iommu/io-pgtable: Introduce tlb_flush_walk() and tlb_flush_leaf()

 * struct iommu_flush_ops - IOMMU callbacks for TLB and page table management.

 *

 * @tlb_flush_all:  Synchronously invalidate the entire TLB context.

 * @tlb_add_flush: Queue up a TLB invalidation for a virtual address range.

 * @tlb_flush_walk: Synchronously invalidate all intermediate TLB state

 *                  (sometimes referred to as the "walk cache") for a virtual

 *                  address range.

 * @tlb_flush_leaf: Synchronously invalidate all leaf TLB state for a virtual

 *                  address range.

 * @tlb_add_flush:  Optional callback to queue up leaf TLB invalidation for a

 *                  virtual address range.  This function exists purely as an

 *                  optimisation for IOMMUs that cannot batch TLB invalidation

 *                  operations efficiently and are therefore better suited to

 *                  issuing them early rather than deferring them until

 *                  iommu_tlb_sync().

 * @tlb_sync:       Ensure any queued TLB invalidation has taken effect, and

 *                  any corresponding page table updates are visible to the

 *                  IOMMU.

 */

struct iommu_flush_ops {

	void (*tlb_flush_all)(void *cookie);

	void (*tlb_flush_walk)(unsigned long iova, size_t size, size_t granule,

			       void *cookie);

	void (*tlb_flush_leaf)(unsigned long iova, size_t size, size_t granule,

			       void *cookie);

	void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,

			      bool leaf, void *cookie);

	void (*tlb_sync)(void *cookie);