linux/sound/core/init.c
Takashi Iwai 495000a386 ALSA: core: Remove debugfs at disconnection
The card-specific debugfs entries are removed at the last stage of
card free phase, and it's performed after synchronization of the
closes of all opened fds.  This works fine for most cases, but it can
be potentially problematic for a hotplug device like USB-audio.  Due
to the nature of snd_card_free_when_closed(), the card free isn't
called immediately after the driver removal for a hotplug device, but
it's left until the last fd is closed.  It implies that the card
debugfs entries also remain.  Meanwhile, when a new device is inserted
before the last close and the very same card slot is assigned, the
driver tries to create the card debugfs root again on the very same
path.  This conflicts with the remaining entry, and results in the
kernel warning such as:
  debugfs: Directory 'card0' with parent 'sound' already present!
with the missing debugfs entry afterwards.

For avoiding such conflicts, remove debugfs entries at the device
disconnection phase instead.  The jack kctl debugfs entries get
removed in snd_jack_dev_disconnect() instead of each kctl
private_free.

Fixes: 2d670ea2bd ("ALSA: jack: implement software jack injection via debugfs")
Link: https://lore.kernel.org/r/20240524151256.32521-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-05-27 09:28:21 +02:00

1165 lines
30 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Initialization routines
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/ctype.h>
#include <linux/pm.h>
#include <linux/debugfs.h>
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/info.h>
/* monitor files for graceful shutdown (hotplug) */
struct snd_monitor_file {
struct file *file;
const struct file_operations *disconnected_f_op;
struct list_head shutdown_list; /* still need to shutdown */
struct list_head list; /* link of monitor files */
};
static DEFINE_SPINLOCK(shutdown_lock);
static LIST_HEAD(shutdown_files);
static const struct file_operations snd_shutdown_f_ops;
/* locked for registering/using */
static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
static struct snd_card *snd_cards[SNDRV_CARDS];
static DEFINE_MUTEX(snd_card_mutex);
static char *slots[SNDRV_CARDS];
module_param_array(slots, charp, NULL, 0444);
MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
/* return non-zero if the given index is reserved for the given
* module via slots option
*/
static int module_slot_match(struct module *module, int idx)
{
int match = 1;
#ifdef CONFIG_MODULES
const char *s1, *s2;
if (!module || !*module->name || !slots[idx])
return 0;
s1 = module->name;
s2 = slots[idx];
if (*s2 == '!') {
match = 0; /* negative match */
s2++;
}
/* compare module name strings
* hyphens are handled as equivalent with underscore
*/
for (;;) {
char c1 = *s1++;
char c2 = *s2++;
if (c1 == '-')
c1 = '_';
if (c2 == '-')
c2 = '_';
if (c1 != c2)
return !match;
if (!c1)
break;
}
#endif /* CONFIG_MODULES */
return match;
}
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
#endif
static int check_empty_slot(struct module *module, int slot)
{
return !slots[slot] || !*slots[slot];
}
/* return an empty slot number (>= 0) found in the given bitmask @mask.
* @mask == -1 == 0xffffffff means: take any free slot up to 32
* when no slot is available, return the original @mask as is.
*/
static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
struct module *module)
{
int slot;
for (slot = 0; slot < SNDRV_CARDS; slot++) {
if (slot < 32 && !(mask & (1U << slot)))
continue;
if (!test_bit(slot, snd_cards_lock)) {
if (check(module, slot))
return slot; /* found */
}
}
return mask; /* unchanged */
}
/* the default release callback set in snd_device_alloc() */
static void default_release_alloc(struct device *dev)
{
kfree(dev);
}
/**
* snd_device_alloc - Allocate and initialize struct device for sound devices
* @dev_p: pointer to store the allocated device
* @card: card to assign, optional
*
* For releasing the allocated device, call put_device().
*/
int snd_device_alloc(struct device **dev_p, struct snd_card *card)
{
struct device *dev;
*dev_p = NULL;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
device_initialize(dev);
if (card)
dev->parent = &card->card_dev;
dev->class = &sound_class;
dev->release = default_release_alloc;
*dev_p = dev;
return 0;
}
EXPORT_SYMBOL_GPL(snd_device_alloc);
static int snd_card_init(struct snd_card *card, struct device *parent,
int idx, const char *xid, struct module *module,
size_t extra_size);
static int snd_card_do_free(struct snd_card *card);
static const struct attribute_group card_dev_attr_group;
static void release_card_device(struct device *dev)
{
snd_card_do_free(dev_to_snd_card(dev));
}
/**
* snd_card_new - create and initialize a soundcard structure
* @parent: the parent device object
* @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
* @xid: card identification (ASCII string)
* @module: top level module for locking
* @extra_size: allocate this extra size after the main soundcard structure
* @card_ret: the pointer to store the created card instance
*
* The function allocates snd_card instance via kzalloc with the given
* space for the driver to use freely. The allocated struct is stored
* in the given card_ret pointer.
*
* Return: Zero if successful or a negative error code.
*/
int snd_card_new(struct device *parent, int idx, const char *xid,
struct module *module, int extra_size,
struct snd_card **card_ret)
{
struct snd_card *card;
int err;
if (snd_BUG_ON(!card_ret))
return -EINVAL;
*card_ret = NULL;
if (extra_size < 0)
extra_size = 0;
card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
if (!card)
return -ENOMEM;
err = snd_card_init(card, parent, idx, xid, module, extra_size);
if (err < 0)
return err; /* card is freed by error handler */
*card_ret = card;
return 0;
}
EXPORT_SYMBOL(snd_card_new);
static void __snd_card_release(struct device *dev, void *data)
{
snd_card_free(data);
}
/**
* snd_devm_card_new - managed snd_card object creation
* @parent: the parent device object
* @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
* @xid: card identification (ASCII string)
* @module: top level module for locking
* @extra_size: allocate this extra size after the main soundcard structure
* @card_ret: the pointer to store the created card instance
*
* This function works like snd_card_new() but manages the allocated resource
* via devres, i.e. you don't need to free explicitly.
*
* When a snd_card object is created with this function and registered via
* snd_card_register(), the very first devres action to call snd_card_free()
* is added automatically. In that way, the resource disconnection is assured
* at first, then released in the expected order.
*
* If an error happens at the probe before snd_card_register() is called and
* there have been other devres resources, you'd need to free the card manually
* via snd_card_free() call in the error; otherwise it may lead to UAF due to
* devres call orders. You can use snd_card_free_on_error() helper for
* handling it more easily.
*
* Return: zero if successful, or a negative error code
*/
int snd_devm_card_new(struct device *parent, int idx, const char *xid,
struct module *module, size_t extra_size,
struct snd_card **card_ret)
{
struct snd_card *card;
int err;
*card_ret = NULL;
card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
GFP_KERNEL);
if (!card)
return -ENOMEM;
card->managed = true;
err = snd_card_init(card, parent, idx, xid, module, extra_size);
if (err < 0) {
devres_free(card); /* in managed mode, we need to free manually */
return err;
}
devres_add(parent, card);
*card_ret = card;
return 0;
}
EXPORT_SYMBOL_GPL(snd_devm_card_new);
/**
* snd_card_free_on_error - a small helper for handling devm probe errors
* @dev: the managed device object
* @ret: the return code from the probe callback
*
* This function handles the explicit snd_card_free() call at the error from
* the probe callback. It's just a small helper for simplifying the error
* handling with the managed devices.
*
* Return: zero if successful, or a negative error code
*/
int snd_card_free_on_error(struct device *dev, int ret)
{
struct snd_card *card;
if (!ret)
return 0;
card = devres_find(dev, __snd_card_release, NULL, NULL);
if (card)
snd_card_free(card);
return ret;
}
EXPORT_SYMBOL_GPL(snd_card_free_on_error);
static int snd_card_init(struct snd_card *card, struct device *parent,
int idx, const char *xid, struct module *module,
size_t extra_size)
{
int err;
if (extra_size > 0)
card->private_data = (char *)card + sizeof(struct snd_card);
if (xid)
strscpy(card->id, xid, sizeof(card->id));
err = 0;
scoped_guard(mutex, &snd_card_mutex) {
if (idx < 0) /* first check the matching module-name slot */
idx = get_slot_from_bitmask(idx, module_slot_match, module);
if (idx < 0) /* if not matched, assign an empty slot */
idx = get_slot_from_bitmask(idx, check_empty_slot, module);
if (idx < 0)
err = -ENODEV;
else if (idx < snd_ecards_limit) {
if (test_bit(idx, snd_cards_lock))
err = -EBUSY; /* invalid */
} else if (idx >= SNDRV_CARDS)
err = -ENODEV;
if (!err) {
set_bit(idx, snd_cards_lock); /* lock it */
if (idx >= snd_ecards_limit)
snd_ecards_limit = idx + 1; /* increase the limit */
}
}
if (err < 0) {
dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
idx, snd_ecards_limit - 1, err);
if (!card->managed)
kfree(card); /* manually free here, as no destructor called */
return err;
}
card->dev = parent;
card->number = idx;
WARN_ON(IS_MODULE(CONFIG_SND) && !module);
card->module = module;
INIT_LIST_HEAD(&card->devices);
init_rwsem(&card->controls_rwsem);
rwlock_init(&card->ctl_files_rwlock);
INIT_LIST_HEAD(&card->controls);
INIT_LIST_HEAD(&card->ctl_files);
#ifdef CONFIG_SND_CTL_FAST_LOOKUP
xa_init(&card->ctl_numids);
xa_init(&card->ctl_hash);
#endif
spin_lock_init(&card->files_lock);
INIT_LIST_HEAD(&card->files_list);
mutex_init(&card->memory_mutex);
#ifdef CONFIG_PM
init_waitqueue_head(&card->power_sleep);
init_waitqueue_head(&card->power_ref_sleep);
atomic_set(&card->power_ref, 0);
#endif
init_waitqueue_head(&card->remove_sleep);
card->sync_irq = -1;
device_initialize(&card->card_dev);
card->card_dev.parent = parent;
card->card_dev.class = &sound_class;
card->card_dev.release = release_card_device;
card->card_dev.groups = card->dev_groups;
card->dev_groups[0] = &card_dev_attr_group;
err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
if (err < 0)
goto __error;
snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
dev_driver_string(card->dev), dev_name(&card->card_dev));
/* the control interface cannot be accessed from the user space until */
/* snd_cards_bitmask and snd_cards are set with snd_card_register */
err = snd_ctl_create(card);
if (err < 0) {
dev_err(parent, "unable to register control minors\n");
goto __error;
}
err = snd_info_card_create(card);
if (err < 0) {
dev_err(parent, "unable to create card info\n");
goto __error_ctl;
}
#ifdef CONFIG_SND_DEBUG
card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev),
sound_debugfs_root);
#endif
return 0;
__error_ctl:
snd_device_free_all(card);
__error:
put_device(&card->card_dev);
return err;
}
/**
* snd_card_ref - Get the card object from the index
* @idx: the card index
*
* Returns a card object corresponding to the given index or NULL if not found.
* Release the object via snd_card_unref().
*
* Return: a card object or NULL
*/
struct snd_card *snd_card_ref(int idx)
{
struct snd_card *card;
guard(mutex)(&snd_card_mutex);
card = snd_cards[idx];
if (card)
get_device(&card->card_dev);
return card;
}
EXPORT_SYMBOL_GPL(snd_card_ref);
/* return non-zero if a card is already locked */
int snd_card_locked(int card)
{
guard(mutex)(&snd_card_mutex);
return test_bit(card, snd_cards_lock);
}
static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
{
return -ENODEV;
}
static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return -ENODEV;
}
static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
return -ENODEV;
}
static int snd_disconnect_release(struct inode *inode, struct file *file)
{
struct snd_monitor_file *df = NULL, *_df;
scoped_guard(spinlock, &shutdown_lock) {
list_for_each_entry(_df, &shutdown_files, shutdown_list) {
if (_df->file == file) {
df = _df;
list_del_init(&df->shutdown_list);
break;
}
}
}
if (likely(df)) {
if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
df->disconnected_f_op->fasync(-1, file, 0);
return df->disconnected_f_op->release(inode, file);
}
panic("%s(%p, %p) failed!", __func__, inode, file);
}
static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
{
return EPOLLERR | EPOLLNVAL;
}
static long snd_disconnect_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
return -ENODEV;
}
static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
{
return -ENODEV;
}
static int snd_disconnect_fasync(int fd, struct file *file, int on)
{
return -ENODEV;
}
static const struct file_operations snd_shutdown_f_ops =
{
.owner = THIS_MODULE,
.llseek = snd_disconnect_llseek,
.read = snd_disconnect_read,
.write = snd_disconnect_write,
.release = snd_disconnect_release,
.poll = snd_disconnect_poll,
.unlocked_ioctl = snd_disconnect_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = snd_disconnect_ioctl,
#endif
.mmap = snd_disconnect_mmap,
.fasync = snd_disconnect_fasync
};
/**
* snd_card_disconnect - disconnect all APIs from the file-operations (user space)
* @card: soundcard structure
*
* Disconnects all APIs from the file-operations (user space).
*
* Return: Zero, otherwise a negative error code.
*
* Note: The current implementation replaces all active file->f_op with special
* dummy file operations (they do nothing except release).
*/
void snd_card_disconnect(struct snd_card *card)
{
struct snd_monitor_file *mfile;
if (!card)
return;
scoped_guard(spinlock, &card->files_lock) {
if (card->shutdown)
return;
card->shutdown = 1;
/* replace file->f_op with special dummy operations */
list_for_each_entry(mfile, &card->files_list, list) {
/* it's critical part, use endless loop */
/* we have no room to fail */
mfile->disconnected_f_op = mfile->file->f_op;
scoped_guard(spinlock, &shutdown_lock)
list_add(&mfile->shutdown_list, &shutdown_files);
mfile->file->f_op = &snd_shutdown_f_ops;
fops_get(mfile->file->f_op);
}
}
#ifdef CONFIG_PM
/* wake up sleepers here before other callbacks for avoiding potential
* deadlocks with other locks (e.g. in kctls);
* then this notifies the shutdown and sleepers would abort immediately
*/
wake_up_all(&card->power_sleep);
#endif
/* notify all connected devices about disconnection */
/* at this point, they cannot respond to any calls except release() */
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
#endif
/* notify all devices that we are disconnected */
snd_device_disconnect_all(card);
if (card->sync_irq > 0)
synchronize_irq(card->sync_irq);
snd_info_card_disconnect(card);
#ifdef CONFIG_SND_DEBUG
debugfs_remove(card->debugfs_root);
card->debugfs_root = NULL;
#endif
if (card->registered) {
device_del(&card->card_dev);
card->registered = false;
}
/* disable fops (user space) operations for ALSA API */
scoped_guard(mutex, &snd_card_mutex) {
snd_cards[card->number] = NULL;
clear_bit(card->number, snd_cards_lock);
}
snd_power_sync_ref(card);
}
EXPORT_SYMBOL(snd_card_disconnect);
/**
* snd_card_disconnect_sync - disconnect card and wait until files get closed
* @card: card object to disconnect
*
* This calls snd_card_disconnect() for disconnecting all belonging components
* and waits until all pending files get closed.
* It assures that all accesses from user-space finished so that the driver
* can release its resources gracefully.
*/
void snd_card_disconnect_sync(struct snd_card *card)
{
snd_card_disconnect(card);
guard(spinlock_irq)(&card->files_lock);
wait_event_lock_irq(card->remove_sleep,
list_empty(&card->files_list),
card->files_lock);
}
EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
static int snd_card_do_free(struct snd_card *card)
{
card->releasing = true;
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
#endif
snd_device_free_all(card);
if (card->private_free)
card->private_free(card);
if (snd_info_card_free(card) < 0) {
dev_warn(card->dev, "unable to free card info\n");
/* Not fatal error */
}
if (card->release_completion)
complete(card->release_completion);
if (!card->managed)
kfree(card);
return 0;
}
/**
* snd_card_free_when_closed - Disconnect the card, free it later eventually
* @card: soundcard structure
*
* Unlike snd_card_free(), this function doesn't try to release the card
* resource immediately, but tries to disconnect at first. When the card
* is still in use, the function returns before freeing the resources.
* The card resources will be freed when the refcount gets to zero.
*
* Return: zero if successful, or a negative error code
*/
void snd_card_free_when_closed(struct snd_card *card)
{
if (!card)
return;
snd_card_disconnect(card);
put_device(&card->card_dev);
return;
}
EXPORT_SYMBOL(snd_card_free_when_closed);
/**
* snd_card_free - frees given soundcard structure
* @card: soundcard structure
*
* This function releases the soundcard structure and the all assigned
* devices automatically. That is, you don't have to release the devices
* by yourself.
*
* This function waits until the all resources are properly released.
*
* Return: Zero. Frees all associated devices and frees the control
* interface associated to given soundcard.
*/
void snd_card_free(struct snd_card *card)
{
DECLARE_COMPLETION_ONSTACK(released);
/* The call of snd_card_free() is allowed from various code paths;
* a manual call from the driver and the call via devres_free, and
* we need to avoid double-free. Moreover, the release via devres
* may call snd_card_free() twice due to its nature, we need to have
* the check here at the beginning.
*/
if (card->releasing)
return;
card->release_completion = &released;
snd_card_free_when_closed(card);
/* wait, until all devices are ready for the free operation */
wait_for_completion(&released);
}
EXPORT_SYMBOL(snd_card_free);
/* retrieve the last word of shortname or longname */
static const char *retrieve_id_from_card_name(const char *name)
{
const char *spos = name;
while (*name) {
if (isspace(*name) && isalnum(name[1]))
spos = name + 1;
name++;
}
return spos;
}
/* return true if the given id string doesn't conflict any other card ids */
static bool card_id_ok(struct snd_card *card, const char *id)
{
int i;
if (!snd_info_check_reserved_words(id))
return false;
for (i = 0; i < snd_ecards_limit; i++) {
if (snd_cards[i] && snd_cards[i] != card &&
!strcmp(snd_cards[i]->id, id))
return false;
}
return true;
}
/* copy to card->id only with valid letters from nid */
static void copy_valid_id_string(struct snd_card *card, const char *src,
const char *nid)
{
char *id = card->id;
while (*nid && !isalnum(*nid))
nid++;
if (isdigit(*nid))
*id++ = isalpha(*src) ? *src : 'D';
while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
if (isalnum(*nid))
*id++ = *nid;
nid++;
}
*id = 0;
}
/* Set card->id from the given string
* If the string conflicts with other ids, add a suffix to make it unique.
*/
static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
const char *nid)
{
int len, loops;
bool is_default = false;
char *id;
copy_valid_id_string(card, src, nid);
id = card->id;
again:
/* use "Default" for obviously invalid strings
* ("card" conflicts with proc directories)
*/
if (!*id || !strncmp(id, "card", 4)) {
strcpy(id, "Default");
is_default = true;
}
len = strlen(id);
for (loops = 0; loops < SNDRV_CARDS; loops++) {
char *spos;
char sfxstr[5]; /* "_012" */
int sfxlen;
if (card_id_ok(card, id))
return; /* OK */
/* Add _XYZ suffix */
sprintf(sfxstr, "_%X", loops + 1);
sfxlen = strlen(sfxstr);
if (len + sfxlen >= sizeof(card->id))
spos = id + sizeof(card->id) - sfxlen - 1;
else
spos = id + len;
strcpy(spos, sfxstr);
}
/* fallback to the default id */
if (!is_default) {
*id = 0;
goto again;
}
/* last resort... */
dev_err(card->dev, "unable to set card id (%s)\n", id);
if (card->proc_root->name)
strscpy(card->id, card->proc_root->name, sizeof(card->id));
}
/**
* snd_card_set_id - set card identification name
* @card: soundcard structure
* @nid: new identification string
*
* This function sets the card identification and checks for name
* collisions.
*/
void snd_card_set_id(struct snd_card *card, const char *nid)
{
/* check if user specified own card->id */
if (card->id[0] != '\0')
return;
guard(mutex)(&snd_card_mutex);
snd_card_set_id_no_lock(card, nid, nid);
}
EXPORT_SYMBOL(snd_card_set_id);
static ssize_t id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
return sysfs_emit(buf, "%s\n", card->id);
}
static ssize_t id_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
char buf1[sizeof(card->id)];
size_t copy = count > sizeof(card->id) - 1 ?
sizeof(card->id) - 1 : count;
size_t idx;
int c;
for (idx = 0; idx < copy; idx++) {
c = buf[idx];
if (!isalnum(c) && c != '_' && c != '-')
return -EINVAL;
}
memcpy(buf1, buf, copy);
buf1[copy] = '\0';
guard(mutex)(&snd_card_mutex);
if (!card_id_ok(NULL, buf1))
return -EEXIST;
strcpy(card->id, buf1);
snd_info_card_id_change(card);
return count;
}
static DEVICE_ATTR_RW(id);
static ssize_t number_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
return sysfs_emit(buf, "%i\n", card->number);
}
static DEVICE_ATTR_RO(number);
static struct attribute *card_dev_attrs[] = {
&dev_attr_id.attr,
&dev_attr_number.attr,
NULL
};
static const struct attribute_group card_dev_attr_group = {
.attrs = card_dev_attrs,
};
/**
* snd_card_add_dev_attr - Append a new sysfs attribute group to card
* @card: card instance
* @group: attribute group to append
*
* Return: zero if successful, or a negative error code
*/
int snd_card_add_dev_attr(struct snd_card *card,
const struct attribute_group *group)
{
int i;
/* loop for (arraysize-1) here to keep NULL at the last entry */
for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
if (!card->dev_groups[i]) {
card->dev_groups[i] = group;
return 0;
}
}
dev_err(card->dev, "Too many groups assigned\n");
return -ENOSPC;
}
EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
static void trigger_card_free(void *data)
{
snd_card_free(data);
}
/**
* snd_card_register - register the soundcard
* @card: soundcard structure
*
* This function registers all the devices assigned to the soundcard.
* Until calling this, the ALSA control interface is blocked from the
* external accesses. Thus, you should call this function at the end
* of the initialization of the card.
*
* Return: Zero otherwise a negative error code if the registration failed.
*/
int snd_card_register(struct snd_card *card)
{
int err;
if (snd_BUG_ON(!card))
return -EINVAL;
if (!card->registered) {
err = device_add(&card->card_dev);
if (err < 0)
return err;
card->registered = true;
} else {
if (card->managed)
devm_remove_action(card->dev, trigger_card_free, card);
}
if (card->managed) {
err = devm_add_action(card->dev, trigger_card_free, card);
if (err < 0)
return err;
}
err = snd_device_register_all(card);
if (err < 0)
return err;
scoped_guard(mutex, &snd_card_mutex) {
if (snd_cards[card->number]) {
/* already registered */
return snd_info_card_register(card); /* register pending info */
}
if (*card->id) {
/* make a unique id name from the given string */
char tmpid[sizeof(card->id)];
memcpy(tmpid, card->id, sizeof(card->id));
snd_card_set_id_no_lock(card, tmpid, tmpid);
} else {
/* create an id from either shortname or longname */
const char *src;
src = *card->shortname ? card->shortname : card->longname;
snd_card_set_id_no_lock(card, src,
retrieve_id_from_card_name(src));
}
snd_cards[card->number] = card;
}
err = snd_info_card_register(card);
if (err < 0)
return err;
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
#endif
return 0;
}
EXPORT_SYMBOL(snd_card_register);
#ifdef CONFIG_SND_PROC_FS
static void snd_card_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
guard(mutex)(&snd_card_mutex);
card = snd_cards[idx];
if (card) {
count++;
snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
idx,
card->id,
card->driver,
card->shortname);
snd_iprintf(buffer, " %s\n",
card->longname);
}
}
if (!count)
snd_iprintf(buffer, "--- no soundcards ---\n");
}
#ifdef CONFIG_SND_OSSEMUL
void snd_card_info_read_oss(struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
guard(mutex)(&snd_card_mutex);
card = snd_cards[idx];
if (card) {
count++;
snd_iprintf(buffer, "%s\n", card->longname);
}
}
if (!count) {
snd_iprintf(buffer, "--- no soundcards ---\n");
}
}
#endif
#ifdef CONFIG_MODULES
static void snd_card_module_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx;
struct snd_card *card;
for (idx = 0; idx < SNDRV_CARDS; idx++) {
guard(mutex)(&snd_card_mutex);
card = snd_cards[idx];
if (card)
snd_iprintf(buffer, "%2i %s\n",
idx, card->module->name);
}
}
#endif
int __init snd_card_info_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
if (! entry)
return -ENOMEM;
entry->c.text.read = snd_card_info_read;
if (snd_info_register(entry) < 0)
return -ENOMEM; /* freed in error path */
#ifdef CONFIG_MODULES
entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
if (!entry)
return -ENOMEM;
entry->c.text.read = snd_card_module_info_read;
if (snd_info_register(entry) < 0)
return -ENOMEM; /* freed in error path */
#endif
return 0;
}
#endif /* CONFIG_SND_PROC_FS */
/**
* snd_component_add - add a component string
* @card: soundcard structure
* @component: the component id string
*
* This function adds the component id string to the supported list.
* The component can be referred from the alsa-lib.
*
* Return: Zero otherwise a negative error code.
*/
int snd_component_add(struct snd_card *card, const char *component)
{
char *ptr;
int len = strlen(component);
ptr = strstr(card->components, component);
if (ptr != NULL) {
if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
return 1;
}
if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
snd_BUG();
return -ENOMEM;
}
if (card->components[0] != '\0')
strcat(card->components, " ");
strcat(card->components, component);
return 0;
}
EXPORT_SYMBOL(snd_component_add);
/**
* snd_card_file_add - add the file to the file list of the card
* @card: soundcard structure
* @file: file pointer
*
* This function adds the file to the file linked-list of the card.
* This linked-list is used to keep tracking the connection state,
* and to avoid the release of busy resources by hotplug.
*
* Return: zero or a negative error code.
*/
int snd_card_file_add(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile;
mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
if (mfile == NULL)
return -ENOMEM;
mfile->file = file;
mfile->disconnected_f_op = NULL;
INIT_LIST_HEAD(&mfile->shutdown_list);
guard(spinlock)(&card->files_lock);
if (card->shutdown) {
kfree(mfile);
return -ENODEV;
}
list_add(&mfile->list, &card->files_list);
get_device(&card->card_dev);
return 0;
}
EXPORT_SYMBOL(snd_card_file_add);
/**
* snd_card_file_remove - remove the file from the file list
* @card: soundcard structure
* @file: file pointer
*
* This function removes the file formerly added to the card via
* snd_card_file_add() function.
* If all files are removed and snd_card_free_when_closed() was
* called beforehand, it processes the pending release of
* resources.
*
* Return: Zero or a negative error code.
*/
int snd_card_file_remove(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile, *found = NULL;
scoped_guard(spinlock, &card->files_lock) {
list_for_each_entry(mfile, &card->files_list, list) {
if (mfile->file == file) {
list_del(&mfile->list);
scoped_guard(spinlock, &shutdown_lock)
list_del(&mfile->shutdown_list);
if (mfile->disconnected_f_op)
fops_put(mfile->disconnected_f_op);
found = mfile;
break;
}
}
if (list_empty(&card->files_list))
wake_up_all(&card->remove_sleep);
}
if (!found) {
dev_err(card->dev, "card file remove problem (%p)\n", file);
return -ENOENT;
}
kfree(found);
put_device(&card->card_dev);
return 0;
}
EXPORT_SYMBOL(snd_card_file_remove);
#ifdef CONFIG_PM
/**
* snd_power_ref_and_wait - wait until the card gets powered up
* @card: soundcard structure
*
* Take the power_ref reference count of the given card, and
* wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
* The refcount is down again while sleeping until power-up, hence this
* function can be used for syncing the floating control ops accesses,
* typically around calling control ops.
*
* The caller needs to pull down the refcount via snd_power_unref() later
* no matter whether the error is returned from this function or not.
*
* Return: Zero if successful, or a negative error code.
*/
int snd_power_ref_and_wait(struct snd_card *card)
{
snd_power_ref(card);
if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
return 0;
wait_event_cmd(card->power_sleep,
card->shutdown ||
snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
snd_power_unref(card), snd_power_ref(card));
return card->shutdown ? -ENODEV : 0;
}
EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
/**
* snd_power_wait - wait until the card gets powered up (old form)
* @card: soundcard structure
*
* Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
*
* Return: Zero if successful, or a negative error code.
*/
int snd_power_wait(struct snd_card *card)
{
int ret;
ret = snd_power_ref_and_wait(card);
snd_power_unref(card);
return ret;
}
EXPORT_SYMBOL(snd_power_wait);
#endif /* CONFIG_PM */