With checks! This will allow safe access to the current state, while ensuring that the correct locks are held.
Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com --- include/drm/drm_atomic.h | 66 ++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_modeset_lock.h | 21 ++++++++++++++ 2 files changed, 87 insertions(+)
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index e527684dd394..462408a2d1b8 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -334,6 +334,72 @@ __drm_atomic_get_current_plane_state(struct drm_atomic_state *state, return plane->state; }
+ +/** + * drm_atomic_get_current_plane_state - get current plane state + * @plane: plane to grab + * + * This function returns the current plane state for the given plane, + * with extra locking checks to make sure that the plane state can be + * retrieved safely. + * + * Returns: + * + * Pointer to the current plane state. + */ +static inline struct drm_plane_state * +drm_atomic_get_current_plane_state(struct drm_plane *plane) +{ + struct drm_plane_state *plane_state = plane->state; + struct drm_crtc *crtc = plane_state ? plane_state->crtc : NULL; + + if (crtc) + drm_modeset_lock_assert_one_held(&plane->mutex, &crtc->mutex); + else + drm_modeset_lock_assert_held(&plane->mutex); + + return plane_state; +} + +/** + * drm_atomic_get_current_crtc_state - get current crtc state + * @crtc: crtc to grab + * + * This function returns the current crtc state for the given crtc, + * with extra locking checks to make sure that the crtc state can be + * retrieved safely. + * + * Returns: + * + * Pointer to the current crtc state. + */ +static inline struct drm_crtc_state * +drm_atomic_get_current_crtc_state(struct drm_crtc *crtc) +{ + drm_modeset_lock_assert_held(&crtc->mutex); + + return crtc->state; +} + +/** + * drm_atomic_get_current_connector_state - get current connector state + * @connector: connector to grab + * + * This function returns the current connector state for the given connector, + * with extra locking checks to make sure that the connector state can be + * retrieved safely. + * + * Returns: + * + * Pointer to the current connector state. + */ +#define drm_atomic_get_current_connector_state(connector) \ +({ /* Implemented as macro to avoid including drmP for struct drm_device */ \ + struct drm_connector *con__ = (connector); \ + drm_modeset_lock_assert_held(&con__->dev->mode_config.connection_mutex); \ + con__->state; \ +}) + int __must_check drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state, struct drm_display_mode *mode); diff --git a/include/drm/drm_modeset_lock.h b/include/drm/drm_modeset_lock.h index d918ce45ec2c..7635ff18ab99 100644 --- a/include/drm/drm_modeset_lock.h +++ b/include/drm/drm_modeset_lock.h @@ -109,6 +109,27 @@ static inline bool drm_modeset_is_locked(struct drm_modeset_lock *lock) return ww_mutex_is_locked(&lock->mutex); }
+static inline void drm_modeset_lock_assert_held(struct drm_modeset_lock *lock) +{ +#ifdef CONFIG_LOCKDEP + lockdep_assert_held(&lock->mutex.base); +#else + WARN_ON(!drm_modeset_is_locked(lock)); +#endif +} + +static inline void drm_modeset_lock_assert_one_held(struct drm_modeset_lock *lock1, + struct drm_modeset_lock *lock2) +{ +#ifdef CONFIG_LOCKDEP + WARN_ON(debug_locks && + !lockdep_is_held(&lock1->mutex.base) && + !lockdep_is_held(&lock2->mutex.base)); +#else + WARN_ON(!drm_modeset_is_locked(lock1) && !drm_modeset_is_locked(lock2)); +#endif +} + int drm_modeset_lock(struct drm_modeset_lock *lock, struct drm_modeset_acquire_ctx *ctx); int drm_modeset_lock_interruptible(struct drm_modeset_lock *lock,