net/mlx5_core: Use coherent memory for command interface page

Use coherent memory for the commands descriptor page. Take measures to make
sure the page is aligned to MLX5_ADAPTER_PAGE_SIZE as required by the hardware.

Reported-by: Yevgeny Kliteynik <kliteyn@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 166d931..8d8ca6d 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -232,6 +232,9 @@
 };
 
 struct mlx5_cmd {
+	void	       *cmd_alloc_buf;
+	dma_addr_t	alloc_dma;
+	int		alloc_size;
 	void	       *cmd_buf;
 	dma_addr_t	dma;
 	u16		cmdif_rev;