net/mlx5e: Prevent WQE metadata conflicts between timestamping and offloads

Update the WQE metadata assignment to avoid overriding existing
metadata when setting the sysport timestamp ID. Since timestamp IDs are
limited to 256 values, they use only the lower 8 bits of the metadata
field.

To avoid conflicts, move IPsec and MACsec metadata ID to bits 8 and 9,
and shift the MACsec fs_id accordingly. This ensures safe coexistence
of timestamping and offload features that use the same metadata field.

Signed-off-by: Carolina Jubran <[e-mail]>
Reviewed-by: Jianbo Liu <[e-mail]>
Reviewed-by: Patrisious Haddad <[e-mail]>
Reviewed-by: Dragos Tatulea <[e-mail]>
Signed-off-by: Tariq Toukan <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Reviewed-by: Simon Horman <[e-mail]>
Signed-off-by: Leon Romanovsky <[e-mail]>

drivers/net/ethernet/mellanox/mlx5/core/en_tx.c

···
 				 struct mlx5_wqe_eth_seg *eseg)
 {
 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
-		eseg->flow_table_metadata =
+		eseg->flow_table_metadata |=
 			cpu_to_be32(mlx5e_ptp_metadata_fifo_peek(&ptpsq->metadata_freelist));
 }
 

drivers/net/ethernet/mellanox/mlx5/core/lib/macsec_fs.c

···
 		 mlx5_macsec_fs_set_tx_fs_id(fs_id));
 	MLX5_SET(set_action_in, action, offset,
 		 MLX5_ETH_WQE_FT_META_MACSEC_SHIFT);
-	MLX5_SET(set_action_in, action, length, 32);
+	MLX5_SET(set_action_in, action, length, 8);
 
 	modify_hdr = mlx5_modify_header_alloc(mdev, MLX5_FLOW_NAMESPACE_RDMA_TX_MACSEC,
 					      1, action);

include/linux/mlx5/qp.h

···
 	MLX5_ETH_WQE_SWP_OUTER_L4_UDP   = 1 << 5,
 };
 
-/* Base shift for metadata bits used by timestamping, IPsec, and MACsec */
-#define MLX5_ETH_WQE_FT_META_SHIFT 0
+/* Metadata bits 0-7 are used by timestamping */
+/* Base shift for metadata bits used by IPsec and MACsec */
+#define MLX5_ETH_WQE_FT_META_SHIFT 8
 
 enum {
 	MLX5_ETH_WQE_FT_META_IPSEC = BIT(0) << MLX5_ETH_WQE_FT_META_SHIFT,