drm/fbdev: Add fbdev-shmem

Browse source

Add an fbdev emulation for SHMEM-based memory managers. The code is
similar to fbdev-generic, but does not require an additional shadow
buffer for mmap(). Fbdev-shmem operates directly on the buffer object's
SHMEM pages. Fbdev's deferred-I/O mechanism updates the hardware state
on write operations.

The memory pages of GEM SHMEM cannot be detected by fbdefio. Therefore
fbdev-shmem implements the .get_page() hook in struct fb_deferred_io.
The fbdefio helpers call this hook to retrieve the page directly from
fbdev-shmem instead of trying to detect it internally.

v3:
- clarify on get_page mechanism in commit description (Javier)
v2:
- use drm_driver_legacy_fb_format() (Geert)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-9-tzimmermann@suse.de

...

This commit is contained in:

Thomas Zimmermann 2024-04-19 10:29:01 +02:00

parent 747bda7bb5

commit 150f431a08

3 changed files with 332 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

1

drivers/gpu/drm/Makefile

View file

316

drivers/gpu/drm/drm_fbdev_shmem.c

View file

15

include/drm/drm_fbdev_shmem.h

View file