net: microchip: sparx5: Add TC template support

This adds support for using the "template add" and "template destroy"
functionality to change the port keyset configuration.

If the VCAP lookup already contains rules, the port keyset is left
unchanged, as a change would make these rules unusable.

When the template is destroyed the port keyset configuration is restored.
The filters using the template chain will automatically be deleted by the
TC framework.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/sparx5/sparx5_tc_flower.c

@@ -28,6 +28,14 @@ struct sparx5_multiple_rules {
 	struct sparx5_wildcard_rule rule[SPX5_MAX_RULE_SIZE];
 };
 
+struct sparx5_tc_flower_template {
+	struct list_head list; /* for insertion in the list of templates */
+	int cid; /* chain id */
+	enum vcap_keyfield_set orig; /* keyset used before the template */
+	enum vcap_keyfield_set keyset; /* new keyset used by template */
+	u16 l3_proto; /* protocol specified in the template */
+};
+
 static int
 sparx5_tc_flower_es0_tpid(struct vcap_tc_flower_parse_usage *st)
 {
@@ -382,7 +390,7 @@ static int sparx5_tc_select_protocol_keyset(struct net_device *ndev,
 	/* Find the keysets that the rule can use */
 	matches.keysets = keysets;
 	matches.max = ARRAY_SIZE(keysets);
-	if (vcap_rule_find_keysets(vrule, &matches) == 0)
+	if (!vcap_rule_find_keysets(vrule, &matches))
 		return -EINVAL;
 
 	/* Find the keysets that the port configuration supports */
@@ -996,6 +1004,73 @@ static int sparx5_tc_action_vlan_push(struct vcap_admin *admin,
 	return err;
 }
 
+/* Remove rule keys that may prevent templates from matching a keyset */
+static void sparx5_tc_flower_simplify_rule(struct vcap_admin *admin,
+					   struct vcap_rule *vrule,
+					   u16 l3_proto)
+{
+	switch (admin->vtype) {
+	case VCAP_TYPE_IS0:
+		vcap_rule_rem_key(vrule, VCAP_KF_ETYPE);
+		switch (l3_proto) {
+		case ETH_P_IP:
+			break;
+		case ETH_P_IPV6:
+			vcap_rule_rem_key(vrule, VCAP_KF_IP_SNAP_IS);
+			break;
+		default:
+			break;
+		}
+		break;
+	case VCAP_TYPE_ES2:
+		switch (l3_proto) {
+		case ETH_P_IP:
+			if (vrule->keyset == VCAP_KFS_IP4_OTHER)
+				vcap_rule_rem_key(vrule, VCAP_KF_TCP_IS);
+			break;
+		case ETH_P_IPV6:
+			if (vrule->keyset == VCAP_KFS_IP6_STD)
+				vcap_rule_rem_key(vrule, VCAP_KF_TCP_IS);
+			vcap_rule_rem_key(vrule, VCAP_KF_IP4_IS);
+			break;
+		default:
+			break;
+		}
+		break;
+	case VCAP_TYPE_IS2:
+		switch (l3_proto) {
+		case ETH_P_IP:
+		case ETH_P_IPV6:
+			vcap_rule_rem_key(vrule, VCAP_KF_IP4_IS);
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+static bool sparx5_tc_flower_use_template(struct net_device *ndev,
+					  struct flow_cls_offload *fco,
+					  struct vcap_admin *admin,
+					  struct vcap_rule *vrule)
+{
+	struct sparx5_port *port = netdev_priv(ndev);
+	struct sparx5_tc_flower_template *ftp;
+
+	list_for_each_entry(ftp, &port->tc_templates, list) {
+		if (ftp->cid != fco->common.chain_index)
+			continue;
+
+		vcap_set_rule_set_keyset(vrule, ftp->keyset);
+		sparx5_tc_flower_simplify_rule(admin, vrule, ftp->l3_proto);
+		return true;
+	}
+	return false;
+}
+
 static int sparx5_tc_flower_replace(struct net_device *ndev,
 				    struct flow_cls_offload *fco,
 				    struct vcap_admin *admin,
@@ -1122,12 +1197,14 @@ static int sparx5_tc_flower_replace(struct net_device *ndev,
 			goto out;
 	}
 
-	err = sparx5_tc_select_protocol_keyset(ndev, vrule, admin,
-					       state.l3_proto, &multi);
-	if (err) {
-		NL_SET_ERR_MSG_MOD(fco->common.extack,
-				   "No matching port keyset for filter protocol and keys");
-		goto out;
+	if (!sparx5_tc_flower_use_template(ndev, fco, admin, vrule)) {
+		err = sparx5_tc_select_protocol_keyset(ndev, vrule, admin,
+						       state.l3_proto, &multi);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(fco->common.extack,
+					   "No matching port keyset for filter protocol and keys");
+			goto out;
+		}
 	}
 
 	/* provide the l3 protocol to guide the keyset selection */
@@ -1259,6 +1336,120 @@ static int sparx5_tc_flower_stats(struct net_device *ndev,
 	return err;
 }
 
+static int sparx5_tc_flower_template_create(struct net_device *ndev,
+					    struct flow_cls_offload *fco,
+					    struct vcap_admin *admin)
+{
+	struct sparx5_port *port = netdev_priv(ndev);
+	struct vcap_tc_flower_parse_usage state = {
+		.fco = fco,
+		.l3_proto = ETH_P_ALL,
+		.admin = admin,
+	};
+	struct sparx5_tc_flower_template *ftp;
+	struct vcap_keyset_list kslist = {};
+	enum vcap_keyfield_set keysets[10];
+	struct vcap_control *vctrl;
+	struct vcap_rule *vrule;
+	int count, err;
+
+	if (admin->vtype == VCAP_TYPE_ES0) {
+		pr_err("%s:%d: %s\n", __func__, __LINE__,
+		       "VCAP does not support templates");
+		return -EINVAL;
+	}
+
+	count = vcap_admin_rule_count(admin, fco->common.chain_index);
+	if (count > 0) {
+		pr_err("%s:%d: %s\n", __func__, __LINE__,
+		       "Filters are already present");
+		return -EBUSY;
+	}
+
+	ftp = kzalloc(sizeof(*ftp), GFP_KERNEL);
+	if (!ftp)
+		return -ENOMEM;
+
+	ftp->cid = fco->common.chain_index;
+	ftp->orig = VCAP_KFS_NO_VALUE;
+	ftp->keyset = VCAP_KFS_NO_VALUE;
+
+	vctrl = port->sparx5->vcap_ctrl;
+	vrule = vcap_alloc_rule(vctrl, ndev, fco->common.chain_index,
+				VCAP_USER_TC, fco->common.prio, 0);
+	if (IS_ERR(vrule)) {
+		err = PTR_ERR(vrule);
+		goto err_rule;
+	}
+
+	state.vrule = vrule;
+	state.frule = flow_cls_offload_flow_rule(fco);
+	err = sparx5_tc_use_dissectors(&state, admin, vrule);
+	if (err) {
+		pr_err("%s:%d: key error: %d\n", __func__, __LINE__, err);
+		goto out;
+	}
+
+	ftp->l3_proto = state.l3_proto;
+
+	sparx5_tc_flower_simplify_rule(admin, vrule, state.l3_proto);
+
+	/* Find the keysets that the rule can use */
+	kslist.keysets = keysets;
+	kslist.max = ARRAY_SIZE(keysets);
+	if (!vcap_rule_find_keysets(vrule, &kslist)) {
+		pr_err("%s:%d: %s\n", __func__, __LINE__,
+		       "Could not find a suitable keyset");
+		err = -ENOENT;
+		goto out;
+	}
+
+	ftp->keyset = vcap_select_min_rule_keyset(vctrl, admin->vtype, &kslist);
+	kslist.cnt = 0;
+	sparx5_vcap_set_port_keyset(ndev, admin, fco->common.chain_index,
+				    state.l3_proto,
+				    ftp->keyset,
+				    &kslist);
+
+	if (kslist.cnt > 0)
+		ftp->orig = kslist.keysets[0];
+
+	/* Store new template */
+	list_add_tail(&ftp->list, &port->tc_templates);
+	vcap_free_rule(vrule);
+	return 0;
+
+out:
+	vcap_free_rule(vrule);
+err_rule:
+	kfree(ftp);
+	return err;
+}
+
+static int sparx5_tc_flower_template_destroy(struct net_device *ndev,
+					     struct flow_cls_offload *fco,
+					     struct vcap_admin *admin)
+{
+	struct sparx5_port *port = netdev_priv(ndev);
+	struct sparx5_tc_flower_template *ftp, *tmp;
+	int err = -ENOENT;
+
+	/* Rules using the template are removed by the tc framework */
+	list_for_each_entry_safe(ftp, tmp, &port->tc_templates, list) {
+		if (ftp->cid != fco->common.chain_index)
+			continue;
+
+		sparx5_vcap_set_port_keyset(ndev, admin,
+					    fco->common.chain_index,
+					    ftp->l3_proto, ftp->orig,
+					    NULL);
+		list_del(&ftp->list);
+		kfree(ftp);
+		break;
+	}
+	return err;
+}
+
 int sparx5_tc_flower(struct net_device *ndev, struct flow_cls_offload *fco,
 		     bool ingress)
 {
@@ -1282,6 +1473,10 @@ int sparx5_tc_flower(struct net_device *ndev, struct flow_cls_offload *fco,
 		return sparx5_tc_flower_destroy(ndev, fco, admin);
 	case FLOW_CLS_STATS:
 		return sparx5_tc_flower_stats(ndev, fco, admin);
+	case FLOW_CLS_TMPLT_CREATE:
+		return sparx5_tc_flower_template_create(ndev, fco, admin);
+	case FLOW_CLS_TMPLT_DESTROY:
+		return sparx5_tc_flower_template_destroy(ndev, fco, admin);
 	default:
 		return -EOPNOTSUPP;
 	}