mlxsw: core_acl_flex_actions: Add mirror sampler action

Add core functionality required to support mirror sampler action in the
policy engine. The switch driver (e.g., 'mlxsw_spectrum') is required to
implement the sampler_add() / sampler_del() callbacks that perform the
necessary configuration before the sampler action can be installed. The
next patch will implement it for Spectrum-{2,3}, while Spectrum-1 will
return an error, given it is not supported.

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

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

@@ -2007,3 +2007,134 @@ int mlxsw_afa_block_append_l4port(struct mlxsw_afa_block *block, bool is_dport,
 	return 0;
 }
 EXPORT_SYMBOL(mlxsw_afa_block_append_l4port);
+
+/* Mirror Sampler Action
+ * ---------------------
+ * The SAMPLER_ACTION is used to mirror packets with a probability (sampling).
+ */
+
+#define MLXSW_AFA_SAMPLER_CODE 0x13
+#define MLXSW_AFA_SAMPLER_SIZE 1
+
+/* afa_sampler_mirror_agent
+ * Mirror (SPAN) agent.
+ */
+MLXSW_ITEM32(afa, sampler, mirror_agent, 0x04, 0, 3);
+
+#define MLXSW_AFA_SAMPLER_RATE_MAX (BIT(24) - 1)
+
+/* afa_sampler_mirror_probability_rate
+ * Mirroring probability.
+ * Valid values are 1 to 2^24 - 1
+ */
+MLXSW_ITEM32(afa, sampler, mirror_probability_rate, 0x08, 0, 24);
+
+static void mlxsw_afa_sampler_pack(char *payload, u8 mirror_agent, u32 rate)
+{
+	mlxsw_afa_sampler_mirror_agent_set(payload, mirror_agent);
+	mlxsw_afa_sampler_mirror_probability_rate_set(payload, rate);
+}
+
+struct mlxsw_afa_sampler {
+	struct mlxsw_afa_resource resource;
+	int span_id;
+	u8 local_port;
+	bool ingress;
+};
+
+static void mlxsw_afa_sampler_destroy(struct mlxsw_afa_block *block,
+				      struct mlxsw_afa_sampler *sampler)
+{
+	mlxsw_afa_resource_del(&sampler->resource);
+	block->afa->ops->sampler_del(block->afa->ops_priv, sampler->local_port,
+				     sampler->span_id, sampler->ingress);
+	kfree(sampler);
+}
+
+static void mlxsw_afa_sampler_destructor(struct mlxsw_afa_block *block,
+					 struct mlxsw_afa_resource *resource)
+{
+	struct mlxsw_afa_sampler *sampler;
+
+	sampler = container_of(resource, struct mlxsw_afa_sampler, resource);
+	mlxsw_afa_sampler_destroy(block, sampler);
+}
+
+static struct mlxsw_afa_sampler *
+mlxsw_afa_sampler_create(struct mlxsw_afa_block *block, u8 local_port,
+			 struct psample_group *psample_group, u32 rate,
+			 u32 trunc_size, bool truncate, bool ingress,
+			 struct netlink_ext_ack *extack)
+{
+	struct mlxsw_afa_sampler *sampler;
+	int err;
+
+	sampler = kzalloc(sizeof(*sampler), GFP_KERNEL);
+	if (!sampler)
+		return ERR_PTR(-ENOMEM);
+
+	err = block->afa->ops->sampler_add(block->afa->ops_priv, local_port,
+					   psample_group, rate, trunc_size,
+					   truncate, ingress, &sampler->span_id,
+					   extack);
+	if (err)
+		goto err_sampler_add;
+
+	sampler->ingress = ingress;
+	sampler->local_port = local_port;
+	sampler->resource.destructor = mlxsw_afa_sampler_destructor;
+	mlxsw_afa_resource_add(block, &sampler->resource);
+	return sampler;
+
+err_sampler_add:
+	kfree(sampler);
+	return ERR_PTR(err);
+}
+
+static int
+mlxsw_afa_block_append_allocated_sampler(struct mlxsw_afa_block *block,
+					 u8 mirror_agent, u32 rate)
+{
+	char *act = mlxsw_afa_block_append_action(block, MLXSW_AFA_SAMPLER_CODE,
+						  MLXSW_AFA_SAMPLER_SIZE);
+
+	if (IS_ERR(act))
+		return PTR_ERR(act);
+	mlxsw_afa_sampler_pack(act, mirror_agent, rate);
+	return 0;
+}
+
+int mlxsw_afa_block_append_sampler(struct mlxsw_afa_block *block, u8 local_port,
+				   struct psample_group *psample_group,
+				   u32 rate, u32 trunc_size, bool truncate,
+				   bool ingress,
+				   struct netlink_ext_ack *extack)
+{
+	struct mlxsw_afa_sampler *sampler;
+	int err;
+
+	if (rate > MLXSW_AFA_SAMPLER_RATE_MAX) {
+		NL_SET_ERR_MSG_MOD(extack, "Sampling rate is too high");
+		return -EINVAL;
+	}
+
+	sampler = mlxsw_afa_sampler_create(block, local_port, psample_group,
+					   rate, trunc_size, truncate, ingress,
+					   extack);
+	if (IS_ERR(sampler))
+		return PTR_ERR(sampler);
+
+	err = mlxsw_afa_block_append_allocated_sampler(block, sampler->span_id,
+						       rate);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "Cannot append sampler action");
+		goto err_append_allocated_sampler;
+	}
+
+	return 0;
+
+err_append_allocated_sampler:
+	mlxsw_afa_sampler_destroy(block, sampler);
+	return err;
+}
+EXPORT_SYMBOL(mlxsw_afa_block_append_sampler);

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

@@ -30,6 +30,12 @@ struct mlxsw_afa_ops {
 			   u16 *p_policer_index,
 			   struct netlink_ext_ack *extack);
 	void (*policer_del)(void *priv, u16 policer_index);
+	int (*sampler_add)(void *priv, u8 local_port,
+			   struct psample_group *psample_group, u32 rate,
+			   u32 trunc_size, bool truncate, bool ingress,
+			   int *p_span_id, struct netlink_ext_ack *extack);
+	void (*sampler_del)(void *priv, u8 local_port, int span_id,
+			    bool ingress);
 	bool dummy_first_set;
 };
 
@@ -92,5 +98,10 @@ int mlxsw_afa_block_append_police(struct mlxsw_afa_block *block,
 				  u32 fa_index, u64 rate_bytes_ps, u32 burst,
 				  u16 *p_policer_index,
 				  struct netlink_ext_ack *extack);
+int mlxsw_afa_block_append_sampler(struct mlxsw_afa_block *block, u8 local_port,
+				   struct psample_group *psample_group,
+				   u32 rate, u32 trunc_size, bool truncate,
+				   bool ingress,
+				   struct netlink_ext_ack *extack);
 
 #endif