Make fbdev's built-in helpers for reading and writing I/O and system
memory available to DRM. Replace DRM's internal helpers.
The first patch resolves a bug that's been in the fbdev code for
more than 15 years. Makes the read/write helpers work successfully
with the IGT tests.
Patches 2 to 4 streamline fbdev's file-I/O code and remove a few
duplicate checks.
Patch 5 moves the default-I/O code into the new helpers fb_cfb_read()
and fb_cfb_write(); patch 6 uses them in DRM. This allows us to remove
quite a bit of code from DRM's internal fbdev helpers.
Tested with i915 and simpledrm.
The next step here is to remove the drm_fb_helper_{cfb,sys}_*()
entirely. They where mostly introduced because fbdev doesn't protect
it's public interfaces with an CONFIG_FB preprocessor guards. But all
of DRM driver's fbdev emulation won't be build without CONFIG_FB, so
this is not an issue in practice. Removing the DRM wrappers will
further simplify the DRM code.
Thomas Zimmermann (6):
fbdev: Return number of bytes read or written
fbdev: Use screen_buffer in fb_sys_{read,write}()
fbdev: Don't re-validate info->state in fb_ops implementations
fbdev: Validate info->screen_{base,buffer} in fb_ops implementations
fbdev: Move CFB read and write code into helper functions
drm/fb-helper: Use fb_{cfb,sys}_{read, write}()
drivers/gpu/drm/drm_fb_helper.c | 174 +------------------------
drivers/video/fbdev/cobalt_lcdfb.c | 6 +
drivers/video/fbdev/core/Makefile | 2 +-
drivers/video/fbdev/core/fb_cfb_fops.c | 126 ++++++++++++++++++
drivers/video/fbdev/core/fb_sys_fops.c | 36 ++---
drivers/video/fbdev/core/fbmem.c | 111 +---------------
drivers/video/fbdev/sm712fb.c | 10 +-
include/linux/fb.h | 10 ++
8 files changed, 173 insertions(+), 302 deletions(-)
create mode 100644 drivers/video/fbdev/core/fb_cfb_fops.c
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2.40.0
