IB/mlx5: Add contiguous ODP support

Currenlty ODP supports only regular MMU pages.
Add ODP support for regions consisting of physically contiguous chunks
of arbitrary order (huge pages for instance) to improve performance.

Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/mem.c

@@ -61,13 +61,12 @@ void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr,
 	int entry;
 	unsigned long page_shift = umem->page_shift;
 
-	/* With ODP we must always match OS page size. */
 	if (umem->odp_data) {
-		*count = ib_umem_page_count(umem);
-		*shift = PAGE_SHIFT;
-		*ncont = *count;
+		*ncont = ib_umem_page_count(umem);
+		*count = *ncont << (page_shift - PAGE_SHIFT);
+		*shift = page_shift;
 		if (order)
-			*order = ilog2(roundup_pow_of_two(*count));
+			*order = ilog2(roundup_pow_of_two(*ncont));
 
 		return;
 	}