diff options
Diffstat (limited to 'sound/core/control.c')
| -rw-r--r-- | sound/core/control.c | 2478 |
1 files changed, 2478 insertions, 0 deletions
diff --git a/sound/core/control.c b/sound/core/control.c new file mode 100644 index 000000000..82aa1af1d --- /dev/null +++ b/sound/core/control.c @@ -0,0 +1,2478 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Routines for driver control interface + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> + */ + +#include <linux/threads.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/time.h> +#include <linux/mm.h> +#include <linux/math64.h> +#include <linux/sched/signal.h> +#include <sound/core.h> +#include <sound/minors.h> +#include <sound/info.h> +#include <sound/control.h> + +// Max allocation size for user controls. +static int max_user_ctl_alloc_size = 8 * 1024 * 1024; +module_param_named(max_user_ctl_alloc_size, max_user_ctl_alloc_size, int, 0444); +MODULE_PARM_DESC(max_user_ctl_alloc_size, "Max allocation size for user controls"); + +#define MAX_CONTROL_COUNT 1028 + +struct snd_kctl_ioctl { + struct list_head list; /* list of all ioctls */ + snd_kctl_ioctl_func_t fioctl; +}; + +static DECLARE_RWSEM(snd_ioctl_rwsem); +static DECLARE_RWSEM(snd_ctl_layer_rwsem); +static LIST_HEAD(snd_control_ioctls); +#ifdef CONFIG_COMPAT +static LIST_HEAD(snd_control_compat_ioctls); +#endif +static struct snd_ctl_layer_ops *snd_ctl_layer; + +static int snd_ctl_open(struct inode *inode, struct file *file) +{ + unsigned long flags; + struct snd_card *card; + struct snd_ctl_file *ctl; + int i, err; + + err = stream_open(inode, file); + if (err < 0) + return err; + + card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL); + if (!card) { + err = -ENODEV; + goto __error1; + } + err = snd_card_file_add(card, file); + if (err < 0) { + err = -ENODEV; + goto __error1; + } + if (!try_module_get(card->module)) { + err = -EFAULT; + goto __error2; + } + ctl = kzalloc(sizeof(*ctl), GFP_KERNEL); + if (ctl == NULL) { + err = -ENOMEM; + goto __error; + } + INIT_LIST_HEAD(&ctl->events); + init_waitqueue_head(&ctl->change_sleep); + spin_lock_init(&ctl->read_lock); + ctl->card = card; + for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++) + ctl->preferred_subdevice[i] = -1; + ctl->pid = get_pid(task_pid(current)); + file->private_data = ctl; + write_lock_irqsave(&card->ctl_files_rwlock, flags); + list_add_tail(&ctl->list, &card->ctl_files); + write_unlock_irqrestore(&card->ctl_files_rwlock, flags); + snd_card_unref(card); + return 0; + + __error: + module_put(card->module); + __error2: + snd_card_file_remove(card, file); + __error1: + if (card) + snd_card_unref(card); + return err; +} + +static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl) +{ + unsigned long flags; + struct snd_kctl_event *cread; + + spin_lock_irqsave(&ctl->read_lock, flags); + while (!list_empty(&ctl->events)) { + cread = snd_kctl_event(ctl->events.next); + list_del(&cread->list); + kfree(cread); + } + spin_unlock_irqrestore(&ctl->read_lock, flags); +} + +static int snd_ctl_release(struct inode *inode, struct file *file) +{ + unsigned long flags; + struct snd_card *card; + struct snd_ctl_file *ctl; + struct snd_kcontrol *control; + unsigned int idx; + + ctl = file->private_data; + file->private_data = NULL; + card = ctl->card; + write_lock_irqsave(&card->ctl_files_rwlock, flags); + list_del(&ctl->list); + write_unlock_irqrestore(&card->ctl_files_rwlock, flags); + down_write(&card->controls_rwsem); + list_for_each_entry(control, &card->controls, list) + for (idx = 0; idx < control->count; idx++) + if (control->vd[idx].owner == ctl) + control->vd[idx].owner = NULL; + up_write(&card->controls_rwsem); + snd_fasync_free(ctl->fasync); + snd_ctl_empty_read_queue(ctl); + put_pid(ctl->pid); + kfree(ctl); + module_put(card->module); + snd_card_file_remove(card, file); + return 0; +} + +/** + * snd_ctl_notify - Send notification to user-space for a control change + * @card: the card to send notification + * @mask: the event mask, SNDRV_CTL_EVENT_* + * @id: the ctl element id to send notification + * + * This function adds an event record with the given id and mask, appends + * to the list and wakes up the user-space for notification. This can be + * called in the atomic context. + */ +void snd_ctl_notify(struct snd_card *card, unsigned int mask, + struct snd_ctl_elem_id *id) +{ + unsigned long flags; + struct snd_ctl_file *ctl; + struct snd_kctl_event *ev; + + if (snd_BUG_ON(!card || !id)) + return; + if (card->shutdown) + return; + read_lock_irqsave(&card->ctl_files_rwlock, flags); +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) + card->mixer_oss_change_count++; +#endif + list_for_each_entry(ctl, &card->ctl_files, list) { + if (!ctl->subscribed) + continue; + spin_lock(&ctl->read_lock); + list_for_each_entry(ev, &ctl->events, list) { + if (ev->id.numid == id->numid) { + ev->mask |= mask; + goto _found; + } + } + ev = kzalloc(sizeof(*ev), GFP_ATOMIC); + if (ev) { + ev->id = *id; + ev->mask = mask; + list_add_tail(&ev->list, &ctl->events); + } else { + dev_err(card->dev, "No memory available to allocate event\n"); + } + _found: + wake_up(&ctl->change_sleep); + spin_unlock(&ctl->read_lock); + snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN); + } + read_unlock_irqrestore(&card->ctl_files_rwlock, flags); +} +EXPORT_SYMBOL(snd_ctl_notify); + +/** + * snd_ctl_notify_one - Send notification to user-space for a control change + * @card: the card to send notification + * @mask: the event mask, SNDRV_CTL_EVENT_* + * @kctl: the pointer with the control instance + * @ioff: the additional offset to the control index + * + * This function calls snd_ctl_notify() and does additional jobs + * like LED state changes. + */ +void snd_ctl_notify_one(struct snd_card *card, unsigned int mask, + struct snd_kcontrol *kctl, unsigned int ioff) +{ + struct snd_ctl_elem_id id = kctl->id; + struct snd_ctl_layer_ops *lops; + + id.index += ioff; + id.numid += ioff; + snd_ctl_notify(card, mask, &id); + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + lops->lnotify(card, mask, kctl, ioff); + up_read(&snd_ctl_layer_rwsem); +} +EXPORT_SYMBOL(snd_ctl_notify_one); + +/** + * snd_ctl_new - create a new control instance with some elements + * @kctl: the pointer to store new control instance + * @count: the number of elements in this control + * @access: the default access flags for elements in this control + * @file: given when locking these elements + * + * Allocates a memory object for a new control instance. The instance has + * elements as many as the given number (@count). Each element has given + * access permissions (@access). Each element is locked when @file is given. + * + * Return: 0 on success, error code on failure + */ +static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count, + unsigned int access, struct snd_ctl_file *file) +{ + unsigned int idx; + + if (count == 0 || count > MAX_CONTROL_COUNT) + return -EINVAL; + + *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL); + if (!*kctl) + return -ENOMEM; + + for (idx = 0; idx < count; idx++) { + (*kctl)->vd[idx].access = access; + (*kctl)->vd[idx].owner = file; + } + (*kctl)->count = count; + + return 0; +} + +/** + * snd_ctl_new1 - create a control instance from the template + * @ncontrol: the initialization record + * @private_data: the private data to set + * + * Allocates a new struct snd_kcontrol instance and initialize from the given + * template. When the access field of ncontrol is 0, it's assumed as + * READWRITE access. When the count field is 0, it's assumes as one. + * + * Return: The pointer of the newly generated instance, or %NULL on failure. + */ +struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol, + void *private_data) +{ + struct snd_kcontrol *kctl; + unsigned int count; + unsigned int access; + int err; + + if (snd_BUG_ON(!ncontrol || !ncontrol->info)) + return NULL; + + count = ncontrol->count; + if (count == 0) + count = 1; + + access = ncontrol->access; + if (access == 0) + access = SNDRV_CTL_ELEM_ACCESS_READWRITE; + access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE | + SNDRV_CTL_ELEM_ACCESS_VOLATILE | + SNDRV_CTL_ELEM_ACCESS_INACTIVE | + SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE | + SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND | + SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK | + SNDRV_CTL_ELEM_ACCESS_LED_MASK | + SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK); + + err = snd_ctl_new(&kctl, count, access, NULL); + if (err < 0) + return NULL; + + /* The 'numid' member is decided when calling snd_ctl_add(). */ + kctl->id.iface = ncontrol->iface; + kctl->id.device = ncontrol->device; + kctl->id.subdevice = ncontrol->subdevice; + if (ncontrol->name) { + strscpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name)); + if (strcmp(ncontrol->name, kctl->id.name) != 0) + pr_warn("ALSA: Control name '%s' truncated to '%s'\n", + ncontrol->name, kctl->id.name); + } + kctl->id.index = ncontrol->index; + + kctl->info = ncontrol->info; + kctl->get = ncontrol->get; + kctl->put = ncontrol->put; + kctl->tlv.p = ncontrol->tlv.p; + + kctl->private_value = ncontrol->private_value; + kctl->private_data = private_data; + + return kctl; +} +EXPORT_SYMBOL(snd_ctl_new1); + +/** + * snd_ctl_free_one - release the control instance + * @kcontrol: the control instance + * + * Releases the control instance created via snd_ctl_new() + * or snd_ctl_new1(). + * Don't call this after the control was added to the card. + */ +void snd_ctl_free_one(struct snd_kcontrol *kcontrol) +{ + if (kcontrol) { + if (kcontrol->private_free) + kcontrol->private_free(kcontrol); + kfree(kcontrol); + } +} +EXPORT_SYMBOL(snd_ctl_free_one); + +static bool snd_ctl_remove_numid_conflict(struct snd_card *card, + unsigned int count) +{ + struct snd_kcontrol *kctl; + + /* Make sure that the ids assigned to the control do not wrap around */ + if (card->last_numid >= UINT_MAX - count) + card->last_numid = 0; + + list_for_each_entry(kctl, &card->controls, list) { + if (kctl->id.numid < card->last_numid + 1 + count && + kctl->id.numid + kctl->count > card->last_numid + 1) { + card->last_numid = kctl->id.numid + kctl->count - 1; + return true; + } + } + return false; +} + +static int snd_ctl_find_hole(struct snd_card *card, unsigned int count) +{ + unsigned int iter = 100000; + + while (snd_ctl_remove_numid_conflict(card, count)) { + if (--iter == 0) { + /* this situation is very unlikely */ + dev_err(card->dev, "unable to allocate new control numid\n"); + return -ENOMEM; + } + } + return 0; +} + +/* check whether the given id is contained in the given kctl */ +static bool elem_id_matches(const struct snd_kcontrol *kctl, + const struct snd_ctl_elem_id *id) +{ + return kctl->id.iface == id->iface && + kctl->id.device == id->device && + kctl->id.subdevice == id->subdevice && + !strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)) && + kctl->id.index <= id->index && + kctl->id.index + kctl->count > id->index; +} + +#ifdef CONFIG_SND_CTL_FAST_LOOKUP +/* Compute a hash key for the corresponding ctl id + * It's for the name lookup, hence the numid is excluded. + * The hash key is bound in LONG_MAX to be used for Xarray key. + */ +#define MULTIPLIER 37 +static unsigned long get_ctl_id_hash(const struct snd_ctl_elem_id *id) +{ + int i; + unsigned long h; + + h = id->iface; + h = MULTIPLIER * h + id->device; + h = MULTIPLIER * h + id->subdevice; + for (i = 0; i < SNDRV_CTL_ELEM_ID_NAME_MAXLEN && id->name[i]; i++) + h = MULTIPLIER * h + id->name[i]; + h = MULTIPLIER * h + id->index; + h &= LONG_MAX; + return h; +} + +/* add hash entries to numid and ctl xarray tables */ +static void add_hash_entries(struct snd_card *card, + struct snd_kcontrol *kcontrol) +{ + struct snd_ctl_elem_id id = kcontrol->id; + int i; + + xa_store_range(&card->ctl_numids, kcontrol->id.numid, + kcontrol->id.numid + kcontrol->count - 1, + kcontrol, GFP_KERNEL); + + for (i = 0; i < kcontrol->count; i++) { + id.index = kcontrol->id.index + i; + if (xa_insert(&card->ctl_hash, get_ctl_id_hash(&id), + kcontrol, GFP_KERNEL)) { + /* skip hash for this entry, noting we had collision */ + card->ctl_hash_collision = true; + dev_dbg(card->dev, "ctl_hash collision %d:%s:%d\n", + id.iface, id.name, id.index); + } + } +} + +/* remove hash entries that have been added */ +static void remove_hash_entries(struct snd_card *card, + struct snd_kcontrol *kcontrol) +{ + struct snd_ctl_elem_id id = kcontrol->id; + struct snd_kcontrol *matched; + unsigned long h; + int i; + + for (i = 0; i < kcontrol->count; i++) { + xa_erase(&card->ctl_numids, id.numid); + h = get_ctl_id_hash(&id); + matched = xa_load(&card->ctl_hash, h); + if (matched && (matched == kcontrol || + elem_id_matches(matched, &id))) + xa_erase(&card->ctl_hash, h); + id.index++; + id.numid++; + } +} +#else /* CONFIG_SND_CTL_FAST_LOOKUP */ +static inline void add_hash_entries(struct snd_card *card, + struct snd_kcontrol *kcontrol) +{ +} +static inline void remove_hash_entries(struct snd_card *card, + struct snd_kcontrol *kcontrol) +{ +} +#endif /* CONFIG_SND_CTL_FAST_LOOKUP */ + +enum snd_ctl_add_mode { + CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE, +}; + +/* add/replace a new kcontrol object; call with card->controls_rwsem locked */ +static int __snd_ctl_add_replace(struct snd_card *card, + struct snd_kcontrol *kcontrol, + enum snd_ctl_add_mode mode) +{ + struct snd_ctl_elem_id id; + unsigned int idx; + struct snd_kcontrol *old; + int err; + + id = kcontrol->id; + if (id.index > UINT_MAX - kcontrol->count) + return -EINVAL; + + old = snd_ctl_find_id(card, &id); + if (!old) { + if (mode == CTL_REPLACE) + return -EINVAL; + } else { + if (mode == CTL_ADD_EXCLUSIVE) { + dev_err(card->dev, + "control %i:%i:%i:%s:%i is already present\n", + id.iface, id.device, id.subdevice, id.name, + id.index); + return -EBUSY; + } + + err = snd_ctl_remove(card, old); + if (err < 0) + return err; + } + + if (snd_ctl_find_hole(card, kcontrol->count) < 0) + return -ENOMEM; + + list_add_tail(&kcontrol->list, &card->controls); + card->controls_count += kcontrol->count; + kcontrol->id.numid = card->last_numid + 1; + card->last_numid += kcontrol->count; + + add_hash_entries(card, kcontrol); + + for (idx = 0; idx < kcontrol->count; idx++) + snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx); + + return 0; +} + +static int snd_ctl_add_replace(struct snd_card *card, + struct snd_kcontrol *kcontrol, + enum snd_ctl_add_mode mode) +{ + int err = -EINVAL; + + if (! kcontrol) + return err; + if (snd_BUG_ON(!card || !kcontrol->info)) + goto error; + + down_write(&card->controls_rwsem); + err = __snd_ctl_add_replace(card, kcontrol, mode); + up_write(&card->controls_rwsem); + if (err < 0) + goto error; + return 0; + + error: + snd_ctl_free_one(kcontrol); + return err; +} + +/** + * snd_ctl_add - add the control instance to the card + * @card: the card instance + * @kcontrol: the control instance to add + * + * Adds the control instance created via snd_ctl_new() or + * snd_ctl_new1() to the given card. Assigns also an unique + * numid used for fast search. + * + * It frees automatically the control which cannot be added. + * + * Return: Zero if successful, or a negative error code on failure. + * + */ +int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol) +{ + return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE); +} +EXPORT_SYMBOL(snd_ctl_add); + +/** + * snd_ctl_replace - replace the control instance of the card + * @card: the card instance + * @kcontrol: the control instance to replace + * @add_on_replace: add the control if not already added + * + * Replaces the given control. If the given control does not exist + * and the add_on_replace flag is set, the control is added. If the + * control exists, it is destroyed first. + * + * It frees automatically the control which cannot be added or replaced. + * + * Return: Zero if successful, or a negative error code on failure. + */ +int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, + bool add_on_replace) +{ + return snd_ctl_add_replace(card, kcontrol, + add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE); +} +EXPORT_SYMBOL(snd_ctl_replace); + +static int __snd_ctl_remove(struct snd_card *card, + struct snd_kcontrol *kcontrol, + bool remove_hash) +{ + unsigned int idx; + + if (snd_BUG_ON(!card || !kcontrol)) + return -EINVAL; + list_del(&kcontrol->list); + + if (remove_hash) + remove_hash_entries(card, kcontrol); + + card->controls_count -= kcontrol->count; + for (idx = 0; idx < kcontrol->count; idx++) + snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx); + snd_ctl_free_one(kcontrol); + return 0; +} + +/** + * snd_ctl_remove - remove the control from the card and release it + * @card: the card instance + * @kcontrol: the control instance to remove + * + * Removes the control from the card and then releases the instance. + * You don't need to call snd_ctl_free_one(). You must be in + * the write lock - down_write(&card->controls_rwsem). + * + * Return: 0 if successful, or a negative error code on failure. + */ +int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol) +{ + return __snd_ctl_remove(card, kcontrol, true); +} +EXPORT_SYMBOL(snd_ctl_remove); + +/** + * snd_ctl_remove_id - remove the control of the given id and release it + * @card: the card instance + * @id: the control id to remove + * + * Finds the control instance with the given id, removes it from the + * card list and releases it. + * + * Return: 0 if successful, or a negative error code on failure. + */ +int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id) +{ + struct snd_kcontrol *kctl; + int ret; + + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, id); + if (kctl == NULL) { + up_write(&card->controls_rwsem); + return -ENOENT; + } + ret = snd_ctl_remove(card, kctl); + up_write(&card->controls_rwsem); + return ret; +} +EXPORT_SYMBOL(snd_ctl_remove_id); + +/** + * snd_ctl_remove_user_ctl - remove and release the unlocked user control + * @file: active control handle + * @id: the control id to remove + * + * Finds the control instance with the given id, removes it from the + * card list and releases it. + * + * Return: 0 if successful, or a negative error code on failure. + */ +static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file, + struct snd_ctl_elem_id *id) +{ + struct snd_card *card = file->card; + struct snd_kcontrol *kctl; + int idx, ret; + + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, id); + if (kctl == NULL) { + ret = -ENOENT; + goto error; + } + if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) { + ret = -EINVAL; + goto error; + } + for (idx = 0; idx < kctl->count; idx++) + if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) { + ret = -EBUSY; + goto error; + } + ret = snd_ctl_remove(card, kctl); +error: + up_write(&card->controls_rwsem); + return ret; +} + +/** + * snd_ctl_activate_id - activate/inactivate the control of the given id + * @card: the card instance + * @id: the control id to activate/inactivate + * @active: non-zero to activate + * + * Finds the control instance with the given id, and activate or + * inactivate the control together with notification, if changed. + * The given ID data is filled with full information. + * + * Return: 0 if unchanged, 1 if changed, or a negative error code on failure. + */ +int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, + int active) +{ + struct snd_kcontrol *kctl; + struct snd_kcontrol_volatile *vd; + unsigned int index_offset; + int ret; + + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, id); + if (kctl == NULL) { + ret = -ENOENT; + goto unlock; + } + index_offset = snd_ctl_get_ioff(kctl, id); + vd = &kctl->vd[index_offset]; + ret = 0; + if (active) { + if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)) + goto unlock; + vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE; + } else { + if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE) + goto unlock; + vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE; + } + snd_ctl_build_ioff(id, kctl, index_offset); + downgrade_write(&card->controls_rwsem); + snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset); + up_read(&card->controls_rwsem); + return 1; + + unlock: + up_write(&card->controls_rwsem); + return ret; +} +EXPORT_SYMBOL_GPL(snd_ctl_activate_id); + +/** + * snd_ctl_rename_id - replace the id of a control on the card + * @card: the card instance + * @src_id: the old id + * @dst_id: the new id + * + * Finds the control with the old id from the card, and replaces the + * id with the new one. + * + * Return: Zero if successful, or a negative error code on failure. + */ +int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id, + struct snd_ctl_elem_id *dst_id) +{ + struct snd_kcontrol *kctl; + + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, src_id); + if (kctl == NULL) { + up_write(&card->controls_rwsem); + return -ENOENT; + } + remove_hash_entries(card, kctl); + kctl->id = *dst_id; + kctl->id.numid = card->last_numid + 1; + card->last_numid += kctl->count; + add_hash_entries(card, kctl); + up_write(&card->controls_rwsem); + return 0; +} +EXPORT_SYMBOL(snd_ctl_rename_id); + +/** + * snd_ctl_rename - rename the control on the card + * @card: the card instance + * @kctl: the control to rename + * @name: the new name + * + * Renames the specified control on the card to the new name. + * + * Make sure to take the control write lock - down_write(&card->controls_rwsem). + */ +void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl, + const char *name) +{ + remove_hash_entries(card, kctl); + + if (strscpy(kctl->id.name, name, sizeof(kctl->id.name)) < 0) + pr_warn("ALSA: Renamed control new name '%s' truncated to '%s'\n", + name, kctl->id.name); + + add_hash_entries(card, kctl); +} +EXPORT_SYMBOL(snd_ctl_rename); + +#ifndef CONFIG_SND_CTL_FAST_LOOKUP +static struct snd_kcontrol * +snd_ctl_find_numid_slow(struct snd_card *card, unsigned int numid) +{ + struct snd_kcontrol *kctl; + + list_for_each_entry(kctl, &card->controls, list) { + if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid) + return kctl; + } + return NULL; +} +#endif /* !CONFIG_SND_CTL_FAST_LOOKUP */ + +/** + * snd_ctl_find_numid - find the control instance with the given number-id + * @card: the card instance + * @numid: the number-id to search + * + * Finds the control instance with the given number-id from the card. + * + * The caller must down card->controls_rwsem before calling this function + * (if the race condition can happen). + * + * Return: The pointer of the instance if found, or %NULL if not. + * + */ +struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid) +{ + if (snd_BUG_ON(!card || !numid)) + return NULL; +#ifdef CONFIG_SND_CTL_FAST_LOOKUP + return xa_load(&card->ctl_numids, numid); +#else + return snd_ctl_find_numid_slow(card, numid); +#endif +} +EXPORT_SYMBOL(snd_ctl_find_numid); + +/** + * snd_ctl_find_id - find the control instance with the given id + * @card: the card instance + * @id: the id to search + * + * Finds the control instance with the given id from the card. + * + * The caller must down card->controls_rwsem before calling this function + * (if the race condition can happen). + * + * Return: The pointer of the instance if found, or %NULL if not. + * + */ +struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card, + struct snd_ctl_elem_id *id) +{ + struct snd_kcontrol *kctl; + + if (snd_BUG_ON(!card || !id)) + return NULL; + if (id->numid != 0) + return snd_ctl_find_numid(card, id->numid); +#ifdef CONFIG_SND_CTL_FAST_LOOKUP + kctl = xa_load(&card->ctl_hash, get_ctl_id_hash(id)); + if (kctl && elem_id_matches(kctl, id)) + return kctl; + if (!card->ctl_hash_collision) + return NULL; /* we can rely on only hash table */ +#endif + /* no matching in hash table - try all as the last resort */ + list_for_each_entry(kctl, &card->controls, list) + if (elem_id_matches(kctl, id)) + return kctl; + + return NULL; +} +EXPORT_SYMBOL(snd_ctl_find_id); + +static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl, + unsigned int cmd, void __user *arg) +{ + struct snd_ctl_card_info *info; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (! info) + return -ENOMEM; + down_read(&snd_ioctl_rwsem); + info->card = card->number; + strscpy(info->id, card->id, sizeof(info->id)); + strscpy(info->driver, card->driver, sizeof(info->driver)); + strscpy(info->name, card->shortname, sizeof(info->name)); + strscpy(info->longname, card->longname, sizeof(info->longname)); + strscpy(info->mixername, card->mixername, sizeof(info->mixername)); + strscpy(info->components, card->components, sizeof(info->components)); + up_read(&snd_ioctl_rwsem); + if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) { + kfree(info); + return -EFAULT; + } + kfree(info); + return 0; +} + +static int snd_ctl_elem_list(struct snd_card *card, + struct snd_ctl_elem_list *list) +{ + struct snd_kcontrol *kctl; + struct snd_ctl_elem_id id; + unsigned int offset, space, jidx; + int err = 0; + + offset = list->offset; + space = list->space; + + down_read(&card->controls_rwsem); + list->count = card->controls_count; + list->used = 0; + if (space > 0) { + list_for_each_entry(kctl, &card->controls, list) { + if (offset >= kctl->count) { + offset -= kctl->count; + continue; + } + for (jidx = offset; jidx < kctl->count; jidx++) { + snd_ctl_build_ioff(&id, kctl, jidx); + if (copy_to_user(list->pids + list->used, &id, + sizeof(id))) { + err = -EFAULT; + goto out; + } + list->used++; + if (!--space) + goto out; + } + offset = 0; + } + } + out: + up_read(&card->controls_rwsem); + return err; +} + +static int snd_ctl_elem_list_user(struct snd_card *card, + struct snd_ctl_elem_list __user *_list) +{ + struct snd_ctl_elem_list list; + int err; + + if (copy_from_user(&list, _list, sizeof(list))) + return -EFAULT; + err = snd_ctl_elem_list(card, &list); + if (err) + return err; + if (copy_to_user(_list, &list, sizeof(list))) + return -EFAULT; + + return 0; +} + +/* Check whether the given kctl info is valid */ +static int snd_ctl_check_elem_info(struct snd_card *card, + const struct snd_ctl_elem_info *info) +{ + static const unsigned int max_value_counts[] = { + [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128, + [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128, + [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128, + [SNDRV_CTL_ELEM_TYPE_BYTES] = 512, + [SNDRV_CTL_ELEM_TYPE_IEC958] = 1, + [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64, + }; + + if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN || + info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) { + if (card) + dev_err(card->dev, + "control %i:%i:%i:%s:%i: invalid type %d\n", + info->id.iface, info->id.device, + info->id.subdevice, info->id.name, + info->id.index, info->type); + return -EINVAL; + } + if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED && + info->value.enumerated.items == 0) { + if (card) + dev_err(card->dev, + "control %i:%i:%i:%s:%i: zero enum items\n", + info->id.iface, info->id.device, + info->id.subdevice, info->id.name, + info->id.index); + return -EINVAL; + } + if (info->count > max_value_counts[info->type]) { + if (card) + dev_err(card->dev, + "control %i:%i:%i:%s:%i: invalid count %d\n", + info->id.iface, info->id.device, + info->id.subdevice, info->id.name, + info->id.index, info->count); + return -EINVAL; + } + + return 0; +} + +/* The capacity of struct snd_ctl_elem_value.value.*/ +static const unsigned int value_sizes[] = { + [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long), + [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long), + [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int), + [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char), + [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958), + [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long), +}; + +/* fill the remaining snd_ctl_elem_value data with the given pattern */ +static void fill_remaining_elem_value(struct snd_ctl_elem_value *control, + struct snd_ctl_elem_info *info, + u32 pattern) +{ + size_t offset = value_sizes[info->type] * info->count; + + offset = DIV_ROUND_UP(offset, sizeof(u32)); + memset32((u32 *)control->value.bytes.data + offset, pattern, + sizeof(control->value) / sizeof(u32) - offset); +} + +/* check whether the given integer ctl value is valid */ +static int sanity_check_int_value(struct snd_card *card, + const struct snd_ctl_elem_value *control, + const struct snd_ctl_elem_info *info, + int i, bool print_error) +{ + long long lval, lmin, lmax, lstep; + u64 rem; + + switch (info->type) { + default: + case SNDRV_CTL_ELEM_TYPE_BOOLEAN: + lval = control->value.integer.value[i]; + lmin = 0; + lmax = 1; + lstep = 0; + break; + case SNDRV_CTL_ELEM_TYPE_INTEGER: + lval = control->value.integer.value[i]; + lmin = info->value.integer.min; + lmax = info->value.integer.max; + lstep = info->value.integer.step; + break; + case SNDRV_CTL_ELEM_TYPE_INTEGER64: + lval = control->value.integer64.value[i]; + lmin = info->value.integer64.min; + lmax = info->value.integer64.max; + lstep = info->value.integer64.step; + break; + case SNDRV_CTL_ELEM_TYPE_ENUMERATED: + lval = control->value.enumerated.item[i]; + lmin = 0; + lmax = info->value.enumerated.items - 1; + lstep = 0; + break; + } + + if (lval < lmin || lval > lmax) { + if (print_error) + dev_err(card->dev, + "control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n", + control->id.iface, control->id.device, + control->id.subdevice, control->id.name, + control->id.index, lval, lmin, lmax, i); + return -EINVAL; + } + if (lstep) { + div64_u64_rem(lval, lstep, &rem); + if (rem) { + if (print_error) + dev_err(card->dev, + "control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n", + control->id.iface, control->id.device, + control->id.subdevice, control->id.name, + control->id.index, lval, lstep, i); + return -EINVAL; + } + } + + return 0; +} + +/* check whether the all input values are valid for the given elem value */ +static int sanity_check_input_values(struct snd_card *card, + const struct snd_ctl_elem_value *control, + const struct snd_ctl_elem_info *info, + bool print_error) +{ + int i, ret; + + switch (info->type) { + case SNDRV_CTL_ELEM_TYPE_BOOLEAN: + case SNDRV_CTL_ELEM_TYPE_INTEGER: + case SNDRV_CTL_ELEM_TYPE_INTEGER64: + case SNDRV_CTL_ELEM_TYPE_ENUMERATED: + for (i = 0; i < info->count; i++) { + ret = sanity_check_int_value(card, control, info, i, + print_error); + if (ret < 0) + return ret; + } + break; + default: + break; + } + + return 0; +} + +/* perform sanity checks to the given snd_ctl_elem_value object */ +static int sanity_check_elem_value(struct snd_card *card, + const struct snd_ctl_elem_value *control, + const struct snd_ctl_elem_info *info, + u32 pattern) +{ + size_t offset; + int ret; + u32 *p; + + ret = sanity_check_input_values(card, control, info, true); + if (ret < 0) + return ret; + + /* check whether the remaining area kept untouched */ + offset = value_sizes[info->type] * info->count; + offset = DIV_ROUND_UP(offset, sizeof(u32)); + p = (u32 *)control->value.bytes.data + offset; + for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) { + if (*p != pattern) { + ret = -EINVAL; + break; + } + *p = 0; /* clear the checked area */ + } + + return ret; +} + +static int __snd_ctl_elem_info(struct snd_card *card, + struct snd_kcontrol *kctl, + struct snd_ctl_elem_info *info, + struct snd_ctl_file *ctl) +{ + struct snd_kcontrol_volatile *vd; + unsigned int index_offset; + int result; + +#ifdef CONFIG_SND_DEBUG + info->access = 0; +#endif + result = snd_power_ref_and_wait(card); + if (!result) + result = kctl->info(kctl, info); + snd_power_unref(card); + if (result >= 0) { + snd_BUG_ON(info->access); + index_offset = snd_ctl_get_ioff(kctl, &info->id); + vd = &kctl->vd[index_offset]; + snd_ctl_build_ioff(&info->id, kctl, index_offset); + info->access = vd->access; + if (vd->owner) { + info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK; + if (vd->owner == ctl) + info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER; + info->owner = pid_vnr(vd->owner->pid); + } else { + info->owner = -1; + } + if (!snd_ctl_skip_validation(info) && + snd_ctl_check_elem_info(card, info) < 0) + result = -EINVAL; + } + return result; +} + +static int snd_ctl_elem_info(struct snd_ctl_file *ctl, + struct snd_ctl_elem_info *info) +{ + struct snd_card *card = ctl->card; + struct snd_kcontrol *kctl; + int result; + + down_read(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, &info->id); + if (kctl == NULL) + result = -ENOENT; + else + result = __snd_ctl_elem_info(card, kctl, info, ctl); + up_read(&card->controls_rwsem); + return result; +} + +static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl, + struct snd_ctl_elem_info __user *_info) +{ + struct snd_ctl_elem_info info; + int result; + + if (copy_from_user(&info, _info, sizeof(info))) + return -EFAULT; + result = snd_ctl_elem_info(ctl, &info); + if (result < 0) + return result; + /* drop internal access flags */ + info.access &= ~(SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK| + SNDRV_CTL_ELEM_ACCESS_LED_MASK); + if (copy_to_user(_info, &info, sizeof(info))) + return -EFAULT; + return result; +} + +static int snd_ctl_elem_read(struct snd_card *card, + struct snd_ctl_elem_value *control) +{ + struct snd_kcontrol *kctl; + struct snd_kcontrol_volatile *vd; + unsigned int index_offset; + struct snd_ctl_elem_info info; + const u32 pattern = 0xdeadbeef; + int ret; + + down_read(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, &control->id); + if (kctl == NULL) { + ret = -ENOENT; + goto unlock; + } + + index_offset = snd_ctl_get_ioff(kctl, &control->id); + vd = &kctl->vd[index_offset]; + if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL) { + ret = -EPERM; + goto unlock; + } + + snd_ctl_build_ioff(&control->id, kctl, index_offset); + +#ifdef CONFIG_SND_CTL_DEBUG + /* info is needed only for validation */ + memset(&info, 0, sizeof(info)); + info.id = control->id; + ret = __snd_ctl_elem_info(card, kctl, &info, NULL); + if (ret < 0) + goto unlock; +#endif + + if (!snd_ctl_skip_validation(&info)) + fill_remaining_elem_value(control, &info, pattern); + ret = snd_power_ref_and_wait(card); + if (!ret) + ret = kctl->get(kctl, control); + snd_power_unref(card); + if (ret < 0) + goto unlock; + if (!snd_ctl_skip_validation(&info) && + sanity_check_elem_value(card, control, &info, pattern) < 0) { + dev_err(card->dev, + "control %i:%i:%i:%s:%i: access overflow\n", + control->id.iface, control->id.device, + control->id.subdevice, control->id.name, + control->id.index); + ret = -EINVAL; + goto unlock; + } +unlock: + up_read(&card->controls_rwsem); + return ret; +} + +static int snd_ctl_elem_read_user(struct snd_card *card, + struct snd_ctl_elem_value __user *_control) +{ + struct snd_ctl_elem_value *control; + int result; + + control = memdup_user(_control, sizeof(*control)); + if (IS_ERR(control)) + return PTR_ERR(control); + + result = snd_ctl_elem_read(card, control); + if (result < 0) + goto error; + + if (copy_to_user(_control, control, sizeof(*control))) + result = -EFAULT; + error: + kfree(control); + return result; +} + +static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file, + struct snd_ctl_elem_value *control) +{ + struct snd_kcontrol *kctl; + struct snd_kcontrol_volatile *vd; + unsigned int index_offset; + int result; + + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, &control->id); + if (kctl == NULL) { + up_write(&card->controls_rwsem); + return -ENOENT; + } + + index_offset = snd_ctl_get_ioff(kctl, &control->id); + vd = &kctl->vd[index_offset]; + if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL || + (file && vd->owner && vd->owner != file)) { + up_write(&card->controls_rwsem); + return -EPERM; + } + + snd_ctl_build_ioff(&control->id, kctl, index_offset); + result = snd_power_ref_and_wait(card); + /* validate input values */ + if (IS_ENABLED(CONFIG_SND_CTL_INPUT_VALIDATION) && !result) { + struct snd_ctl_elem_info info; + + memset(&info, 0, sizeof(info)); + info.id = control->id; + result = __snd_ctl_elem_info(card, kctl, &info, NULL); + if (!result) + result = sanity_check_input_values(card, control, &info, + false); + } + if (!result) + result = kctl->put(kctl, control); + snd_power_unref(card); + if (result < 0) { + up_write(&card->controls_rwsem); + return result; + } + + if (result > 0) { + downgrade_write(&card->controls_rwsem); + snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset); + up_read(&card->controls_rwsem); + } else { + up_write(&card->controls_rwsem); + } + + return 0; +} + +static int snd_ctl_elem_write_user(struct snd_ctl_file *file, + struct snd_ctl_elem_value __user *_control) +{ + struct snd_ctl_elem_value *control; + struct snd_card *card; + int result; + + control = memdup_user(_control, sizeof(*control)); + if (IS_ERR(control)) + return PTR_ERR(control); + + card = file->card; + result = snd_ctl_elem_write(card, file, control); + if (result < 0) + goto error; + + if (copy_to_user(_control, control, sizeof(*control))) + result = -EFAULT; + error: + kfree(control); + return result; +} + +static int snd_ctl_elem_lock(struct snd_ctl_file *file, + struct snd_ctl_elem_id __user *_id) +{ + struct snd_card *card = file->card; + struct snd_ctl_elem_id id; + struct snd_kcontrol *kctl; + struct snd_kcontrol_volatile *vd; + int result; + + if (copy_from_user(&id, _id, sizeof(id))) + return -EFAULT; + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, &id); + if (kctl == NULL) { + result = -ENOENT; + } else { + vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; + if (vd->owner != NULL) + result = -EBUSY; + else { + vd->owner = file; + result = 0; + } + } + up_write(&card->controls_rwsem); + return result; +} + +static int snd_ctl_elem_unlock(struct snd_ctl_file *file, + struct snd_ctl_elem_id __user *_id) +{ + struct snd_card *card = file->card; + struct snd_ctl_elem_id id; + struct snd_kcontrol *kctl; + struct snd_kcontrol_volatile *vd; + int result; + + if (copy_from_user(&id, _id, sizeof(id))) + return -EFAULT; + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, &id); + if (kctl == NULL) { + result = -ENOENT; + } else { + vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; + if (vd->owner == NULL) + result = -EINVAL; + else if (vd->owner != file) + result = -EPERM; + else { + vd->owner = NULL; + result = 0; + } + } + up_write(&card->controls_rwsem); + return result; +} + +struct user_element { + struct snd_ctl_elem_info info; + struct snd_card *card; + char *elem_data; /* element data */ + unsigned long elem_data_size; /* size of element data in bytes */ + void *tlv_data; /* TLV data */ + unsigned long tlv_data_size; /* TLV data size */ + void *priv_data; /* private data (like strings for enumerated type) */ +}; + +// check whether the addition (in bytes) of user ctl element may overflow the limit. +static bool check_user_elem_overflow(struct snd_card *card, ssize_t add) +{ + return (ssize_t)card->user_ctl_alloc_size + add > max_user_ctl_alloc_size; +} + +static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + struct user_element *ue = kcontrol->private_data; + unsigned int offset; + + offset = snd_ctl_get_ioff(kcontrol, &uinfo->id); + *uinfo = ue->info; + snd_ctl_build_ioff(&uinfo->id, kcontrol, offset); + + return 0; +} + +static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + struct user_element *ue = kcontrol->private_data; + const char *names; + unsigned int item; + unsigned int offset; + + item = uinfo->value.enumerated.item; + + offset = snd_ctl_get_ioff(kcontrol, &uinfo->id); + *uinfo = ue->info; + snd_ctl_build_ioff(&uinfo->id, kcontrol, offset); + + item = min(item, uinfo->value.enumerated.items - 1); + uinfo->value.enumerated.item = item; + + names = ue->priv_data; + for (; item > 0; --item) + names += strlen(names) + 1; + strcpy(uinfo->value.enumerated.name, names); + + return 0; +} + +static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + struct user_element *ue = kcontrol->private_data; + unsigned int size = ue->elem_data_size; + char *src = ue->elem_data + + snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size; + + memcpy(&ucontrol->value, src, size); + return 0; +} + +static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + int change; + struct user_element *ue = kcontrol->private_data; + unsigned int size = ue->elem_data_size; + char *dst = ue->elem_data + + snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size; + + change = memcmp(&ucontrol->value, dst, size) != 0; + if (change) + memcpy(dst, &ucontrol->value, size); + return change; +} + +/* called in controls_rwsem write lock */ +static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf, + unsigned int size) +{ + struct user_element *ue = kctl->private_data; + unsigned int *container; + unsigned int mask = 0; + int i; + int change; + + if (size > 1024 * 128) /* sane value */ + return -EINVAL; + + // does the TLV size change cause overflow? + if (check_user_elem_overflow(ue->card, (ssize_t)(size - ue->tlv_data_size))) + return -ENOMEM; + + container = vmemdup_user(buf, size); + if (IS_ERR(container)) + return PTR_ERR(container); + + change = ue->tlv_data_size != size; + if (!change) + change = memcmp(ue->tlv_data, container, size) != 0; + if (!change) { + kvfree(container); + return 0; + } + + if (ue->tlv_data == NULL) { + /* Now TLV data is available. */ + for (i = 0; i < kctl->count; ++i) + kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ; + mask = SNDRV_CTL_EVENT_MASK_INFO; + } else { + ue->card->user_ctl_alloc_size -= ue->tlv_data_size; + ue->tlv_data_size = 0; + kvfree(ue->tlv_data); + } + + ue->tlv_data = container; + ue->tlv_data_size = size; + // decremented at private_free. + ue->card->user_ctl_alloc_size += size; + + mask |= SNDRV_CTL_EVENT_MASK_TLV; + for (i = 0; i < kctl->count; ++i) + snd_ctl_notify_one(ue->card, mask, kctl, i); + + return change; +} + +static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf, + unsigned int size) +{ + struct user_element *ue = kctl->private_data; + + if (ue->tlv_data_size == 0 || ue->tlv_data == NULL) + return -ENXIO; + + if (size < ue->tlv_data_size) + return -ENOSPC; + + if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size)) + return -EFAULT; + + return 0; +} + +static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag, + unsigned int size, unsigned int __user *buf) +{ + if (op_flag == SNDRV_CTL_TLV_OP_WRITE) + return replace_user_tlv(kctl, buf, size); + else + return read_user_tlv(kctl, buf, size); +} + +/* called in controls_rwsem write lock */ +static int snd_ctl_elem_init_enum_names(struct user_element *ue) +{ + char *names, *p; + size_t buf_len, name_len; + unsigned int i; + const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr; + + buf_len = ue->info.value.enumerated.names_length; + if (buf_len > 64 * 1024) + return -EINVAL; + + if (check_user_elem_overflow(ue->card, buf_len)) + return -ENOMEM; + names = vmemdup_user((const void __user *)user_ptrval, buf_len); + if (IS_ERR(names)) + return PTR_ERR(names); + + /* check that there are enough valid names */ + p = names; + for (i = 0; i < ue->info.value.enumerated.items; ++i) { + name_len = strnlen(p, buf_len); + if (name_len == 0 || name_len >= 64 || name_len == buf_len) { + kvfree(names); + return -EINVAL; + } + p += name_len + 1; + buf_len -= name_len + 1; + } + + ue->priv_data = names; + ue->info.value.enumerated.names_ptr = 0; + // increment the allocation size; decremented again at private_free. + ue->card->user_ctl_alloc_size += ue->info.value.enumerated.names_length; + + return 0; +} + +static size_t compute_user_elem_size(size_t size, unsigned int count) +{ + return sizeof(struct user_element) + size * count; +} + +static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol) +{ + struct user_element *ue = kcontrol->private_data; + + // decrement the allocation size. + ue->card->user_ctl_alloc_size -= compute_user_elem_size(ue->elem_data_size, kcontrol->count); + ue->card->user_ctl_alloc_size -= ue->tlv_data_size; + if (ue->priv_data) + ue->card->user_ctl_alloc_size -= ue->info.value.enumerated.names_length; + + kvfree(ue->tlv_data); + kvfree(ue->priv_data); + kfree(ue); +} + +static int snd_ctl_elem_add(struct snd_ctl_file *file, + struct snd_ctl_elem_info *info, int replace) +{ + struct snd_card *card = file->card; + struct snd_kcontrol *kctl; + unsigned int count; + unsigned int access; + long private_size; + size_t alloc_size; + struct user_element *ue; + unsigned int offset; + int err; + + if (!*info->id.name) + return -EINVAL; + if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name)) + return -EINVAL; + + /* Delete a control to replace them if needed. */ + if (replace) { + info->id.numid = 0; + err = snd_ctl_remove_user_ctl(file, &info->id); + if (err) + return err; + } + + /* Check the number of elements for this userspace control. */ + count = info->owner; + if (count == 0) + count = 1; + + /* Arrange access permissions if needed. */ + access = info->access; + if (access == 0) + access = SNDRV_CTL_ELEM_ACCESS_READWRITE; + access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE | + SNDRV_CTL_ELEM_ACCESS_INACTIVE | + SNDRV_CTL_ELEM_ACCESS_TLV_WRITE); + + /* In initial state, nothing is available as TLV container. */ + if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) + access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK; + access |= SNDRV_CTL_ELEM_ACCESS_USER; + + /* + * Check information and calculate the size of data specific to + * this userspace control. + */ + /* pass NULL to card for suppressing error messages */ + err = snd_ctl_check_elem_info(NULL, info); + if (err < 0) + return err; + /* user-space control doesn't allow zero-size data */ + if (info->count < 1) + return -EINVAL; + private_size = value_sizes[info->type] * info->count; + alloc_size = compute_user_elem_size(private_size, count); + + down_write(&card->controls_rwsem); + if (check_user_elem_overflow(card, alloc_size)) { + err = -ENOMEM; + goto unlock; + } + + /* + * Keep memory object for this userspace control. After passing this + * code block, the instance should be freed by snd_ctl_free_one(). + * + * Note that these elements in this control are locked. + */ + err = snd_ctl_new(&kctl, count, access, file); + if (err < 0) + goto unlock; + memcpy(&kctl->id, &info->id, sizeof(kctl->id)); + ue = kzalloc(alloc_size, GFP_KERNEL); + if (!ue) { + kfree(kctl); + err = -ENOMEM; + goto unlock; + } + kctl->private_data = ue; + kctl->private_free = snd_ctl_elem_user_free; + + // increment the allocated size; decremented again at private_free. + card->user_ctl_alloc_size += alloc_size; + + /* Set private data for this userspace control. */ + ue->card = card; + ue->info = *info; + ue->info.access = 0; + ue->elem_data = (char *)ue + sizeof(*ue); + ue->elem_data_size = private_size; + if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) { + err = snd_ctl_elem_init_enum_names(ue); + if (err < 0) { + snd_ctl_free_one(kctl); + goto unlock; + } + } + + /* Set callback functions. */ + if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) + kctl->info = snd_ctl_elem_user_enum_info; + else + kctl->info = snd_ctl_elem_user_info; + if (access & SNDRV_CTL_ELEM_ACCESS_READ) + kctl->get = snd_ctl_elem_user_get; + if (access & SNDRV_CTL_ELEM_ACCESS_WRITE) + kctl->put = snd_ctl_elem_user_put; + if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) + kctl->tlv.c = snd_ctl_elem_user_tlv; + + /* This function manage to free the instance on failure. */ + err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE); + if (err < 0) { + snd_ctl_free_one(kctl); + goto unlock; + } + offset = snd_ctl_get_ioff(kctl, &info->id); + snd_ctl_build_ioff(&info->id, kctl, offset); + /* + * Here we cannot fill any field for the number of elements added by + * this operation because there're no specific fields. The usage of + * 'owner' field for this purpose may cause any bugs to userspace + * applications because the field originally means PID of a process + * which locks the element. + */ + unlock: + up_write(&card->controls_rwsem); + return err; +} + +static int snd_ctl_elem_add_user(struct snd_ctl_file *file, + struct snd_ctl_elem_info __user *_info, int replace) +{ + struct snd_ctl_elem_info info; + int err; + + if (copy_from_user(&info, _info, sizeof(info))) + return -EFAULT; + err = snd_ctl_elem_add(file, &info, replace); + if (err < 0) + return err; + if (copy_to_user(_info, &info, sizeof(info))) { + snd_ctl_remove_user_ctl(file, &info.id); + return -EFAULT; + } + + return 0; +} + +static int snd_ctl_elem_remove(struct snd_ctl_file *file, + struct snd_ctl_elem_id __user *_id) +{ + struct snd_ctl_elem_id id; + + if (copy_from_user(&id, _id, sizeof(id))) + return -EFAULT; + return snd_ctl_remove_user_ctl(file, &id); +} + +static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr) +{ + int subscribe; + if (get_user(subscribe, ptr)) + return -EFAULT; + if (subscribe < 0) { + subscribe = file->subscribed; + if (put_user(subscribe, ptr)) + return -EFAULT; + return 0; + } + if (subscribe) { + file->subscribed = 1; + return 0; + } else if (file->subscribed) { + snd_ctl_empty_read_queue(file); + file->subscribed = 0; + } + return 0; +} + +static int call_tlv_handler(struct snd_ctl_file *file, int op_flag, + struct snd_kcontrol *kctl, + struct snd_ctl_elem_id *id, + unsigned int __user *buf, unsigned int size) +{ + static const struct { + int op; + int perm; + } pairs[] = { + {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ}, + {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE}, + {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND}, + }; + struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)]; + int i, ret; + + /* Check support of the request for this element. */ + for (i = 0; i < ARRAY_SIZE(pairs); ++i) { + if (op_flag == pairs[i].op && (vd->access & pairs[i].perm)) + break; + } + if (i == ARRAY_SIZE(pairs)) + return -ENXIO; + + if (kctl->tlv.c == NULL) + return -ENXIO; + + /* Write and command operations are not allowed for locked element. */ + if (op_flag != SNDRV_CTL_TLV_OP_READ && + vd->owner != NULL && vd->owner != file) + return -EPERM; + + ret = snd_power_ref_and_wait(file->card); + if (!ret) + ret = kctl->tlv.c(kctl, op_flag, size, buf); + snd_power_unref(file->card); + return ret; +} + +static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id, + unsigned int __user *buf, unsigned int size) +{ + struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)]; + unsigned int len; + + if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ)) + return -ENXIO; + + if (kctl->tlv.p == NULL) + return -ENXIO; + + len = sizeof(unsigned int) * 2 + kctl->tlv.p[1]; + if (size < len) + return -ENOMEM; + + if (copy_to_user(buf, kctl->tlv.p, len)) + return -EFAULT; + + return 0; +} + +static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file, + struct snd_ctl_tlv __user *buf, + int op_flag) +{ + struct snd_ctl_tlv header; + unsigned int __user *container; + unsigned int container_size; + struct snd_kcontrol *kctl; + struct snd_ctl_elem_id id; + struct snd_kcontrol_volatile *vd; + + if (copy_from_user(&header, buf, sizeof(header))) + return -EFAULT; + + /* In design of control core, numerical ID starts at 1. */ + if (header.numid == 0) + return -EINVAL; + + /* At least, container should include type and length fields. */ + if (header.length < sizeof(unsigned int) * 2) + return -EINVAL; + container_size = header.length; + container = buf->tlv; + + kctl = snd_ctl_find_numid(file->card, header.numid); + if (kctl == NULL) + return -ENOENT; + + /* Calculate index of the element in this set. */ + id = kctl->id; + snd_ctl_build_ioff(&id, kctl, header.numid - id.numid); + vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; + + if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) { + return call_tlv_handler(file, op_flag, kctl, &id, container, + container_size); + } else { + if (op_flag == SNDRV_CTL_TLV_OP_READ) { + return read_tlv_buf(kctl, &id, container, + container_size); + } + } + + /* Not supported. */ + return -ENXIO; +} + +static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct snd_ctl_file *ctl; + struct snd_card *card; + struct snd_kctl_ioctl *p; + void __user *argp = (void __user *)arg; + int __user *ip = argp; + int err; + + ctl = file->private_data; + card = ctl->card; + if (snd_BUG_ON(!card)) + return -ENXIO; + switch (cmd) { + case SNDRV_CTL_IOCTL_PVERSION: + return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0; + case SNDRV_CTL_IOCTL_CARD_INFO: + return snd_ctl_card_info(card, ctl, cmd, argp); + case SNDRV_CTL_IOCTL_ELEM_LIST: + return snd_ctl_elem_list_user(card, argp); + case SNDRV_CTL_IOCTL_ELEM_INFO: + return snd_ctl_elem_info_user(ctl, argp); + case SNDRV_CTL_IOCTL_ELEM_READ: + return snd_ctl_elem_read_user(card, argp); + case SNDRV_CTL_IOCTL_ELEM_WRITE: + return snd_ctl_elem_write_user(ctl, argp); + case SNDRV_CTL_IOCTL_ELEM_LOCK: + return snd_ctl_elem_lock(ctl, argp); + case SNDRV_CTL_IOCTL_ELEM_UNLOCK: + return snd_ctl_elem_unlock(ctl, argp); + case SNDRV_CTL_IOCTL_ELEM_ADD: + return snd_ctl_elem_add_user(ctl, argp, 0); + case SNDRV_CTL_IOCTL_ELEM_REPLACE: + return snd_ctl_elem_add_user(ctl, argp, 1); + case SNDRV_CTL_IOCTL_ELEM_REMOVE: + return snd_ctl_elem_remove(ctl, argp); + case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS: + return snd_ctl_subscribe_events(ctl, ip); + case SNDRV_CTL_IOCTL_TLV_READ: + down_read(&ctl->card->controls_rwsem); + err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ); + up_read(&ctl->card->controls_rwsem); + return err; + case SNDRV_CTL_IOCTL_TLV_WRITE: + down_write(&ctl->card->controls_rwsem); + err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE); + up_write(&ctl->card->controls_rwsem); + return err; + case SNDRV_CTL_IOCTL_TLV_COMMAND: + down_write(&ctl->card->controls_rwsem); + err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD); + up_write(&ctl->card->controls_rwsem); + return err; + case SNDRV_CTL_IOCTL_POWER: + return -ENOPROTOOPT; + case SNDRV_CTL_IOCTL_POWER_STATE: + return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0; + } + down_read(&snd_ioctl_rwsem); + list_for_each_entry(p, &snd_control_ioctls, list) { + err = p->fioctl(card, ctl, cmd, arg); + if (err != -ENOIOCTLCMD) { + up_read(&snd_ioctl_rwsem); + return err; + } + } + up_read(&snd_ioctl_rwsem); + dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd); + return -ENOTTY; +} + +static ssize_t snd_ctl_read(struct file *file, char __user *buffer, + size_t count, loff_t * offset) +{ + struct snd_ctl_file *ctl; + int err = 0; + ssize_t result = 0; + + ctl = file->private_data; + if (snd_BUG_ON(!ctl || !ctl->card)) + return -ENXIO; + if (!ctl->subscribed) + return -EBADFD; + if (count < sizeof(struct snd_ctl_event)) + return -EINVAL; + spin_lock_irq(&ctl->read_lock); + while (count >= sizeof(struct snd_ctl_event)) { + struct snd_ctl_event ev; + struct snd_kctl_event *kev; + while (list_empty(&ctl->events)) { + wait_queue_entry_t wait; + if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) { + err = -EAGAIN; + goto __end_lock; + } + init_waitqueue_entry(&wait, current); + add_wait_queue(&ctl->change_sleep, &wait); + set_current_state(TASK_INTERRUPTIBLE); + spin_unlock_irq(&ctl->read_lock); + schedule(); + remove_wait_queue(&ctl->change_sleep, &wait); + if (ctl->card->shutdown) + return -ENODEV; + if (signal_pending(current)) + return -ERESTARTSYS; + spin_lock_irq(&ctl->read_lock); + } + kev = snd_kctl_event(ctl->events.next); + ev.type = SNDRV_CTL_EVENT_ELEM; + ev.data.elem.mask = kev->mask; + ev.data.elem.id = kev->id; + list_del(&kev->list); + spin_unlock_irq(&ctl->read_lock); + kfree(kev); + if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) { + err = -EFAULT; + goto __end; + } + spin_lock_irq(&ctl->read_lock); + buffer += sizeof(struct snd_ctl_event); + count -= sizeof(struct snd_ctl_event); + result += sizeof(struct snd_ctl_event); + } + __end_lock: + spin_unlock_irq(&ctl->read_lock); + __end: + return result > 0 ? result : err; +} + +static __poll_t snd_ctl_poll(struct file *file, poll_table * wait) +{ + __poll_t mask; + struct snd_ctl_file *ctl; + + ctl = file->private_data; + if (!ctl->subscribed) + return 0; + poll_wait(file, &ctl->change_sleep, wait); + + mask = 0; + if (!list_empty(&ctl->events)) + mask |= EPOLLIN | EPOLLRDNORM; + + return mask; +} + +/* + * register the device-specific control-ioctls. + * called from each device manager like pcm.c, hwdep.c, etc. + */ +static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists) +{ + struct snd_kctl_ioctl *pn; + + pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL); + if (pn == NULL) + return -ENOMEM; + pn->fioctl = fcn; + down_write(&snd_ioctl_rwsem); + list_add_tail(&pn->list, lists); + up_write(&snd_ioctl_rwsem); + return 0; +} + +/** + * snd_ctl_register_ioctl - register the device-specific control-ioctls + * @fcn: ioctl callback function + * + * called from each device manager like pcm.c, hwdep.c, etc. + * + * Return: zero if successful, or a negative error code + */ +int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn) +{ + return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls); +} +EXPORT_SYMBOL(snd_ctl_register_ioctl); + +#ifdef CONFIG_COMPAT +/** + * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat + * control-ioctls + * @fcn: ioctl callback function + * + * Return: zero if successful, or a negative error code + */ +int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn) +{ + return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls); +} +EXPORT_SYMBOL(snd_ctl_register_ioctl_compat); +#endif + +/* + * de-register the device-specific control-ioctls. + */ +static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, + struct list_head *lists) +{ + struct snd_kctl_ioctl *p; + + if (snd_BUG_ON(!fcn)) + return -EINVAL; + down_write(&snd_ioctl_rwsem); + list_for_each_entry(p, lists, list) { + if (p->fioctl == fcn) { + list_del(&p->list); + up_write(&snd_ioctl_rwsem); + kfree(p); + return 0; + } + } + up_write(&snd_ioctl_rwsem); + snd_BUG(); + return -EINVAL; +} + +/** + * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls + * @fcn: ioctl callback function to unregister + * + * Return: zero if successful, or a negative error code + */ +int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn) +{ + return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls); +} +EXPORT_SYMBOL(snd_ctl_unregister_ioctl); + +#ifdef CONFIG_COMPAT +/** + * snd_ctl_unregister_ioctl_compat - de-register the device-specific compat + * 32bit control-ioctls + * @fcn: ioctl callback function to unregister + * + * Return: zero if successful, or a negative error code + */ +int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn) +{ + return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls); +} +EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat); +#endif + +static int snd_ctl_fasync(int fd, struct file * file, int on) +{ + struct snd_ctl_file *ctl; + + ctl = file->private_data; + return snd_fasync_helper(fd, file, on, &ctl->fasync); +} + +/* return the preferred subdevice number if already assigned; + * otherwise return -1 + */ +int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type) +{ + struct snd_ctl_file *kctl; + int subdevice = -1; + unsigned long flags; + + read_lock_irqsave(&card->ctl_files_rwlock, flags); + list_for_each_entry(kctl, &card->ctl_files, list) { + if (kctl->pid == task_pid(current)) { + subdevice = kctl->preferred_subdevice[type]; + if (subdevice != -1) + break; + } + } + read_unlock_irqrestore(&card->ctl_files_rwlock, flags); + return subdevice; +} +EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice); + +/* + * ioctl32 compat + */ +#ifdef CONFIG_COMPAT +#include "control_compat.c" +#else +#define snd_ctl_ioctl_compat NULL +#endif + +/* + * control layers (audio LED etc.) + */ + +/** + * snd_ctl_request_layer - request to use the layer + * @module_name: Name of the kernel module (NULL == build-in) + * + * Return: zero if successful, or an error code when the module cannot be loaded + */ +int snd_ctl_request_layer(const char *module_name) +{ + struct snd_ctl_layer_ops *lops; + + if (module_name == NULL) + return 0; + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + if (strcmp(lops->module_name, module_name) == 0) + break; + up_read(&snd_ctl_layer_rwsem); + if (lops) + return 0; + return request_module(module_name); +} +EXPORT_SYMBOL_GPL(snd_ctl_request_layer); + +/** + * snd_ctl_register_layer - register new control layer + * @lops: operation structure + * + * The new layer can track all control elements and do additional + * operations on top (like audio LED handling). + */ +void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops) +{ + struct snd_card *card; + int card_number; + + down_write(&snd_ctl_layer_rwsem); + lops->next = snd_ctl_layer; + snd_ctl_layer = lops; + up_write(&snd_ctl_layer_rwsem); + for (card_number = 0; card_number < SNDRV_CARDS; card_number++) { + card = snd_card_ref(card_number); + if (card) { + down_read(&card->controls_rwsem); + lops->lregister(card); + up_read(&card->controls_rwsem); + snd_card_unref(card); + } + } +} +EXPORT_SYMBOL_GPL(snd_ctl_register_layer); + +/** + * snd_ctl_disconnect_layer - disconnect control layer + * @lops: operation structure + * + * It is expected that the information about tracked cards + * is freed before this call (the disconnect callback is + * not called here). + */ +void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops) +{ + struct snd_ctl_layer_ops *lops2, *prev_lops2; + + down_write(&snd_ctl_layer_rwsem); + for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) { + if (lops2 == lops) { + if (!prev_lops2) + snd_ctl_layer = lops->next; + else + prev_lops2->next = lops->next; + break; + } + prev_lops2 = lops2; + } + up_write(&snd_ctl_layer_rwsem); +} +EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer); + +/* + * INIT PART + */ + +static const struct file_operations snd_ctl_f_ops = +{ + .owner = THIS_MODULE, + .read = snd_ctl_read, + .open = snd_ctl_open, + .release = snd_ctl_release, + .llseek = no_llseek, + .poll = snd_ctl_poll, + .unlocked_ioctl = snd_ctl_ioctl, + .compat_ioctl = snd_ctl_ioctl_compat, + .fasync = snd_ctl_fasync, +}; + +/* + * registration of the control device + */ +static int snd_ctl_dev_register(struct snd_device *device) +{ + struct snd_card *card = device->device_data; + struct snd_ctl_layer_ops *lops; + int err; + + err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1, + &snd_ctl_f_ops, card, &card->ctl_dev); + if (err < 0) + return err; + down_read(&card->controls_rwsem); + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + lops->lregister(card); + up_read(&snd_ctl_layer_rwsem); + up_read(&card->controls_rwsem); + return 0; +} + +/* + * disconnection of the control device + */ +static int snd_ctl_dev_disconnect(struct snd_device *device) +{ + struct snd_card *card = device->device_data; + struct snd_ctl_file *ctl; + struct snd_ctl_layer_ops *lops; + unsigned long flags; + + read_lock_irqsave(&card->ctl_files_rwlock, flags); + list_for_each_entry(ctl, &card->ctl_files, list) { + wake_up(&ctl->change_sleep); + snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR); + } + read_unlock_irqrestore(&card->ctl_files_rwlock, flags); + + down_read(&card->controls_rwsem); + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + lops->ldisconnect(card); + up_read(&snd_ctl_layer_rwsem); + up_read(&card->controls_rwsem); + + return snd_unregister_device(&card->ctl_dev); +} + +/* + * free all controls + */ +static int snd_ctl_dev_free(struct snd_device *device) +{ + struct snd_card *card = device->device_data; + struct snd_kcontrol *control; + + down_write(&card->controls_rwsem); + while (!list_empty(&card->controls)) { + control = snd_kcontrol(card->controls.next); + __snd_ctl_remove(card, control, false); + } + +#ifdef CONFIG_SND_CTL_FAST_LOOKUP + xa_destroy(&card->ctl_numids); + xa_destroy(&card->ctl_hash); +#endif + up_write(&card->controls_rwsem); + put_device(&card->ctl_dev); + return 0; +} + +/* + * create control core: + * called from init.c + */ +int snd_ctl_create(struct snd_card *card) +{ + static const struct snd_device_ops ops = { + .dev_free = snd_ctl_dev_free, + .dev_register = snd_ctl_dev_register, + .dev_disconnect = snd_ctl_dev_disconnect, + }; + int err; + + if (snd_BUG_ON(!card)) + return -ENXIO; + if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS)) + return -ENXIO; + + snd_device_initialize(&card->ctl_dev, card); + dev_set_name(&card->ctl_dev, "controlC%d", card->number); + + err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops); + if (err < 0) + put_device(&card->ctl_dev); + return err; +} + +/* + * Frequently used control callbacks/helpers + */ + +/** + * snd_ctl_boolean_mono_info - Helper function for a standard boolean info + * callback with a mono channel + * @kcontrol: the kcontrol instance + * @uinfo: info to store + * + * This is a function that can be used as info callback for a standard + * boolean control with a single mono channel. + * + * Return: Zero (always successful) + */ +int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN; + uinfo->count = 1; + uinfo->value.integer.min = 0; + uinfo->value.integer.max = 1; + return 0; +} +EXPORT_SYMBOL(snd_ctl_boolean_mono_info); + +/** + * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info + * callback with stereo two channels + * @kcontrol: the kcontrol instance + * @uinfo: info to store + * + * This is a function that can be used as info callback for a standard + * boolean control with stereo two channels. + * + * Return: Zero (always successful) + */ +int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN; + uinfo->count = 2; + uinfo->value.integer.min = 0; + uinfo->value.integer.max = 1; + return 0; +} +EXPORT_SYMBOL(snd_ctl_boolean_stereo_info); + +/** + * snd_ctl_enum_info - fills the info structure for an enumerated control + * @info: the structure to be filled + * @channels: the number of the control's channels; often one + * @items: the number of control values; also the size of @names + * @names: an array containing the names of all control values + * + * Sets all required fields in @info to their appropriate values. + * If the control's accessibility is not the default (readable and writable), + * the caller has to fill @info->access. + * + * Return: Zero (always successful) + */ +int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels, + unsigned int items, const char *const names[]) +{ + info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED; + info->count = channels; + info->value.enumerated.items = items; + if (!items) + return 0; + if (info->value.enumerated.item >= items) + info->value.enumerated.item = items - 1; + WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name), + "ALSA: too long item name '%s'\n", + names[info->value.enumerated.item]); + strscpy(info->value.enumerated.name, + names[info->value.enumerated.item], + sizeof(info->value.enumerated.name)); + return 0; +} +EXPORT_SYMBOL(snd_ctl_enum_info); 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