control.c

Linux Kernel 2.6.9 for OMAP1710

		return -ENOENT;
	}
	kctl->id = *dst_id;
	kctl->id.numid = card->last_numid + 1;
	card->last_numid += kctl->count;
	up_write(&card->controls_rwsem);
	return 0;
}

/**
 * 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.
 *
 * Returns the pointer of the instance if found, or NULL if not.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
 */
snd_kcontrol_t *snd_ctl_find_numid(snd_card_t * card, unsigned int numid)
{
	struct list_head *list;
	snd_kcontrol_t *kctl;

	snd_runtime_check(card != NULL && numid != 0, return NULL);
	list_for_each(list, &card->controls) {
		kctl = snd_kcontrol(list);
		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
			return kctl;
	}
	return NULL;
}

/**
 * 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.
 *
 * Returns the pointer of the instance if found, or NULL if not.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
 */
snd_kcontrol_t *snd_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id)
{
	struct list_head *list;
	snd_kcontrol_t *kctl;

	snd_runtime_check(card != NULL && id != NULL, return NULL);
	if (id->numid != 0)
		return snd_ctl_find_numid(card, id->numid);
	list_for_each(list, &card->controls) {
		kctl = snd_kcontrol(list);
		if (kctl->id.iface != id->iface)
			continue;
		if (kctl->id.device != id->device)
			continue;
		if (kctl->id.subdevice != id->subdevice)
			continue;
		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
			continue;
		if (kctl->id.index > id->index)
			continue;
		if (kctl->id.index + kctl->count <= id->index)
			continue;
		return kctl;
	}
	return NULL;
}

static int snd_ctl_card_info(snd_card_t * card, snd_ctl_file_t * ctl,
			     unsigned int cmd, void __user *arg)
{
	snd_ctl_card_info_t info;

	memset(&info, 0, sizeof(info));
	down_read(&snd_ioctl_rwsem);
	info.card = card->number;
	strlcpy(info.id, card->id, sizeof(info.id));
	strlcpy(info.driver, card->driver, sizeof(info.driver));
	strlcpy(info.name, card->shortname, sizeof(info.name));
	strlcpy(info.longname, card->longname, sizeof(info.longname));
	strlcpy(info.mixername, card->mixername, sizeof(info.mixername));
	strlcpy(info.components, card->components, sizeof(info.components));
	up_read(&snd_ioctl_rwsem);
	if (copy_to_user(arg, &info, sizeof(snd_ctl_card_info_t)))
		return -EFAULT;
	return 0;
}

static int snd_ctl_elem_list(snd_card_t *card, snd_ctl_elem_list_t __user *_list)
{
	struct list_head *plist;
	snd_ctl_elem_list_t list;
	snd_kcontrol_t *kctl;
	snd_ctl_elem_id_t *dst, *id;
	unsigned int offset, space, first, jidx;
	
	if (copy_from_user(&list, _list, sizeof(list)))
		return -EFAULT;
	offset = list.offset;
	space = list.space;
	first = 0;
	/* try limit maximum space */
	if (space > 16384)
		return -ENOMEM;
	if (space > 0) {
		/* allocate temporary buffer for atomic operation */
		dst = vmalloc(space * sizeof(snd_ctl_elem_id_t));
		if (dst == NULL)
			return -ENOMEM;
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		plist = card->controls.next;
		while (plist != &card->controls) {
			if (offset == 0)
				break;
			kctl = snd_kcontrol(plist);
			if (offset < kctl->count)
				break;
			offset -= kctl->count;
			plist = plist->next;
		}
		list.used = 0;
		id = dst;
		while (space > 0 && plist != &card->controls) {
			kctl = snd_kcontrol(plist);
			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
				snd_ctl_build_ioff(id, kctl, jidx);
				id++;
				space--;
				list.used++;
			}
			plist = plist->next;
			offset = 0;
		}
		up_read(&card->controls_rwsem);
		if (list.used > 0 && copy_to_user(list.pids, dst, list.used * sizeof(snd_ctl_elem_id_t))) {
			vfree(dst);
			return -EFAULT;
		}
		vfree(dst);
	} else {
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		up_read(&card->controls_rwsem);
	}
	if (copy_to_user(_list, &list, sizeof(list)))
		return -EFAULT;
	return 0;
}

static int snd_ctl_elem_info(snd_ctl_file_t *ctl, snd_ctl_elem_info_t __user *_info)
{
	snd_card_t *card = ctl->card;
	snd_ctl_elem_info_t info;
	snd_kcontrol_t *kctl;
	snd_kcontrol_volatile_t *vd;
	unsigned int index_offset;
	int result;
	
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &info.id);
	if (kctl == NULL) {
		up_read(&card->controls_rwsem);
		return -ENOENT;
	}
#ifdef CONFIG_SND_DEBUG
	info.access = 0;
#endif
	result = kctl->info(kctl, &info);
	if (result >= 0) {
		snd_assert(info.access == 0, );
		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 = vd->owner_pid;
		} else {
			info.owner = -1;
		}
	}
	up_read(&card->controls_rwsem);
	if (result >= 0)
		if (copy_to_user(_info, &info, sizeof(info)))
			return -EFAULT;
	return result;
}

static int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t __user *_control)
{
	snd_ctl_elem_value_t *control;
	snd_kcontrol_t *kctl;
	snd_kcontrol_volatile_t *vd;
	unsigned int index_offset;
	int result, indirect;
	
	control = kmalloc(sizeof(*control), GFP_KERNEL);
	if (control == NULL)
		return -ENOMEM;	
	if (copy_from_user(control, _control, sizeof(*control)))
		return -EFAULT;
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
		if (control->indirect != indirect) {
			result = -EACCES;
		} else {
			if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
				snd_ctl_build_ioff(&control->id, kctl, index_offset);
				result = kctl->get(kctl, control);
			} else {
				result = -EPERM;
			}
		}
	}
	up_read(&card->controls_rwsem);
	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			return -EFAULT;
	kfree(control);
	return result;
}

static int snd_ctl_elem_write(snd_ctl_file_t *file, snd_ctl_elem_value_t __user *_control)
{
	snd_card_t *card = file->card;
	snd_ctl_elem_value_t *control;
	snd_kcontrol_t *kctl;
	snd_kcontrol_volatile_t *vd;
	unsigned int index_offset;
	int result, indirect;

	control = kmalloc(sizeof(*control), GFP_KERNEL);
	if (control == NULL)
		return -ENOMEM;	
	if (copy_from_user(control, _control, sizeof(*control)))
		return -EFAULT;
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
		if (control->indirect != indirect) {
			result = -EACCES;
		} else {
			if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
			    kctl->put == NULL ||
			    (vd->owner != NULL && vd->owner != file)) {
				result = -EPERM;
			} else {
				snd_ctl_build_ioff(&control->id, kctl, index_offset);
				result = kctl->put(kctl, control);
			}
			if (result > 0) {
				up_read(&card->controls_rwsem);
				snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
				result = 0;
				goto __unlocked;
			}
		}
	}
	up_read(&card->controls_rwsem);
      __unlocked:
	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			return -EFAULT;
	kfree(control);
	return result;
}

static int snd_ctl_elem_lock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
{
	snd_card_t *card = file->card;
	snd_ctl_elem_id_t id;
	snd_kcontrol_t *kctl;
	snd_kcontrol_volatile_t *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;
			vd->owner_pid = current->pid;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

static int snd_ctl_elem_unlock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
{
	snd_card_t *card = file->card;
	snd_ctl_elem_id_t id;
	snd_kcontrol_t *kctl;
	snd_kcontrol_volatile_t *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;
			vd->owner_pid = 0;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

struct user_element {
	enum sndrv_ctl_elem_type type;	/* element type */
	unsigned int elem_count;	/* count of elements */
	union {
		struct {
			unsigned int items;
		} enumerated;
	} u;
	void *elem_data;		/* element data */
	unsigned long elem_data_size;	/* size of element data in bytes */
	void *priv_data;		/* private data (like strings for enumerated type) */
	unsigned long priv_data_size;	/* size of private data in bytes */
	unsigned short dimen_count;	/* count of dimensions */
	unsigned short dimen[0];	/* array of dimensions */
};

static int snd_ctl_elem_user_info(snd_kcontrol_t *kcontrol, snd_ctl_elem_info_t *uinfo)
{
	struct user_element *ue = kcontrol->private_data;

	uinfo->type = ue->type;
	uinfo->count = ue->elem_count;
	if (ue->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
		uinfo->value.enumerated.items = ue->u.enumerated.items;
		if (uinfo->value.enumerated.item >= ue->u.enumerated.items)
			uinfo->value.enumerated.item = 0;
		strlcpy(uinfo->value.enumerated.name,
			(char *)ue->priv_data + uinfo->value.enumerated.item * 64,
			64);
	}
	return 0;
}

static int snd_ctl_elem_user_get(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
{
	struct user_element *ue = kcontrol->private_data;

	memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
	return 0;
}

static int snd_ctl_elem_user_put(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
{
	int change;
	struct user_element *ue = kcontrol->private_data;
	
	change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size);
	memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
	return !!change;
}

static void snd_ctl_elem_user_free(snd_kcontrol_t * kcontrol)
{
	kfree(kcontrol->private_data);
}

static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_info, int replace)
{
	snd_card_t *card = file->card;
	snd_ctl_elem_info_t info;
	snd_kcontrol_t kctl, *_kctl;
	unsigned int access;
	long private_size, dimen_size, extra_size;
	struct user_element *ue;
	int idx, err;
	
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
	if (info.count > 1024)
		return -EINVAL;
	access = info.access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
		 (info.access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
		 		 SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
	if (access & (SNDRV_CTL_ELEM_ACCESS_DINDIRECT | SNDRV_CTL_ELEM_ACCESS_INDIRECT))
		return -EINVAL;
	info.id.numid = 0;
	memset(&kctl, 0, sizeof(kctl));
	down_write(&card->controls_rwsem);
	if (!!((_kctl = snd_ctl_find_id(card, &info.id)) != NULL) ^ replace) {
		up_write(&card->controls_rwsem);
		return !replace ? -EBUSY : -ENOENT;
	}
	if (replace) {
		err = snd_ctl_remove(card, _kctl);
		if (err < 0) {
			up_write(&card->controls_rwsem);
			return err;
		}
	}
	up_write(&card->controls_rwsem);
	memcpy(&kctl.id, &info.id, sizeof(info.id));