Re: [PATCH 13/19] drm/msm: Set the global virtual address range from the IOMMU domain

On Thu 13 Aug 21:41 CDT 2020, Rob Clark wrote:

From: Jordan Crouse jcrouse@codeaurora.org

Use the aperture settings from the IOMMU domain to set up the virtual address range for the GPU. This allows us to transparently deal with IOMMU side features (like split pagetables).

Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org

Signed-off-by: Jordan Crouse jcrouse@codeaurora.org Signed-off-by: Rob Clark robdclark@chromium.org

---

drivers/gpu/drm/msm/adreno/adreno_gpu.c | 13 +++++++++++-- drivers/gpu/drm/msm/msm_iommu.c | 7 +++++++ 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index 533a34b4cce2..34e6242c1767 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -192,9 +192,18 @@ adreno_iommu_create_address_space(struct msm_gpu *gpu, struct iommu_domain *iommu = iommu_domain_alloc(&platform_bus_type); struct msm_mmu *mmu = msm_iommu_new(&pdev->dev, iommu); struct msm_gem_address_space *aspace;

• u64 start, size;

• aspace = msm_gem_address_space_create(mmu, "gpu", SZ_16M,

• 0xffffffff - SZ_16M);
  

• /*

• * Use the aperture start or SZ_16M, whichever is greater. This will
  

• * ensure that we align with the allocated pagetable range while still
  

• * allowing room in the lower 32 bits for GMEM and whatnot
  

• */
  

• start = max_t(u64, SZ_16M, iommu->geometry.aperture_start);

• size = iommu->geometry.aperture_end - start + 1;

• aspace = msm_gem_address_space_create(mmu, "gpu",

• start & GENMASK(48, 0), size);
  
  

  if (IS_ERR(aspace) && !IS_ERR(mmu)) mmu->funcs->destroy(mmu);

diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c index 3a381a9674c9..1b6635504069 100644 --- a/drivers/gpu/drm/msm/msm_iommu.c +++ b/drivers/gpu/drm/msm/msm_iommu.c @@ -36,6 +36,10 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova, struct msm_iommu *iommu = to_msm_iommu(mmu); size_t ret;

• /* The arm-smmu driver expects the addresses to be sign extended */
• if (iova & BIT_ULL(48))

• iova |= GENMASK_ULL(63, 49);
  

• ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot); WARN_ON(!ret);

@@ -46,6 +50,9 @@ static int msm_iommu_unmap(struct msm_mmu *mmu, uint64_t iova, size_t len) { struct msm_iommu *iommu = to_msm_iommu(mmu);

• if (iova & BIT_ULL(48))

• iova |= GENMASK_ULL(63, 49);
  

• iommu_unmap(iommu->domain, iova, len);

  return 0;

-- 2.26.2