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-rw-r--r--sound/core/control.c2478
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);