Unverified Commit b0906904 authored by Paul Cercueil's avatar Paul Cercueil
Browse files

drm: Add and export function drm_fb_cma_sync_non_coherent 



This function can be used by drivers that use damage clips and have
CMA GEM objects backed by non-coherent memory. Calling this function
in a plane's .atomic_update ensures that all the data in the backing
memory have been written to RAM.

v3: - Only sync data if using GEM objects backed by non-coherent memory.
    - Use a drm_device pointer instead of device pointer in prototype

v5: - Rename to drm_fb_cma_sync_non_coherent
    - Invert loops for better cache locality
    - Only sync BOs that have the non-coherent flag
    - Move to drm_fb_cma_helper.c to avoid circular dependency

Signed-off-by: default avatarPaul Cercueil <paul@crapouillou.net>
Acked-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210523170415.90410-3-paul@crapouillou.net
parent cf8ccbc7

drivers/gpu/drm/drm_fb_cma_helper.c

+46 −0
Original line number Diff line number Diff line
@@ -9,12 +9,14 @@ 
 *  Copyright (C) 2012 Red Hat

 */



#include <drm/drm_damage_helper.h>

#include <drm/drm_fb_cma_helper.h>

#include <drm/drm_fourcc.h>

#include <drm/drm_framebuffer.h>

#include <drm/drm_gem_cma_helper.h>

#include <drm/drm_gem_framebuffer_helper.h>

#include <drm/drm_plane.h>

#include <linux/dma-mapping.h>

#include <linux/module.h>



/**
@@ -97,3 +99,47 @@ dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb, 
	return paddr;

}

EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_addr);



/**

 * drm_fb_cma_sync_non_coherent - Sync GEM object to non-coherent backing

 *	memory

 * @drm: DRM device

 * @old_state: Old plane state

 * @state: New plane state

 *

 * This function can be used by drivers that use damage clips and have

 * CMA GEM objects backed by non-coherent memory. Calling this function

 * in a plane's .atomic_update ensures that all the data in the backing

 * memory have been written to RAM.

 */

void drm_fb_cma_sync_non_coherent(struct drm_device *drm,

				  struct drm_plane_state *old_state,

				  struct drm_plane_state *state)

{

	const struct drm_format_info *finfo = state->fb->format;

	struct drm_atomic_helper_damage_iter iter;

	const struct drm_gem_cma_object *cma_obj;

	unsigned int offset, i;

	struct drm_rect clip;

	dma_addr_t daddr;

	size_t nb_bytes;



	for (i = 0; i < finfo->num_planes; i++) {

		cma_obj = drm_fb_cma_get_gem_obj(state->fb, i);

		if (!cma_obj->map_noncoherent)

			continue;



		daddr = drm_fb_cma_get_gem_addr(state->fb, state, i);

		drm_atomic_helper_damage_iter_init(&iter, old_state, state);



		drm_atomic_for_each_plane_damage(&iter, &clip) {

			/* Ignore x1/x2 values, invalidate complete lines */

			offset = clip.y1 * state->fb->pitches[i];



			nb_bytes = (clip.y2 - clip.y1) * state->fb->pitches[i];

			dma_sync_single_for_device(drm->dev, daddr + offset,

						   nb_bytes, DMA_TO_DEVICE);

		}

	}

}

EXPORT_SYMBOL_GPL(drm_fb_cma_sync_non_coherent);

include/drm/drm_fb_cma_helper.h

+5 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 


#include <linux/types.h>



struct drm_device;

struct drm_framebuffer;

struct drm_plane_state;
@@ -14,5 +15,9 @@ dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb, 
				   struct drm_plane_state *state,

				   unsigned int plane);



void drm_fb_cma_sync_non_coherent(struct drm_device *drm,

				  struct drm_plane_state *old_state,

				  struct drm_plane_state *state);



#endif