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| author | Jocelyn Falempe <jfalempe@redhat.com> | 2025-04-07 15:42:26 +0200 |
|---|---|---|
| committer | Jocelyn Falempe <jfalempe@redhat.com> | 2025-04-10 10:50:58 +0200 |
| commit | c9ff2808790f0fd4ca16f30f63abe70914a5a292 (patch) | |
| tree | 7606514928c0403c97537b7e16eaff0433c4f360 /include | |
| parent | mm/kmap: Add kmap_local_page_try_from_panic() (diff) | |
| download | linux-c9ff2808790f0fd4ca16f30f63abe70914a5a292.tar.gz linux-c9ff2808790f0fd4ca16f30f63abe70914a5a292.zip | |
drm/panic: Add support to scanout buffer as array of pages
Some drivers like virtio-gpu, don't map the scanout buffer in the
kernel. Calling vmap() in a panic handler is not safe, and writing an
atomic_vmap() API is more complex than expected [1].
So instead, pass the array of pages of the scanout buffer to the
panic handler, and map only one page at a time to draw the pixels.
This is obviously slow, but acceptable for a panic handler.
[1] https://lore.kernel.org/dri-devel/20250305152555.318159-1-ryasuoka@redhat.com/
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Simona Vetter <simona@ffwll.ch>
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250407140138.162383-3-jfalempe@redhat.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/drm/drm_panic.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/include/drm/drm_panic.h b/include/drm/drm_panic.h index ff78d00c3da5..310c88c4d336 100644 --- a/include/drm/drm_panic.h +++ b/include/drm/drm_panic.h @@ -40,6 +40,16 @@ struct drm_scanout_buffer { struct iosys_map map[DRM_FORMAT_MAX_PLANES]; /** + * @pages: Optional, if the scanout buffer is not mapped, set this field + * to the array of pages of the scanout buffer. The panic code will use + * kmap_local_page_try_from_panic() to map one page at a time to write + * all the pixels. This array shouldn't be allocated from the + * get_scanoutbuffer() callback. + * The scanout buffer should be in linear format. + */ + struct page **pages; + + /** * @width: Width of the scanout buffer, in pixels. */ unsigned int width; @@ -57,7 +67,7 @@ struct drm_scanout_buffer { /** * @set_pixel: Optional function, to set a pixel color on the * framebuffer. It allows to handle special tiling format inside the - * driver. + * driver. It takes precedence over the @map and @pages fields. */ void (*set_pixel)(struct drm_scanout_buffer *sb, unsigned int x, unsigned int y, u32 color); |