Some hardware variants contain a system cache or the last level cache(llc). This cache is typically a large block which is shared by multiple clients on the SOC. GPU uses the system cache to cache both the GPU data buffers(like textures) as well the SMMU pagetables. This helps with improved render performance as well as lower power consumption by reducing the bus traffic to the system memory.
The system cache architecture allows the cache to be split into slices which then be used by multiple SOC clients. This patch series is an effort to enable and use two of those slices perallocated for the GPU, one for the GPU data buffers and another for the GPU SMMU hardware pagetables.
Patch 1 adds a init_context_bank implementation hook to set SCTLR.HUPCF. Patch 2,3,6,7 adds system cache support in SMMU and GPU driver. Patch 4 and 5 are minor cleanups for arm-smmu impl.
Changes in v3: * Fix domain attribute setting to before iommu_attach_device() * Fix few code style and checkpatch warnings * Rebase on top of Jordan's latest split pagetables and per-instance pagetables support [1][2]
Changes in v2: * Addressed review comments and rebased on top of Jordan's split pagetables series
[1] https://lore.kernel.org/patchwork/cover/1264446/ [2] https://lore.kernel.org/patchwork/cover/1264460/
Jordan Crouse (1): iommu/arm-smmu: Add a init_context_bank implementation hook
Sai Prakash Ranjan (4): iommu/io-pgtable-arm: Add support to use system cache iommu/arm-smmu: Add domain attribute for system cache iommu: arm-smmu-impl: Remove unwanted extra blank lines iommu: arm-smmu-impl: Convert to use of_match_node() for qcom impl
Sharat Masetty (2): drm/msm: rearrange the gpu_rmw() function drm/msm/a6xx: Add support for using system cache(LLC)
drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 82 +++++++++++++++++++++++++ drivers/gpu/drm/msm/adreno/a6xx_gpu.h | 3 + drivers/gpu/drm/msm/adreno/adreno_gpu.c | 23 ++++++- drivers/gpu/drm/msm/msm_drv.c | 8 +++ drivers/gpu/drm/msm/msm_drv.h | 1 + drivers/gpu/drm/msm/msm_gpu.h | 5 +- drivers/gpu/drm/msm/msm_iommu.c | 3 + drivers/gpu/drm/msm/msm_mmu.h | 4 ++ drivers/iommu/arm-smmu-impl.c | 13 ++-- drivers/iommu/arm-smmu-qcom.c | 13 ++++ drivers/iommu/arm-smmu.c | 46 +++++++++----- drivers/iommu/arm-smmu.h | 13 ++++ drivers/iommu/io-pgtable-arm.c | 7 ++- include/linux/io-pgtable.h | 4 ++ include/linux/iommu.h | 1 + 15 files changed, 198 insertions(+), 28 deletions(-)