[v6,00/10] Support GEM object mappings from I/O memory

Message

Thomas Zimmermann Oct. 28, 2020, 7:35 p.m. UTC

DRM's fbdev console uses regular load and store operations to update
framebuffer memory. The bochs driver on sparc64 requires the use of
I/O-specific load and store operations. We have a workaround, but need
a long-term solution to the problem.

This patchset changes GEM's vmap/vunmap interfaces to forward pointers
of type struct dma_buf_map and updates the generic fbdev emulation to
use them correctly. This enables I/O-memory operations on all framebuffers
that require and support them.

Patches #1 to #4 prepare VRAM helpers and drivers.

Next is the update of the GEM vmap functions. Patch #5 adds vmap and vunmap
that is usable with TTM-based GEM drivers, and patch #6 updates GEM's
vmap/vunmap callback to forward instances of type struct dma_buf_map. While
the patch touches many files throughout the DRM modules, the applied changes
are mostly trivial interface fixes. Several TTM-based GEM drivers now use
the new vmap code. Patch #7 updates GEM's internal vmap/vunmap functions to
forward struct dma_buf_map.

With struct dma_buf_map propagated through the layers, patches #8 to #10
convert DRM clients and generic fbdev emulation to use it. Updating the
fbdev framebuffer will select the correct functions, either for system or
I/O memory.

v6:
	* don't call page_to_phys() on fbdev framebuffers in I/O memory;
	  warn instead (Daniel)
v5:
	* rebase onto latest TTM changes (Christian)
	* support TTM premapped memory correctly (Christian)
	* implement fb_read/fb_write internally (Sam, Daniel)
	* cleanups
v4:
	* provide TTM vmap/vunmap plus GEM helpers and convert drivers
	  over (Christian, Daniel)
	* remove several empty functions
	* more TODOs and documentation (Daniel)
v3:
	* recreate the whole patchset on top of struct dma_buf_map
v2:
	* RFC patchset

Thomas Zimmermann (10):
  drm/vram-helper: Remove invariant parameters from internal kmap
    function
  drm/cma-helper: Remove empty drm_gem_cma_prime_vunmap()
  drm/etnaviv: Remove empty etnaviv_gem_prime_vunmap()
  drm/exynos: Remove empty exynos_drm_gem_prime_{vmap,vunmap}()
  drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers
  drm/gem: Use struct dma_buf_map in GEM vmap ops and convert GEM
    backends
  drm/gem: Update internal GEM vmap/vunmap interfaces to use struct
    dma_buf_map
  drm/gem: Store client buffer mappings as struct dma_buf_map
  dma-buf-map: Add memcpy and pointer-increment interfaces
  drm/fb_helper: Support framebuffers in I/O memory

 Documentation/gpu/todo.rst                  |  37 ++-
 drivers/gpu/drm/Kconfig                     |   2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c |  36 ---
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h |   2 -
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c     |   5 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.h  |   1 -
 drivers/gpu/drm/ast/ast_cursor.c            |  27 +-
 drivers/gpu/drm/ast/ast_drv.h               |   7 +-
 drivers/gpu/drm/bochs/bochs_kms.c           |   1 -
 drivers/gpu/drm/drm_client.c                |  38 +--
 drivers/gpu/drm/drm_fb_helper.c             | 257 ++++++++++++++++++--
 drivers/gpu/drm/drm_gem.c                   |  29 ++-
 drivers/gpu/drm/drm_gem_cma_helper.c        |  27 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c      |  48 ++--
 drivers/gpu/drm/drm_gem_ttm_helper.c        |  38 +++
 drivers/gpu/drm/drm_gem_vram_helper.c       | 117 ++++-----
 drivers/gpu/drm/drm_internal.h              |   5 +-
 drivers/gpu/drm/drm_prime.c                 |  14 +-
 drivers/gpu/drm/etnaviv/etnaviv_drv.h       |   3 +-
 drivers/gpu/drm/etnaviv/etnaviv_gem.c       |   1 -
 drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c |  12 +-
 drivers/gpu/drm/exynos/exynos_drm_gem.c     |  12 -
 drivers/gpu/drm/exynos/exynos_drm_gem.h     |   2 -
 drivers/gpu/drm/lima/lima_gem.c             |   6 +-
 drivers/gpu/drm/lima/lima_sched.c           |  11 +-
 drivers/gpu/drm/mgag200/mgag200_mode.c      |  10 +-
 drivers/gpu/drm/nouveau/Kconfig             |   1 +
 drivers/gpu/drm/nouveau/nouveau_bo.h        |   2 -
 drivers/gpu/drm/nouveau/nouveau_gem.c       |   6 +-
 drivers/gpu/drm/nouveau/nouveau_gem.h       |   2 -
 drivers/gpu/drm/nouveau/nouveau_prime.c     |  20 --
 drivers/gpu/drm/panfrost/panfrost_perfcnt.c |  14 +-
 drivers/gpu/drm/qxl/qxl_display.c           |  11 +-
 drivers/gpu/drm/qxl/qxl_draw.c              |  14 +-
 drivers/gpu/drm/qxl/qxl_drv.h               |  11 +-
 drivers/gpu/drm/qxl/qxl_object.c            |  31 ++-
 drivers/gpu/drm/qxl/qxl_object.h            |   2 +-
 drivers/gpu/drm/qxl/qxl_prime.c             |  12 +-
 drivers/gpu/drm/radeon/radeon.h             |   1 -
 drivers/gpu/drm/radeon/radeon_gem.c         |   7 +-
 drivers/gpu/drm/radeon/radeon_prime.c       |  20 --
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c |  22 +-
 drivers/gpu/drm/rockchip/rockchip_drm_gem.h |   4 +-
 drivers/gpu/drm/tiny/cirrus.c               |  10 +-
 drivers/gpu/drm/tiny/gm12u320.c             |  10 +-
 drivers/gpu/drm/ttm/ttm_bo_util.c           |  72 ++++++
 drivers/gpu/drm/udl/udl_modeset.c           |   8 +-
 drivers/gpu/drm/vboxvideo/vbox_mode.c       |  11 +-
 drivers/gpu/drm/vc4/vc4_bo.c                |   7 +-
 drivers/gpu/drm/vc4/vc4_drv.h               |   2 +-
 drivers/gpu/drm/vgem/vgem_drv.c             |  16 +-
 drivers/gpu/drm/vkms/vkms_plane.c           |  15 +-
 drivers/gpu/drm/vkms/vkms_writeback.c       |  22 +-
 drivers/gpu/drm/xen/xen_drm_front_gem.c     |  18 +-
 drivers/gpu/drm/xen/xen_drm_front_gem.h     |   6 +-
 include/drm/drm_client.h                    |   7 +-
 include/drm/drm_gem.h                       |   5 +-
 include/drm/drm_gem_cma_helper.h            |   3 +-
 include/drm/drm_gem_shmem_helper.h          |   4 +-
 include/drm/drm_gem_ttm_helper.h            |   6 +
 include/drm/drm_gem_vram_helper.h           |  14 +-
 include/drm/drm_mode_config.h               |  12 -
 include/drm/ttm/ttm_bo_api.h                |  28 +++
 include/linux/dma-buf-map.h                 |  93 ++++++-
 64 files changed, 859 insertions(+), 438 deletions(-)

--
2.29.0