net/mlx5e: Introduce tc offload support

Extend ndo_setup_tc() to support ingress tc offloading. Will be used by
later patches to offload tc flower filter.

Feature is off by default and could be enabled by issuing:
 # ethtool  -K eth0 hw-tc-offload on

Offloads flow table is dynamically created when first filter is
added.
Rules are saved in a hash table that is maintained by the consumer (for
example - the flower offload in the next patch).
When last filter is removed and no filters exist in the hash table, the
offload flow table is destroyed.

Signed-off-by: Amir Vadai <amir@vadai.me>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 131 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
new file mode 100644
index 000000000000..1dc715d50244
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/mlx5/fs.h>
+#include <linux/mlx5/device.h>
+#include <linux/rhashtable.h>
+#include "en.h"
+#include "en_tc.h"
+
+struct mlx5e_tc_flow {
+	struct rhash_head	node;
+	u64			cookie;
+	struct mlx5_flow_rule	*rule;
+};
+
+#define MLX5E_TC_FLOW_TABLE_NUM_ENTRIES 1024
+#define MLX5E_TC_FLOW_TABLE_NUM_GROUPS 4
+
+static struct mlx5_flow_rule *mlx5e_tc_add_flow(struct mlx5e_priv *priv,
+						u32 *match_c, u32 *match_v,
+						u32 action, u32 flow_tag)
+{
+	struct mlx5_flow_destination dest = {
+		.type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE,
+		{.ft = priv->fts.vlan.t},
+	};
+	struct mlx5_flow_rule *rule;
+	bool table_created = false;
+
+	if (IS_ERR_OR_NULL(priv->fts.tc.t)) {
+		priv->fts.tc.t =
+			mlx5_create_auto_grouped_flow_table(priv->fts.ns, 0,
+							    MLX5E_TC_FLOW_TABLE_NUM_ENTRIES,
+							    MLX5E_TC_FLOW_TABLE_NUM_GROUPS);
+		if (IS_ERR(priv->fts.tc.t)) {
+			netdev_err(priv->netdev,
+				   "Failed to create tc offload table\n");
+			return ERR_CAST(priv->fts.tc.t);
+		}
+
+		table_created = true;
+	}
+
+	rule = mlx5_add_flow_rule(priv->fts.tc.t, MLX5_MATCH_OUTER_HEADERS,
+				  match_c, match_v,
+				  action, flow_tag,
+				  action & MLX5_FLOW_CONTEXT_ACTION_FWD_DEST ? &dest : NULL);
+
+	if (IS_ERR(rule) && table_created) {
+		mlx5_destroy_flow_table(priv->fts.tc.t);
+		priv->fts.tc.t = NULL;
+	}
+
+	return rule;
+}
+
+static void mlx5e_tc_del_flow(struct mlx5e_priv *priv,
+			      struct mlx5_flow_rule *rule)
+{
+	mlx5_del_flow_rule(rule);
+
+	if (!mlx5e_tc_num_filters(priv)) {
+		mlx5_destroy_flow_table(priv->fts.tc.t);
+		priv->fts.tc.t = NULL;
+	}
+}
+
+static const struct rhashtable_params mlx5e_tc_flow_ht_params = {
+	.head_offset = offsetof(struct mlx5e_tc_flow, node),
+	.key_offset = offsetof(struct mlx5e_tc_flow, cookie),
+	.key_len = sizeof(((struct mlx5e_tc_flow *)0)->cookie),
+	.automatic_shrinking = true,
+};
+
+int mlx5e_tc_init(struct mlx5e_priv *priv)
+{
+	struct mlx5e_tc_flow_table *tc = &priv->fts.tc;
+
+	tc->ht_params = mlx5e_tc_flow_ht_params;
+	return rhashtable_init(&tc->ht, &tc->ht_params);
+}
+
+static void _mlx5e_tc_del_flow(void *ptr, void *arg)
+{
+	struct mlx5e_tc_flow *flow = ptr;
+	struct mlx5e_priv *priv = arg;
+
+	mlx5e_tc_del_flow(priv, flow->rule);
+	kfree(flow);
+}
+
+void mlx5e_tc_cleanup(struct mlx5e_priv *priv)
+{
+	struct mlx5e_tc_flow_table *tc = &priv->fts.tc;
+
+	rhashtable_free_and_destroy(&tc->ht, _mlx5e_tc_del_flow, priv);
+
+	if (!IS_ERR_OR_NULL(priv->fts.tc.t)) {
+		mlx5_destroy_flow_table(priv->fts.tc.t);
+		priv->fts.tc.t = NULL;
+	}
+}