diff --git a/drivers/gpu/drm/drm_fb_dma_helper.c b/drivers/gpu/drm/drm_fb_dma_helper.c index 3b535ad1b07cb85d4131a61ab5e3f453d721006b..c79b5078303feafb10dc4f2fc427cc5016d6d8af 100644 --- a/drivers/gpu/drm/drm_fb_dma_helper.c +++ b/drivers/gpu/drm/drm_fb_dma_helper.c @@ -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); diff --git a/include/drm/drm_fb_dma_helper.h b/include/drm/drm_fb_dma_helper.h index d5e036c578019b47abab96f753a5aee0610dfa5c..61f24c2aba2fa1007453a0a7428eb9d237196da7 100644 --- a/include/drm/drm_fb_dma_helper.h +++ b/include/drm/drm_fb_dma_helper.h @@ -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