diff options
Diffstat (limited to 'sys/dev/pci/drm')
| -rw-r--r-- | sys/dev/pci/drm/drm_auth.c | 25 | ||||
| -rw-r--r-- | sys/dev/pci/drm/include/drm/drm_auth.h | 1 | ||||
| -rw-r--r-- | sys/dev/pci/drm/include/drm/drm_file.h | 6 |
3 files changed, 32 insertions, 0 deletions
diff --git a/sys/dev/pci/drm/drm_auth.c b/sys/dev/pci/drm/drm_auth.c index a711e05c700..e8ead2bd29a 100644 --- a/sys/dev/pci/drm/drm_auth.c +++ b/sys/dev/pci/drm/drm_auth.c @@ -382,6 +382,31 @@ struct drm_master *drm_master_get(struct drm_master *master) } EXPORT_SYMBOL(drm_master_get); +/** + * drm_file_get_master - reference &drm_file.master of @file_priv + * @file_priv: DRM file private + * + * Increments the reference count of @file_priv's &drm_file.master and returns + * the &drm_file.master. If @file_priv has no &drm_file.master, returns NULL. + * + * Master pointers returned from this function should be unreferenced using + * drm_master_put(). + */ +struct drm_master *drm_file_get_master(struct drm_file *file_priv) +{ + struct drm_master *master = NULL; + + spin_lock(&file_priv->master_lookup_lock); + if (!file_priv->master) + goto unlock; + master = drm_master_get(file_priv->master); + +unlock: + spin_unlock(&file_priv->master_lookup_lock); + return master; +} +EXPORT_SYMBOL(drm_file_get_master); + static void drm_master_destroy(struct kref *kref) { struct drm_master *master = container_of(kref, struct drm_master, refcount); diff --git a/sys/dev/pci/drm/include/drm/drm_auth.h b/sys/dev/pci/drm/include/drm/drm_auth.h index 6bf8b2b7899..f99d3417f30 100644 --- a/sys/dev/pci/drm/include/drm/drm_auth.h +++ b/sys/dev/pci/drm/include/drm/drm_auth.h @@ -107,6 +107,7 @@ struct drm_master { }; struct drm_master *drm_master_get(struct drm_master *master); +struct drm_master *drm_file_get_master(struct drm_file *file_priv); void drm_master_put(struct drm_master **master); bool drm_is_current_master(struct drm_file *fpriv); diff --git a/sys/dev/pci/drm/include/drm/drm_file.h b/sys/dev/pci/drm/include/drm/drm_file.h index 9decb43c711..ac50dd66602 100644 --- a/sys/dev/pci/drm/include/drm/drm_file.h +++ b/sys/dev/pci/drm/include/drm/drm_file.h @@ -237,6 +237,12 @@ struct drm_file { * this only matches &drm_device.master if the master is the currently * active one. * + * When dereferencing this pointer, either hold struct + * &drm_device.master_mutex for the duration of the pointer's use, or + * use drm_file_get_master() if struct &drm_device.master_mutex is not + * currently held and there is no other need to hold it. This prevents + * @master from being freed during use. + * * See also @authentication and @is_master and the :ref:`section on * primary nodes and authentication <drm_primary_node>`. */ |