nfp: flower: offload MPLS set action

Recent additions to the kernel include a TC action module to manipulate
MPLS headers on packets. Such actions are available to offload via the
flow_offload intermediate representation API.

Modify the NFP driver to allow the offload of MPLS set actions to
firmware. Set actions update the outermost MPLS header. The offload
includes a mask to specify which fields should be set.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/flower/action.c

@@ -70,6 +70,37 @@ nfp_fl_pop_mpls(struct nfp_fl_pop_mpls *pop_mpls,
 	pop_mpls->ethtype = act->mpls_pop.proto;
 }
 
+static void
+nfp_fl_set_mpls(struct nfp_fl_set_mpls *set_mpls,
+		const struct flow_action_entry *act)
+{
+	size_t act_size = sizeof(struct nfp_fl_set_mpls);
+	u32 mpls_lse = 0, mpls_mask = 0;
+
+	set_mpls->head.jump_id = NFP_FL_ACTION_OPCODE_SET_MPLS;
+	set_mpls->head.len_lw = act_size >> NFP_FL_LW_SIZ;
+
+	if (act->mpls_mangle.label != ACT_MPLS_LABEL_NOT_SET) {
+		mpls_lse |= act->mpls_mangle.label << MPLS_LS_LABEL_SHIFT;
+		mpls_mask |= MPLS_LS_LABEL_MASK;
+	}
+	if (act->mpls_mangle.tc != ACT_MPLS_TC_NOT_SET) {
+		mpls_lse |= act->mpls_mangle.tc << MPLS_LS_TC_SHIFT;
+		mpls_mask |= MPLS_LS_TC_MASK;
+	}
+	if (act->mpls_mangle.bos != ACT_MPLS_BOS_NOT_SET) {
+		mpls_lse |= act->mpls_mangle.bos << MPLS_LS_S_SHIFT;
+		mpls_mask |= MPLS_LS_S_MASK;
+	}
+	if (act->mpls_mangle.ttl) {
+		mpls_lse |= act->mpls_mangle.ttl << MPLS_LS_TTL_SHIFT;
+		mpls_mask |= MPLS_LS_TTL_MASK;
+	}
+
+	set_mpls->lse = cpu_to_be32(mpls_lse);
+	set_mpls->lse_mask = cpu_to_be32(mpls_mask);
+}
+
 static void nfp_fl_pop_vlan(struct nfp_fl_pop_vlan *pop_vlan)
 {
 	size_t act_size = sizeof(struct nfp_fl_pop_vlan);
@@ -917,6 +948,7 @@ nfp_flower_loop_action(struct nfp_app *app, const struct flow_action_entry *act,
 	struct nfp_fl_push_mpls *psh_m;
 	struct nfp_fl_pop_vlan *pop_v;
 	struct nfp_fl_pop_mpls *pop_m;
+	struct nfp_fl_set_mpls *set_m;
 	int err;
 
 	switch (act->id) {
@@ -1050,6 +1082,19 @@ nfp_flower_loop_action(struct nfp_app *app, const struct flow_action_entry *act,
 		nfp_fl_pop_mpls(pop_m, act);
 		*a_len += sizeof(struct nfp_fl_pop_mpls);
 		break;
+	case FLOW_ACTION_MPLS_MANGLE:
+		if (*a_len +
+		    sizeof(struct nfp_fl_set_mpls) > NFP_FL_MAX_A_SIZ) {
+			NL_SET_ERR_MSG_MOD(extack, "unsupported offload: maximum allowed action list size exceeded at set MPLS");
+			return -EOPNOTSUPP;
+		}
+
+		set_m = (struct nfp_fl_set_mpls *)&nfp_fl->action_data[*a_len];
+		nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_NULL);
+
+		nfp_fl_set_mpls(set_m, act);
+		*a_len += sizeof(struct nfp_fl_set_mpls);
+		break;
 	default:
 		/* Currently we do not handle any other actions. */
 		NL_SET_ERR_MSG_MOD(extack, "unsupported offload: unsupported action in action list");

drivers/net/ethernet/netronome/nfp/flower/cmsg.h

@@ -72,6 +72,7 @@
 #define NFP_FL_ACTION_OPCODE_POP_MPLS		4
 #define NFP_FL_ACTION_OPCODE_SET_IPV4_TUNNEL	6
 #define NFP_FL_ACTION_OPCODE_SET_ETHERNET	7
+#define NFP_FL_ACTION_OPCODE_SET_MPLS		8
 #define NFP_FL_ACTION_OPCODE_SET_IPV4_ADDRS	9
 #define NFP_FL_ACTION_OPCODE_SET_IPV4_TTL_TOS	10
 #define NFP_FL_ACTION_OPCODE_SET_IPV6_SRC	11
@@ -245,6 +246,13 @@ struct nfp_fl_pop_mpls {
 	__be16 ethtype;
 };
 
+struct nfp_fl_set_mpls {
+	struct nfp_fl_act_head head;
+	__be16 reserved;
+	__be32 lse_mask;
+	__be32 lse;
+};
+
 /* Metadata with L2 (1W/4B)
  * ----------------------------------------------------------------
  *    3                   2                   1