/**
* Get a unique magic number (ioctl).
*
* \param inode device inode.
* \param filp file pointer.
* \param cmd command.
* \param arg pointer to a resulting drm_auth structure.
* \return zero on success, or a negative number on failure.
*
* If there is a magic number in drm_file::magic then use it, otherwise
* searches an unique non-zero magic number and add it associating it with \p
* filp.
*/
int drm_getmagic(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
static drm_magic_t sequence = 0;
static DEFINE_SPINLOCK(lock);
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_auth_t auth;
/* Find unique magic */
if (priv->magic) {
auth.magic = priv->magic;
} else {
do {
spin_lock(&lock);
if (!sequence) ++sequence; /* reserve 0 */
auth.magic = sequence++;
spin_unlock(&lock);
} while (drm_find_file(dev, auth.magic));
priv->magic = auth.magic;
drm_add_magic(dev, priv, auth.magic);
}
DRM_DEBUG("%u\n", auth.magic);
if (copy_to_user((drm_auth_t __user *)arg, &auth, sizeof(auth)))
return -EFAULT;
return 0;
}
/**
* Called by the client, this returns a unique magic number to be authorized
* by the master.
*
* The master may use its own knowledge of the client (such as the X
* connection that the magic is passed over) to determine if the magic number
* should be authenticated.
*/
int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
static drm_magic_t sequence = 0;
struct drm_auth *auth = data;
/* Find unique magic */
if (file_priv->magic) {
auth->magic = file_priv->magic;
} else {
DRM_LOCK();
do {
int old = sequence;
auth->magic = old+1;
if (!atomic_cmpset_int(&sequence, old, auth->magic))
continue;
} while (drm_find_file(dev, auth->magic));
file_priv->magic = auth->magic;
drm_add_magic(dev, file_priv, auth->magic);
DRM_UNLOCK();
}
DRM_DEBUG("%u\n", auth->magic);
return 0;
}
/*ARGSUSED*/
int
drm_getmagic(DRM_IOCTL_ARGS)
{
DRM_DEVICE;
static drm_magic_t sequence = 0;
drm_auth_t auth;
/* Find unique magic */
if (fpriv->magic) {
auth.magic = fpriv->magic;
} else {
do {
int old = sequence;
auth.magic = old+1;
if (!atomic_cmpset_int(&sequence, old, auth.magic))
continue;
} while (drm_find_file(dev, auth.magic));
fpriv->magic = auth.magic;
(void) drm_add_magic(dev, fpriv, auth.magic);
}
DRM_DEBUG("drm_getmagic: %u", auth.magic);
DRM_COPYTO_WITH_RETURN((void *)data, &auth, sizeof (auth));
return (0);
}
/**
* Get a unique magic number (ioctl).
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg pointer to a resulting drm_auth structure.
* \return zero on success, or a negative number on failure.
*
* If there is a magic number in drm_file::magic then use it, otherwise
* searches an unique non-zero magic number and add it associating it with \p
* file_priv.
* This ioctl needs protection by the drm_global_mutex, which protects
* struct drm_file::magic and struct drm_magic_entry::priv.
*/
int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
static drm_magic_t sequence = 0;
static struct spinlock lock = SPINLOCK_INITIALIZER(&lock, "drm_gm");
struct drm_auth *auth = data;
/* Find unique magic */
if (file_priv->magic) {
auth->magic = file_priv->magic;
} else {
do {
spin_lock(&lock);
if (!sequence)
++sequence; /* reserve 0 */
auth->magic = sequence++;
spin_unlock(&lock);
} while (drm_find_file(dev, auth->magic));
file_priv->magic = auth->magic;
drm_add_magic(dev, file_priv, auth->magic);
}
DRM_DEBUG("%u\n", auth->magic);
return 0;
}
int drm_getmagic(DRM_IOCTL_ARGS)
{
DRM_DEVICE;
static drm_magic_t sequence = 0;
drm_auth_t auth;
drm_file_t *priv;
DRM_LOCK();
priv = drm_find_file_by_proc(dev, p);
DRM_UNLOCK();
if (priv == NULL) {
DRM_ERROR("can't find authenticator\n");
return EINVAL;
}
/* Find unique magic */
if (priv->magic) {
auth.magic = priv->magic;
} else {
do {
int old = sequence;
auth.magic = old+1;
if (!atomic_cmpset_int(&sequence, old, auth.magic))
continue;
} while (drm_find_file(dev, auth.magic));
priv->magic = auth.magic;
drm_add_magic(dev, priv, auth.magic);
}
DRM_DEBUG("%u\n", auth.magic);
DRM_COPY_TO_USER_IOCTL((drm_auth_t *)data, auth, sizeof(auth));
return 0;
}
