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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#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)static DEFINE_MUTEX(mixer_oss_notify_mutex);static int (*mixer_oss_notify_callback)(struct snd_card *card, int cmd);
void snd_mixer_oss_notify(struct snd_card *card, int cmd){ guard(mutex)(&mixer_oss_notify_mutex); if (mixer_oss_notify_callback) mixer_oss_notify_callback(card, cmd);}EXPORT_SYMBOL(snd_mixer_oss_notify);
void snd_mixer_oss_set_notify(int (*callback)(struct snd_card *, int)){ /* Wait for callbacks, including a final module_put(), to return. */ guard(mutex)(&mixer_oss_notify_mutex); mixer_oss_notify_callback = callback;}EXPORT_SYMBOL(snd_mixer_oss_set_notify);#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_obj(*dev); 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_flex(*card, private_data_area, extra_size); 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. * * Caveat: if an error happens at the probe before snd_card_register() is * called and there have been other devres resources that are referred at the * card-level destructor call, you'd still need to free the card manually; * otherwise it may lead to UAF due to devres call orders. Instead of a manual * snd_card_free() call, you can use the automatic clean-up for the card * pointer via __free(snd_card_free), too. In this case, don't forget to do * NULL-clear the card pointer before the successful return! * * 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, struct_size(card, private_data_area, 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);
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 = card->private_data_area; 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 = get_device(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->controls_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); snd_refcount_init(&card->power_ref);#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; }
#ifdef CONFIG_SND_DEBUG card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev), sound_debugfs_root);#endif#ifdef CONFIG_SND_CTL_DEBUG card->value_buf = kmalloc_obj(*card->value_buf); if (!card->value_buf) { err = -ENOMEM; goto __error; }#endif return 0;
__error: snd_card_free(card); 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) snd_mixer_oss_notify(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); }
/* order card->shutdown store against power_ref read */ smp_mb(); 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){ bool managed = card->managed;
card->releasing = true;#if IS_ENABLED(CONFIG_SND_MIXER_OSS) snd_mixer_oss_notify(card, SND_MIXER_OSS_NOTIFY_FREE);#endif snd_device_free_all(card); kfree(card->components); card->components = NULL; card->components_alloc_size = 0; if (card->private_free) card->private_free(card);#ifdef CONFIG_SND_CTL_DEBUG kfree(card->value_buf);#endif if (snd_info_card_free(card) < 0) { dev_warn(card->dev, "unable to free card info\n"); /* Not fatal error */ } put_device(card->dev); if (card->release_completion) complete(card->release_completion); if (!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);
/* check, if the character is in the valid ASCII range */static inline bool safe_ascii_char(char c){ return isascii(c) && isalnum(c);}
/* 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) && safe_ascii_char(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 && !safe_ascii_char(*nid)) nid++; if (isdigit(*nid)) *id++ = isalpha(*src) ? *src : 'D'; while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) { if (safe_ascii_char(*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)) { strscpy(card->id, "Default"); is_default = true; }
len = strlen(id); for (loops = 0; loops < SNDRV_CARDS; loops++) { char sfxstr[5]; /* "_012" */ int sfxlen, slen;
if (card_id_ok(card, id)) return; /* OK */
/* Add _XYZ suffix */ sfxlen = scnprintf(sfxstr, sizeof(sfxstr), "_%X", loops + 1); if (len + sfxlen >= sizeof(card->id)) slen = sizeof(card->id) - sfxlen - 1; else slen = len; strscpy(id + slen, sfxstr, sizeof(card->id) - slen); } /* 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 (!safe_ascii_char(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; strscpy(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) snd_mixer_oss_notify(card, SND_MIXER_OSS_NOTIFY_REGISTER);#endif return 0;}EXPORT_SYMBOL(snd_card_register);
#ifdef CONFIG_SND_PROC_FSstatic 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_OSSEMULvoid 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_MODULESstatic 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); unsigned int cur_len, need_len;
guard(rwsem_write)(&snd_ioctl_rwsem);
if (card->components) { ptr = strstr(card->components, component); if (ptr) { if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */ return 1; } cur_len = strlen(card->components) + 1; } else { cur_len = 0; }
need_len = cur_len + len + 1; if (need_len > 512) { snd_BUG(); return -ENOMEM; }
if (need_len > card->components_alloc_size) { unsigned int new_alloc = roundup(need_len, 32);
ptr = krealloc(card->components, new_alloc, GFP_KERNEL); if (!ptr) return -ENOMEM; if (!card->components) ptr[0] = '\0'; card->components = ptr; card->components_alloc_size = new_alloc; }
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_obj(*mfile); 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 * when this function returns 0. * * Return: Zero if successful, or a negative error code. */int snd_power_ref_and_wait(struct snd_card *card){ snd_power_ref(card); /* order power_ref increment against card->shutdown read */ smp_mb__after_atomic(); if (snd_power_get_state(card) != SNDRV_CTL_POWER_D0) { 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)); } if (card->shutdown) { snd_power_unref(card); return -ENODEV; } return 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); if (!ret) snd_power_unref(card); return ret;}EXPORT_SYMBOL(snd_power_wait);#endif /* CONFIG_PM */