IB/mlx5: Add support for GRE flow specification

This patch introduces support for the GRE flow spec and
allowing the creation of rules based on the protocol and
key fields that are part of GRE protocol header.

Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/main.c

@@ -2448,6 +2448,7 @@ static void set_tos(void *outer_c, void *outer_v, u8 mask, u8 val)
 #define LAST_TUNNEL_FIELD tunnel_id
 #define LAST_FLOW_TAG_FIELD tag_id
 #define LAST_DROP_FIELD size
+#define LAST_DROP_FIELD size
 
 /* Field is the last supported field */
 #define FIELDS_NOT_SUPPORTED(filter, field)\
@@ -2689,6 +2690,29 @@ static int parse_flow_attr(struct mlx5_core_dev *mdev, u32 *match_c,
 		MLX5_SET(fte_match_set_lyr_2_4, headers_v, udp_dport,
 			 ntohs(ib_spec->tcp_udp.val.dst_port));
 		break;
+	case IB_FLOW_SPEC_GRE:
+		if (ib_spec->gre.mask.c_ks_res0_ver)
+			return -EOPNOTSUPP;
+
+		MLX5_SET(fte_match_set_lyr_2_4, headers_c, ip_protocol,
+			 0xff);
+		MLX5_SET(fte_match_set_lyr_2_4, headers_v, ip_protocol,
+			 IPPROTO_GRE);
+
+		MLX5_SET(fte_match_set_misc, misc_params_c, gre_protocol,
+			 0xffff);
+		MLX5_SET(fte_match_set_misc, misc_params_v, gre_protocol,
+			 ntohs(ib_spec->gre.val.protocol));
+
+		memcpy(MLX5_ADDR_OF(fte_match_set_misc, misc_params_c,
+				    gre_key_h),
+		       &ib_spec->gre.mask.key,
+		       sizeof(ib_spec->gre.mask.key));
+		memcpy(MLX5_ADDR_OF(fte_match_set_misc, misc_params_v,
+				    gre_key_h),
+		       &ib_spec->gre.val.key,
+		       sizeof(ib_spec->gre.val.key));
+		break;
 	case IB_FLOW_SPEC_VXLAN_TUNNEL:
 		if (FIELDS_NOT_SUPPORTED(ib_spec->tunnel.mask,
 					 LAST_TUNNEL_FIELD))