linux.git/drivers/video/fbdev/core/sysimgblt.c, branch for-next

fbdev: Warn on incorrect framebuffer access

2023-11-29T11:20:50+00:00

Test in framebuffer read, write and drawing helpers if FBINFO_VIRTFB
has been set correctly. Framebuffers in I/O memory should only be
accessed with the architecture's respective helpers. Framebuffers
in system memory should be accessed with the regular load and
store operations. Presumably not all drivers get this right, so we
now warn about it.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-32-tzimmermann@suse.de

fbdev: fix potential OOB read in fast_imageblit()

2023-06-24T19:55:11+00:00

There is a potential OOB read at fast_imageblit, for
"colortab[(*src >> 4)]" can become a negative value due to
"const char *s = image->data, *src".
This change makes sure the index for colortab always positive
or zero.

Similar commit:
https://patchwork.kernel.org/patch/11746067

Potential bug report:
https://groups.google.com/g/syzkaller-bugs/c/9ubBXKeKXf4/m/k-QXy4UgAAAJ

Signed-off-by: Zhang Shurong 
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller

fbdev: Fix sys_imageblit() for arbitrary image widths

2022-03-24T23:55:52+00:00

Commit 6f29e04938bf ("fbdev: Improve performance of sys_imageblit()")
broke sys_imageblit() for image width that are not aligned to 8-bit
boundaries. Fix this by handling the trailing pixels on each line
separately. The performance improvements in the original commit do not
regress by this change.

Signed-off-by: Thomas Zimmermann 
Fixes: 6f29e04938bf ("fbdev: Improve performance of sys_imageblit()")
Cc: Thomas Zimmermann 
Cc: Javier Martinez Canillas 
Cc: Sam Ravnborg 
Tested-by: Geert Uytterhoeven 
Reviewed-by: Javier Martinez Canillas 
Signed-off-by: Dave Airlie 
Link: https://patchwork.freedesktop.org/patch/msgid/20220313192952.12058-2-tzimmermann@suse.de

fbdev: Improve performance of sys_imageblit()

2022-03-02T19:20:46+00:00

Improve the performance of sys_imageblit() by manually unrolling
the inner blitting loop and moving some invariants out. The compiler
failed to do this automatically. The resulting binary code was even
slower than the cfb_imageblit() helper, which uses the same algorithm,
but operates on I/O memory.

A microbenchmark measures the average number of CPU cycles
for sys_imageblit() after a stabilizing period of a few minutes
(i7-4790, FullHD, simpledrm, kernel with debugging). The value
for CFB is given as a reference.

  sys_imageblit(), new: 25934 cycles
  sys_imageblit(), old: 35944 cycles
  cfb_imageblit():      30566 cycles

In the optimized case, sys_imageblit() is now ~30% faster than before
and ~20% faster than cfb_imageblit().

v2:
	* move switch out of inner loop (Gerd)
	* remove test for alignment of dst1 (Sam)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Acked-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20220223193804.18636-3-tzimmermann@suse.de

fbdev: move fbdev core files to separate directory

2014-04-17T05:10:19+00:00

Instead of having fbdev framework core files at the root fbdev
directory, mixed with random fbdev device drivers, move the fbdev core
files to a separate core directory. This makes it much clearer which of
the files are actually part of the fbdev framework, and which are part
of device drivers.

Signed-off-by: Tomi Valkeinen 
Acked-by: Laurent Pinchart 
Acked-by: Geert Uytterhoeven 
Acked-by: Rob Clark 
Acked-by: Jingoo Han 
Acked-by: Daniel Vetter