_closed); |
618 | |
619 | /** |
620 | * snd_card_free - frees given soundcard structure |
621 | * @card: soundcard structure |
622 | * |
623 | * This function releases the soundcard structure and the all assigned |
624 | * devices automatically. That is, you don't have to release the devices |
625 | * by yourself. |
626 | * |
627 | * This function waits until the all resources are properly released. |
628 | * |
629 | * Return: Zero. Frees all associated devices and frees the control |
630 | * interface associated to given soundcard. |
631 | */ |
632 | void snd_card_free(struct snd_card *card) |
633 | { |
634 | DECLARE_COMPLETION_ONSTACK(released); |
635 | |
636 | /* The call of snd_card_free() is allowed from various code paths; |
637 | * a manual call from the driver and the call via devres_free, and |
638 | * we need to avoid double-free. Moreover, the release via devres |
639 | * may call snd_card_free() twice due to its nature, we need to have |
640 | * the check here at the beginning. |
641 | */ |
642 | if (card->releasing) |
643 | return; |
644 | |
645 | card->release_completion = &released; |
646 | snd_card_free_when_closed(card); |
647 | |
648 | /* wait, until all devices are ready for the free operation */ |
649 | wait_for_completion(&released); |
650 | } |
651 | EXPORT_SYMBOL(snd_card_free); |
652 | |
653 | /* retrieve the last word of shortname or longname */ |
654 | static const char *retrieve_id_from_card_name(const char *name) |
655 | { |
656 | const char *spos = name; |
657 | |
658 | while (*name) { |
659 | if (isspace(*name) && isalnum(name[1])) |
660 | spos = name + 1; |
661 | name++; |
662 | } |
663 | return spos; |
664 | } |
665 | |
666 | /* return true if the given id string doesn't conflict any other card ids */ |
667 | static bool card_id_ok(struct snd_card *card, const char *id) |
668 | { |
669 | int i; |
670 | if (!snd_info_check_reserved_words(str: id)) |
671 | return false; |
672 | for (i = 0; i < snd_ecards_limit; i++) { |
673 | if (snd_cards[i] && snd_cards[i] != card && |
674 | !strcmp(snd_cards[i]->id, id)) |
675 | return false; |
676 | } |
677 | return true; |
678 | } |
679 | |
680 | /* copy to card->id only with valid letters from nid */ |
681 | static void copy_valid_id_string(struct snd_card *card, const char *src, |
682 | const char *nid) |
683 | { |
684 | char *id = card->id; |
685 | |
686 | while (*nid && !isalnum(*nid)) |
687 | nid++; |
688 | if (isdigit(c: *nid)) |
689 | *id++ = isalpha(*src) ? *src : 'D'; |
690 | while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) { |
691 | if (isalnum(*nid)) |
692 | *id++ = *nid; |
693 | nid++; |
694 | } |
695 | *id = 0; |
696 | } |
697 | |
698 | /* Set card->id from the given string |
699 | * If the string conflicts with other ids, add a suffix to make it unique. |
700 | */ |
701 | static void snd_card_set_id_no_lock(struct snd_card *card, const char *src, |
702 | const char *nid) |
703 | { |
704 | int len, loops; |
705 | bool is_default = false; |
706 | char *id; |
707 | |
708 | copy_valid_id_string(card, src, nid); |
709 | id = card->id; |
710 | |
711 | again: |
712 | /* use "Default" for obviously invalid strings |
713 | * ("card" conflicts with proc directories) |
714 | */ |
715 | if (!*id || !strncmp(id, "card" , 4)) { |
716 | strcpy(p: id, q: "Default" ); |
717 | is_default = true; |
718 | } |
719 | |
720 | len = strlen(id); |
721 | for (loops = 0; loops < SNDRV_CARDS; loops++) { |
722 | char *spos; |
723 | char sfxstr[5]; /* "_012" */ |
724 | int sfxlen; |
725 | |
726 | if (card_id_ok(card, id)) |
727 | return; /* OK */ |
728 | |
729 | /* Add _XYZ suffix */ |
730 | sprintf(buf: sfxstr, fmt: "_%X" , loops + 1); |
731 | sfxlen = strlen(sfxstr); |
732 | if (len + sfxlen >= sizeof(card->id)) |
733 | spos = id + sizeof(card->id) - sfxlen - 1; |
734 | else |
735 | spos = id + len; |
736 | strcpy(p: spos, q: sfxstr); |
737 | } |
738 | /* fallback to the default id */ |
739 | if (!is_default) { |
740 | *id = 0; |
741 | goto again; |
742 | } |
743 | /* last resort... */ |
744 | dev_err(card->dev, "unable to set card id (%s)\n" , id); |
745 | if (card->proc_root->name) |
746 | strscpy(card->id, card->proc_root->name, sizeof(card->id)); |
747 | } |
748 | |
749 | /** |
750 | * snd_card_set_id - set card identification name |
751 | * @card: soundcard structure |
752 | * @nid: new identification string |
753 | * |
754 | * This function sets the card identification and checks for name |
755 | * collisions. |
756 | */ |
757 | void snd_card_set_id(struct snd_card *card, const char *nid) |
758 | { |
759 | /* check if user specified own card->id */ |
760 | if (card->id[0] != '\0') |
761 | return; |
762 | guard(mutex)(T: &snd_card_mutex); |
763 | snd_card_set_id_no_lock(card, src: nid, nid); |
764 | } |
765 | EXPORT_SYMBOL(snd_card_set_id); |
766 | |
767 | static ssize_t id_show(struct device *dev, |
768 | struct device_attribute *attr, char *buf) |
769 | { |
770 | struct snd_card *card = container_of(dev, struct snd_card, card_dev); |
771 | return sysfs_emit(buf, fmt: "%s\n" , card->id); |
772 | } |
773 | |
774 | static ssize_t id_store(struct device *dev, struct device_attribute *attr, |
775 | const char *buf, size_t count) |
776 | { |
777 | struct snd_card *card = container_of(dev, struct snd_card, card_dev); |
778 | char buf1[sizeof(card->id)]; |
779 | size_t copy = count > sizeof(card->id) - 1 ? |
780 | sizeof(card->id) - 1 : count; |
781 | size_t idx; |
782 | int c; |
783 | |
784 | for (idx = 0; idx < copy; idx++) { |
785 | c = buf[idx]; |
786 | if (!isalnum(c) && c != '_' && c != '-') |
787 | return -EINVAL; |
788 | } |
789 | memcpy(buf1, buf, copy); |
790 | buf1[copy] = '\0'; |
791 | guard(mutex)(T: &snd_card_mutex); |
792 | if (!card_id_ok(NULL, id: buf1)) |
793 | return -EEXIST; |
794 | strcpy(p: card->id, q: buf1); |
795 | snd_info_card_id_change(card); |
796 | |
797 | return count; |
798 | } |
799 | |
800 | static DEVICE_ATTR_RW(id); |
801 | |
802 | static ssize_t number_show(struct device *dev, |
803 | struct device_attribute *attr, char *buf) |
804 | { |
805 | struct snd_card *card = container_of(dev, struct snd_card, card_dev); |
806 | return sysfs_emit(buf, fmt: "%i\n" , card->number); |
807 | } |
808 | |
809 | static DEVICE_ATTR_RO(number); |
810 | |
811 | static struct attribute *card_dev_attrs[] = { |
812 | &dev_attr_id.attr, |
813 | &dev_attr_number.attr, |
814 | NULL |
815 | }; |
816 | |
817 | static const struct attribute_group card_dev_attr_group = { |
818 | .attrs = card_dev_attrs, |
819 | }; |
820 | |
821 | /** |
822 | * snd_card_add_dev_attr - Append a new sysfs attribute group to card |
823 | * @card: card instance |
824 | * @group: attribute group to append |
825 | * |
826 | * Return: zero if successful, or a negative error code |
827 | */ |
828 | int snd_card_add_dev_attr(struct snd_card *card, |
829 | const struct attribute_group *group) |
830 | { |
831 | int i; |
832 | |
833 | /* loop for (arraysize-1) here to keep NULL at the last entry */ |
834 | for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) { |
835 | if (!card->dev_groups[i]) { |
836 | card->dev_groups[i] = group; |
837 | return 0; |
838 | } |
839 | } |
840 | |
841 | dev_err(card->dev, "Too many groups assigned\n" ); |
842 | return -ENOSPC; |
843 | } |
844 | EXPORT_SYMBOL_GPL(snd_card_add_dev_attr); |
845 | |
846 | static void trigger_card_free(void *data) |
847 | { |
848 | snd_card_free(data); |
849 | } |
850 | |
851 | /** |
852 | * snd_card_register - register the soundcard |
853 | * @card: soundcard structure |
854 | * |
855 | * This function registers all the devices assigned to the soundcard. |
856 | * Until calling this, the ALSA control interface is blocked from the |
857 | * external accesses. Thus, you should call this function at the end |
858 | * of the initialization of the card. |
859 | * |
860 | * Return: Zero otherwise a negative error code if the registration failed. |
861 | */ |
862 | int snd_card_register(struct snd_card *card) |
863 | { |
864 | int err; |
865 | |
866 | if (snd_BUG_ON(!card)) |
867 | return -EINVAL; |
868 | |
869 | if (!card->registered) { |
870 | err = device_add(dev: &card->card_dev); |
871 | if (err < 0) |
872 | return err; |
873 | card->registered = true; |
874 | } else { |
875 | if (card->managed) |
876 | devm_remove_action(dev: card->dev, action: trigger_card_free, data: card); |
877 | } |
878 | |
879 | if (card->managed) { |
880 | err = devm_add_action(card->dev, trigger_card_free, card); |
881 | if (err < 0) |
882 | return err; |
883 | } |
884 | |
885 | err = snd_device_register_all(card); |
886 | if (err < 0) |
887 | return err; |
888 | scoped_guard(mutex, &snd_card_mutex) { |
889 | if (snd_cards[card->number]) { |
890 | /* already registered */ |
891 | return snd_info_card_register(card); /* register pending info */ |
892 | } |
893 | if (*card->id) { |
894 | /* make a unique id name from the given string */ |
895 | char tmpid[sizeof(card->id)]; |
896 | |
897 | memcpy(tmpid, card->id, sizeof(card->id)); |
898 | snd_card_set_id_no_lock(card, src: tmpid, nid: tmpid); |
899 | } else { |
900 | /* create an id from either shortname or longname */ |
901 | const char *src; |
902 | |
903 | src = *card->shortname ? card->shortname : card->longname; |
904 | snd_card_set_id_no_lock(card, src, |
905 | nid: retrieve_id_from_card_name(name: src)); |
906 | } |
907 | snd_cards[card->number] = card; |
908 | } |
909 | err = snd_info_card_register(card); |
910 | if (err < 0) |
911 | return err; |
912 | |
913 | #if IS_ENABLED(CONFIG_SND_MIXER_OSS) |
914 | if (snd_mixer_oss_notify_callback) |
915 | snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER); |
916 | #endif |
917 | return 0; |
918 | } |
919 | EXPORT_SYMBOL(snd_card_register); |
920 | |
921 | #ifdef CONFIG_SND_PROC_FS |
922 | static void snd_card_info_read(struct snd_info_entry *entry, |
923 | struct snd_info_buffer *buffer) |
924 | { |
925 | int idx, count; |
926 | struct snd_card *card; |
927 | |
928 | for (idx = count = 0; idx < SNDRV_CARDS; idx++) { |
929 | guard(mutex)(T: &snd_card_mutex); |
930 | card = snd_cards[idx]; |
931 | if (card) { |
932 | count++; |
933 | snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n" , |
934 | idx, |
935 | card->id, |
936 | card->driver, |
937 | card->shortname); |
938 | snd_iprintf(buffer, " %s\n" , |
939 | card->longname); |
940 | } |
941 | } |
942 | if (!count) |
943 | snd_iprintf(buffer, "--- no soundcards ---\n" ); |
944 | } |
945 | |
946 | #ifdef CONFIG_SND_OSSEMUL |
947 | void snd_card_info_read_oss(struct snd_info_buffer *buffer) |
948 | { |
949 | int idx, count; |
950 | struct snd_card *card; |
951 | |
952 | for (idx = count = 0; idx < SNDRV_CARDS; idx++) { |
953 | guard(mutex)(T: &snd_card_mutex); |
954 | card = snd_cards[idx]; |
955 | if (card) { |
956 | count++; |
957 | snd_iprintf(buffer, "%s\n" , card->longname); |
958 | } |
959 | } |
960 | if (!count) { |
961 | snd_iprintf(buffer, "--- no soundcards ---\n" ); |
962 | } |
963 | } |
964 | |
965 | #endif |
966 | |
967 | #ifdef MODULE |
968 | static void snd_card_module_info_read(struct snd_info_entry *entry, |
969 | struct snd_info_buffer *buffer) |
970 | { |
971 | int idx; |
972 | struct snd_card *card; |
973 | |
974 | for (idx = 0; idx < SNDRV_CARDS; idx++) { |
975 | guard(mutex)(&snd_card_mutex); |
976 | card = snd_cards[idx]; |
977 | if (card) |
978 | snd_iprintf(buffer, "%2i %s\n" , |
979 | idx, card->module->name); |
980 | } |
981 | } |
982 | #endif |
983 | |
984 | int __init snd_card_info_init(void) |
985 | { |
986 | struct snd_info_entry *entry; |
987 | |
988 | entry = snd_info_create_module_entry(THIS_MODULE, name: "cards" , NULL); |
989 | if (! entry) |
990 | return -ENOMEM; |
991 | entry->c.text.read = snd_card_info_read; |
992 | if (snd_info_register(entry) < 0) |
993 | return -ENOMEM; /* freed in error path */ |
994 | |
995 | #ifdef MODULE |
996 | entry = snd_info_create_module_entry(THIS_MODULE, "modules" , NULL); |
997 | if (!entry) |
998 | return -ENOMEM; |
999 | entry->c.text.read = snd_card_module_info_read; |
1000 | if (snd_info_register(entry) < 0) |
1001 | return -ENOMEM; /* freed in error path */ |
1002 | #endif |
1003 | |
1004 | return 0; |
1005 | } |
1006 | #endif /* CONFIG_SND_PROC_FS */ |
1007 | |
1008 | /** |
1009 | * snd_component_add - add a component string |
1010 | * @card: soundcard structure |
1011 | * @component: the component id string |
1012 | * |
1013 | * This function adds the component id string to the supported list. |
1014 | * The component can be referred from the alsa-lib. |
1015 | * |
1016 | * Return: Zero otherwise a negative error code. |
1017 | */ |
1018 | |
1019 | int snd_component_add(struct snd_card *card, const char *component) |
1020 | { |
1021 | char *ptr; |
1022 | int len = strlen(component); |
1023 | |
1024 | ptr = strstr(card->components, component); |
1025 | if (ptr != NULL) { |
1026 | if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */ |
1027 | return 1; |
1028 | } |
1029 | if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) { |
1030 | snd_BUG(); |
1031 | return -ENOMEM; |
1032 | } |
1033 | if (card->components[0] != '\0') |
1034 | strcat(p: card->components, q: " " ); |
1035 | strcat(p: card->components, q: component); |
1036 | return 0; |
1037 | } |
1038 | EXPORT_SYMBOL(snd_component_add); |
1039 | |
1040 | /** |
1041 | * snd_card_file_add - add the file to the file list of the card |
1042 | * @card: soundcard structure |
1043 | * @file: file pointer |
1044 | * |
1045 | * This function adds the file to the file linked-list of the card. |
1046 | * This linked-list is used to keep tracking the connection state, |
1047 | * and to avoid the release of busy resources by hotplug. |
1048 | * |
1049 | * Return: zero or a negative error code. |
1050 | */ |
1051 | int snd_card_file_add(struct snd_card *card, struct file *file) |
1052 | { |
1053 | struct snd_monitor_file *mfile; |
1054 | |
1055 | mfile = kmalloc(size: sizeof(*mfile), GFP_KERNEL); |
1056 | if (mfile == NULL) |
1057 | return -ENOMEM; |
1058 | mfile->file = file; |
1059 | mfile->disconnected_f_op = NULL; |
1060 | INIT_LIST_HEAD(list: &mfile->shutdown_list); |
1061 | guard(spinlock)(l: &card->files_lock); |
1062 | if (card->shutdown) { |
1063 | kfree(objp: mfile); |
1064 | return -ENODEV; |
1065 | } |
1066 | list_add(new: &mfile->list, head: &card->files_list); |
1067 | get_device(dev: &card->card_dev); |
1068 | return 0; |
1069 | } |
1070 | EXPORT_SYMBOL(snd_card_file_add); |
1071 | |
1072 | /** |
1073 | * snd_card_file_remove - remove the file from the file list |
1074 | * @card: soundcard structure |
1075 | * @file: file pointer |
1076 | * |
1077 | * This function removes the file formerly added to the card via |
1078 | * snd_card_file_add() function. |
1079 | * If all files are removed and snd_card_free_when_closed() was |
1080 | * called beforehand, it processes the pending release of |
1081 | * resources. |
1082 | * |
1083 | * Return: Zero or a negative error code. |
1084 | */ |
1085 | int snd_card_file_remove(struct snd_card *card, struct file *file) |
1086 | { |
1087 | struct snd_monitor_file *mfile, *found = NULL; |
1088 | |
1089 | scoped_guard(spinlock, &card->files_lock) { |
1090 | list_for_each_entry(mfile, &card->files_list, list) { |
1091 | if (mfile->file == file) { |
1092 | list_del(entry: &mfile->list); |
1093 | scoped_guard(spinlock, &shutdown_lock) |
1094 | list_del(entry: &mfile->shutdown_list); |
1095 | if (mfile->disconnected_f_op) |
1096 | fops_put(mfile->disconnected_f_op); |
1097 | found = mfile; |
1098 | break; |
1099 | } |
1100 | } |
1101 | if (list_empty(head: &card->files_list)) |
1102 | wake_up_all(&card->remove_sleep); |
1103 | } |
1104 | if (!found) { |
1105 | dev_err(card->dev, "card file remove problem (%p)\n" , file); |
1106 | return -ENOENT; |
1107 | } |
1108 | kfree(objp: found); |
1109 | put_device(dev: &card->card_dev); |
1110 | return 0; |
1111 | } |
1112 | EXPORT_SYMBOL(snd_card_file_remove); |
1113 | |
1114 | #ifdef CONFIG_PM |
1115 | /** |
1116 | * snd_power_ref_and_wait - wait until the card gets powered up |
1117 | * @card: soundcard structure |
1118 | * |
1119 | * Take the power_ref reference count of the given card, and |
1120 | * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state. |
1121 | * The refcount is down again while sleeping until power-up, hence this |
1122 | * function can be used for syncing the floating control ops accesses, |
1123 | * typically around calling control ops. |
1124 | * |
1125 | * The caller needs to pull down the refcount via snd_power_unref() later |
1126 | * no matter whether the error is returned from this function or not. |
1127 | * |
1128 | * Return: Zero if successful, or a negative error code. |
1129 | */ |
1130 | int snd_power_ref_and_wait(struct snd_card *card) |
1131 | { |
1132 | snd_power_ref(card); |
1133 | if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0) |
1134 | return 0; |
1135 | wait_event_cmd(card->power_sleep, |
1136 | card->shutdown || |
1137 | snd_power_get_state(card) == SNDRV_CTL_POWER_D0, |
1138 | snd_power_unref(card), snd_power_ref(card)); |
1139 | return card->shutdown ? -ENODEV : 0; |
1140 | } |
1141 | EXPORT_SYMBOL_GPL(snd_power_ref_and_wait); |
1142 | |
1143 | /** |
1144 | * snd_power_wait - wait until the card gets powered up (old form) |
1145 | * @card: soundcard structure |
1146 | * |
1147 | * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state. |
1148 | * |
1149 | * Return: Zero if successful, or a negative error code. |
1150 | */ |
1151 | int snd_power_wait(struct snd_card *card) |
1152 | { |
1153 | int ret; |
1154 | |
1155 | ret = snd_power_ref_and_wait(card); |
1156 | snd_power_unref(card); |
1157 | return ret; |
1158 | } |
1159 | EXPORT_SYMBOL(snd_power_wait); |
1160 | #endif /* CONFIG_PM */ |
1161 | |