From 6dd7b6ce43acd70f75ae285fee8eeb2dd4933dce Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Mon, 8 Feb 2021 12:55:34 +0100 Subject: drm: Add additional atomic helpers for shadow-buffered planes Several drivers use GEM buffer objects as shadow buffers for the actual framebuffer memory. Right now, drivers do these vmap operations in their commit tail, which is actually not allowed by the locking rules for the dma-buf reservation lock. The involved BO has to be vmapped in the plane's prepare_fb callback and vunmapped in cleanup_fb. This patch introduces atomic helpers for such shadow planes. Plane functions manage the plane state for shadow planes. The provided implementations for prepare_fb and cleanup_fb vmap and vunmap all BOs of struct drm_plane_state.fb. The mappings are afterwards available in the plane's commit-tail functions. For now, all rsp drivers use the simple KMS helpers, so we add the plane callbacks and wrappers for simple KMS. The internal plane functions can later be exported as needed. v3: * documentation fixes v2: * make duplicate_state interface compatible with struct drm_plane_funcs Signed-off-by: Thomas Zimmermann Tested-by: Gerd Hoffmann Acked-by: Gerd Hoffmann Link: https://patchwork.freedesktop.org/patch/msgid/20210208115538.6430-4-tzimmermann@suse.de --- include/drm/drm_gem_atomic_helper.h | 73 +++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 include/drm/drm_gem_atomic_helper.h (limited to 'include/drm') 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 + +#include + +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__ */ -- cgit v1.2.3