drm/msm: Set the global virtual address range from the IOMMU domain

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).
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/gpu/drm/msm/adreno/adreno_gpu.c

@@ -192,6 +192,7 @@ adreno_iommu_create_address_space(struct msm_gpu *gpu,
 	struct iommu_domain *iommu;
 	struct msm_mmu *mmu;
 	struct msm_gem_address_space *aspace;
+	u64 start, size;
 
 	iommu = iommu_domain_alloc(&platform_bus_type);
 	if (!iommu)
@@ -199,8 +200,16 @@ adreno_iommu_create_address_space(struct msm_gpu *gpu,
 
 	mmu = msm_iommu_new(&pdev->dev, iommu);
 
-	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);

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;