The master_lookup_lock spinlock can be useful as an inner lock for other attributes that are currently protected by drm_device.master_mutex.
However, since the spinlock belongs to struct drm_file, its use case is limited to serializing accesses by a single drm_file. Moving this lock into struct drm_device allows us to use it for structures that are accessed by multiple drm_files, such as drm_master.magic_map.
Signed-off-by: Desmond Cheong Zhi Xi desmondcheongzx@gmail.com --- drivers/gpu/drm/drm_auth.c | 18 +++++++++--------- drivers/gpu/drm/drm_drv.c | 1 + drivers/gpu/drm/drm_file.c | 1 - include/drm/drm_device.h | 3 +++ include/drm/drm_file.h | 10 ++++------ 5 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index 60a6b21474b1..8efb58aa7d95 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -63,7 +63,7 @@
static bool drm_is_current_master_locked(struct drm_file *fpriv) { - lockdep_assert_once(lockdep_is_held(&fpriv->master_lookup_lock) || + lockdep_assert_once(lockdep_is_held(&fpriv->minor->dev->master_lookup_lock) || lockdep_is_held(&fpriv->minor->dev->master_mutex));
return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master; @@ -83,9 +83,9 @@ bool drm_is_current_master(struct drm_file *fpriv) { bool ret;
- spin_lock(&fpriv->master_lookup_lock); + spin_lock(&fpriv->minor->dev->master_lookup_lock); ret = drm_is_current_master_locked(fpriv); - spin_unlock(&fpriv->master_lookup_lock); + spin_unlock(&fpriv->minor->dev->master_lookup_lock);
return ret; } @@ -174,9 +174,9 @@ static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) new_master = drm_master_create(dev); if (!new_master) return -ENOMEM; - spin_lock(&fpriv->master_lookup_lock); + spin_lock(&dev->master_lookup_lock); fpriv->master = new_master; - spin_unlock(&fpriv->master_lookup_lock); + spin_unlock(&dev->master_lookup_lock);
fpriv->is_master = 1; fpriv->authenticated = 1; @@ -338,9 +338,9 @@ int drm_master_open(struct drm_file *file_priv) if (!dev->master) { ret = drm_new_set_master(dev, file_priv); } else { - spin_lock(&file_priv->master_lookup_lock); + spin_lock(&dev->master_lookup_lock); file_priv->master = drm_master_get(dev->master); - spin_unlock(&file_priv->master_lookup_lock); + spin_unlock(&dev->master_lookup_lock); } mutex_unlock(&dev->master_mutex);
@@ -405,13 +405,13 @@ struct drm_master *drm_file_get_master(struct drm_file *file_priv) { struct drm_master *master = NULL;
- spin_lock(&file_priv->master_lookup_lock); + spin_lock(&file_priv->minor->dev->master_lookup_lock); if (!file_priv->master) goto unlock; master = drm_master_get(file_priv->master);
unlock: - spin_unlock(&file_priv->master_lookup_lock); + spin_unlock(&file_priv->minor->dev->master_lookup_lock); return master; } EXPORT_SYMBOL(drm_file_get_master); diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 7a5097467ba5..218c16f11c80 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -612,6 +612,7 @@ static int drm_dev_init(struct drm_device *dev, mutex_init(&dev->filelist_mutex); mutex_init(&dev->clientlist_mutex); mutex_init(&dev->master_mutex); + spin_lock_init(&dev->master_lookup_lock);
ret = drmm_add_action(dev, drm_dev_init_release, NULL); if (ret) diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index ed25168619fc..b8679bbaea69 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -176,7 +176,6 @@ struct drm_file *drm_file_alloc(struct drm_minor *minor) init_waitqueue_head(&file->event_wait); file->event_space = 4096; /* set aside 4k for event buffer */
- spin_lock_init(&file->master_lookup_lock); mutex_init(&file->event_read_lock);
if (drm_core_check_feature(dev, DRIVER_GEM)) diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h index 604b1d1b2d72..506eb2784819 100644 --- a/include/drm/drm_device.h +++ b/include/drm/drm_device.h @@ -152,6 +152,9 @@ struct drm_device { */ struct mutex master_mutex;
+ /** @master_lookup_lock: Serializes &drm_file.master. */ + spinlock_t master_lookup_lock; + /** * @open_count: * diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h index a3acb7ac3550..0536e9612a46 100644 --- a/include/drm/drm_file.h +++ b/include/drm/drm_file.h @@ -227,15 +227,16 @@ struct drm_file { * @master: * * Master this node is currently associated with. Protected by struct - * &drm_device.master_mutex, and serialized by @master_lookup_lock. + * &drm_device.master_mutex, and serialized by + * &drm_device.master_lookup_lock. * * Only relevant if drm_is_primary_client() returns true. Note that * this only matches &drm_device.master if the master is the currently * active one. * * To update @master, both &drm_device.master_mutex and - * @master_lookup_lock need to be held, therefore holding either of - * them is safe and enough for the read side. + * &drm_device.master_lookup_lock need to be held, therefore holding + * either of them is safe and enough for the read side. * * When dereferencing this pointer, either hold struct * &drm_device.master_mutex for the duration of the pointer's use, or @@ -248,9 +249,6 @@ struct drm_file { */ struct drm_master *master;
- /** @master_lock: Serializes @master. */ - spinlock_t master_lookup_lock; - /** @pid: Process that opened this file. */ struct pid *pid;