drm/msm: Consoldate mmu ->map and mmu ->map_sg

For all intents and purposes the mmu ->map function has used a
scatter gather list for some time. Drop the pretense and just
make both the SMMU and IOMMU flavors use the sg flavor of their
respective iommu API functions. As a result we can drop the
map_sg hooks in the SMMU driver and get rid of a considerable
amount of re-invented wheels in the IOMMU driver.

Change-Id: Ic0dedbadc4724c8ae389892fb85610435c5c08cf
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>

4 files changed, 22 insertions, 141 deletions

diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
index 2a4906752b70..d549874b95fc 100644
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -48,8 +48,7 @@ static void smmu_aspace_unmap_vma(struct msm_gem_address_space *aspace,
 		aspace->mmu->funcs->unmap_dma_buf(aspace->mmu,
 			sgt, buf, DMA_BIDIRECTIONAL);
 	else
-		aspace->mmu->funcs->unmap_sg(aspace->mmu, sgt,
-			DMA_BIDIRECTIONAL);
+		aspace->mmu->funcs->unmap(aspace->mmu, 0, sgt);
 
 	vma->iova = 0;
 
@@ -68,8 +67,7 @@ static int smmu_aspace_map_vma(struct msm_gem_address_space *aspace,
 		ret = aspace->mmu->funcs->map_dma_buf(aspace->mmu, sgt, buf,
 			DMA_BIDIRECTIONAL);
 	else
-		ret = aspace->mmu->funcs->map_sg(aspace->mmu, sgt,
-			DMA_BIDIRECTIONAL);
+		ret = aspace->mmu->funcs->map(aspace->mmu, 0, sgt, flags);
 
 	if (!ret)
 		vma->iova = sg_dma_address(sgt->sgl);
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 99579bfaadef..a4ece31aa25a 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -200,9 +200,6 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
 {
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
 	struct iommu_domain *domain = iommu->domain;
-	struct scatterlist *sg;
-	uint64_t da = iova;
-	unsigned int i, j;
 	int ret;
 	u32 prot = IOMMU_READ;
 
@@ -218,57 +215,31 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
 	if ((flags & MSM_BO_CACHED) && msm_iommu_coherent(mmu))
 		prot |= IOMMU_CACHE;
 
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
-		phys_addr_t pa = sg_phys(sg) - sg->offset;
-		size_t bytes = sg->length + sg->offset;
-
-		VERB("map[%d]: %016llx %pa(%zx)", i, iova, &pa, bytes);
-
-		ret = iommu_map(domain, da, pa, bytes, prot);
-		if (ret)
-			goto fail;
-
-		da += bytes;
-	}
-
-	return 0;
-
-fail:
-	da = iova;
+	/* iommu_map_sg returns the number of bytes mapped */
+	ret =  iommu_map_sg(domain, iova, sgt->sgl, sgt->nents, prot);
+	if (ret)
+		sgt->sgl->dma_address = iova;
 
-	for_each_sg(sgt->sgl, sg, i, j) {
-		size_t bytes = sg->length + sg->offset;
-		iommu_unmap(domain, da, bytes);
-		da += bytes;
-	}
-	return ret;
+	return ret ? 0 : -ENOMEM;
 }
 
-static int msm_iommu_unmap(struct msm_mmu *mmu, uint64_t iova,
+static void msm_iommu_unmap(struct msm_mmu *mmu, uint64_t iova,
 		struct sg_table *sgt)
 {
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
 	struct iommu_domain *domain = iommu->domain;
 	struct scatterlist *sg;
-	uint64_t da = iova;
-	int i;
-
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
-		size_t bytes = sg->length + sg->offset;
-		size_t unmapped;
+	size_t len = 0;
+	int ret, i;
 
-		unmapped = iommu_unmap(domain, da, bytes);
-		if (unmapped < bytes)
-			return unmapped;
+	for_each_sg(sgt->sgl, sg, sgt->nents, i)
+		len += sg->length;
 
-		VERB("unmap[%d]: %016llx(%zx)", i, iova, bytes);
+	ret = iommu_unmap(domain, iova, len);
+	if (ret != len)
+		dev_warn(mmu->dev, "could not unmap iova %llx\n", iova);
 
-		BUG_ON(!PAGE_ALIGNED(bytes));
-
-		da += bytes;
-	}
-
-	return 0;
+	sgt->sgl->dma_address = 0;
 }
 
 static void msm_iommu_destroy(struct msm_mmu *mmu)
diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
index 4d8f55c1d7d5..35c8be71a88b 100644
--- a/drivers/gpu/drm/msm/msm_mmu.h
+++ b/drivers/gpu/drm/msm/msm_mmu.h
@@ -35,11 +35,7 @@ struct msm_mmu_funcs {
 	void (*detach)(struct msm_mmu *mmu);
 	int (*map)(struct msm_mmu *mmu, uint64_t iova, struct sg_table *sgt,
 			u32 flags);
-	int (*unmap)(struct msm_mmu *mmu, uint64_t iova, struct sg_table *sgt);
-	int (*map_sg)(struct msm_mmu *mmu, struct sg_table *sgt,
-			enum dma_data_direction dir);
-	void (*unmap_sg)(struct msm_mmu *mmu, struct sg_table *sgt,
-		enum dma_data_direction dir);
+	void (*unmap)(struct msm_mmu *mmu, uint64_t iova, struct sg_table *sgt);
 	int (*map_dma_buf)(struct msm_mmu *mmu, struct sg_table *sgt,
 			struct dma_buf *dma_buf, int dir);
 	void (*unmap_dma_buf)(struct msm_mmu *mmu, struct sg_table *sgt,
diff --git a/drivers/gpu/drm/msm/msm_smmu.c b/drivers/gpu/drm/msm/msm_smmu.c
index 5cdcde12ee52..f794fee41c0c 100644
--- a/drivers/gpu/drm/msm/msm_smmu.c
+++ b/drivers/gpu/drm/msm/msm_smmu.c
@@ -109,103 +109,21 @@ static int msm_smmu_map(struct msm_mmu *mmu, uint64_t iova,
 {
 	struct msm_smmu *smmu = to_msm_smmu(mmu);
 	struct msm_smmu_client *client = msm_smmu_to_client(smmu);
-	struct iommu_domain *domain;
-	struct scatterlist *sg;
-	uint64_t da = iova;
-	unsigned int i, j;
 	int ret;
 
-	if (!client)
-		return -ENODEV;
-
-	domain = client->mmu_mapping->domain;
-	if (!domain || !sgt)
-		return -EINVAL;
-
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
-		u32 pa = sg_phys(sg) - sg->offset;
-		size_t bytes = sg->length + sg->offset;
-
-		VERB("map[%d]: %16llx %08x(%zx)", i, iova, pa, bytes);
-
-		ret = iommu_map(domain, da, pa, bytes,
-			IOMMU_READ | IOMMU_WRITE);
-		if (ret)
-			goto fail;
-
-		da += bytes;
-	}
-
-	return 0;
-
-fail:
-	da = iova;
-
-	for_each_sg(sgt->sgl, sg, i, j) {
-		size_t bytes = sg->length + sg->offset;
-
-		iommu_unmap(domain, da, bytes);
-		da += bytes;
-	}
-	return ret;
-}
-
-static int msm_smmu_map_sg(struct msm_mmu *mmu, struct sg_table *sgt,
-		enum dma_data_direction dir)
-{
-	struct msm_smmu *smmu = to_msm_smmu(mmu);
-	struct msm_smmu_client *client = msm_smmu_to_client(smmu);
-	int ret;
+	ret = dma_map_sg(client->dev, sgt->sgl, sgt->nents,
+			DMA_BIDIRECTIONAL);
 
-	ret = dma_map_sg(client->dev, sgt->sgl, sgt->nents, dir);
-	if (ret != sgt->nents)
-		return -ENOMEM;
-
-	return 0;
+	return (ret != sgt->nents) ? -ENOMEM : 0;
 }
 
-static void msm_smmu_unmap_sg(struct msm_mmu *mmu, struct sg_table *sgt,
-		enum dma_data_direction dir)
-{
-	struct msm_smmu *smmu = to_msm_smmu(mmu);
-	struct msm_smmu_client *client = msm_smmu_to_client(smmu);
-
-	dma_unmap_sg(client->dev, sgt->sgl, sgt->nents, dir);
-}
-
-static int msm_smmu_unmap(struct msm_mmu *mmu, uint64_t iova,
+static void msm_smmu_unmap(struct msm_mmu *mmu, uint64_t iova,
 		struct sg_table *sgt)
 {
 	struct msm_smmu *smmu = to_msm_smmu(mmu);
 	struct msm_smmu_client *client = msm_smmu_to_client(smmu);
-	struct iommu_domain *domain;
-	struct scatterlist *sg;
-	uint64_t da = iova;
-	int i;
 
-	if (!client)
-		return -ENODEV;
-
-	domain = client->mmu_mapping->domain;
-	if (!domain || !sgt)
-		return -EINVAL;
-
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
-		size_t bytes = sg->length + sg->offset;
-		size_t unmapped;
-
-		unmapped = iommu_unmap(domain, da, bytes);
-		if (unmapped < bytes)
-			return unmapped;
-
-		VERB("unmap[%d]: %16llx(%zx)", i, iova, bytes);
-
-		WARN_ON(!PAGE_ALIGNED(bytes));
-
-		da += bytes;
-	}
-
-	return 0;
+	dma_unmap_sg(client->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
 }
 
 static void msm_smmu_destroy(struct msm_mmu *mmu)
@@ -249,8 +167,6 @@ static const struct msm_mmu_funcs funcs = {
 	.attach = msm_smmu_attach,
 	.detach = msm_smmu_detach,
 	.map = msm_smmu_map,
-	.map_sg = msm_smmu_map_sg,
-	.unmap_sg = msm_smmu_unmap_sg,
 	.unmap = msm_smmu_unmap,
 	.map_dma_buf = msm_smmu_map_dma_buf,
 	.unmap_dma_buf = msm_smmu_unmap_dma_buf,