1 files changed, 73 insertions, 0 deletions
diff --git a/include/drm/drm_gem_atomic_helper.h b/include/drm/drm_gem_atomic_helper.h
new file mode 100644
index 000000000000..08b96ccea325
--- /dev/null
+++ b/include/drm/drm_gem_atomic_helper.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DRM_GEM_ATOMIC_HELPER_H__
+#define __DRM_GEM_ATOMIC_HELPER_H__
+
+#include <linux/dma-buf-map.h>
+
+#include <drm/drm_plane.h>
+
+struct drm_simple_display_pipe;
+
+/*
+ * Helpers for planes with shadow buffers
+ */
+
+/**
+ * struct drm_shadow_plane_state - plane state for planes with shadow buffers
+ *
+ * For planes that use a shadow buffer, struct drm_shadow_plane_state
+ * provides the regular plane state plus mappings of the shadow buffer
+ * into kernel address space.
+ */
+struct drm_shadow_plane_state {
+	/** @base: plane state */
+	struct drm_plane_state base;
+
+	/* Transitional state - do not export or duplicate */
+
+	/**
+	 * @map: Mappings of the plane's framebuffer BOs in to kernel address space
+	 *
+	 * The memory mappings stored in map should be established in the plane's
+	 * prepare_fb callback and removed in the cleanup_fb callback.
+	 */
+	struct dma_buf_map map[4];
+};
+
+/**
+ * to_drm_shadow_plane_state - upcasts from struct drm_plane_state
+ * @state: the plane state
+ */
+static inline struct drm_shadow_plane_state *
+to_drm_shadow_plane_state(struct drm_plane_state *state)
+{
+	return container_of(state, struct drm_shadow_plane_state, base);
+}
+
+int drm_gem_simple_kms_prepare_shadow_fb(struct drm_simple_display_pipe *pipe,
+					 struct drm_plane_state *plane_state);
+void drm_gem_simple_kms_cleanup_shadow_fb(struct drm_simple_display_pipe *pipe,
+					  struct drm_plane_state *plane_state);
+void drm_gem_simple_kms_reset_shadow_plane(struct drm_simple_display_pipe *pipe);
+struct drm_plane_state *
+drm_gem_simple_kms_duplicate_shadow_plane_state(struct drm_simple_display_pipe *pipe);
+void drm_gem_simple_kms_destroy_shadow_plane_state(struct drm_simple_display_pipe *pipe,
+						   struct drm_plane_state *plane_state);
+
+/**
+ * DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS -
+ *	Initializes struct drm_simple_display_pipe_funcs for shadow-buffered planes
+ *
+ * Drivers may use GEM BOs as shadow buffers over the framebuffer memory. This
+ * macro initializes struct drm_simple_display_pipe_funcs to use the rsp helper
+ * functions.
+ */
+#define DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS \
+	.prepare_fb = drm_gem_simple_kms_prepare_shadow_fb, \
+	.cleanup_fb = drm_gem_simple_kms_cleanup_shadow_fb, \
+	.reset_plane = drm_gem_simple_kms_reset_shadow_plane, \
+	.duplicate_plane_state = drm_gem_simple_kms_duplicate_shadow_plane_state, \
+	.destroy_plane_state = drm_gem_simple_kms_destroy_shadow_plane_state
+
+#endif /* __DRM_GEM_ATOMIC_HELPER_H__ */