mlxsw: spectrum: Register switched port analyzers (SPAN) as resource

The switch supports an enhanced switched port analyzer that enables
selecting network traffic for analysis by a network analyzer.

SPAN agents are configured and consumed whenever a tc filter is added
with a mirror action to a new destination. The destination can either be
a physical port (e.g., swp1), a VLAN device or a gretap.

Expose the maximum number of SPAN agents and their current usage to the
user.

Signed-off-by: Danielle Ratson <danieller@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -5202,14 +5202,61 @@ static int mlxsw_sp2_resources_kvd_register(struct mlxsw_core *mlxsw_core)
 					 &kvd_size_params);
 }
 
+static int mlxsw_sp_resources_span_register(struct mlxsw_core *mlxsw_core)
+{
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
+	struct devlink_resource_size_params span_size_params;
+	u32 max_span;
+
+	if (!MLXSW_CORE_RES_VALID(mlxsw_core, MAX_SPAN))
+		return -EIO;
+
+	max_span = MLXSW_CORE_RES_GET(mlxsw_core, MAX_SPAN);
+	devlink_resource_size_params_init(&span_size_params, max_span, max_span,
+					  1, DEVLINK_RESOURCE_UNIT_ENTRY);
+
+	return devlink_resource_register(devlink, MLXSW_SP_RESOURCE_NAME_SPAN,
+					 max_span, MLXSW_SP_RESOURCE_SPAN,
+					 DEVLINK_RESOURCE_ID_PARENT_TOP,
+					 &span_size_params);
+}
+
 static int mlxsw_sp1_resources_register(struct mlxsw_core *mlxsw_core)
 {
-	return mlxsw_sp1_resources_kvd_register(mlxsw_core);
+	int err;
+
+	err = mlxsw_sp1_resources_kvd_register(mlxsw_core);
+	if (err)
+		return err;
+
+	err = mlxsw_sp_resources_span_register(mlxsw_core);
+	if (err)
+		goto err_resources_span_register;
+
+	return 0;
+
+err_resources_span_register:
+	devlink_resources_unregister(priv_to_devlink(mlxsw_core), NULL);
+	return err;
 }
 
 static int mlxsw_sp2_resources_register(struct mlxsw_core *mlxsw_core)
 {
-	return mlxsw_sp2_resources_kvd_register(mlxsw_core);
+	int err;
+
+	err = mlxsw_sp2_resources_kvd_register(mlxsw_core);
+	if (err)
+		return err;
+
+	err = mlxsw_sp_resources_span_register(mlxsw_core);
+	if (err)
+		goto err_resources_span_register;
+
+	return 0;
+
+err_resources_span_register:
+	devlink_resources_unregister(priv_to_devlink(mlxsw_core), NULL);
+	return err;
 }
 
 static int mlxsw_sp_kvd_sizes_get(struct mlxsw_core *mlxsw_core,

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

@@ -48,6 +48,8 @@
 #define MLXSW_SP_RESOURCE_NAME_KVD_LINEAR_CHUNKS "chunks"
 #define MLXSW_SP_RESOURCE_NAME_KVD_LINEAR_LARGE_CHUNKS "large_chunks"
 
+#define MLXSW_SP_RESOURCE_NAME_SPAN "span_agents"
+
 enum mlxsw_sp_resource_id {
 	MLXSW_SP_RESOURCE_KVD = 1,
 	MLXSW_SP_RESOURCE_KVD_LINEAR,
@@ -56,6 +58,7 @@ enum mlxsw_sp_resource_id {
 	MLXSW_SP_RESOURCE_KVD_LINEAR_SINGLE,
 	MLXSW_SP_RESOURCE_KVD_LINEAR_CHUNKS,
 	MLXSW_SP_RESOURCE_KVD_LINEAR_LARGE_CHUNKS,
+	MLXSW_SP_RESOURCE_SPAN,
 };
 
 struct mlxsw_sp_port;

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

@@ -14,8 +14,23 @@
 #include "spectrum_span.h"
 #include "spectrum_switchdev.h"
 
+static u64 mlxsw_sp_span_occ_get(void *priv)
+{
+	const struct mlxsw_sp *mlxsw_sp = priv;
+	u64 occ = 0;
+	int i;
+
+	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
+		if (mlxsw_sp->span.entries[i].ref_count)
+			occ++;
+	}
+
+	return occ;
+}
+
 int mlxsw_sp_span_init(struct mlxsw_sp *mlxsw_sp)
 {
+	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
 	int i;
 
 	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, MAX_SPAN))
@@ -36,13 +51,19 @@ int mlxsw_sp_span_init(struct mlxsw_sp *mlxsw_sp)
 		curr->id = i;
 	}
 
+	devlink_resource_occ_get_register(devlink, MLXSW_SP_RESOURCE_SPAN,
+					  mlxsw_sp_span_occ_get, mlxsw_sp);
+
 	return 0;
 }
 
 void mlxsw_sp_span_fini(struct mlxsw_sp *mlxsw_sp)
 {
+	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
 	int i;
 
+	devlink_resource_occ_get_unregister(devlink, MLXSW_SP_RESOURCE_SPAN);
+
 	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
 		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];