mlxsw: spectrum_flower: Offload FLOW_ACTION_PRIORITY

Offload action skbedit priority when keyed to a flower classifier. The
skb->priority field in Linux is very generic, so only allow setting the
bottom 8 priorities and bounce anything else.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c

@@ -1273,6 +1273,24 @@ mlxsw_afa_qos_switch_prio_pack(char *payload,
 	mlxsw_afa_qos_switch_prio_set(payload, prio);
 }
 
+int mlxsw_afa_block_append_qos_switch_prio(struct mlxsw_afa_block *block,
+					   u8 prio,
+					   struct netlink_ext_ack *extack)
+{
+	char *act = mlxsw_afa_block_append_action(block,
+						  MLXSW_AFA_QOS_CODE,
+						  MLXSW_AFA_QOS_SIZE);
+
+	if (IS_ERR(act)) {
+		NL_SET_ERR_MSG_MOD(extack, "Cannot append QOS action");
+		return PTR_ERR(act);
+	}
+	mlxsw_afa_qos_switch_prio_pack(act, MLXSW_AFA_QOS_CMD_SET,
+				       prio);
+	return 0;
+}
+EXPORT_SYMBOL(mlxsw_afa_block_append_qos_switch_prio);
+
 /* Forwarding Action
  * -----------------
  * Forwarding Action can be used to implement Policy Based Switching (PBS)

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.h

@@ -62,6 +62,9 @@ int mlxsw_afa_block_append_fwd(struct mlxsw_afa_block *block,
 int mlxsw_afa_block_append_vlan_modify(struct mlxsw_afa_block *block,
 				       u16 vid, u8 pcp, u8 et,
 				       struct netlink_ext_ack *extack);
+int mlxsw_afa_block_append_qos_switch_prio(struct mlxsw_afa_block *block,
+					   u8 prio,
+					   struct netlink_ext_ack *extack);
 int mlxsw_afa_block_append_allocated_counter(struct mlxsw_afa_block *block,
 					     u32 counter_index);
 int mlxsw_afa_block_append_counter(struct mlxsw_afa_block *block,

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -746,6 +746,9 @@ int mlxsw_sp_acl_rulei_act_vlan(struct mlxsw_sp *mlxsw_sp,
 				struct mlxsw_sp_acl_rule_info *rulei,
 				u32 action, u16 vid, u16 proto, u8 prio,
 				struct netlink_ext_ack *extack);
+int mlxsw_sp_acl_rulei_act_priority(struct mlxsw_sp *mlxsw_sp,
+				    struct mlxsw_sp_acl_rule_info *rulei,
+				    u32 prio, struct netlink_ext_ack *extack);
 int mlxsw_sp_acl_rulei_act_count(struct mlxsw_sp *mlxsw_sp,
 				 struct mlxsw_sp_acl_rule_info *rulei,
 				 struct netlink_ext_ack *extack);

drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c

@@ -638,6 +638,23 @@ int mlxsw_sp_acl_rulei_act_vlan(struct mlxsw_sp *mlxsw_sp,
 	}
 }
 
+int mlxsw_sp_acl_rulei_act_priority(struct mlxsw_sp *mlxsw_sp,
+				    struct mlxsw_sp_acl_rule_info *rulei,
+				    u32 prio, struct netlink_ext_ack *extack)
+{
+	/* Even though both Linux and Spectrum switches support 16 priorities,
+	 * spectrum_qdisc only processes the first eight priomap elements, and
+	 * the DCB and PFC features are tied to 8 priorities as well. Therefore
+	 * bounce attempts to prioritize packets to higher priorities.
+	 */
+	if (prio >= IEEE_8021QAZ_MAX_TCS) {
+		NL_SET_ERR_MSG_MOD(extack, "Only priorities 0..7 are supported");
+		return -EINVAL;
+	}
+	return mlxsw_afa_block_append_qos_switch_prio(rulei->act_block, prio,
+						      extack);
+}
+
 int mlxsw_sp_acl_rulei_act_count(struct mlxsw_sp *mlxsw_sp,
 				 struct mlxsw_sp_acl_rule_info *rulei,
 				 struct netlink_ext_ack *extack)

drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c

@@ -154,6 +154,10 @@ static int mlxsw_sp_flower_parse_actions(struct mlxsw_sp *mlxsw_sp,
 							   act->id, vid,
 							   proto, prio, extack);
 			}
+		case FLOW_ACTION_PRIORITY:
+			return mlxsw_sp_acl_rulei_act_priority(mlxsw_sp, rulei,
+							       act->priority,
+							       extack);
 		default:
 			NL_SET_ERR_MSG_MOD(extack, "Unsupported action");
 			dev_err(mlxsw_sp->bus_info->dev, "Unsupported action\n");