GEM VRAM helpers used to pin the BO in their implementation of vmap, so that they could not be relocated. In recent discussions, [1][2] it became clear that this is incorrect for in-kernel use cases, such as fbdev emulation; which should rather depend on the reservation lock to prevent relocation.
This patchset addresses the issue by introducing the new interfaces vmap_local and vunmap_local throughout dma-buf and GEM. It further adds support to DRM's CMA, SHMEM and VRAM helpers and finally converts fbdev emulation to the new interface.
Patches 1 and 2 add the vmap_local infrastructure throughout dma-buf, GEM and PRIME.
Patches 3 to 11 add implementations of vmap_local to DRM's various GEM helper libraries. Due to the simple nature of these libraries, existing vmap code can be reused easily. Several drivers are updated as well to use the new interfaces.
Patch 12 converts generic fbdev emulation to use vmap_local. Only DRM drivers that use GEM helpers currently use fbdev emulation, so patches 3 to 11 covered all necessary instances.
Finally patch 13 removes drm_gem_vram_vmap() functionality, which is now unused.
I smoke-tested the patchset with ast (VRAM helpers), mgag200 (SHMEM) and vc4 (CMA). I also tested with a version of radeon (raw TTM) that had been converted to generic fbdev emulation.
v4: * move driver changes out of SHMEM and VRAM patches (Daniel) * call dma_buf_vmap_local() in SHMEM implementation (Daniel) * remove unused drm_gem_vram_vmap() functionality * update documentation (Daniel) v3: * rewrite patchset around vmap_local v2: * make importers acquire resv locks by themselves * document dma-buf vmap/vunmap ops
[1] https://patchwork.freedesktop.org/patch/400054/?series=83765&rev=1 [2] https://patchwork.freedesktop.org/patch/405407/?series=84401&rev=2
Thomas Zimmermann (13): dma-buf: Add vmap_local and vnumap_local operations drm/gem: Create infrastructure for GEM vmap_local drm/cma-helper: Provide a vmap function for short-term mappings drm/shmem-helper: Provide a vmap function for short-term mappings drm/mgag200: Use drm_gem_shmem_vmap_local() in damage handling drm/cirrus: Use drm_gem_shmem_vmap_local() in damage handling drm/gm12u320: Use drm_gem_shmem_vmap_local() in damage handling drm/udl: Use drm_gem_shmem_vmap_local() in damage handling drm/vram-helper: Provide a vmap function for short-term mappings drm/ast: Use drm_gem_vram_vmap_local() in cursor update drm/vboxvideo: Use drm_gem_vram_vmap_local() in cursor update drm/fb-helper: Move BO locking from DRM client to fbdev damage worker drm/vram-helper: Remove unused drm_gem_vram_{vmap,vunmap}()
drivers/dma-buf/dma-buf.c | 81 ++++++++++++++ drivers/gpu/drm/ast/ast_cursor.c | 37 +++++-- drivers/gpu/drm/drm_client.c | 94 +++++++++++++++++ drivers/gpu/drm/drm_fb_helper.c | 41 ++++---- drivers/gpu/drm/drm_gem.c | 28 +++++ drivers/gpu/drm/drm_gem_cma_helper.c | 27 +++++ drivers/gpu/drm/drm_gem_shmem_helper.c | 90 ++++++++++++++-- drivers/gpu/drm/drm_gem_vram_helper.c | 139 ++++++++----------------- drivers/gpu/drm/drm_internal.h | 2 + drivers/gpu/drm/drm_prime.c | 39 +++++++ drivers/gpu/drm/mgag200/mgag200_mode.c | 16 ++- drivers/gpu/drm/tiny/cirrus.c | 10 +- drivers/gpu/drm/tiny/gm12u320.c | 14 ++- drivers/gpu/drm/udl/udl_modeset.c | 18 ++-- drivers/gpu/drm/vboxvideo/vbox_mode.c | 15 +-- drivers/gpu/drm/vc4/vc4_bo.c | 1 + drivers/gpu/drm/virtio/virtgpu_prime.c | 2 + include/drm/drm_client.h | 4 + include/drm/drm_gem.h | 21 ++++ include/drm/drm_gem_cma_helper.h | 1 + include/drm/drm_gem_shmem_helper.h | 2 + include/drm/drm_gem_vram_helper.h | 4 +- include/drm/drm_prime.h | 2 + include/linux/dma-buf.h | 34 ++++++ 24 files changed, 566 insertions(+), 156 deletions(-)
-- 2.29.2