From: Thomas Zimmermann Date: Tue, 25 Oct 2022 10:17:36 +0000 (+0200) Subject: drm/atomic-helper: Add {begin,end}_fb_access to plane helpers X-Git-Tag: v6.6.17~3937^2~23^2~1347 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=94d879eaf7fb02a0d022a190278b3fd45b1efbd7;p=platform%2Fkernel%2Flinux-rpi.git 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: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20221025101737.8874-2-tzimmermann@suse.de --- diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 1a586b3..d579fd8f 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -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; @@ -2828,6 +2849,13 @@ void drm_atomic_helper_cleanup_planes(struct drm_device *dev, 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; diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c index b6a0110..1de0a08 100644 --- a/drivers/gpu/drm/drm_gem_atomic_helper.c +++ b/drivers/gpu/drm/drm_gem_atomic_helper.c @@ -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) diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c index 31233c6..3ef420e 100644 --- a/drivers/gpu/drm/drm_simple_kms_helper.c +++ b/drivers/gpu/drm/drm_simple_kms_helper.c @@ -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, }; diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index fafa70a..d9f2254a 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -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: * @@ -1212,6 +1221,36 @@ struct drm_plane_helper_funcs { 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: * * Drivers should check plane specific constraints in this hook. diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h index 0b3647e6..2298fe3 100644 --- a/include/drm/drm_simple_kms_helper.h +++ b/include/drm/drm_simple_kms_helper.h @@ -136,6 +136,26 @@ struct drm_simple_display_pipe_funcs { 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: * * Optional, called by &drm_crtc_funcs.enable_vblank. Please read