iommu: Move iotlb_sync_map out from __iommu_map

In the end of __iommu_map, It alway call iotlb_sync_map.

This patch moves iotlb_sync_map out from __iommu_map since it is
unnecessary to call this for each sg segment especially iotlb_sync_map
is flush tlb all currently. Add a little helper _iommu_map for this.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210107122909.16317-2-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/iommu/iommu.c

@@ -2426,9 +2426,6 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
 		size -= pgsize;
 	}
 
-	if (ops->iotlb_sync_map)
-		ops->iotlb_sync_map(domain);
-
 	/* unroll mapping in case something went wrong */
 	if (ret)
 		iommu_unmap(domain, orig_iova, orig_size - size);
@@ -2438,18 +2435,31 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
 	return ret;
 }
 
+static int _iommu_map(struct iommu_domain *domain, unsigned long iova,
+		      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+{
+	const struct iommu_ops *ops = domain->ops;
+	int ret;
+
+	ret = __iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
+	if (ret == 0 && ops->iotlb_sync_map)
+		ops->iotlb_sync_map(domain);
+
+	return ret;
+}
+
 int iommu_map(struct iommu_domain *domain, unsigned long iova,
 	      phys_addr_t paddr, size_t size, int prot)
 {
 	might_sleep();
-	return __iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
+	return _iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
 }
 EXPORT_SYMBOL_GPL(iommu_map);
 
 int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova,
 	      phys_addr_t paddr, size_t size, int prot)
 {
-	return __iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC);
+	return _iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC);
 }
 EXPORT_SYMBOL_GPL(iommu_map_atomic);
 
@@ -2533,6 +2543,7 @@ static size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 			     struct scatterlist *sg, unsigned int nents, int prot,
 			     gfp_t gfp)
 {
+	const struct iommu_ops *ops = domain->ops;
 	size_t len = 0, mapped = 0;
 	phys_addr_t start;
 	unsigned int i = 0;
@@ -2563,6 +2574,8 @@ static size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 			sg = sg_next(sg);
 	}
 
+	if (ops->iotlb_sync_map)
+		ops->iotlb_sync_map(domain);
 	return mapped;
 
 out_err: