drm/i915: Add crtc state duplication/destruction functions

The atomic helpers need these to prepare a new state object when
starting a new atomic operation.
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_atomic.c

@@ -200,3 +200,38 @@ intel_connector_atomic_get_property(struct drm_connector *connector,
 
 	return -EINVAL;
 }
+
+/*
+ * intel_crtc_duplicate_state - duplicate crtc state
+ * @crtc: drm crtc
+ *
+ * Allocates and returns a copy of the crtc state (both common and
+ * Intel-specific) for the specified crtc.
+ *
+ * Returns: The newly allocated crtc state, or NULL on failure.
+ */
+struct drm_crtc_state *
+intel_crtc_duplicate_state(struct drm_crtc *crtc)
+{
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+
+	if (WARN_ON(!intel_crtc->config))
+		return kzalloc(sizeof(*intel_crtc->config), GFP_KERNEL);
+
+	return kmemdup(intel_crtc->config, sizeof(*intel_crtc->config),
+		       GFP_KERNEL);
+}
+
+/**
+ * intel_crtc_destroy_state - destroy crtc state
+ * @crtc: drm crtc
+ *
+ * Destroys the crtc state (both common and Intel-specific) for the
+ * specified crtc.
+ */
+void
+intel_crtc_destroy_state(struct drm_crtc *crtc,
+			  struct drm_crtc_state *state)
+{
+	drm_atomic_helper_crtc_destroy_state(crtc, state);
+}

drivers/gpu/drm/i915/intel_display.c

@@ -11652,6 +11652,8 @@ static const struct drm_crtc_funcs intel_crtc_funcs = {
 	.set_config = intel_crtc_set_config,
 	.destroy = intel_crtc_destroy,
 	.page_flip = intel_crtc_page_flip,
+	.atomic_duplicate_state = intel_crtc_duplicate_state,
+	.atomic_destroy_state = intel_crtc_destroy_state,
 };
 
 static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,

drivers/gpu/drm/i915/intel_drv.h

@@ -1258,6 +1258,9 @@ int intel_connector_atomic_get_property(struct drm_connector *connector,
 					const struct drm_connector_state *state,
 					struct drm_property *property,
 					uint64_t *val);
+struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc *crtc);
+void intel_crtc_destroy_state(struct drm_crtc *crtc,
+			       struct drm_crtc_state *state);
 
 /* intel_atomic_plane.c */
 struct intel_plane_state *intel_create_plane_state(struct drm_plane *plane);