linux/drivers/gpu/drm/bochs
Thomas Zimmermann 222ec45f4c drm/fb_helper: Support framebuffers in I/O memory
At least sparc64 requires I/O-specific access to framebuffers. This
patch updates the fbdev console accordingly.

For drivers with direct access to the framebuffer memory, the callback
functions in struct fb_ops test for the type of memory and call the rsp
fb_sys_ of fb_cfb_ functions. Read and write operations are implemented
internally by DRM's fbdev helper.

For drivers that employ a shadow buffer, fbdev's blit function retrieves
the framebuffer address as struct dma_buf_map, and uses dma_buf_map
interfaces to access the buffer.

The bochs driver on sparc64 uses a workaround to flag the framebuffer as
I/O memory and avoid a HW exception. With the introduction of struct
dma_buf_map, this is not required any longer. The patch removes the rsp
code from both, bochs and fbdev.

v7:
	* use min_t(size_t,) (kernel test robot)
	* return the number of bytes read/written, if any (fbdev testcase)
v5:
	* implement fb_read/fb_write internally (Daniel, Sam)
v4:
	* move dma_buf_map changes into separate patch (Daniel)
	* TODO list: comment on fbdev updates (Daniel)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-11-tzimmermann@suse.de
2020-11-09 09:20:00 +01:00
..
bochs_drv.c drm/<drivers>: Constify struct drm_driver 2020-11-06 10:31:26 +01:00
bochs_hw.c Linux 5.6 2020-03-31 15:15:47 +10:00
bochs_kms.c drm/fb_helper: Support framebuffers in I/O memory 2020-11-09 09:20:00 +01:00
bochs_mm.c drm/vram: Have VRAM MM call GEM VRAM functions directly 2019-09-12 19:54:42 +02:00
bochs.h drm/bochs: Drop explicit drm_mode_config_cleanup 2020-03-26 15:46:09 +01:00
Kconfig drm/vram: fix Kconfig 2019-09-10 08:53:08 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00