[v3,00/12] drm: Improve fbdev emulation for DMA-able framebuffers

Message

Thomas Zimmermann July 7, 2023, 8:31 a.m. UTC

Add fbdev helpers for framebuffers in DMA-able memory and update
fbdev emulation in the respective DRM drivers. DMA memory used to
handled as system memory. Improve this and prepare for possible
future changes.

Patch 1 adds initializer macros for struct fb_ops and a Kconfig
token for framebuffers in DMA memory.

Patches 2 to 5 update fbdev-dma and tegra. No functional changes
are expected as both used system memory before.

Patches 6 and 7 update exynos to use DMA helpers. Exynos incorrectly
used fbdev's I/O-memory helpers. Fix this.

Patches 8 to 10 update omapdrm to use DMA helpers. Patch 7 first
reworks the driver's mmap to current best practices. This also makes
it suitable for use with fbdev, which patches 8 and 9 implement.

Patchies 11 removes some fbdev macros for system memory that are now
unused; patch 12 fixes some comments.

The patchset would ideally go through drm-misc-next. Future patches
can build upon it and update fbdev drivers in similar ways.

v3:
	* set screen_buffer in tegra (Thierry)
v2:
	* fix omap mmap flags
	* drop FBINFO_DEFAULT from patches
	* minor cleanups

Thomas Zimmermann (12):
  fbdev: Add fb_ops init macros for framebuffers in DMA-able memory
  drm/fbdev-dma: Use fbdev DMA helpers
  drm/tegra: Use fbdev DMA helpers
  drm/tegra: Set fbdev FBINFO_VIRTFB flag
  drm/tegra: Store pointer to vmap'ed framebuffer in screen_buffer
  drm/exynos: Use fbdev DMA helpers
  drm/exynos: Set fbdev FBINFO_VIRTFB flag
  drm/omapdrm: Set VM flags in GEM-object mmap function
  drm/omapdrm: Use GEM mmap for fbdev emulation
  drm/omapdrm: Set fbdev FBINFO_VIRTFB flag
  fbdev: Remove FB_DEFAULT_SYS_OPS
  fbdev: Harmonize some comments in <linux/fb.h>

 drivers/gpu/drm/Kconfig                   |  2 +-
 drivers/gpu/drm/drm_fbdev_dma.c           |  4 ++--
 drivers/gpu/drm/exynos/Kconfig            |  2 +-
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c |  5 ++--
 drivers/gpu/drm/omapdrm/Kconfig           |  2 +-
 drivers/gpu/drm/omapdrm/omap_drv.c        | 12 +---------
 drivers/gpu/drm/omapdrm/omap_fbdev.c      | 16 +++++++++++--
 drivers/gpu/drm/omapdrm/omap_gem.c        | 24 +++++--------------
 drivers/gpu/drm/omapdrm/omap_gem.h        |  3 ---
 drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c |  7 +-----
 drivers/gpu/drm/tegra/Kconfig             |  2 +-
 drivers/gpu/drm/tegra/fbdev.c             |  7 +++---
 drivers/video/fbdev/Kconfig               |  8 +++++++
 include/linux/fb.h                        | 29 ++++++++++-------------
 14 files changed, 56 insertions(+), 67 deletions(-)