ALSA: core: reduce stack usage related to snd_ctl_new()
The callers of snd_ctl_new() need to have 'struct snd_kcontrol' data, and pass the data as template. Then, the function allocates the structure data again and copy from the template. This is a waste of resources. Especially, the callers use large stack for the template. This commit removes a need of template for the function, thus, changes the prototype of snd_ctl_new(). Furthermore, this commit changes the code of callers, snd_ctl_new1() and snd_ctl_elem_add() for better shape. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto
Takashi Iwai
parent
4ed56666b7
commit
2225e79b9b
1 changed files with 131 additions and 84 deletions
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@ -192,36 +192,43 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask,
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EXPORT_SYMBOL(snd_ctl_notify);
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/**
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* snd_ctl_new - create a control instance from the template
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* @control: the control template
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* @access: the default control access
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* snd_ctl_new - create a new control instance with some elements
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* @kctl: the pointer to store new control instance
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* @count: the number of elements in this control
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* @access: the default access flags for elements in this control
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* @file: given when locking these elements
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*
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* Allocates a new struct snd_kcontrol instance and copies the given template
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* to the new instance. It does not copy volatile data (access).
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* Allocates a memory object for a new control instance. The instance has
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* elements as many as the given number (@count). Each element has given
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* access permissions (@access). Each element is locked when @file is given.
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*
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* Return: The pointer of the new instance, or %NULL on failure.
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* Return: 0 on success, error code on failure
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*/
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static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
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unsigned int access)
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static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
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unsigned int access, struct snd_ctl_file *file)
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{
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struct snd_kcontrol *kctl;
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unsigned int size;
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unsigned int idx;
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if (snd_BUG_ON(!control || !control->count))
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return NULL;
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if (count == 0 || count > MAX_CONTROL_COUNT)
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return -EINVAL;
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if (control->count > MAX_CONTROL_COUNT)
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return NULL;
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size = sizeof(struct snd_kcontrol);
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size += sizeof(struct snd_kcontrol_volatile) * count;
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kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
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if (kctl == NULL) {
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*kctl = kzalloc(size, GFP_KERNEL);
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if (*kctl == NULL) {
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pr_err("ALSA: Cannot allocate control instance\n");
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return NULL;
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return -ENOMEM;
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}
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*kctl = *control;
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for (idx = 0; idx < kctl->count; idx++)
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kctl->vd[idx].access = access;
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return kctl;
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for (idx = 0; idx < count; idx++) {
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(*kctl)->vd[idx].access = access;
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(*kctl)->vd[idx].owner = file;
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}
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(*kctl)->count = count;
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return 0;
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}
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/**
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@ -238,37 +245,53 @@ static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
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struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
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void *private_data)
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{
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struct snd_kcontrol kctl;
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struct snd_kcontrol *kctl;
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unsigned int count;
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unsigned int access;
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int err;
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if (snd_BUG_ON(!ncontrol || !ncontrol->info))
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return NULL;
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memset(&kctl, 0, sizeof(kctl));
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kctl.id.iface = ncontrol->iface;
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kctl.id.device = ncontrol->device;
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kctl.id.subdevice = ncontrol->subdevice;
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count = ncontrol->count;
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if (count == 0)
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count = 1;
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access = ncontrol->access;
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if (access == 0)
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access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
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access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
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SNDRV_CTL_ELEM_ACCESS_VOLATILE |
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SNDRV_CTL_ELEM_ACCESS_INACTIVE |
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SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
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SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
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SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
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err = snd_ctl_new(&kctl, count, access, NULL);
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if (err < 0)
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return NULL;
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/* The 'numid' member is decided when calling snd_ctl_add(). */
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kctl->id.iface = ncontrol->iface;
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kctl->id.device = ncontrol->device;
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kctl->id.subdevice = ncontrol->subdevice;
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if (ncontrol->name) {
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strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
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if (strcmp(ncontrol->name, kctl.id.name) != 0)
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strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
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if (strcmp(ncontrol->name, kctl->id.name) != 0)
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pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
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ncontrol->name, kctl.id.name);
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ncontrol->name, kctl->id.name);
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}
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kctl.id.index = ncontrol->index;
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kctl.count = ncontrol->count ? ncontrol->count : 1;
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access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
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(ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
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SNDRV_CTL_ELEM_ACCESS_VOLATILE|
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SNDRV_CTL_ELEM_ACCESS_INACTIVE|
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SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
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SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
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SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
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kctl.info = ncontrol->info;
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kctl.get = ncontrol->get;
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kctl.put = ncontrol->put;
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kctl.tlv.p = ncontrol->tlv.p;
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kctl.private_value = ncontrol->private_value;
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kctl.private_data = private_data;
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return snd_ctl_new(&kctl, access);
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kctl->id.index = ncontrol->index;
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kctl->info = ncontrol->info;
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kctl->get = ncontrol->get;
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kctl->put = ncontrol->put;
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kctl->tlv.p = ncontrol->tlv.p;
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kctl->private_value = ncontrol->private_value;
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kctl->private_data = private_data;
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return kctl;
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}
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EXPORT_SYMBOL(snd_ctl_new1);
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@ -1179,44 +1202,48 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
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[SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
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};
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struct snd_card *card = file->card;
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struct snd_kcontrol kctl, *_kctl;
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struct snd_kcontrol *kctl;
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unsigned int count;
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unsigned int access;
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long private_size;
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struct user_element *ue;
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int idx, err;
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access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
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(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
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SNDRV_CTL_ELEM_ACCESS_INACTIVE|
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SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
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info->id.numid = 0;
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memset(&kctl, 0, sizeof(kctl));
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int err;
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/* Delete a control to replace them if needed. */
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if (replace) {
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info->id.numid = 0;
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err = snd_ctl_remove_user_ctl(file, &info->id);
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if (err)
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return err;
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}
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if (card->user_ctl_count >= MAX_USER_CONTROLS)
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/*
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* The number of userspace controls are counted control by control,
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* not element by element.
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*/
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if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
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return -ENOMEM;
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memcpy(&kctl.id, &info->id, sizeof(info->id));
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kctl.count = info->owner ? info->owner : 1;
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access |= SNDRV_CTL_ELEM_ACCESS_USER;
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if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
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kctl.info = snd_ctl_elem_user_enum_info;
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else
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kctl.info = snd_ctl_elem_user_info;
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if (access & SNDRV_CTL_ELEM_ACCESS_READ)
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kctl.get = snd_ctl_elem_user_get;
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if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
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kctl.put = snd_ctl_elem_user_put;
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if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
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kctl.tlv.c = snd_ctl_elem_user_tlv;
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access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
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}
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/* Check the number of elements for this userspace control. */
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count = info->owner;
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if (count == 0)
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count = 1;
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/* Arrange access permissions if needed. */
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access = info->access;
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if (access == 0)
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access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
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access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
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SNDRV_CTL_ELEM_ACCESS_INACTIVE |
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SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
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if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
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access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
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access |= SNDRV_CTL_ELEM_ACCESS_USER;
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/*
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* Check information and calculate the size of data specific to
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* this userspace control.
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*/
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if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
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info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
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return -EINVAL;
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@ -1226,11 +1253,27 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
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if (info->count < 1 ||
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info->count > max_value_counts[info->type])
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return -EINVAL;
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private_size = value_sizes[info->type] * info->count;
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ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
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if (ue == NULL)
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/*
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* Keep memory object for this userspace control. After passing this
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* code block, the instance should be freed by snd_ctl_free_one().
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*
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* Note that these elements in this control are locked.
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*/
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err = snd_ctl_new(&kctl, count, access, file);
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if (err < 0)
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return err;
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kctl->private_data = kzalloc(sizeof(struct user_element) + private_size,
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GFP_KERNEL);
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if (kctl->private_data == NULL) {
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kfree(kctl);
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return -ENOMEM;
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}
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kctl->private_free = snd_ctl_elem_user_free;
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/* Set private data for this userspace control. */
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ue = (struct user_element *)kctl->private_data;
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ue->card = card;
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ue->info = *info;
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ue->info.access = 0;
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@ -1239,21 +1282,25 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
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if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
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err = snd_ctl_elem_init_enum_names(ue);
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if (err < 0) {
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kfree(ue);
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snd_ctl_free_one(kctl);
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return err;
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}
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}
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kctl.private_free = snd_ctl_elem_user_free;
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_kctl = snd_ctl_new(&kctl, access);
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if (_kctl == NULL) {
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kfree(ue->priv_data);
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kfree(ue);
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return -ENOMEM;
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}
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_kctl->private_data = ue;
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for (idx = 0; idx < _kctl->count; idx++)
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_kctl->vd[idx].owner = file;
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err = snd_ctl_add(card, _kctl);
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/* Set callback functions. */
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if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
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kctl->info = snd_ctl_elem_user_enum_info;
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else
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kctl->info = snd_ctl_elem_user_info;
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if (access & SNDRV_CTL_ELEM_ACCESS_READ)
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kctl->get = snd_ctl_elem_user_get;
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if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
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kctl->put = snd_ctl_elem_user_put;
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if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
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kctl->tlv.c = snd_ctl_elem_user_tlv;
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/* This function manage to free the instance on failure. */
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err = snd_ctl_add(card, kctl);
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if (err < 0)
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return err;
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