Commit 94d879ea authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/atomic-helper: Add {begin,end}_fb_access to plane helpers 



Add {begin,end}_fb_access helpers to run at the beginning and end of
an atomic commit. The begin_fb_access helper acquires resources that
are necessary to perform the atomic commit. It it similar to prepare_fb,
except that the resources are to be released at the end of the commit.
Resources acquired by prepare_fb are held until after the next pageflip.

The end_fb_access helper performs the corresponding resource cleanup.
Atomic helpers call it with the new plane state. This is different from
cleanup_fb, which releases resources of the old plane state.

v2:
	* fix typos in commit message (Javier)

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221025101737.8874-2-tzimmermann@suse.de
parent 260cd59a

drivers/gpu/drm/drm_atomic_helper.c

+31 −3
Original line number Diff line number Diff line
@@ -2536,7 +2536,7 @@ int drm_atomic_helper_prepare_planes(struct drm_device *dev, 
		if (funcs->prepare_fb) {

			ret = funcs->prepare_fb(plane, new_plane_state);

			if (ret)

				goto fail;

				goto fail_prepare_fb;

		} else {

			WARN_ON_ONCE(funcs->cleanup_fb);
@@ -2545,13 +2545,34 @@ int drm_atomic_helper_prepare_planes(struct drm_device *dev, 


			ret = drm_gem_plane_helper_prepare_fb(plane, new_plane_state);

			if (ret)

				goto fail;

				goto fail_prepare_fb;

		}

	}



	for_each_new_plane_in_state(state, plane, new_plane_state, i) {

		const struct drm_plane_helper_funcs *funcs = plane->helper_private;



		if (funcs->begin_fb_access) {

			ret = funcs->begin_fb_access(plane, new_plane_state);

			if (ret)

				goto fail_begin_fb_access;

		}

	}



	return 0;



fail:

fail_begin_fb_access:

	for_each_new_plane_in_state(state, plane, new_plane_state, j) {

		const struct drm_plane_helper_funcs *funcs = plane->helper_private;



		if (j >= i)

			continue;



		if (funcs->end_fb_access)

			funcs->end_fb_access(plane, new_plane_state);

	}

	i = j; /* set i to upper limit to cleanup all planes */

fail_prepare_fb:

	for_each_new_plane_in_state(state, plane, new_plane_state, j) {

		const struct drm_plane_helper_funcs *funcs;
@@ -2827,6 +2848,13 @@ void drm_atomic_helper_cleanup_planes(struct drm_device *dev, 
	struct drm_plane_state *old_plane_state, *new_plane_state;

	int i;



	for_each_oldnew_plane_in_state(old_state, plane, old_plane_state, new_plane_state, i) {

		const struct drm_plane_helper_funcs *funcs = plane->helper_private;



		if (funcs->end_fb_access)

			funcs->end_fb_access(plane, new_plane_state);

	}



	for_each_oldnew_plane_in_state(old_state, plane, old_plane_state, new_plane_state, i) {

		const struct drm_plane_helper_funcs *funcs;

		struct drm_plane_state *plane_state;

drivers/gpu/drm/drm_gem_atomic_helper.c

+9 −10
Original line number Diff line number Diff line
@@ -414,16 +414,14 @@ void drm_gem_cleanup_shadow_fb(struct drm_plane *plane, struct drm_plane_state * 
EXPORT_SYMBOL(drm_gem_cleanup_shadow_fb);



/**

 * drm_gem_simple_kms_prepare_shadow_fb - prepares shadow framebuffers

 * drm_gem_simple_kms_begin_shadow_fb_access - prepares shadow framebuffers for CPU access

 * @pipe: the simple display pipe

 * @plane_state: the plane state of type struct drm_shadow_plane_state

 *

 * This function implements struct drm_simple_display_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.

 * This function implements struct drm_simple_display_funcs.begin_fb_access.

 *

 * See drm_gem_simple_kms_cleanup_shadow_fb() for cleanup.

 * See drm_gem_begin_shadow_fb_access() for details and

 * drm_gem_simple_kms_cleanup_shadow_fb() for cleanup.

 *

 * Returns:

 * 0 on success, or a negative errno code otherwise.
@@ -436,14 +434,15 @@ int drm_gem_simple_kms_prepare_shadow_fb(struct drm_simple_display_pipe *pipe, 
EXPORT_SYMBOL(drm_gem_simple_kms_prepare_shadow_fb);



/**

 * drm_gem_simple_kms_cleanup_shadow_fb - releases shadow framebuffers

 * drm_gem_simple_kms_end_shadow_fb_access - releases shadow framebuffers from CPU access

 * @pipe: the simple display pipe

 * @plane_state: the plane state of type struct drm_shadow_plane_state

 *

 * This function implements struct drm_simple_display_funcs.cleanup_fb.

 * This function unmaps all buffer objects of the plane's framebuffer.

 * This function implements struct drm_simple_display_funcs.end_fb_access.

 * It undoes all effects of drm_gem_simple_kms_begin_shadow_fb_access() in

 * reverse order.

 *

 * See drm_gem_simple_kms_prepare_shadow_fb().

 * See drm_gem_simple_kms_begin_shadow_fb_access().

 */

void drm_gem_simple_kms_cleanup_shadow_fb(struct drm_simple_display_pipe *pipe,

					  struct drm_plane_state *plane_state)

drivers/gpu/drm/drm_simple_kms_helper.c

+26 −0
Original line number Diff line number Diff line
@@ -285,6 +285,30 @@ static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane, 
	pipe->funcs->cleanup_fb(pipe, state);

}



static int drm_simple_kms_plane_begin_fb_access(struct drm_plane *plane,

						struct drm_plane_state *new_plane_state)

{

	struct drm_simple_display_pipe *pipe;



	pipe = container_of(plane, struct drm_simple_display_pipe, plane);

	if (!pipe->funcs || !pipe->funcs->begin_fb_access)

		return 0;



	return pipe->funcs->begin_fb_access(pipe, new_plane_state);

}



static void drm_simple_kms_plane_end_fb_access(struct drm_plane *plane,

					       struct drm_plane_state *new_plane_state)

{

	struct drm_simple_display_pipe *pipe;



	pipe = container_of(plane, struct drm_simple_display_pipe, plane);

	if (!pipe->funcs || !pipe->funcs->end_fb_access)

		return;



	pipe->funcs->end_fb_access(pipe, new_plane_state);

}



static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,

						uint32_t format,

						uint64_t modifier)
@@ -295,6 +319,8 @@ static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane, 
static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {

	.prepare_fb = drm_simple_kms_plane_prepare_fb,

	.cleanup_fb = drm_simple_kms_plane_cleanup_fb,

	.begin_fb_access = drm_simple_kms_plane_begin_fb_access,

	.end_fb_access = drm_simple_kms_plane_end_fb_access,

	.atomic_check = drm_simple_kms_plane_atomic_check,

	.atomic_update = drm_simple_kms_plane_atomic_update,

};

include/drm/drm_modeset_helper_vtables.h

+40 −1
Original line number Diff line number Diff line
@@ -1184,11 +1184,20 @@ struct drm_plane_helper_funcs { 
	 * can call drm_gem_plane_helper_prepare_fb() from their @prepare_fb

	 * hook.

	 *

	 * The resources acquired in @prepare_fb persist after the end of

	 * the atomic commit. Resources that can be release at the commit's end

	 * should be acquired in @begin_fb_access and released in @end_fb_access.

	 * For example, a GEM buffer's pin operation belongs into @prepare_fb to

	 * keep the buffer pinned after the commit. But a vmap operation for

	 * shadow-plane helpers belongs into @begin_fb_access, so that atomic

	 * helpers remove the mapping at the end of the commit.

	 *

	 * The helpers will call @cleanup_fb with matching arguments for every

	 * successful call to this hook.

	 *

	 * This callback is used by the atomic modeset helpers and by the

	 * transitional plane helpers, but it is optional.

	 * transitional plane helpers, but it is optional. See @begin_fb_access

	 * for preparing per-commit resources.

	 *

	 * RETURNS:

	 *
@@ -1211,6 +1220,36 @@ struct drm_plane_helper_funcs { 
	void (*cleanup_fb)(struct drm_plane *plane,

			   struct drm_plane_state *old_state);



	/**

	 * @begin_fb_access:

	 *

	 * This hook prepares the plane for access during an atomic commit.

	 * In contrast to @prepare_fb, resources acquired in @begin_fb_access,

	 * are released at the end of the atomic commit in @end_fb_access.

	 *

	 * For example, with shadow-plane helpers, the GEM buffer's vmap

	 * operation belongs into @begin_fb_access, so that the buffer's

	 * memory will be unmapped at the end of the commit in @end_fb_access.

	 * But a GEM buffer's pin operation belongs into @prepare_fb

	 * to keep the buffer pinned after the commit.

	 *

	 * The callback is used by the atomic modeset helpers, but it is optional.

	 * See @end_fb_cleanup for undoing the effects of @begin_fb_access and

	 * @prepare_fb for acquiring resources until the next pageflip.

	 *

	 * Returns:

	 * 0 on success, or a negative errno code otherwise.

	 */

	int (*begin_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);



	/**

	 * @end_fb_access:

	 *

	 * This hook cleans up resources allocated by @begin_fb_access. It it called

	 * at the end of a commit for the new plane state.

	 */

	void (*end_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);



	/**

	 * @atomic_check:

	 *

include/drm/drm_simple_kms_helper.h

+20 −0
Original line number Diff line number Diff line
@@ -135,6 +135,26 @@ struct drm_simple_display_pipe_funcs { 
	void (*cleanup_fb)(struct drm_simple_display_pipe *pipe,

			   struct drm_plane_state *plane_state);



	/**

	 * @begin_fb_access:

	 *

	 * Optional, called by &drm_plane_helper_funcs.begin_fb_access. Please read

	 * the documentation for the &drm_plane_helper_funcs.begin_fb_access hook for

	 * more details.

	 */

	int (*begin_fb_access)(struct drm_simple_display_pipe *pipe,

			       struct drm_plane_state *new_plane_state);



	/**

	 * @end_fb_access:

	 *

	 * Optional, called by &drm_plane_helper_funcs.end_fb_access. Please read

	 * the documentation for the &drm_plane_helper_funcs.end_fb_access hook for

	 * more details.

	 */

	void (*end_fb_access)(struct drm_simple_display_pipe *pipe,

			      struct drm_plane_state *plane_state);



	/**

	 * @enable_vblank:

	 *