net/mlx5e: TC, Add support to offload sample action

The following diagram illustrates the hardware model for tc sample action:

        +---------------------+
        + original flow table +
        +---------------------+
        +   original match    +
        +---------------------+
                   |
                   v
+------------------------------------------------+
+                Flow Sampler Object             +
+------------------------------------------------+
+                    sample ratio                +
+------------------------------------------------+
+    sample table id    |    default table id    +
+------------------------------------------------+
           |                            |
           v                            v
+-----------------------------+  +----------------------------------------+
+        sample table         +  + default table per <vport, chain, prio> +
+-----------------------------+  +----------------------------------------+
+ forward to management vport +  +            original match              +
+-----------------------------+  +----------------------------------------+
                                 +            other actions               +
                                 +----------------------------------------+

The sample action is translated to a goto flow table object
destination which samples packets according to the provided
sample ratio. Sampled packets are duplicated. One copy is
processed by a termination table, named the sample table,
which sends the packet to the eswitch manager port (that will
be processed by software).

The second copy is processed by the default table which executes
the subsequent actions. The default table is created per <vport,
chain, prio> tuple as rules with different prios and chains may
overlap.

Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

1 files changed, 41 insertions, 2 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
index 510e9b8b24fe..ac92ffc8a5d3 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
@@ -86,6 +86,26 @@ mlx5_eswitch_set_rule_flow_source(struct mlx5_eswitch *esw,
 				MLX5_FLOW_CONTEXT_FLOW_SOURCE_LOCAL_VPORT;
 }
 
+/* Actually only the upper 16 bits of reg c0 need to be cleared, but the lower 16 bits
+ * are not needed as well in the following process. So clear them all for simplicity.
+ */
+void
+mlx5_eswitch_clear_rule_source_port(struct mlx5_eswitch *esw, struct mlx5_flow_spec *spec)
+{
+	if (mlx5_eswitch_vport_match_metadata_enabled(esw)) {
+		void *misc2;
+
+		misc2 = MLX5_ADDR_OF(fte_match_param, spec->match_value, misc_parameters_2);
+		MLX5_SET(fte_match_set_misc2, misc2, metadata_reg_c_0, 0);
+
+		misc2 = MLX5_ADDR_OF(fte_match_param, spec->match_criteria, misc_parameters_2);
+		MLX5_SET(fte_match_set_misc2, misc2, metadata_reg_c_0, 0);
+
+		if (!memchr_inv(misc2, 0, MLX5_ST_SZ_BYTES(fte_match_set_misc2)))
+			spec->match_criteria_enable &= ~MLX5_MATCH_MISC_PARAMETERS_2;
+	}
+}
+
 static void
 mlx5_eswitch_set_rule_source_port(struct mlx5_eswitch *esw,
 				  struct mlx5_flow_spec *spec,
@@ -157,6 +177,19 @@ esw_cleanup_decap_indir(struct mlx5_eswitch *esw,
 }
 
 static int
+esw_setup_sampler_dest(struct mlx5_flow_destination *dest,
+		       struct mlx5_flow_act *flow_act,
+		       struct mlx5_esw_flow_attr *esw_attr,
+		       int i)
+{
+	flow_act->flags |= FLOW_ACT_IGNORE_FLOW_LEVEL;
+	dest[i].type = MLX5_FLOW_DESTINATION_TYPE_FLOW_SAMPLER;
+	dest[i].sampler_id = esw_attr->sample->sampler_id;
+
+	return 0;
+}
+
+static int
 esw_setup_ft_dest(struct mlx5_flow_destination *dest,
 		  struct mlx5_flow_act *flow_act,
 		  struct mlx5_eswitch *esw,
@@ -385,7 +418,10 @@ esw_setup_dests(struct mlx5_flow_destination *dest,
 	    MLX5_CAP_ESW_FLOWTABLE_FDB(esw->dev, ignore_flow_level))
 		attr->flags |= MLX5_ESW_ATTR_FLAG_SRC_REWRITE;
 
-	if (attr->dest_ft) {
+	if (attr->flags & MLX5_ESW_ATTR_FLAG_SAMPLE) {
+		esw_setup_sampler_dest(dest, flow_act, esw_attr, *i);
+		(*i)++;
+	} else if (attr->dest_ft) {
 		esw_setup_ft_dest(dest, flow_act, esw, attr, spec, *i);
 		(*i)++;
 	} else if (attr->flags & MLX5_ESW_ATTR_FLAG_SLOW_PATH) {
@@ -488,7 +524,10 @@ mlx5_eswitch_add_offloaded_rule(struct mlx5_eswitch *esw,
 	if (flow_act.action & MLX5_FLOW_CONTEXT_ACTION_MOD_HDR)
 		flow_act.modify_hdr = attr->modify_hdr;
 
-	if (split) {
+	/* esw_attr->sample is allocated only when there is a sample action */
+	if (esw_attr->sample && esw_attr->sample->sample_default_tbl) {
+		fdb = esw_attr->sample->sample_default_tbl;
+	} else if (split) {
 		fwd_attr.chain = attr->chain;
 		fwd_attr.prio = attr->prio;
 		fwd_attr.vport = esw_attr->in_rep->vport;