iommu: Remove the ->map_sg indirection

All iommu drivers use the default_iommu_map_sg implementation, and there
is no good reason to ever override it.  Just expose it as iommu_map_sg
directly and remove the indirection, specially in our post-spectre world
where indirect calls are horribly expensive.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu.c

@@ -3192,7 +3192,6 @@ const struct iommu_ops amd_iommu_ops = {
 	.detach_dev = amd_iommu_detach_device,
 	.map = amd_iommu_map,
 	.unmap = amd_iommu_unmap,
-	.map_sg = default_iommu_map_sg,
 	.iova_to_phys = amd_iommu_iova_to_phys,
 	.add_device = amd_iommu_add_device,
 	.remove_device = amd_iommu_remove_device,

drivers/iommu/arm-smmu-v3.c

@@ -1997,7 +1997,6 @@ static struct iommu_ops arm_smmu_ops = {
 	.attach_dev		= arm_smmu_attach_dev,
 	.map			= arm_smmu_map,
 	.unmap			= arm_smmu_unmap,
-	.map_sg			= default_iommu_map_sg,
 	.flush_iotlb_all	= arm_smmu_iotlb_sync,
 	.iotlb_sync		= arm_smmu_iotlb_sync,
 	.iova_to_phys		= arm_smmu_iova_to_phys,

drivers/iommu/arm-smmu.c

@@ -1562,7 +1562,6 @@ static struct iommu_ops arm_smmu_ops = {
 	.attach_dev		= arm_smmu_attach_dev,
 	.map			= arm_smmu_map,
 	.unmap			= arm_smmu_unmap,
-	.map_sg			= default_iommu_map_sg,
 	.flush_iotlb_all	= arm_smmu_iotlb_sync,
 	.iotlb_sync		= arm_smmu_iotlb_sync,
 	.iova_to_phys		= arm_smmu_iova_to_phys,

drivers/iommu/exynos-iommu.c

@@ -1332,7 +1332,6 @@ static const struct iommu_ops exynos_iommu_ops = {
 	.detach_dev = exynos_iommu_detach_device,
 	.map = exynos_iommu_map,
 	.unmap = exynos_iommu_unmap,
-	.map_sg = default_iommu_map_sg,
 	.iova_to_phys = exynos_iommu_iova_to_phys,
 	.device_group = generic_device_group,
 	.add_device = exynos_iommu_add_device,

drivers/iommu/intel-iommu.c

@@ -5308,7 +5308,6 @@ const struct iommu_ops intel_iommu_ops = {
 	.detach_dev		= intel_iommu_detach_device,
 	.map			= intel_iommu_map,
 	.unmap			= intel_iommu_unmap,
-	.map_sg			= default_iommu_map_sg,
 	.iova_to_phys		= intel_iommu_iova_to_phys,
 	.add_device		= intel_iommu_add_device,
 	.remove_device		= intel_iommu_remove_device,

drivers/iommu/iommu.c

@@ -1673,7 +1673,7 @@ size_t iommu_unmap_fast(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_unmap_fast);
 
-size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
+size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 		    struct scatterlist *sg, unsigned int nents, int prot)
 {
 	struct scatterlist *s;
@@ -1714,7 +1714,7 @@ size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 	return 0;
 
 }
-EXPORT_SYMBOL_GPL(default_iommu_map_sg);
+EXPORT_SYMBOL_GPL(iommu_map_sg);
 
 int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr,
 			       phys_addr_t paddr, u64 size, int prot)

drivers/iommu/ipmmu-vmsa.c

@@ -889,7 +889,6 @@ static const struct iommu_ops ipmmu_ops = {
 	.unmap = ipmmu_unmap,
 	.flush_iotlb_all = ipmmu_iotlb_sync,
 	.iotlb_sync = ipmmu_iotlb_sync,
-	.map_sg = default_iommu_map_sg,
 	.iova_to_phys = ipmmu_iova_to_phys,
 	.add_device = ipmmu_add_device,
 	.remove_device = ipmmu_remove_device,

drivers/iommu/msm_iommu.c

@@ -708,7 +708,6 @@ static struct iommu_ops msm_iommu_ops = {
 	.detach_dev = msm_iommu_detach_dev,
 	.map = msm_iommu_map,
 	.unmap = msm_iommu_unmap,
-	.map_sg = default_iommu_map_sg,
 	.iova_to_phys = msm_iommu_iova_to_phys,
 	.add_device = msm_iommu_add_device,
 	.remove_device = msm_iommu_remove_device,

drivers/iommu/mtk_iommu.c

@@ -495,7 +495,6 @@ static struct iommu_ops mtk_iommu_ops = {
 	.detach_dev	= mtk_iommu_detach_device,
 	.map		= mtk_iommu_map,
 	.unmap		= mtk_iommu_unmap,
-	.map_sg		= default_iommu_map_sg,
 	.flush_iotlb_all = mtk_iommu_iotlb_sync,
 	.iotlb_sync	= mtk_iommu_iotlb_sync,
 	.iova_to_phys	= mtk_iommu_iova_to_phys,

drivers/iommu/mtk_iommu_v1.c

@@ -531,7 +531,6 @@ static struct iommu_ops mtk_iommu_ops = {
 	.detach_dev	= mtk_iommu_detach_device,
 	.map		= mtk_iommu_map,
 	.unmap		= mtk_iommu_unmap,
-	.map_sg		= default_iommu_map_sg,
 	.iova_to_phys	= mtk_iommu_iova_to_phys,
 	.add_device	= mtk_iommu_add_device,
 	.remove_device	= mtk_iommu_remove_device,

drivers/iommu/omap-iommu.c

@@ -1548,7 +1548,6 @@ static const struct iommu_ops omap_iommu_ops = {
 	.detach_dev	= omap_iommu_detach_dev,
 	.map		= omap_iommu_map,
 	.unmap		= omap_iommu_unmap,
-	.map_sg		= default_iommu_map_sg,
 	.iova_to_phys	= omap_iommu_iova_to_phys,
 	.add_device	= omap_iommu_add_device,
 	.remove_device	= omap_iommu_remove_device,

drivers/iommu/qcom_iommu.c

@@ -590,7 +590,6 @@ static const struct iommu_ops qcom_iommu_ops = {
 	.detach_dev	= qcom_iommu_detach_dev,
 	.map		= qcom_iommu_map,
 	.unmap		= qcom_iommu_unmap,
-	.map_sg		= default_iommu_map_sg,
 	.flush_iotlb_all = qcom_iommu_iotlb_sync,
 	.iotlb_sync	= qcom_iommu_iotlb_sync,
 	.iova_to_phys	= qcom_iommu_iova_to_phys,

drivers/iommu/rockchip-iommu.c

@@ -1110,7 +1110,6 @@ static const struct iommu_ops rk_iommu_ops = {
 	.detach_dev = rk_iommu_detach_device,
 	.map = rk_iommu_map,
 	.unmap = rk_iommu_unmap,
-	.map_sg = default_iommu_map_sg,
 	.add_device = rk_iommu_add_device,
 	.remove_device = rk_iommu_remove_device,
 	.iova_to_phys = rk_iommu_iova_to_phys,

drivers/iommu/tegra-gart.c

@@ -377,7 +377,6 @@ static const struct iommu_ops gart_iommu_ops = {
 	.remove_device	= gart_iommu_remove_device,
 	.device_group	= generic_device_group,
 	.map		= gart_iommu_map,
-	.map_sg		= default_iommu_map_sg,
 	.unmap		= gart_iommu_unmap,
 	.iova_to_phys	= gart_iommu_iova_to_phys,
 	.pgsize_bitmap	= GART_IOMMU_PGSIZES,

drivers/iommu/tegra-smmu.c

@@ -876,7 +876,6 @@ static const struct iommu_ops tegra_smmu_ops = {
 	.device_group = tegra_smmu_device_group,
 	.map = tegra_smmu_map,
 	.unmap = tegra_smmu_unmap,
-	.map_sg = default_iommu_map_sg,
 	.iova_to_phys = tegra_smmu_iova_to_phys,
 	.of_xlate = tegra_smmu_of_xlate,
 	.pgsize_bitmap = SZ_4K,

include/linux/iommu.h

@@ -166,8 +166,6 @@ struct iommu_resv_region {
  * @detach_dev: detach device from an iommu domain
  * @map: map a physically contiguous memory region to an iommu domain
  * @unmap: unmap a physically contiguous memory region from an iommu domain
- * @map_sg: map a scatter-gather list of physically contiguous memory chunks
- *          to an iommu domain
  * @flush_tlb_all: Synchronously flush all hardware TLBs for this domain
  * @tlb_range_add: Add a given iova range to the flush queue for this domain
  * @tlb_sync: Flush all queued ranges from the hardware TLBs and empty flush
@@ -201,8 +199,6 @@ struct iommu_ops {
 		   phys_addr_t paddr, size_t size, int prot);
 	size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
 		     size_t size);
-	size_t (*map_sg)(struct iommu_domain *domain, unsigned long iova,
-			 struct scatterlist *sg, unsigned int nents, int prot);
 	void (*flush_iotlb_all)(struct iommu_domain *domain);
 	void (*iotlb_range_add)(struct iommu_domain *domain,
 				unsigned long iova, size_t size);
@@ -303,9 +299,8 @@ extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
 			  size_t size);
 extern size_t iommu_unmap_fast(struct iommu_domain *domain,
 			       unsigned long iova, size_t size);
-extern size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
-				struct scatterlist *sg,unsigned int nents,
-				int prot);
+extern size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
+			   struct scatterlist *sg,unsigned int nents, int prot);
 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova);
 extern void iommu_set_fault_handler(struct iommu_domain *domain,
 			iommu_fault_handler_t handler, void *token);
@@ -378,13 +373,6 @@ static inline void iommu_tlb_sync(struct iommu_domain *domain)
 		domain->ops->iotlb_sync(domain);
 }
 
-static inline size_t iommu_map_sg(struct iommu_domain *domain,
-				  unsigned long iova, struct scatterlist *sg,
-				  unsigned int nents, int prot)
-{
-	return domain->ops->map_sg(domain, iova, sg, nents, prot);
-}
-
 /* PCI device grouping function */
 extern struct iommu_group *pci_device_group(struct device *dev);
 /* Generic device grouping function */