net/mlx5e: Allow re-allocating mod header actions

Currently the size of the mod header actions array is deduced from the
number of parsed TC header rewrite actions. However, mod header actions
are also used for setting HW register values. Support the dynamic
reallocation of the mod header array as a pre-step for adding HW
registers mod actions.
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -144,9 +144,7 @@ struct mlx5e_tc_flow_parse_attr {
 	const struct ip_tunnel_info *tun_info[MLX5_MAX_FLOW_FWD_VPORTS];
 	struct net_device *filter_dev;
 	struct mlx5_flow_spec spec;
-	int num_mod_hdr_actions;
-	int max_mod_hdr_actions;
-	void *mod_hdr_actions;
+	struct mlx5e_tc_mod_hdr_acts mod_hdr_acts;
 	int mirred_ifindex[MLX5_MAX_FLOW_FWD_VPORTS];
 };
 
@@ -369,10 +367,10 @@ static int mlx5e_attach_mod_hdr(struct mlx5e_priv *priv,
 	struct mod_hdr_key key;
 	u32 hash_key;
 
-	num_actions  = parse_attr->num_mod_hdr_actions;
+	num_actions  = parse_attr->mod_hdr_acts.num_actions;
 	actions_size = MLX5_MH_ACT_SZ * num_actions;
 
-	key.actions = parse_attr->mod_hdr_actions;
+	key.actions = parse_attr->mod_hdr_acts.actions;
 	key.num_actions = num_actions;
 
 	hash_key = hash_mod_hdr_info(&key);
@@ -962,7 +960,7 @@ mlx5e_tc_add_nic_flow(struct mlx5e_priv *priv,
 	if (attr->action & MLX5_FLOW_CONTEXT_ACTION_MOD_HDR) {
 		err = mlx5e_attach_mod_hdr(priv, flow, parse_attr);
 		flow_act.modify_hdr = attr->modify_hdr;
-		kfree(parse_attr->mod_hdr_actions);
+		dealloc_mod_hdr_actions(&parse_attr->mod_hdr_acts);
 		if (err)
 			return err;
 	}
@@ -1228,7 +1226,7 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv,
 
 	if (attr->action & MLX5_FLOW_CONTEXT_ACTION_MOD_HDR) {
 		err = mlx5e_attach_mod_hdr(priv, flow, parse_attr);
-		kfree(parse_attr->mod_hdr_actions);
+		dealloc_mod_hdr_actions(&parse_attr->mod_hdr_acts);
 		if (err)
 			return err;
 	}
@@ -2391,25 +2389,26 @@ static struct mlx5_fields fields[] = {
 	OFFLOAD(UDP_DPORT, 16, U16_MAX, udp.dest,   0, udp_dport),
 };
 
-/* On input attr->max_mod_hdr_actions tells how many HW actions can be parsed at
- * max from the SW pedit action. On success, attr->num_mod_hdr_actions
- * says how many HW actions were actually parsed.
- */
-static int offload_pedit_fields(struct pedit_headers_action *hdrs,
+static int offload_pedit_fields(struct mlx5e_priv *priv,
+				int namespace,
+				struct pedit_headers_action *hdrs,
 				struct mlx5e_tc_flow_parse_attr *parse_attr,
 				u32 *action_flags,
 				struct netlink_ext_ack *extack)
 {
 	struct pedit_headers *set_masks, *add_masks, *set_vals, *add_vals;
-	int i, action_size, nactions, max_actions, first, last, next_z;
+	int i, action_size, first, last, next_z;
 	void *headers_c, *headers_v, *action, *vals_p;
 	u32 *s_masks_p, *a_masks_p, s_mask, a_mask;
+	struct mlx5e_tc_mod_hdr_acts *mod_acts;
 	struct mlx5_fields *f;
 	unsigned long mask;
 	__be32 mask_be32;
 	__be16 mask_be16;
+	int err;
 	u8 cmd;
 
+	mod_acts = &parse_attr->mod_hdr_acts;
 	headers_c = get_match_headers_criteria(*action_flags, &parse_attr->spec);
 	headers_v = get_match_headers_value(*action_flags, &parse_attr->spec);
 
@@ -2419,11 +2418,6 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 	add_vals = &hdrs[1].vals;
 
 	action_size = MLX5_UN_SZ_BYTES(set_action_in_add_action_in_auto);
-	action = parse_attr->mod_hdr_actions +
-		 parse_attr->num_mod_hdr_actions * action_size;
-
-	max_actions = parse_attr->max_mod_hdr_actions;
-	nactions = parse_attr->num_mod_hdr_actions;
 
 	for (i = 0; i < ARRAY_SIZE(fields); i++) {
 		bool skip;
@@ -2449,13 +2443,6 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 			return -EOPNOTSUPP;
 		}
 
-		if (nactions == max_actions) {
-			NL_SET_ERR_MSG_MOD(extack,
-					   "too many pedit actions, can't offload");
-			printk(KERN_WARNING "mlx5: parsed %d pedit actions, can't do more\n", nactions);
-			return -EOPNOTSUPP;
-		}
-
 		skip = false;
 		if (s_mask) {
 			void *match_mask = headers_c + f->match_offset;
@@ -2502,6 +2489,18 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 			return -EOPNOTSUPP;
 		}
 
+		err = alloc_mod_hdr_actions(priv->mdev, namespace, mod_acts);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "too many pedit actions, can't offload");
+			mlx5_core_warn(priv->mdev,
+				       "mlx5: parsed %d pedit actions, can't do more\n",
+				       mod_acts->num_actions);
+			return err;
+		}
+
+		action = mod_acts->actions +
+			 (mod_acts->num_actions * action_size);
 		MLX5_SET(set_action_in, action, action_type, cmd);
 		MLX5_SET(set_action_in, action, field, f->field);
 
@@ -2524,11 +2523,9 @@ static int offload_pedit_fields(struct pedit_headers_action *hdrs,
 		else if (f->field_bsize == 8)
 			MLX5_SET(set_action_in, action, data, *(u8 *)vals_p >> first);
 
-		action += action_size;
-		nactions++;
+		++mod_acts->num_actions;
 	}
 
-	parse_attr->num_mod_hdr_actions = nactions;
 	return 0;
 }
 
@@ -2541,29 +2538,48 @@ static int mlx5e_flow_namespace_max_modify_action(struct mlx5_core_dev *mdev,
 		return MLX5_CAP_FLOWTABLE_NIC_RX(mdev, max_modify_header_actions);
 }
 
-static int alloc_mod_hdr_actions(struct mlx5e_priv *priv,
-				 struct pedit_headers_action *hdrs,
-				 int namespace,
-				 struct mlx5e_tc_flow_parse_attr *parse_attr)
+int alloc_mod_hdr_actions(struct mlx5_core_dev *mdev,
+			  int namespace,
+			  struct mlx5e_tc_mod_hdr_acts *mod_hdr_acts)
 {
-	int nkeys, action_size, max_actions;
+	int action_size, new_num_actions, max_hw_actions;
+	size_t new_sz, old_sz;
+	void *ret;
 
-	nkeys = hdrs[TCA_PEDIT_KEY_EX_CMD_SET].pedits +
-		hdrs[TCA_PEDIT_KEY_EX_CMD_ADD].pedits;
-	action_size = MLX5_UN_SZ_BYTES(set_action_in_add_action_in_auto);
+	if (mod_hdr_acts->num_actions < mod_hdr_acts->max_actions)
+		return 0;
 
-	max_actions = mlx5e_flow_namespace_max_modify_action(priv->mdev, namespace);
-	/* can get up to crazingly 16 HW actions in 32 bits pedit SW key */
-	max_actions = min(max_actions, nkeys * 16);
+	action_size = MLX5_UN_SZ_BYTES(set_action_in_add_action_in_auto);
 
-	parse_attr->mod_hdr_actions = kcalloc(max_actions, action_size, GFP_KERNEL);
-	if (!parse_attr->mod_hdr_actions)
+	max_hw_actions = mlx5e_flow_namespace_max_modify_action(mdev,
+								namespace);
+	new_num_actions = min(max_hw_actions,
+			      mod_hdr_acts->actions ?
+			      mod_hdr_acts->max_actions * 2 : 1);
+	if (mod_hdr_acts->max_actions == new_num_actions)
+		return -ENOSPC;
+
+	new_sz = action_size * new_num_actions;
+	old_sz = mod_hdr_acts->max_actions * action_size;
+	ret = krealloc(mod_hdr_acts->actions, new_sz, GFP_KERNEL);
+	if (!ret)
 		return -ENOMEM;
 
-	parse_attr->max_mod_hdr_actions = max_actions;
+	memset(ret + old_sz, 0, new_sz - old_sz);
+	mod_hdr_acts->actions = ret;
+	mod_hdr_acts->max_actions = new_num_actions;
+
 	return 0;
 }
 
+void dealloc_mod_hdr_actions(struct mlx5e_tc_mod_hdr_acts *mod_hdr_acts)
+{
+	kfree(mod_hdr_acts->actions);
+	mod_hdr_acts->actions = NULL;
+	mod_hdr_acts->num_actions = 0;
+	mod_hdr_acts->max_actions = 0;
+}
+
 static const struct pedit_headers zero_masks = {};
 
 static int parse_tc_pedit_action(struct mlx5e_priv *priv,
@@ -2616,13 +2632,8 @@ static int alloc_tc_pedit_action(struct mlx5e_priv *priv, int namespace,
 	int err;
 	u8 cmd;
 
-	if (!parse_attr->mod_hdr_actions) {
-		err = alloc_mod_hdr_actions(priv, hdrs, namespace, parse_attr);
-		if (err)
-			goto out_err;
-	}
-
-	err = offload_pedit_fields(hdrs, parse_attr, action_flags, extack);
+	err = offload_pedit_fields(priv, namespace, hdrs, parse_attr,
+				   action_flags, extack);
 	if (err < 0)
 		goto out_dealloc_parsed_actions;
 
@@ -2642,8 +2653,7 @@ static int alloc_tc_pedit_action(struct mlx5e_priv *priv, int namespace,
 	return 0;
 
 out_dealloc_parsed_actions:
-	kfree(parse_attr->mod_hdr_actions);
-out_err:
+	dealloc_mod_hdr_actions(&parse_attr->mod_hdr_acts);
 	return err;
 }
 
@@ -2976,9 +2986,9 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv,
 		/* in case all pedit actions are skipped, remove the MOD_HDR
 		 * flag.
 		 */
-		if (parse_attr->num_mod_hdr_actions == 0) {
+		if (parse_attr->mod_hdr_acts.num_actions == 0) {
 			action &= ~MLX5_FLOW_CONTEXT_ACTION_MOD_HDR;
-			kfree(parse_attr->mod_hdr_actions);
+			dealloc_mod_hdr_actions(&parse_attr->mod_hdr_acts);
 		}
 	}
 
@@ -3564,9 +3574,9 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv,
 		 * flag. we might have set split_count either by pedit or
 		 * pop/push. if there is no pop/push either, reset it too.
 		 */
-		if (parse_attr->num_mod_hdr_actions == 0) {
+		if (parse_attr->mod_hdr_acts.num_actions == 0) {
 			action &= ~MLX5_FLOW_CONTEXT_ACTION_MOD_HDR;
-			kfree(parse_attr->mod_hdr_actions);
+			dealloc_mod_hdr_actions(&parse_attr->mod_hdr_acts);
 			if (!((action & MLX5_FLOW_CONTEXT_ACTION_VLAN_POP) ||
 			      (action & MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH)))
 				attr->split_count = 0;

drivers/net/ethernet/mellanox/mlx5/core/en_tc.h

@@ -108,6 +108,17 @@ bool mlx5e_is_valid_eswitch_fwd_dev(struct mlx5e_priv *priv,
 
 bool mlx5e_tc_rep_update_skb(struct mlx5_cqe64 *cqe, struct sk_buff *skb);
 
+struct mlx5e_tc_mod_hdr_acts {
+	int num_actions;
+	int max_actions;
+	void *actions;
+};
+
+int alloc_mod_hdr_actions(struct mlx5_core_dev *mdev,
+			  int namespace,
+			  struct mlx5e_tc_mod_hdr_acts *mod_hdr_acts);
+void dealloc_mod_hdr_actions(struct mlx5e_tc_mod_hdr_acts *mod_hdr_acts);
+
 #else /* CONFIG_MLX5_ESWITCH */
 static inline int  mlx5e_tc_nic_init(struct mlx5e_priv *priv) { return 0; }
 static inline void mlx5e_tc_nic_cleanup(struct mlx5e_priv *priv) {}