[PATCH v7 5/6] drm/msm: Set the global virtual address range from the IOMMU domain

[Jordan Crouse]

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 at codeaurora.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 89673c7ed473..3e717c1ebb7f 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,
-		0xfffffff);
+	/*
+	 * 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..bbe129867590 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(48))
+		iova |= GENMASK(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(48))
+		iova |= GENMASK(63, 49);
+
 	iommu_unmap(iommu->domain, iova, len);
 
 	return 0;
-- 
2.17.1