[v12,00/13] iommu/arm-smmu: Add Adreno SMMU specific implementation

Message

Jordan Crouse Aug. 10, 2020, 10:26 p.m. UTC

This series adds an Adreno SMMU implementation to arm-smmu to allow GPU hardware
pagetable switching.

The Adreno GPU has built in capabilities to switch the TTBR0 pagetable during
runtime to allow each individual instance or application to have its own
pagetable.  In order to take advantage of the HW capabilities there are certain
requirements needed of the SMMU hardware.

This series adds support for an Adreno specific arm-smmu implementation. The new
implementation 1) ensures that the GPU domain is always assigned context bank 0,
2) enables split pagetable support (TTBR1) so that the instance specific
pagetable can be swapped while the global memory remains in place and 3) shares
the current pagetable configuration with the GPU driver to allow it to create
its own io-pgtable instances.

The series then adds the drm/msm code to enable these features. For targets that
support it allocate new pagetables using the io-pgtable configuration shared by
the arm-smmu driver and swap them in during runtime.

This version of the series merges the previous patchset(s) [1] and [2]
with the following improvements:

v12:
  - Nitpick cleanups in gpu/drm/msm/msm_iommu.c (Rob Clark)
  - Reorg in gpu/drm/msm/msm_gpu.c (Rob Clark)
  - Use the default asid for the context bank so that iommu_tlb_flush_all works
  - Flush the UCHE after a page switch
  - Add the SCTLR.HUPCF patch at the end of the series
v11:
  - Add implementation specific get_attr/set_attr functions (per Rob Clark)
  - Fix context bank allocation (per Bjorn Andersson)
v10:
  - arm-smmu: add implementation hook to allocate context banks
  - arm-smmu: Match the GPU domain by stream ID instead of compatible string
  - arm-smmu: Make DOMAIN_ATTR_PGTABLE_CFG bi-directional. The leaf driver
    queries the configuration to create a pagetable and then sends the newly
    created configuration back to the smmu-driver to enable TTBR0
  - drm/msm: Add context reference counting for submissions
  - drm/msm: Use dummy functions to skip TLB operations on per-instance
    pagetables

[1] https://lists.linuxfoundation.org/pipermail/iommu/2020-June/045653.html
[2] https://lists.linuxfoundation.org/pipermail/iommu/2020-June/045659.html


Jordan Crouse (13):
  iommu/arm-smmu: Pass io-pgtable config to implementation specific
    function
  iommu/arm-smmu: Add support for split pagetables
  iommu/arm-smmu: Prepare for the adreno-smmu implementation
  iommu: Add a domain attribute to get/set a pagetable configuration
  iommu/arm-smmu-qcom: Add implementation for the adreno GPU SMMU
  dt-bindings: arm-smmu: Add compatible string for Adreno GPU SMMU
  drm/msm: Add a context pointer to the submitqueue
  drm/msm: Set the global virtual address range from the IOMMU domain
  drm/msm: Add support to create a local pagetable
  drm/msm: Add support for private address space instances
  drm/msm/a6xx: Add support for per-instance pagetables
  arm: dts: qcom: sm845: Set the compatible string for the GPU SMMU
  iommu/arm-smmu: Add a init_context_bank implementation hook

 .../devicetree/bindings/iommu/arm,smmu.yaml   |   4 +
 arch/arm64/boot/dts/qcom/sdm845.dtsi          |   2 +-
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c         |  12 +-
 drivers/gpu/drm/msm/adreno/a6xx_gpu.c         |  75 ++++++-
 drivers/gpu/drm/msm/adreno/a6xx_gpu.h         |   1 +
 drivers/gpu/drm/msm/adreno/adreno_gpu.c       |  18 +-
 drivers/gpu/drm/msm/adreno/adreno_gpu.h       |   3 +-
 drivers/gpu/drm/msm/msm_drv.c                 |  16 +-
 drivers/gpu/drm/msm/msm_drv.h                 |  13 ++
 drivers/gpu/drm/msm/msm_gem.h                 |   1 +
 drivers/gpu/drm/msm/msm_gem_submit.c          |   8 +-
 drivers/gpu/drm/msm/msm_gem_vma.c             |   9 +
 drivers/gpu/drm/msm/msm_gpu.c                 |  31 ++-
 drivers/gpu/drm/msm/msm_gpu.h                 |  12 +-
 drivers/gpu/drm/msm/msm_gpummu.c              |   2 +-
 drivers/gpu/drm/msm/msm_iommu.c               | 197 +++++++++++++++++-
 drivers/gpu/drm/msm/msm_mmu.h                 |  16 +-
 drivers/gpu/drm/msm/msm_ringbuffer.h          |   1 +
 drivers/gpu/drm/msm/msm_submitqueue.c         |   8 +-
 drivers/iommu/arm/arm-smmu/arm-smmu-impl.c    |   6 +-
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c    | 172 ++++++++++++++-
 drivers/iommu/arm/arm-smmu/arm-smmu.c         | 134 ++++++------
 drivers/iommu/arm/arm-smmu/arm-smmu.h         |  87 +++++++-
 include/linux/iommu.h                         |   1 +
 24 files changed, 708 insertions(+), 121 deletions(-)

Comments

Will Deacon Aug. 13, 2020, 1:19 p.m. UTC | #1

On Mon, Aug 10, 2020 at 04:26:44PM -0600, Jordan Crouse wrote:
> This series adds an Adreno SMMU implementation to arm-smmu to allow GPU hardware
> pagetable switching.
> 
> The Adreno GPU has built in capabilities to switch the TTBR0 pagetable during
> runtime to allow each individual instance or application to have its own
> pagetable.  In order to take advantage of the HW capabilities there are certain
> requirements needed of the SMMU hardware.

"capabilities" is a polite way of putting it ;)

Anyway, modulo two design comments, I think this is about as nice as we're
going to get this. Thanks for persevering, and sorry that you have to deal
with such dreadful hardware.

Hopefully the next version will be the one, although I'd like Robin to take
a quick look as well if he gets a chance.

Will