1 // SPDX-License-Identifier: GPL-2.0-or-later
3 #include <linux/dma-resv.h>
4 #include <linux/dma-fence-chain.h>
20  * The GEM atomic helpers library implements generic atomic-commit
33  * .. code-block:: c
45  * cannot be established by commit-tail functions, such as atomic_update,
48  * The helpers for shadow-buffered planes establish and release mappings,
50  * for commit-tail functions.
52  * Shadow-buffered planes can easily be enabled by using the provided macros
54  * These macros set up the plane and plane-helper callbacks to point to the
55  * shadow-buffer helpers.
57  * .. code-block:: c
71  * In the driver's atomic-update function, shadow-buffer mappings are available
75  * .. code-block:: c
80  *		struct drm_plane_state *plane_state = plane->state;
84  *		// access shadow buffer via shadow_plane_state->map
93  * callbacks. Access to shadow-buffer mappings is similar to regular
96  * .. code-block:: c
110  *		// access shadow buffer via shadow_plane_state->map
119  * drm_gem_plane_helper_prepare_fb() - Prepare a GEM backed framebuffer
139 	struct dma_fence *fence = dma_fence_get(state->fence);  in drm_gem_plane_helper_prepare_fb()
144 	if (!state->fb)  in drm_gem_plane_helper_prepare_fb()
152 	 * which is important to make explicit fencing use-cases work: One  in drm_gem_plane_helper_prepare_fb()
162 	for (i = 0; i < state->fb->format->num_planes; ++i) {  in drm_gem_plane_helper_prepare_fb()
163 		struct drm_gem_object *obj = drm_gem_fb_get_obj(state->fb, i);  in drm_gem_plane_helper_prepare_fb()
167 			ret = -EINVAL;  in drm_gem_plane_helper_prepare_fb()
171 		ret = dma_resv_get_singleton(obj->resv, usage, &new);  in drm_gem_plane_helper_prepare_fb()
179 				ret = -ENOMEM;  in drm_gem_plane_helper_prepare_fb()
184 			fence = &chain->base;  in drm_gem_plane_helper_prepare_fb()
191 	dma_fence_put(state->fence);  in drm_gem_plane_helper_prepare_fb()
192 	state->fence = fence;  in drm_gem_plane_helper_prepare_fb()
202  * Shadow-buffered Planes
206  * __drm_gem_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
208  * @new_shadow_plane_state: the new shadow-buffered plane state
210  * This function duplicates shadow-buffered plane state. This is helpful for drivers
222 	struct drm_plane_state *plane_state = plane->state;  in __drm_gem_duplicate_shadow_plane_state()
226 	__drm_atomic_helper_plane_duplicate_state(plane, &new_shadow_plane_state->base);  in __drm_gem_duplicate_shadow_plane_state()
228 	drm_format_conv_state_copy(&new_shadow_plane_state->fmtcnv_state,  in __drm_gem_duplicate_shadow_plane_state()
229 				   &shadow_plane_state->fmtcnv_state);  in __drm_gem_duplicate_shadow_plane_state()
234  * drm_gem_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
238  * shadow-buffered planes. It assumes the existing state to be of type
253 	struct drm_plane_state *plane_state = plane->state;  in drm_gem_duplicate_shadow_plane_state()
264 	return &new_shadow_plane_state->base;  in drm_gem_duplicate_shadow_plane_state()
269  * __drm_gem_destroy_shadow_plane_state - cleans up shadow-buffered plane state
270  * @shadow_plane_state: the shadow-buffered plane state
272  * This function cleans up shadow-buffered plane state. Helpful for drivers that
277 	drm_format_conv_state_release(&shadow_plane_state->fmtcnv_state);  in __drm_gem_destroy_shadow_plane_state()
278 	__drm_atomic_helper_plane_destroy_state(&shadow_plane_state->base);  in __drm_gem_destroy_shadow_plane_state()
283  * drm_gem_destroy_shadow_plane_state - deletes shadow-buffered plane state
288  * for shadow-buffered planes. It expects that mappings of shadow buffers
303  * __drm_gem_reset_shadow_plane - resets a shadow-buffered plane
305  * @shadow_plane_state: the shadow-buffered plane state
307  * This function resets state for shadow-buffered planes. Helpful
314 		__drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base);  in __drm_gem_reset_shadow_plane()
315 		drm_format_conv_state_init(&shadow_plane_state->fmtcnv_state);  in __drm_gem_reset_shadow_plane()
323  * drm_gem_reset_shadow_plane - resets a shadow-buffered plane
327  * shadow-buffered planes. It assumes the current plane state to be
335 	if (plane->state) {  in drm_gem_reset_shadow_plane()
336 		drm_gem_destroy_shadow_plane_state(plane, plane->state);  in drm_gem_reset_shadow_plane()
337 		plane->state = NULL; /* must be set to NULL here */  in drm_gem_reset_shadow_plane()
348  * drm_gem_begin_shadow_fb_access - prepares shadow framebuffers for CPU access
360  * 0 on success, or a negative errno code otherwise.
365 	struct drm_framebuffer *fb = plane_state->fb;  in drm_gem_begin_shadow_fb_access()
370 	return drm_gem_fb_vmap(fb, shadow_plane_state->map, shadow_plane_state->data);  in drm_gem_begin_shadow_fb_access()
375  * drm_gem_end_shadow_fb_access - releases shadow framebuffers from CPU access
387 	struct drm_framebuffer *fb = plane_state->fb;  in drm_gem_end_shadow_fb_access()
392 	drm_gem_fb_vunmap(fb, shadow_plane_state->map);  in drm_gem_end_shadow_fb_access()
397  * drm_gem_simple_kms_begin_shadow_fb_access - prepares shadow framebuffers for CPU access
407  * 0 on success, or a negative errno code otherwise.
412 	return drm_gem_begin_shadow_fb_access(&pipe->plane, plane_state);  in drm_gem_simple_kms_begin_shadow_fb_access()
417  * drm_gem_simple_kms_end_shadow_fb_access - releases shadow framebuffers from CPU access
430 	drm_gem_end_shadow_fb_access(&pipe->plane, plane_state);  in drm_gem_simple_kms_end_shadow_fb_access()
435  * drm_gem_simple_kms_reset_shadow_plane - resets a shadow-buffered plane
439  * for shadow-buffered planes.
443 	drm_gem_reset_shadow_plane(&pipe->plane);  in drm_gem_simple_kms_reset_shadow_plane()
448  * drm_gem_simple_kms_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
452  * for shadow-buffered planes. It does not duplicate existing mappings of the shadow
462 	return drm_gem_duplicate_shadow_plane_state(&pipe->plane);  in drm_gem_simple_kms_duplicate_shadow_plane_state()
467  * drm_gem_simple_kms_destroy_shadow_plane_state - resets shadow-buffered plane state
472  * for shadow-buffered planes. It expects that mappings of shadow buffers
478 	drm_gem_destroy_shadow_plane_state(&pipe->plane, plane_state);  in drm_gem_simple_kms_destroy_shadow_plane_state()