Hi
Am 09.02.21 um 10:44 schrieb Daniel Vetter:
On Mon, Feb 08, 2021 at 02:50:43PM +0100, Thomas Zimmermann wrote:
Export the helpers for shadow-buffered planes. These will be used by several drivers.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de
drivers/gpu/drm/drm_gem_atomic_helper.c | 148 +++++++++++++++++++++++- include/drm/drm_gem_atomic_helper.h | 32 +++++ 2 files changed, 174 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c index e27762cef360..79b4d3f0495a 100644 --- a/drivers/gpu/drm/drm_gem_atomic_helper.c +++ b/drivers/gpu/drm/drm_gem_atomic_helper.c @@ -14,13 +14,101 @@
- functions for drivers that use GEM objects. Currently, it provides
- plane state and framebuffer BO mappings for planes with shadow
- buffers.
- A driver using a shadow buffer copies the content of the shadow buffers
- into the HW's framebuffer memory during an atomic update. This requires
- a mapping of the shadow buffer into kernel address space. The mappings
- cannot be established by commit-tail functions, such as atomic_update,
- as this would violate locking rules vmap.
"... locking rules around dma_buf_vmap()"?
- The helpers for shadow-buffered planes establish and release mappings,
- and provide struct drm_shadow_plane_state, which stores the plane's mapping
- for commit-tail functons.
- Shadow-buffered planes can easily be enabled by using the provided macros
- DRM_GEM_PLANE_SHADOW_FUNCS and DRM_GEM_SHADOE_PLANE_HELPER_FUNCS.
I think for hyperlinks/highlights we need %CONSTANT? Maybe check what works.
- These macros set up the plane and plane-helper callbacks to point to the
- shadow-buffer helpers.
- .. code-block:: c
- #include <drm/drm/gem_atomic_helper.h>
- struct drm_plane_funcs driver_plane_funcs = {
...,
DRM_GEM_SHADOW_PLANE_FUNCS,
- };
- struct drm_plane_helper_funcs driver_plane_helper_funcs = {
...,
DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
- };
- In the driver's atomic-update function, shadow-buffer mappings are available
- from the plane state. Use to_drm_shadow_plane_state() to upcast from
- struct drm_plane_state.
- .. code-block:: c
- void driver_plane_atomic_update(struct drm_plane *plane,
struct drm_plane_state *old_plane_state)
- {
struct drm_plane_state *plane_state = plane->state;
struct drm_shadow_plane_state *shadow_plane_state =
to_drm_shadow_plane_state(plane_state);
// access shadow buffer via shadow_plane_state->map
- }
- A mapping address for each of the framebuffer's buffer object is stored in
- struct drm_shadow_plane_state.map. The mappings are valid while the state
- is being used.
- Drivers that use struct drm_simple_display_pipe can use
- DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS to initialize the rsp
- callbacks. Access to shadow-buffer mappings is similar to regular
- atomic_update.
- .. code-block:: c
- struct drm_simple_display_pipe_funcs driver_pipe_funcs = {
...,
DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
- };
- void driver_pipe_enable(struct drm_simple_display_pipe *pipe,
struct drm_crtc_state *crtc_state,
struct drm_plane_state *plane_state)
- {
struct drm_shadow_plane_state *shadow_plane_state =
to_drm_shadow_plane_state(plane_state);
// access shadow buffer via shadow_plane_state->map
- }
*/
/*
- Shadow-buffered Planes
*/
-static struct drm_plane_state * +/**
- drm_gem_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
- @plane: the plane
- This function implements struct drm_plane_funcs.atomic_duplicate_state for
Does this hyperlink automatically? I didn't know it works since for members I just always use &struct.member myself.
Ah, ok. Fixed. This work with struct &name.field. The % only adds formatting to constants.
Best regards Thomas
- shadow-buffered planes. It assumes the existing state to be of type
- struct drm_shadow_plane_state and it allocates the new state to be of this
- type.
- The function does not duplicate existing mappings of the shadow buffers.
- Mappings are maintained during the atomic commit by the plane's prepare_fb
- and cleanup_fb helpers. See drm_gem_prepare_shadow_fb() and drm_gem_cleanup_shadow_fb()
- for corresponding helpers.
- Returns:
- A pointer to a new plane state on success, or NULL otherwise.
- */
+struct drm_plane_state * drm_gem_duplicate_shadow_plane_state(struct drm_plane *plane) { struct drm_plane_state *plane_state = plane->state; @@ -36,9 +124,19 @@ drm_gem_duplicate_shadow_plane_state(struct drm_plane *plane)
return &new_shadow_plane_state->base; } +EXPORT_SYMBOL(drm_gem_duplicate_shadow_plane_state);
-static void drm_gem_destroy_shadow_plane_state(struct drm_plane *plane,
struct drm_plane_state *plane_state)+/**
- drm_gem_destroy_shadow_plane_state - deletes shadow-buffered plane state
- @plane: the plane
- @plane_state: the plane state of type struct drm_shadow_plane_state
- This function implements struct drm_plane_funcs.atomic_destroy_state
- for shadow-buffered planes. It expects that mappings of shadow buffers
- have been released already.
- */
+void drm_gem_destroy_shadow_plane_state(struct drm_plane *plane,
struct drm_plane_state *plane_state)@@ -46,8 +144,18 @@ static void drm_gem_destroy_shadow_plane_state(struct drm_plane *plane, __drm_atomic_helper_plane_destroy_state(&shadow_plane_state->base); kfree(shadow_plane_state); } +EXPORT_SYMBOL(drm_gem_destroy_shadow_plane_state);
-static void drm_gem_reset_shadow_plane(struct drm_plane *plane) +/**
- drm_gem_reset_shadow_plane - resets a shadow-buffered plane
- @plane: the plane
- This function implements struct drm_plane_funcs.reset_plane for
- shadow-buffered planes. It assumes the current plane state to be
- of type struct drm_shadow_plane and it allocates the new state of
- this type.
- */
+void drm_gem_reset_shadow_plane(struct drm_plane *plane) { struct drm_shadow_plane_state *shadow_plane_state;
@@ -61,8 +169,24 @@ static void drm_gem_reset_shadow_plane(struct drm_plane *plane) return; __drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base); } +EXPORT_SYMBOL(drm_gem_reset_shadow_plane);
-static int drm_gem_prepare_shadow_fb(struct drm_plane *plane, struct drm_plane_state *plane_state) +/**
- drm_gem_prepare_shadow_fb - prepares shadow framebuffers
- @plane: the plane
- @plane_state: the plane state of type struct drm_shadow_plane_state
- This function implements struct drm_plane_helper_funcs.prepare_fb. It
- maps all buffer objects of the plane's framebuffer into kernel address
- space and stores them in struct drm_shadow_plane_state.map. The
- framebuffer will be synchronized as part of the atomic commit.
- See drm_gem_cleanup_shadow_fb() for cleanup.
- Returns:
- 0 on success, or a negative errno code otherwise.
- */
+int drm_gem_prepare_shadow_fb(struct drm_plane *plane, struct drm_plane_state *plane_state) { struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state); struct drm_framebuffer *fb = plane_state->fb; @@ -100,8 +224,19 @@ static int drm_gem_prepare_shadow_fb(struct drm_plane *plane, struct drm_plane_s } return ret; } +EXPORT_SYMBOL(drm_gem_prepare_shadow_fb);
-static void drm_gem_cleanup_shadow_fb(struct drm_plane *plane, struct drm_plane_state *plane_state) +/**
- drm_gem_cleanup_shadow_fb - releases shadow framebuffers
- @plane: the plane
- @plane_state: the plane state of type struct drm_shadow_plane_state
- This function implements struct drm_plane_helper_funcs.cleanup_fb.
- This function unmaps all buffer objects of the plane's framebuffer.
- See drm_gem_prepare_shadow_fb() for more inforamtion.
- */
+void drm_gem_cleanup_shadow_fb(struct drm_plane *plane, struct drm_plane_state *plane_state) { struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state); struct drm_framebuffer *fb = plane_state->fb; @@ -119,6 +254,7 @@ static void drm_gem_cleanup_shadow_fb(struct drm_plane *plane, struct drm_plane_ drm_gem_vunmap(obj, &shadow_plane_state->map[i]); } } +EXPORT_SYMBOL(drm_gem_cleanup_shadow_fb);
/**
- drm_gem_simple_kms_prepare_shadow_fb - prepares shadow framebuffers
diff --git a/include/drm/drm_gem_atomic_helper.h b/include/drm/drm_gem_atomic_helper.h index 08b96ccea325..7abf40bdab3d 100644 --- a/include/drm/drm_gem_atomic_helper.h +++ b/include/drm/drm_gem_atomic_helper.h @@ -45,6 +45,38 @@ to_drm_shadow_plane_state(struct drm_plane_state *state) return container_of(state, struct drm_shadow_plane_state, base); }
+void drm_gem_reset_shadow_plane(struct drm_plane *plane); +struct drm_plane_state *drm_gem_duplicate_shadow_plane_state(struct drm_plane *plane); +void drm_gem_destroy_shadow_plane_state(struct drm_plane *plane,
struct drm_plane_state *plane_state);+/**
- DRM_GEM_SHADOW_PLANE_FUNCS -
- Initializes struct drm_plane_funcs for shadow-buffered planes
- Drivers may use GEM BOs as shadow buffers over the framebuffer memory. This
- macro initializes struct drm_plane_funcs to use the rsp helper functions.
- */
+#define DRM_GEM_SHADOW_PLANE_FUNCS \
- .reset = drm_gem_reset_shadow_plane, \
- .atomic_duplicate_state = drm_gem_duplicate_shadow_plane_state, \
- .atomic_destroy_state = drm_gem_destroy_shadow_plane_state
+int drm_gem_prepare_shadow_fb(struct drm_plane *plane, struct drm_plane_state *plane_state); +void drm_gem_cleanup_shadow_fb(struct drm_plane *plane, struct drm_plane_state *plane_state);
+/**
- DRM_GEM_SHADOW_PLANE_HELPER_FUNCS -
- Initializes struct drm_plane_helper_funcs for shadow-buffered planes
- Drivers may use GEM BOs as shadow buffers over the framebuffer memory. This
- macro initializes struct drm_plane_helper_funcs to use the rsp helper
- functions.
- */
+#define DRM_GEM_SHADOW_PLANE_HELPER_FUNCS \
- .prepare_fb = drm_gem_prepare_shadow_fb, \
- .cleanup_fb = drm_gem_cleanup_shadow_fb
- 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,
Very nice and thoroughly explained docs!
Thanks, Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
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