Commit 879b3b65 authored by Jocelyn Falempe's avatar Jocelyn Falempe
Browse files

drm/fb_dma: Add generic get_scanout_buffer() for drm_panic 



This was initialy done for imx6, but should work on most drivers
using drm_fb_dma_helper.

v8:
 * Replace get_scanout_buffer() logic with drm_panic_set_buffer()
   (Thomas Zimmermann)

v9:
 * go back to get_scanout_buffer()
 * move get_scanout_buffer() to plane helper functions

v12:
 * Rename drm_panic_gem_get_scanout_buffer to drm_fb_dma_get_scanout_buffer
   (Thomas Zimmermann)
 * Remove the #ifdef CONFIG_DRM_PANIC, and build it unconditionnaly, as
   it's a small function. (Thomas Zimmermann)

Signed-off-by: default avatarJocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240409163432.352518-6-jfalempe@redhat.com


Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 813ca3aa

drivers/gpu/drm/drm_fb_dma_helper.c

+42 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <drm/drm_framebuffer.h>

#include <drm/drm_gem_dma_helper.h>

#include <drm/drm_gem_framebuffer_helper.h>

#include <drm/drm_panic.h>

#include <drm/drm_plane.h>

#include <linux/dma-mapping.h>

#include <linux/module.h>
@@ -148,3 +149,44 @@ void drm_fb_dma_sync_non_coherent(struct drm_device *drm, 
	}

}

EXPORT_SYMBOL_GPL(drm_fb_dma_sync_non_coherent);



/**

 * drm_fb_dma_get_scanout_buffer - Provide a scanout buffer in case of panic

 * @plane: DRM primary plane

 * @drm_scanout_buffer: scanout buffer for the panic handler

 * Returns: 0 or negative error code

 *

 * Generic get_scanout_buffer() implementation, for drivers that uses the

 * drm_fb_dma_helper. It won't call vmap in the panic context, so the driver

 * should make sure the primary plane is vmapped, otherwise the panic screen

 * won't get displayed.

 */

int drm_fb_dma_get_scanout_buffer(struct drm_plane *plane,

				  struct drm_scanout_buffer *sb)

{

	struct drm_gem_dma_object *dma_obj;

	struct drm_framebuffer *fb;



	fb = plane->state->fb;

	/* Only support linear modifier */

	if (fb->modifier != DRM_FORMAT_MOD_LINEAR)

		return -ENODEV;



	dma_obj = drm_fb_dma_get_gem_obj(fb, 0);



	/* Buffer should be accessible from the CPU */

	if (dma_obj->base.import_attach)

		return -ENODEV;



	/* Buffer should be already mapped to CPU */

	if (!dma_obj->vaddr)

		return -ENODEV;



	iosys_map_set_vaddr(&sb->map[0], dma_obj->vaddr);

	sb->format = fb->format;

	sb->height = fb->height;

	sb->width = fb->width;

	sb->pitch[0] = fb->pitches[0];

	return 0;

}

EXPORT_SYMBOL(drm_fb_dma_get_scanout_buffer);

include/drm/drm_fb_dma_helper.h

+4 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
struct drm_device;

struct drm_framebuffer;

struct drm_plane_state;

struct drm_scanout_buffer;



struct drm_gem_dma_object *drm_fb_dma_get_gem_obj(struct drm_framebuffer *fb,

	unsigned int plane);
@@ -19,5 +20,8 @@ void drm_fb_dma_sync_non_coherent(struct drm_device *drm, 
				  struct drm_plane_state *old_state,

				  struct drm_plane_state *state);



int drm_panic_gem_get_scanout_buffer(struct drm_plane *plane,

				     struct drm_scanout_buffer *sb);



#endif