@@ -98,10 +98,10 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
struct drm_master *master;
int ret = 0;
- mutex_lock(&dev->master_mutex);
+ spin_lock(&dev->master_lookup_lock);
master = file_priv->master;
if (!master) {
- mutex_unlock(&dev->master_mutex);
+ spin_unlock(&dev->master_lookup_lock);
return -EINVAL;
}
@@ -112,7 +112,7 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
file_priv->magic = ret;
}
auth->magic = file_priv->magic;
- mutex_unlock(&dev->master_mutex);
+ spin_unlock(&dev->master_lookup_lock);
DRM_DEBUG("%u\n", auth->magic);
@@ -127,13 +127,13 @@ int drm_authmagic(struct drm_device *dev, void *data,
DRM_DEBUG("%u\n", auth->magic);
- mutex_lock(&dev->master_mutex);
+ spin_lock(&dev->master_lookup_lock);
file = idr_find(&file_priv->master->magic_map, auth->magic);
if (file) {
file->authenticated = 1;
idr_replace(&file_priv->master->magic_map, NULL, auth->magic);
}
- mutex_unlock(&dev->master_mutex);
+ spin_unlock(&dev->master_lookup_lock);
return file ? 0 : -EINVAL;
}
@@ -366,8 +366,10 @@ void drm_master_release(struct drm_file *file_priv)
if (!master)
goto unlock;
+ spin_lock(&dev->master_lookup_lock);
if (file_priv->magic)
idr_remove(&master->magic_map, file_priv->magic);
+ spin_unlock(&dev->master_lookup_lock);
if (!drm_is_current_master_locked(file_priv))
goto out;
@@ -119,21 +119,21 @@ int drm_getunique(struct drm_device *dev, void *data,
struct drm_unique *u = data;
struct drm_master *master;
- mutex_lock(&dev->master_mutex);
+ spin_lock(&dev->master_lookup_lock);
master = file_priv->master;
if (!master) {
- mutex_unlock(&dev->master_mutex);
+ spin_unlock(&dev->master_lookup_lock);
return -EINVAL;
}
if (u->unique_len >= master->unique_len) {
if (copy_to_user(u->unique, master->unique, master->unique_len)) {
- mutex_unlock(&dev->master_mutex);
+ spin_unlock(&dev->master_lookup_lock);
return -EFAULT;
}
}
u->unique_len = master->unique_len;
- mutex_unlock(&dev->master_mutex);
+ spin_unlock(&dev->master_lookup_lock);
return 0;
}
@@ -405,7 +405,9 @@ static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *f
* Version 1.1 includes tying of DRM to specific device
* Version 1.4 has proper PCI domain support
*/
+ spin_lock(&dev->master_lookup_lock);
retcode = drm_set_busid(dev, file_priv);
+ spin_unlock(&dev->master_lookup_lock);
if (retcode)
goto done;
}
@@ -67,17 +67,17 @@ struct drm_master {
struct drm_device *dev;
/**
* @unique: Unique identifier: e.g. busid. Protected by
- * &drm_device.master_mutex.
+ * &drm_device.master_lookup_lock.
*/
char *unique;
/**
* @unique_len: Length of unique field. Protected by
- * &drm_device.master_mutex.
+ * &drm_device.master_lookup_lock.
*/
int unique_len;
/**
* @magic_map: Map of used authentication tokens. Protected by
- * &drm_device.master_mutex.
+ * &drm_device.master_lookup_lock.
*/
struct idr magic_map;
void *driver_priv;
@@ -152,7 +152,12 @@ struct drm_device {
*/
struct mutex master_mutex;
- /** @master_lookup_lock: Serializes &drm_file.master. */
+ /**
+ * @master_lookup_lock:
+ *
+ * Serializes &drm_file.master, &drm_master.magic_map,
+ * &drm_master.unique, and &drm_master.unique_len.
+ */
spinlock_t master_lookup_lock;
/**
Currently, drm_device.master_mutex is used to serialize writes to the drm_master.magic_map idr and to protect drm_master.unique{_len}. In preparation for converting drm_device.master_mutex into an outer rwsem that might be read locked before entering some of these functions, we can instead serialize access to drm_master.magic_map and drm_master.unique{_len} using drm_device.master_lookup_lock which is an inner lock. Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> --- drivers/gpu/drm/drm_auth.c | 12 +++++++----- drivers/gpu/drm/drm_ioctl.c | 10 ++++++---- include/drm/drm_auth.h | 6 +++--- include/drm/drm_device.h | 7 ++++++- 4 files changed, 22 insertions(+), 13 deletions(-)