[PATCH 0/3] iommu/drm/msm: Allow non-coherent masters to use system cache

Sai Prakash Ranjan saiprakash.ranjan at codeaurora.org
Mon Jan 11 14:15:02 UTC 2021


commit ecd7274fb4cd ("iommu: Remove unused IOMMU_SYS_CACHE_ONLY flag")
removed unused IOMMU_SYS_CACHE_ONLY prot flag and along with it went
the memory type setting required for the non-coherent masters to use
system cache. Now that system cache support for GPU is added, we will
need to set the right PTE attribute for GPU buffers to be sys cached.
Without this, the system cache lines are not allocated for GPU.

So the patches in this series introduces a new prot flag IOMMU_LLC,
renames IO_PGTABLE_QUIRK_ARM_OUTER_WBWA to IO_PGTABLE_QUIRK_PTW_LLC
and makes GPU the user of this protection flag.

The series slightly depends on following 2 patches posted earlier and
is based on msm-next branch:
 * https://lore.kernel.org/patchwork/patch/1363008/
 * https://lore.kernel.org/patchwork/patch/1363010/

Sai Prakash Ranjan (3):
  iommu/io-pgtable: Rename last-level cache quirk to
    IO_PGTABLE_QUIRK_PTW_LLC
  iommu/io-pgtable-arm: Add IOMMU_LLC page protection flag
  drm/msm: Use IOMMU_LLC page protection flag to map gpu buffers

 drivers/gpu/drm/msm/adreno/a6xx_gpu.c   | 3 +++
 drivers/gpu/drm/msm/adreno/adreno_gpu.c | 2 +-
 drivers/gpu/drm/msm/msm_iommu.c         | 3 +++
 drivers/gpu/drm/msm/msm_mmu.h           | 4 ++++
 drivers/iommu/io-pgtable-arm.c          | 9 ++++++---
 include/linux/io-pgtable.h              | 6 +++---
 include/linux/iommu.h                   | 6 ++++++
 7 files changed, 26 insertions(+), 7 deletions(-)


base-commit: 00fd44a1a4700718d5d962432b55c09820f7e709
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