iommu/io-pgtable: Introduce map_pages() as a page table op

Mapping memory into io-pgtables follows the same semantics
that unmapping memory used to follow (i.e. a buffer will be
mapped one page block per call to the io-pgtable code). This
means that it can be optimized in the same way that unmapping
memory was, so add a map_pages() callback to the io-pgtable
ops structure, so that a range of pages of the same size
can be mapped within the same call.

Signed-off-by: Isaac J. Manjarres <[email protected]>
Suggested-by: Will Deacon <[email protected]>
Signed-off-by: Georgi Djakov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>

Author: Isaac J. Manjarres

include/linux/io-pgtable.h

@@ -143,6 +143,7 @@ struct io_pgtable_cfg {
  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
  *
  * @map:          Map a physically contiguous memory region.
+ * @map_pages:    Map a physically contiguous range of pages of the same size.
  * @unmap:        Unmap a physically contiguous memory region.
  * @unmap_pages:  Unmap a range of virtually contiguous pages of the same size.
  * @iova_to_phys: Translate iova to physical address.
@@ -153,6 +154,9 @@ struct io_pgtable_cfg {
 struct io_pgtable_ops {
 	int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
 		   phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
+	int (*map_pages)(struct io_pgtable_ops *ops, unsigned long iova,
+			 phys_addr_t paddr, size_t pgsize, size_t pgcount,
+			 int prot, gfp_t gfp, size_t *mapped);
 	size_t (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
 			size_t size, struct iommu_iotlb_gather *gather);
 	size_t (*unmap_pages)(struct io_pgtable_ops *ops, unsigned long iova,