1 // SPDX-License-Identifier: GPL-2.0-or-later
3 #include <linux/dma-resv.h>
4 #include <linux/dma-fence-chain.h>
19  * The GEM atomic helpers library implements generic atomic-commit
32  * .. code-block:: c
44  * cannot be established by commit-tail functions, such as atomic_update,
47  * The helpers for shadow-buffered planes establish and release mappings,
49  * for commit-tail functions.
51  * Shadow-buffered planes can easily be enabled by using the provided macros
53  * These macros set up the plane and plane-helper callbacks to point to the
54  * shadow-buffer helpers.
56  * .. code-block:: c
70  * In the driver's atomic-update function, shadow-buffer mappings are available
74  * .. code-block:: c
79  *		struct drm_plane_state *plane_state = plane->state;
83  *		// access shadow buffer via shadow_plane_state->map
92  * callbacks. Access to shadow-buffer mappings is similar to regular
95  * .. code-block:: c
109  *		// access shadow buffer via shadow_plane_state->map
118  * drm_gem_plane_helper_prepare_fb() - Prepare a GEM backed framebuffer
138 	struct dma_fence *fence = dma_fence_get(state->fence);  in drm_gem_plane_helper_prepare_fb()
143 	if (!state->fb)  in drm_gem_plane_helper_prepare_fb()
151 	 * which is important to make explicit fencing use-cases work: One  in drm_gem_plane_helper_prepare_fb()
161 	for (i = 0; i < state->fb->format->num_planes; ++i) {  in drm_gem_plane_helper_prepare_fb()
162 		struct drm_gem_object *obj = drm_gem_fb_get_obj(state->fb, i);  in drm_gem_plane_helper_prepare_fb()
166 			ret = -EINVAL;  in drm_gem_plane_helper_prepare_fb()
170 		ret = dma_resv_get_singleton(obj->resv, usage, &new);  in drm_gem_plane_helper_prepare_fb()
178 				ret = -ENOMEM;  in drm_gem_plane_helper_prepare_fb()
183 			fence = &chain->base;  in drm_gem_plane_helper_prepare_fb()
190 	dma_fence_put(state->fence);  in drm_gem_plane_helper_prepare_fb()
191 	state->fence = fence;  in drm_gem_plane_helper_prepare_fb()
201  * Shadow-buffered Planes
205  * __drm_gem_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
207  * @new_shadow_plane_state: the new shadow-buffered plane state
209  * This function duplicates shadow-buffered plane state. This is helpful for drivers
221 	struct drm_plane_state *plane_state = plane->state;  in __drm_gem_duplicate_shadow_plane_state()
225 	__drm_atomic_helper_plane_duplicate_state(plane, &new_shadow_plane_state->base);  in __drm_gem_duplicate_shadow_plane_state()
227 	drm_format_conv_state_copy(&new_shadow_plane_state->fmtcnv_state,  in __drm_gem_duplicate_shadow_plane_state()
228 				   &shadow_plane_state->fmtcnv_state);  in __drm_gem_duplicate_shadow_plane_state()
233  * drm_gem_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
237  * shadow-buffered planes. It assumes the existing state to be of type
252 	struct drm_plane_state *plane_state = plane->state;  in drm_gem_duplicate_shadow_plane_state()
263 	return &new_shadow_plane_state->base;  in drm_gem_duplicate_shadow_plane_state()
268  * __drm_gem_destroy_shadow_plane_state - cleans up shadow-buffered plane state
269  * @shadow_plane_state: the shadow-buffered plane state
271  * This function cleans up shadow-buffered plane state. Helpful for drivers that
276 	drm_format_conv_state_release(&shadow_plane_state->fmtcnv_state);  in __drm_gem_destroy_shadow_plane_state()
277 	__drm_atomic_helper_plane_destroy_state(&shadow_plane_state->base);  in __drm_gem_destroy_shadow_plane_state()
282  * drm_gem_destroy_shadow_plane_state - deletes shadow-buffered plane state
287  * for shadow-buffered planes. It expects that mappings of shadow buffers
302  * __drm_gem_reset_shadow_plane - resets a shadow-buffered plane
304  * @shadow_plane_state: the shadow-buffered plane state
306  * This function resets state for shadow-buffered planes. Helpful
312 	__drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base);  in __drm_gem_reset_shadow_plane()
313 	drm_format_conv_state_init(&shadow_plane_state->fmtcnv_state);  in __drm_gem_reset_shadow_plane()
318  * drm_gem_reset_shadow_plane - resets a shadow-buffered plane
322  * shadow-buffered planes. It assumes the current plane state to be
330 	if (plane->state) {  in drm_gem_reset_shadow_plane()
331 		drm_gem_destroy_shadow_plane_state(plane, plane->state);  in drm_gem_reset_shadow_plane()
332 		plane->state = NULL; /* must be set to NULL here */  in drm_gem_reset_shadow_plane()
343  * drm_gem_begin_shadow_fb_access - prepares shadow framebuffers for CPU access
355  * 0 on success, or a negative errno code otherwise.
360 	struct drm_framebuffer *fb = plane_state->fb;  in drm_gem_begin_shadow_fb_access()
365 	return drm_gem_fb_vmap(fb, shadow_plane_state->map, shadow_plane_state->data);  in drm_gem_begin_shadow_fb_access()
370  * drm_gem_end_shadow_fb_access - releases shadow framebuffers from CPU access
382 	struct drm_framebuffer *fb = plane_state->fb;  in drm_gem_end_shadow_fb_access()
387 	drm_gem_fb_vunmap(fb, shadow_plane_state->map);  in drm_gem_end_shadow_fb_access()
392  * drm_gem_simple_kms_begin_shadow_fb_access - prepares shadow framebuffers for CPU access
402  * 0 on success, or a negative errno code otherwise.
407 	return drm_gem_begin_shadow_fb_access(&pipe->plane, plane_state);  in drm_gem_simple_kms_begin_shadow_fb_access()
412  * drm_gem_simple_kms_end_shadow_fb_access - releases shadow framebuffers from CPU access
425 	drm_gem_end_shadow_fb_access(&pipe->plane, plane_state);  in drm_gem_simple_kms_end_shadow_fb_access()
430  * drm_gem_simple_kms_reset_shadow_plane - resets a shadow-buffered plane
434  * for shadow-buffered planes.
438 	drm_gem_reset_shadow_plane(&pipe->plane);  in drm_gem_simple_kms_reset_shadow_plane()
443  * drm_gem_simple_kms_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
447  * for shadow-buffered planes. It does not duplicate existing mappings of the shadow
457 	return drm_gem_duplicate_shadow_plane_state(&pipe->plane);  in drm_gem_simple_kms_duplicate_shadow_plane_state()
462  * drm_gem_simple_kms_destroy_shadow_plane_state - resets shadow-buffered plane state
467  * for shadow-buffered planes. It expects that mappings of shadow buffers
473 	drm_gem_destroy_shadow_plane_state(&pipe->plane, plane_state);  in drm_gem_simple_kms_destroy_shadow_plane_state()