iommu/amd/io-pgtable: Implement unmap_pages io_pgtable_ops callback

Implement the io_pgtable_ops->unmap_pages() callback for AMD driver
and deprecate io_pgtable_ops->unmap callback.

Also if fetch_pte() returns NULL then return from unmap_mapages()
instead of trying to continue to unmap remaining pages.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20220825063939.8360-3-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: hegdevasant

drivers/iommu/amd/io_pgtable.c

@@ -435,17 +435,18 @@ static int iommu_v1_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
 	return ret;
 }
 
-static unsigned long iommu_v1_unmap_page(struct io_pgtable_ops *ops,
-				      unsigned long iova,
-				      size_t size,
-				      struct iommu_iotlb_gather *gather)
+static unsigned long iommu_v1_unmap_pages(struct io_pgtable_ops *ops,
+					  unsigned long iova,
+					  size_t pgsize, size_t pgcount,
+					  struct iommu_iotlb_gather *gather)
 {
 	struct amd_io_pgtable *pgtable = io_pgtable_ops_to_data(ops);
 	unsigned long long unmapped;
 	unsigned long unmap_size;
 	u64 *pte;
+	size_t size = pgcount << __ffs(pgsize);
 
-	BUG_ON(!is_power_of_2(size));
+	BUG_ON(!is_power_of_2(pgsize));
 
 	unmapped = 0;
 
@@ -457,14 +458,14 @@ static unsigned long iommu_v1_unmap_page(struct io_pgtable_ops *ops,
 			count = PAGE_SIZE_PTE_COUNT(unmap_size);
 			for (i = 0; i < count; i++)
 				pte[i] = 0ULL;
+		} else {
+			return unmapped;
 		}
 
 		iova = (iova & ~(unmap_size - 1)) + unmap_size;
 		unmapped += unmap_size;
 	}
 
-	BUG_ON(unmapped && !is_power_of_2(unmapped));
-
 	return unmapped;
 }
 
@@ -524,7 +525,7 @@ static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *coo
 	cfg->tlb            = &v1_flush_ops;
 
 	pgtable->iop.ops.map_pages    = iommu_v1_map_pages;
-	pgtable->iop.ops.unmap        = iommu_v1_unmap_page;
+	pgtable->iop.ops.unmap_pages  = iommu_v1_unmap_pages;
 	pgtable->iop.ops.iova_to_phys = iommu_v1_iova_to_phys;
 
 	return &pgtable->iop;