Christian König
2022-Aug-24 14:15 UTC
[PATCH v3 0/9] Move all drivers to a common dma-buf locking convention
Reviewed-by: Christian K?nig <christian.koenig at amd.com> to patches #2-#4 Am 24.08.22 um 12:22 schrieb Dmitry Osipenko:> Hello, > > This series moves all drivers to a dynamic dma-buf locking specification. > From now on all dma-buf importers are made responsible for holding > dma-buf's reservation lock around all operations performed over dma-bufs > in accordance to the locking specification. This allows us to utilize > reservation lock more broadly around kernel without fearing of a potential > deadlocks. > > This patchset passes all i915 selftests. It was also tested using VirtIO, > Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested cases > of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where appropriate), > which covers majority of kernel drivers since rest of the drivers share > same or similar code paths. > > Changelog: > > v3: - Factored out dma_buf_mmap_unlocked() and attachment functions > into aseparate patches, like was suggested by Christian K?nig. > > - Corrected and factored out dma-buf locking documentation into > a separate patch, like was suggested by Christian K?nig. > > - Intel driver dropped the reservation locking fews days ago from > its BO-release code path, but we need that locking for the imported > GEMs because in the end that code path unmaps the imported GEM. > So I added back the locking needed by the imported GEMs, updating > the "dma-buf attachment locking specification" patch appropriately. > > - Tested Nouveau+Intel dma-buf import/export combo. > > - Tested udmabuf import to i915/Nouveau/AMDGPU. > > - Fixed few places in Etnaviv, Panfrost and Lima drivers that I missed > to switch to locked dma-buf vmapping in the drm/gem: Take reservation > lock for vmap/vunmap operations" patch. In a result invalidated the > Christian's r-b that he gave to v2. > > - Added locked dma-buf vmap/vunmap functions that are needed for fixing > vmappping of Etnaviv, Panfrost and Lima drivers mentioned above. > I actually had this change stashed for the drm-shmem shrinker patchset, > but then realized that it's already needed by the dma-buf patches. > Also improved my tests to better cover these code paths. > > v2: - Changed locking specification to avoid problems with a cross-driver > ww locking, like was suggested by Christian K?nig. Now the attach/detach > callbacks are invoked without the held lock and exporter should take the > lock. > > - Added "locking convention" documentation that explains which dma-buf > functions and callbacks are locked/unlocked for importers and exporters, > which was requested by Christian K?nig. > > - Added ack from Tomasz Figa to the V4L patches that he gave to v1. > > Dmitry Osipenko (9): > dma-buf: Add _unlocked postfix to function names > dma-buf: Add locked variant of dma_buf_vmap/vunmap() > drm/gem: Take reservation lock for vmap/vunmap operations > dma-buf: Move dma_buf_vmap/vunmap_unlocked() to dynamic locking > specification > dma-buf: Move dma_buf_mmap_unlocked() to dynamic locking specification > dma-buf: Move dma-buf attachment to dynamic locking specification > dma-buf: Document dynamic locking convention > media: videobuf2: Stop using internal dma-buf lock > dma-buf: Remove internal lock > > Documentation/driver-api/dma-buf.rst | 6 + > drivers/dma-buf/dma-buf.c | 276 ++++++++++++++---- > drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 4 +- > drivers/gpu/drm/armada/armada_gem.c | 14 +- > drivers/gpu/drm/drm_client.c | 4 +- > drivers/gpu/drm/drm_gem.c | 24 ++ > drivers/gpu/drm/drm_gem_dma_helper.c | 6 +- > drivers/gpu/drm/drm_gem_framebuffer_helper.c | 6 +- > drivers/gpu/drm/drm_gem_shmem_helper.c | 2 +- > drivers/gpu/drm/drm_gem_ttm_helper.c | 9 +- > drivers/gpu/drm/drm_prime.c | 12 +- > drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 4 +- > drivers/gpu/drm/exynos/exynos_drm_gem.c | 2 +- > drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 6 +- > drivers/gpu/drm/i915/gem/i915_gem_object.c | 12 + > .../drm/i915/gem/selftests/i915_gem_dmabuf.c | 20 +- > drivers/gpu/drm/lima/lima_sched.c | 4 +- > drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 8 +- > drivers/gpu/drm/panfrost/panfrost_dump.c | 4 +- > drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 6 +- > drivers/gpu/drm/qxl/qxl_object.c | 17 +- > drivers/gpu/drm/qxl/qxl_prime.c | 4 +- > drivers/gpu/drm/tegra/gem.c | 27 +- > drivers/infiniband/core/umem_dmabuf.c | 11 +- > .../common/videobuf2/videobuf2-dma-contig.c | 26 +- > .../media/common/videobuf2/videobuf2-dma-sg.c | 23 +- > .../common/videobuf2/videobuf2-vmalloc.c | 17 +- > .../platform/nvidia/tegra-vde/dmabuf-cache.c | 12 +- > drivers/misc/fastrpc.c | 12 +- > drivers/xen/gntdev-dmabuf.c | 14 +- > include/drm/drm_gem.h | 3 + > include/linux/dma-buf.h | 57 ++-- > 32 files changed, 410 insertions(+), 242 deletions(-) >