drm/atomic: Make private objs proper objects

Make the atomic private object stuff less special by introducing proper
base classes for the object and its state. Drivers can embed these in
their own appropriate objects, after which these things will work
exactly like the plane/crtc/connector states during atomic operations.

v2: Reorder to not depend on drm_dynarray (Daniel)

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170712155102.26276-3-ville.syrjala@linux.intel.com

3 files changed, 115 insertions, 56 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index f0482247b31f..b59fd33c5786 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -187,12 +187,15 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
 	}
 
 	for (i = 0; i < state->num_private_objs; i++) {
-		void *obj_state = state->private_objs[i].obj_state;
+		struct drm_private_obj *obj = state->private_objs[i].ptr;
 
-		state->private_objs[i].funcs->destroy_state(obj_state);
-		state->private_objs[i].obj = NULL;
-		state->private_objs[i].obj_state = NULL;
-		state->private_objs[i].funcs = NULL;
+		if (!obj)
+			continue;
+
+		obj->funcs->atomic_destroy_state(obj,
+						 state->private_objs[i].state);
+		state->private_objs[i].ptr = NULL;
+		state->private_objs[i].state = NULL;
 	}
 	state->num_private_objs = 0;
 
@@ -990,11 +993,44 @@ static void drm_atomic_plane_print_state(struct drm_printer *p,
 }
 
 /**
+ * drm_atomic_private_obj_init - initialize private object
+ * @obj: private object
+ * @state: initial private object state
+ * @funcs: pointer to the struct of function pointers that identify the object
+ * type
+ *
+ * Initialize the private object, which can be embedded into any
+ * driver private object that needs its own atomic state.
+ */
+void
+drm_atomic_private_obj_init(struct drm_private_obj *obj,
+			    struct drm_private_state *state,
+			    const struct drm_private_state_funcs *funcs)
+{
+	memset(obj, 0, sizeof(*obj));
+
+	obj->state = state;
+	obj->funcs = funcs;
+}
+EXPORT_SYMBOL(drm_atomic_private_obj_init);
+
+/**
+ * drm_atomic_private_obj_fini - finalize private object
+ * @obj: private object
+ *
+ * Finalize the private object.
+ */
+void
+drm_atomic_private_obj_fini(struct drm_private_obj *obj)
+{
+	obj->funcs->atomic_destroy_state(obj, obj->state);
+}
+EXPORT_SYMBOL(drm_atomic_private_obj_fini);
+
+/**
  * drm_atomic_get_private_obj_state - get private object state
  * @state: global atomic state
  * @obj: private object to get the state for
- * @funcs: pointer to the struct of function pointers that identify the object
- * type
  *
  * This function returns the private object state for the given private object,
  * allocating the state if needed. It does not grab any locks as the caller is
@@ -1004,17 +1040,18 @@ static void drm_atomic_plane_print_state(struct drm_printer *p,
  *
  * Either the allocated state or the error code encoded into a pointer.
  */
-void *
-drm_atomic_get_private_obj_state(struct drm_atomic_state *state, void *obj,
-			      const struct drm_private_state_funcs *funcs)
+struct drm_private_state *
+drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
+				 struct drm_private_obj *obj)
 {
 	int index, num_objs, i;
 	size_t size;
 	struct __drm_private_objs_state *arr;
+	struct drm_private_state *obj_state;
 
 	for (i = 0; i < state->num_private_objs; i++)
-		if (obj == state->private_objs[i].obj)
-			return state->private_objs[i].obj_state;
+		if (obj == state->private_objs[i].ptr)
+			return state->private_objs[i].state;
 
 	num_objs = state->num_private_objs + 1;
 	size = sizeof(*state->private_objs) * num_objs;
@@ -1026,18 +1063,21 @@ drm_atomic_get_private_obj_state(struct drm_atomic_state *state, void *obj,
 	index = state->num_private_objs;
 	memset(&state->private_objs[index], 0, sizeof(*state->private_objs));
 
-	state->private_objs[index].obj_state = funcs->duplicate_state(state, obj);
-	if (!state->private_objs[index].obj_state)
+	obj_state = obj->funcs->atomic_duplicate_state(obj);
+	if (!obj_state)
 		return ERR_PTR(-ENOMEM);
 
-	state->private_objs[index].obj = obj;
-	state->private_objs[index].funcs = funcs;
+	state->private_objs[index].state = obj_state;
+	state->private_objs[index].old_state = obj->state;
+	state->private_objs[index].new_state = obj_state;
+	state->private_objs[index].ptr = obj;
+
 	state->num_private_objs = num_objs;
 
-	DRM_DEBUG_ATOMIC("Added new private object state %p to %p\n",
-			 state->private_objs[index].obj_state, state);
+	DRM_DEBUG_ATOMIC("Added new private object %p state %p to %p\n",
+			 obj, obj_state, state);
 
-	return state->private_objs[index].obj_state;
+	return obj_state;
 }
 EXPORT_SYMBOL(drm_atomic_get_private_obj_state);
 
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 0fed20692df4..fa64b31ae579 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2267,8 +2267,8 @@ void drm_atomic_helper_swap_state(struct drm_atomic_state *state,
 	struct drm_plane *plane;
 	struct drm_plane_state *old_plane_state, *new_plane_state;
 	struct drm_crtc_commit *commit;
-	void *obj, *obj_state;
-	const struct drm_private_state_funcs *funcs;
+	struct drm_private_obj *obj;
+	struct drm_private_state *old_obj_state, *new_obj_state;
 
 	if (stall) {
 		for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
@@ -2330,8 +2330,15 @@ void drm_atomic_helper_swap_state(struct drm_atomic_state *state,
 		plane->state = new_plane_state;
 	}
 
-	__for_each_private_obj(state, obj, obj_state, i, funcs)
-		funcs->swap_state(obj, &state->private_objs[i].obj_state);
+	for_each_oldnew_private_obj_in_state(state, obj, old_obj_state, new_obj_state, i) {
+		WARN_ON(obj->state != old_obj_state);
+
+		old_obj_state->state = state;
+		new_obj_state->state = NULL;
+
+		state->private_objs[i].state = old_obj_state;
+		obj->state = new_obj_state;
+	}
 }
 EXPORT_SYMBOL(drm_atomic_helper_swap_state);
 
@@ -3828,3 +3835,18 @@ fail:
 	return ret;
 }
 EXPORT_SYMBOL(drm_atomic_helper_legacy_gamma_set);
+
+/**
+ * __drm_atomic_helper_private_duplicate_state - copy atomic private state
+ * @obj: CRTC object
+ * @state: new private object state
+ *
+ * Copies atomic state from a private objects's current state and resets inferred values.
+ * This is useful for drivers that subclass the private state.
+ */
+void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
+						     struct drm_private_state *state)
+{
+	memcpy(state, obj->state, sizeof(*state));
+}
+EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 18cecd94acb6..552e71d5aa5f 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -31,6 +31,8 @@
 #include <drm/drmP.h>
 
 #include <drm/drm_fixed.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
 
 /**
  * DOC: dp mst helper
@@ -2992,41 +2994,32 @@ static void drm_dp_destroy_connector_work(struct work_struct *work)
 		(*mgr->cbs->hotplug)(mgr);
 }
 
-void *drm_dp_mst_duplicate_state(struct drm_atomic_state *state, void *obj)
+static struct drm_private_state *
+drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
 {
-	struct drm_dp_mst_topology_mgr *mgr = obj;
-	struct drm_dp_mst_topology_state *new_mst_state;
+	struct drm_dp_mst_topology_state *state;
 
-	if (WARN_ON(!mgr->state))
+	state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL);
+	if (!state)
 		return NULL;
 
-	new_mst_state = kmemdup(mgr->state, sizeof(*new_mst_state), GFP_KERNEL);
-	if (new_mst_state)
-		new_mst_state->state = state;
-	return new_mst_state;
-}
-
-void drm_dp_mst_swap_state(void *obj, void **obj_state_ptr)
-{
-	struct drm_dp_mst_topology_mgr *mgr = obj;
-	struct drm_dp_mst_topology_state **topology_state_ptr;
-
-	topology_state_ptr = (struct drm_dp_mst_topology_state **)obj_state_ptr;
+	__drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
 
-	mgr->state->state = (*topology_state_ptr)->state;
-	swap(*topology_state_ptr, mgr->state);
-	mgr->state->state = NULL;
+	return &state->base;
 }
 
-void drm_dp_mst_destroy_state(void *obj_state)
+static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
+				     struct drm_private_state *state)
 {
-	kfree(obj_state);
+	struct drm_dp_mst_topology_state *mst_state =
+		to_dp_mst_topology_state(state);
+
+	kfree(mst_state);
 }
 
 static const struct drm_private_state_funcs mst_state_funcs = {
-	.duplicate_state = drm_dp_mst_duplicate_state,
-	.swap_state = drm_dp_mst_swap_state,
-	.destroy_state = drm_dp_mst_destroy_state,
+	.atomic_duplicate_state = drm_dp_mst_duplicate_state,
+	.atomic_destroy_state = drm_dp_mst_destroy_state,
 };
 
 /**
@@ -3050,8 +3043,7 @@ struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_a
 	struct drm_device *dev = mgr->dev;
 
 	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
-	return drm_atomic_get_private_obj_state(state, mgr,
-						&mst_state_funcs);
+	return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
 }
 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
 
@@ -3071,6 +3063,8 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
 				 int max_dpcd_transaction_bytes,
 				 int max_payloads, int conn_base_id)
 {
+	struct drm_dp_mst_topology_state *mst_state;
+
 	mutex_init(&mgr->lock);
 	mutex_init(&mgr->qlock);
 	mutex_init(&mgr->payload_lock);
@@ -3099,14 +3093,18 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
 	if (test_calc_pbn_mode() < 0)
 		DRM_ERROR("MST PBN self-test failed\n");
 
-	mgr->state = kzalloc(sizeof(*mgr->state), GFP_KERNEL);
-	if (mgr->state == NULL)
+	mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
+	if (mst_state == NULL)
 		return -ENOMEM;
-	mgr->state->mgr = mgr;
+
+	mst_state->mgr = mgr;
 
 	/* max. time slots - one slot for MTP header */
-	mgr->state->avail_slots = 63;
-	mgr->funcs = &mst_state_funcs;
+	mst_state->avail_slots = 63;
+
+	drm_atomic_private_obj_init(&mgr->base,
+				    &mst_state->base,
+				    &mst_state_funcs);
 
 	return 0;
 }
@@ -3128,8 +3126,7 @@ void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
 	mutex_unlock(&mgr->payload_lock);
 	mgr->dev = NULL;
 	mgr->aux = NULL;
-	kfree(mgr->state);
-	mgr->state = NULL;
+	drm_atomic_private_obj_fini(&mgr->base);
 	mgr->funcs = NULL;
 }
 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);