Merge branch 'mlxsw-expose-number-of-physical-ports'

Ido Schimmel says:

====================
mlxsw: Expose number of physical ports

The switch ASIC has a limited capacity of physical ports that it can
support. While each system is brought up with a different number of
ports, this number can be increased via splitting up to the ASIC's
limit.

Expose physical ports as a devlink resource so that user space will have
visibility into the maximum number of ports that can be supported and
the current occupancy. With this resource it is possible, for example,
to write generic (i.e., not platform dependent) tests for port
splitting.

Patch #1 adds the new resource and patch #2 adds a selftest.

v2:
* Add the physical ports resource as a generic devlink resource so that
  it could be re-used by other device drivers
====================

Link: https://lore.kernel.org/r/20210121131024.2656154-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/networking/devlink/devlink-resource.rst

@@ -23,6 +23,20 @@ current size and related sub resources. To access a sub resource, you
 specify the path of the resource. For example ``/IPv4/fib`` is the id for
 the ``fib`` sub-resource under the ``IPv4`` resource.
 
+Generic Resources
+=================
+
+Generic resources are used to describe resources that can be shared by multiple
+device drivers and their description must be added to the following table:
+
+.. list-table:: List of Generic Resources
+   :widths: 10 90
+
+   * - Name
+     - Description
+   * - ``physical_ports``
+     - A limited capacity of physical ports that the switch ASIC can support
+
 example usage
 -------------
 

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

@@ -84,6 +84,7 @@ struct mlxsw_core {
 	struct mlxsw_thermal *thermal;
 	struct mlxsw_core_port *ports;
 	unsigned int max_ports;
+	atomic_t active_ports_count;
 	bool fw_flash_in_progress;
 	struct {
 		struct devlink_health_reporter *fw_fatal;
@@ -96,8 +97,36 @@ struct mlxsw_core {
 
 #define MLXSW_PORT_MAX_PORTS_DEFAULT	0x40
 
-static int mlxsw_ports_init(struct mlxsw_core *mlxsw_core)
+static u64 mlxsw_ports_occ_get(void *priv)
 {
+	struct mlxsw_core *mlxsw_core = priv;
+
+	return atomic_read(&mlxsw_core->active_ports_count);
+}
+
+static int mlxsw_core_resources_ports_register(struct mlxsw_core *mlxsw_core)
+{
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
+	struct devlink_resource_size_params ports_num_params;
+	u32 max_ports;
+
+	max_ports = mlxsw_core->max_ports - 1;
+	devlink_resource_size_params_init(&ports_num_params, max_ports,
+					  max_ports, 1,
+					  DEVLINK_RESOURCE_UNIT_ENTRY);
+
+	return devlink_resource_register(devlink,
+					 DEVLINK_RESOURCE_GENERIC_NAME_PORTS,
+					 max_ports, MLXSW_CORE_RESOURCE_PORTS,
+					 DEVLINK_RESOURCE_ID_PARENT_TOP,
+					 &ports_num_params);
+}
+
+static int mlxsw_ports_init(struct mlxsw_core *mlxsw_core, bool reload)
+{
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
+	int err;
+
 	/* Switch ports are numbered from 1 to queried value */
 	if (MLXSW_CORE_RES_VALID(mlxsw_core, MAX_SYSTEM_PORT))
 		mlxsw_core->max_ports = MLXSW_CORE_RES_GET(mlxsw_core,
@@ -110,11 +139,30 @@ static int mlxsw_ports_init(struct mlxsw_core *mlxsw_core)
 	if (!mlxsw_core->ports)
 		return -ENOMEM;
 
+	if (!reload) {
+		err = mlxsw_core_resources_ports_register(mlxsw_core);
+		if (err)
+			goto err_resources_ports_register;
+	}
+	atomic_set(&mlxsw_core->active_ports_count, 0);
+	devlink_resource_occ_get_register(devlink, MLXSW_CORE_RESOURCE_PORTS,
+					  mlxsw_ports_occ_get, mlxsw_core);
+
 	return 0;
+
+err_resources_ports_register:
+	kfree(mlxsw_core->ports);
+	return err;
 }
 
-static void mlxsw_ports_fini(struct mlxsw_core *mlxsw_core)
+static void mlxsw_ports_fini(struct mlxsw_core *mlxsw_core, bool reload)
 {
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
+
+	devlink_resource_occ_get_unregister(devlink, MLXSW_CORE_RESOURCE_PORTS);
+	if (!reload)
+		devlink_resources_unregister(priv_to_devlink(mlxsw_core), NULL);
+
 	kfree(mlxsw_core->ports);
 }
 
@@ -1897,7 +1945,7 @@ __mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 			goto err_register_resources;
 	}
 
-	err = mlxsw_ports_init(mlxsw_core);
+	err = mlxsw_ports_init(mlxsw_core, reload);
 	if (err)
 		goto err_ports_init;
 
@@ -1986,7 +2034,7 @@ err_devlink_register:
 err_emad_init:
 	kfree(mlxsw_core->lag.mapping);
 err_alloc_lag_mapping:
-	mlxsw_ports_fini(mlxsw_core);
+	mlxsw_ports_fini(mlxsw_core, reload);
 err_ports_init:
 	if (!reload)
 		devlink_resources_unregister(devlink, NULL);
@@ -2056,7 +2104,7 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core,
 		devlink_unregister(devlink);
 	mlxsw_emad_fini(mlxsw_core);
 	kfree(mlxsw_core->lag.mapping);
-	mlxsw_ports_fini(mlxsw_core);
+	mlxsw_ports_fini(mlxsw_core, reload);
 	if (!reload)
 		devlink_resources_unregister(devlink, NULL);
 	mlxsw_core->bus->fini(mlxsw_core->bus_priv);
@@ -2755,16 +2803,25 @@ int mlxsw_core_port_init(struct mlxsw_core *mlxsw_core, u8 local_port,
 			 const unsigned char *switch_id,
 			 unsigned char switch_id_len)
 {
-	return __mlxsw_core_port_init(mlxsw_core, local_port,
-				      DEVLINK_PORT_FLAVOUR_PHYSICAL,
-				      port_number, split, split_port_subnumber,
-				      splittable, lanes,
-				      switch_id, switch_id_len);
+	int err;
+
+	err = __mlxsw_core_port_init(mlxsw_core, local_port,
+				     DEVLINK_PORT_FLAVOUR_PHYSICAL,
+				     port_number, split, split_port_subnumber,
+				     splittable, lanes,
+				     switch_id, switch_id_len);
+	if (err)
+		return err;
+
+	atomic_inc(&mlxsw_core->active_ports_count);
+	return 0;
 }
 EXPORT_SYMBOL(mlxsw_core_port_init);
 
 void mlxsw_core_port_fini(struct mlxsw_core *mlxsw_core, u8 local_port)
 {
+	atomic_dec(&mlxsw_core->active_ports_count);
+
 	__mlxsw_core_port_fini(mlxsw_core, local_port);
 }
 EXPORT_SYMBOL(mlxsw_core_port_fini);

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

@@ -19,6 +19,11 @@
 #include "cmd.h"
 #include "resources.h"
 
+enum mlxsw_core_resource_id {
+	MLXSW_CORE_RESOURCE_PORTS = 1,
+	MLXSW_CORE_RESOURCE_MAX,
+};
+
 struct mlxsw_core;
 struct mlxsw_core_port;
 struct mlxsw_driver;

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

@@ -52,7 +52,7 @@
 #define MLXSW_SP_RESOURCE_NAME_COUNTERS_RIF "rif"
 
 enum mlxsw_sp_resource_id {
-	MLXSW_SP_RESOURCE_KVD = 1,
+	MLXSW_SP_RESOURCE_KVD = MLXSW_CORE_RESOURCE_MAX,
 	MLXSW_SP_RESOURCE_KVD_LINEAR,
 	MLXSW_SP_RESOURCE_KVD_HASH_SINGLE,
 	MLXSW_SP_RESOURCE_KVD_HASH_DOUBLE,

include/net/devlink.h

@@ -380,6 +380,8 @@ struct devlink_resource {
 
 #define DEVLINK_RESOURCE_ID_PARENT_TOP 0
 
+#define DEVLINK_RESOURCE_GENERIC_NAME_PORTS "physical_ports"
+
 #define __DEVLINK_PARAM_MAX_STRING_VALUE 32
 enum devlink_param_type {
 	DEVLINK_PARAM_TYPE_U8,

net/core/devlink.c

@@ -8617,6 +8617,10 @@ EXPORT_SYMBOL_GPL(devlink_dpipe_table_unregister);
  *	@resource_id: resource's id
  *	@parent_resource_id: resource's parent id
  *	@size_params: size parameters
+ *
+ *	Generic resources should reuse the same names across drivers.
+ *	Please see the generic resources list at:
+ *	Documentation/networking/devlink/devlink-resource.rst
  */
 int devlink_resource_register(struct devlink *devlink,
 			      const char *resource_name,

tools/testing/selftests/drivers/net/mlxsw/port_scale.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test for physical ports resource. The test splits each splittable port
+# to its width and checks that eventually the number of physical ports equals
+# the maximum number of physical ports.
+
+PORT_NUM_NETIFS=0
+
+port_setup_prepare()
+{
+	:
+}
+
+port_cleanup()
+{
+	pre_cleanup
+
+	for port in "${unsplit[@]}"; do
+		devlink port unsplit $port
+		check_err $? "Did not unsplit $netdev"
+	done
+}
+
+split_all_ports()
+{
+	local should_fail=$1; shift
+	local -a unsplit
+
+	# Loop over the splittable netdevs and create tuples of netdev along
+	# with its width. For example:
+	# '$netdev1 $count1 $netdev2 $count2...', when:
+	# $netdev1-2 are splittable netdevs in the device, and
+	# $count1-2 are the netdevs width respectively.
+	while read netdev count <<<$(
+		devlink -j port show |
+		jq -r '.[][] | select(.splittable==true) | "\(.netdev) \(.lanes)"'
+		)
+		[[ ! -z $netdev ]]
+	do
+		devlink port split $netdev count $count
+		check_err $? "Did not split $netdev into $count"
+		unsplit+=( "${netdev}s0" )
+	done
+}
+
+port_test()
+{
+	local max_ports=$1; shift
+	local should_fail=$1; shift
+
+	split_all_ports $should_fail
+
+	occ=$(devlink -j resource show $DEVLINK_DEV \
+	      | jq '.[][][] | select(.name=="physical_ports") |.["occ"]')
+
+	[[ $occ -eq $max_ports ]]
+	if [[ $should_fail -eq 0 ]]; then
+		check_err $? "Mismatch ports number: Expected $max_ports, got $occ."
+	else
+		check_err_fail $should_fail $? "Reached more ports than expected"
+	fi
+
+}

tools/testing/selftests/drivers/net/mlxsw/spectrum-2/port_scale.sh

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+source ../port_scale.sh
+
+port_get_target()
+{
+	local should_fail=$1
+	local target
+
+	target=$(devlink_resource_size_get physical_ports)
+
+	if ((! should_fail)); then
+		echo $target
+	else
+		echo $((target + 1))
+	fi
+}

tools/testing/selftests/drivers/net/mlxsw/spectrum-2/resource_scale.sh

@@ -28,7 +28,7 @@ cleanup()
 
 trap cleanup EXIT
 
-ALL_TESTS="router tc_flower mirror_gre tc_police"
+ALL_TESTS="router tc_flower mirror_gre tc_police port"
 for current_test in ${TESTS:-$ALL_TESTS}; do
 	source ${current_test}_scale.sh
 

tools/testing/selftests/drivers/net/mlxsw/spectrum/port_scale.sh

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+source ../port_scale.sh
+
+port_get_target()
+{
+	local should_fail=$1
+	local target
+
+	target=$(devlink_resource_size_get physical_ports)
+
+	if ((! should_fail)); then
+		echo $target
+	else
+		echo $((target + 1))
+	fi
+}

tools/testing/selftests/drivers/net/mlxsw/spectrum/resource_scale.sh

@@ -22,7 +22,7 @@ cleanup()
 devlink_sp_read_kvd_defaults
 trap cleanup EXIT
 
-ALL_TESTS="router tc_flower mirror_gre tc_police"
+ALL_TESTS="router tc_flower mirror_gre tc_police port"
 for current_test in ${TESTS:-$ALL_TESTS}; do
 	source ${current_test}_scale.sh