drm/atomic: Allow drivers to subclass drm_atomic_state, v3

Drivers may need to store the state of shared resources, such as PLLs
or FIFO space, into the atomic state. Allow this by making it possible
to subclass drm_atomic_state.

Changes since v1:
- Change member names for functions to atomic_state_(alloc,clear)
- Change __drm_atomic_state_new to drm_atomic_state_init
- Allow free function to be overridden too, in case extra memory is
  allocated in alloc.
Changes since v2:
- Rename *_default_free to default_release, to make clear it doesn't
  free the state object itself.

Cc: dri-devel@lists.freedesktop.org
Acked-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 11 insertions, 0 deletions

diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index d78543067700..f0d3a7387d99 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -35,6 +35,11 @@ drm_atomic_state_alloc(struct drm_device *dev);
 void drm_atomic_state_clear(struct drm_atomic_state *state);
 void drm_atomic_state_free(struct drm_atomic_state *state);
 
+int  __must_check
+drm_atomic_state_init(struct drm_device *dev, struct drm_atomic_state *state);
+void drm_atomic_state_default_clear(struct drm_atomic_state *state);
+void drm_atomic_state_default_release(struct drm_atomic_state *state);
+
 struct drm_crtc_state * __must_check
 drm_atomic_get_crtc_state(struct drm_atomic_state *state,
                           struct drm_crtc *crtc);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 5626191f3af0..37c44f27cb9f 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -979,6 +979,9 @@ struct drm_mode_set {
  * @atomic_check: check whether a given atomic state update is possible
  * @atomic_commit: commit an atomic state update previously verified with
  *      atomic_check()
+ * @atomic_state_alloc: allocate a new atomic state
+ * @atomic_state_clear: clear the atomic state
+ * @atomic_state_free: free the atomic state
  *
  * Some global (i.e. not per-CRTC, connector, etc) mode setting functions that
  * involve drivers.
@@ -994,6 +997,9 @@ struct drm_mode_config_funcs {
         int (*atomic_commit)(struct drm_device *dev,
                              struct drm_atomic_state *a,
                              bool async);
+        struct drm_atomic_state *(*atomic_state_alloc)(struct drm_device *dev);
+        void (*atomic_state_clear)(struct drm_atomic_state *state);
+        void (*atomic_state_free)(struct drm_atomic_state *state);
 };
 
 /**