Merge branch 'mlxsw-fw_load_policy'

Ido Schimmel says:

====================
mlxsw: Add 'fw_load_policy' devlink parameter

Shalom says:

Currently, drivers do not have the ability to control the firmware
loading policy and they always use their own fixed policy. This prevents
drivers from running the device with a different firmware version for
testing and/or debugging purposes. For example, testing a firmware bug
fix.

For these situations, the new devlink generic parameter,
'fw_load_policy', gives the ability to control this option and allows
drivers to run with a different firmware version than required by the
driver.

Patch #1 adds the new parameter to devlink. The other two patches, #2
and #3, add support for this parameter in the mlxsw driver.

Example:
  # Query the devlink parameters supported by the device
    $ devlink dev param show
    pci/0000:03:00.0:
      name fw_load_policy type generic
        values:
          cmode driverinit value driver

  # Flash new firmware using ethtool
    $ ethtool -f swp1 mellanox/mlxsw_spectrum-13.1703.4.mfa2

  # Toggle parameter
    $ devlink dev param set pci/0000:03:00.0 name fw_load_policy value flash cmode driverinit

  # devlink reset
    $ devlink dev reload pci/0000:03:00.0

  # Query firmware version to show changes took affect
    $ ethtool -i swp1
    driver: mlxsw_spectrum
    version: 1.0
    firmware-version: 13.1703.4
    expansion-rom-version:
    bus-info: 0000:03:00.0
    supports-statistics: yes
    supports-test: no
    supports-eeprom-access: no
    supports-register-dump: no
    supports-priv-flags: no

iproute2 patches available here:
https://github.com/tshalom/iproute2-next

v2:
* Change 'fw_version_check' to 'fw_load_policy' with values 'driver' and
  'flash' (Jakub)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink-params.txt

@@ -40,3 +40,12 @@ msix_vec_per_pf_min	[DEVICE, GENERIC]
 			for the device initialization. Value is same across all
 			physical functions (PFs) in the device.
 			Type: u32
+
+fw_load_policy		[DEVICE, GENERIC]
+			Controls the device's firmware loading policy.
+			Valid values:
+			* DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_DRIVER (0)
+			  Load firmware version preferred by the driver.
+			* DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_FLASH (1)
+			  Load firmware currently stored in flash.
+			Type: u8

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

@@ -965,7 +965,8 @@ static const struct devlink_ops mlxsw_devlink_ops = {
 	.sb_occ_tc_port_bind_get	= mlxsw_devlink_sb_occ_tc_port_bind_get,
 };
 
-int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
+static int
+__mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 				 const struct mlxsw_bus *mlxsw_bus,
 				 void *bus_priv, bool reload,
 				 struct devlink *devlink)
@@ -1035,6 +1036,12 @@ int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 			goto err_devlink_register;
 	}
 
+	if (mlxsw_driver->params_register && !reload) {
+		err = mlxsw_driver->params_register(mlxsw_core);
+		if (err)
+			goto err_register_params;
+	}
+
 	err = mlxsw_hwmon_init(mlxsw_core, mlxsw_bus_info, &mlxsw_core->hwmon);
 	if (err)
 		goto err_hwmon_init;
@@ -1057,6 +1064,9 @@ int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 err_thermal_init:
 	mlxsw_hwmon_fini(mlxsw_core->hwmon);
 err_hwmon_init:
+	if (mlxsw_driver->params_unregister && !reload)
+		mlxsw_driver->params_unregister(mlxsw_core);
+err_register_params:
 	if (!reload)
 		devlink_unregister(devlink);
 err_devlink_register:
@@ -1076,6 +1086,29 @@ int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 err_devlink_alloc:
 	return err;
 }
+
+int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
+				   const struct mlxsw_bus *mlxsw_bus,
+				   void *bus_priv, bool reload,
+				   struct devlink *devlink)
+{
+	bool called_again = false;
+	int err;
+
+again:
+	err = __mlxsw_core_bus_device_register(mlxsw_bus_info, mlxsw_bus,
+					       bus_priv, reload, devlink);
+	/* -EAGAIN is returned in case the FW was updated. FW needs
+	 * a reset, so lets try to call __mlxsw_core_bus_device_register()
+	 * again.
+	 */
+	if (err == -EAGAIN && !called_again) {
+		called_again = true;
+		goto again;
+	}
+
+	return err;
+}
 EXPORT_SYMBOL(mlxsw_core_bus_device_register);
 
 void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core,
@@ -1097,6 +1130,8 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core,
 		mlxsw_core->driver->fini(mlxsw_core);
 	mlxsw_thermal_fini(mlxsw_core->thermal);
 	mlxsw_hwmon_fini(mlxsw_core->hwmon);
+	if (mlxsw_core->driver->params_unregister && !reload)
+		mlxsw_core->driver->params_unregister(mlxsw_core);
 	if (!reload)
 		devlink_unregister(devlink);
 	mlxsw_emad_fini(mlxsw_core);
@@ -1109,6 +1144,8 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core,
 	return;
 
 reload_fail_deinit:
+	if (mlxsw_core->driver->params_unregister)
+		mlxsw_core->driver->params_unregister(mlxsw_core);
 	devlink_unregister(devlink);
 	devlink_resources_unregister(devlink, NULL);
 	devlink_free(devlink);

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

@@ -282,6 +282,8 @@ struct mlxsw_driver {
 			     const struct mlxsw_config_profile *profile,
 			     u64 *p_single_size, u64 *p_double_size,
 			     u64 *p_linear_size);
+	int (*params_register)(struct mlxsw_core *mlxsw_core);
+	void (*params_unregister)(struct mlxsw_core *mlxsw_core);
 	u8 txhdr_len;
 	const struct mlxsw_config_profile *profile;
 	bool res_query_enabled;

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

@@ -1720,7 +1720,6 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	const char *driver_name = pdev->driver->name;
 	struct mlxsw_pci *mlxsw_pci;
-	bool called_again = false;
 	int err;
 
 	mlxsw_pci = kzalloc(sizeof(*mlxsw_pci), GFP_KERNEL);
@@ -1777,18 +1776,10 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	mlxsw_pci->bus_info.dev = &pdev->dev;
 	mlxsw_pci->id = id;
 
-again:
 	err = mlxsw_core_bus_device_register(&mlxsw_pci->bus_info,
 					     &mlxsw_pci_bus, mlxsw_pci, false,
 					     NULL);
-	/* -EAGAIN is returned in case the FW was updated. FW needs
-	 * a reset, so lets try to call mlxsw_core_bus_device_register()
-	 * again.
-	 */
-	if (err == -EAGAIN && !called_again) {
-		called_again = true;
-		goto again;
-	} else if (err) {
+	if (err) {
 		dev_err(&pdev->dev, "cannot register bus device\n");
 		goto err_bus_device_register;
 	}

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

@@ -318,6 +318,7 @@ static int mlxsw_sp_fw_rev_validate(struct mlxsw_sp *mlxsw_sp)
 	const struct mlxsw_fw_rev *rev = &mlxsw_sp->bus_info->fw_rev;
 	const struct mlxsw_fw_rev *req_rev = mlxsw_sp->req_rev;
 	const char *fw_filename = mlxsw_sp->fw_filename;
+	union devlink_param_value value;
 	const struct firmware *firmware;
 	int err;
 
@@ -325,6 +326,15 @@ static int mlxsw_sp_fw_rev_validate(struct mlxsw_sp *mlxsw_sp)
 	if (!req_rev || !fw_filename)
 		return 0;
 
+	/* Don't check if devlink 'fw_load_policy' param is 'flash' */
+	err = devlink_param_driverinit_value_get(priv_to_devlink(mlxsw_sp->core),
+						 DEVLINK_PARAM_GENERIC_ID_FW_LOAD_POLICY,
+						 &value);
+	if (err)
+		return err;
+	if (value.vu8 == DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_FLASH)
+		return 0;
+
 	/* Validate driver & FW are compatible */
 	if (rev->major != req_rev->major) {
 		WARN(1, "Mismatch in major FW version [%d:%d] is never expected; Please contact support\n",
@@ -4328,6 +4338,52 @@ static int mlxsw_sp_kvd_sizes_get(struct mlxsw_core *mlxsw_core,
 	return 0;
 }
 
+static int
+mlxsw_sp_devlink_param_fw_load_policy_validate(struct devlink *devlink, u32 id,
+					       union devlink_param_value val,
+					       struct netlink_ext_ack *extack)
+{
+	if ((val.vu8 != DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_DRIVER) &&
+	    (val.vu8 != DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_FLASH)) {
+		NL_SET_ERR_MSG_MOD(extack, "'fw_load_policy' must be 'driver' or 'flash'");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct devlink_param mlxsw_sp_devlink_params[] = {
+	DEVLINK_PARAM_GENERIC(FW_LOAD_POLICY,
+			      BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
+			      NULL, NULL,
+			      mlxsw_sp_devlink_param_fw_load_policy_validate),
+};
+
+static int mlxsw_sp_params_register(struct mlxsw_core *mlxsw_core)
+{
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
+	union devlink_param_value value;
+	int err;
+
+	err = devlink_params_register(devlink, mlxsw_sp_devlink_params,
+				      ARRAY_SIZE(mlxsw_sp_devlink_params));
+	if (err)
+		return err;
+
+	value.vu8 = DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_DRIVER;
+	devlink_param_driverinit_value_set(devlink,
+					   DEVLINK_PARAM_GENERIC_ID_FW_LOAD_POLICY,
+					   value);
+	return 0;
+}
+
+static void mlxsw_sp_params_unregister(struct mlxsw_core *mlxsw_core)
+{
+	devlink_params_unregister(priv_to_devlink(mlxsw_core),
+				  mlxsw_sp_devlink_params,
+				  ARRAY_SIZE(mlxsw_sp_devlink_params));
+}
+
 static struct mlxsw_driver mlxsw_sp1_driver = {
 	.kind				= mlxsw_sp1_driver_name,
 	.priv_size			= sizeof(struct mlxsw_sp),
@@ -4349,6 +4405,8 @@ static struct mlxsw_driver mlxsw_sp1_driver = {
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp1_resources_register,
 	.kvd_sizes_get			= mlxsw_sp_kvd_sizes_get,
+	.params_register		= mlxsw_sp_params_register,
+	.params_unregister		= mlxsw_sp_params_unregister,
 	.txhdr_len			= MLXSW_TXHDR_LEN,
 	.profile			= &mlxsw_sp1_config_profile,
 	.res_query_enabled		= true,
@@ -4374,6 +4432,8 @@ static struct mlxsw_driver mlxsw_sp2_driver = {
 	.sb_occ_tc_port_bind_get	= mlxsw_sp_sb_occ_tc_port_bind_get,
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp2_resources_register,
+	.params_register		= mlxsw_sp_params_register,
+	.params_unregister		= mlxsw_sp_params_unregister,
 	.txhdr_len			= MLXSW_TXHDR_LEN,
 	.profile			= &mlxsw_sp2_config_profile,
 	.res_query_enabled		= true,

include/net/devlink.h

@@ -365,6 +365,7 @@ enum devlink_param_generic_id {
 	DEVLINK_PARAM_GENERIC_ID_IGNORE_ARI,
 	DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MAX,
 	DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MIN,
+	DEVLINK_PARAM_GENERIC_ID_FW_LOAD_POLICY,
 
 	/* add new param generic ids above here*/
 	__DEVLINK_PARAM_GENERIC_ID_MAX,
@@ -392,6 +393,9 @@ enum devlink_param_generic_id {
 #define DEVLINK_PARAM_GENERIC_MSIX_VEC_PER_PF_MIN_NAME "msix_vec_per_pf_min"
 #define DEVLINK_PARAM_GENERIC_MSIX_VEC_PER_PF_MIN_TYPE DEVLINK_PARAM_TYPE_U32
 
+#define DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_NAME "fw_load_policy"
+#define DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_TYPE DEVLINK_PARAM_TYPE_U8
+
 #define DEVLINK_PARAM_GENERIC(_id, _cmodes, _get, _set, _validate)	\
 {									\
 	.id = DEVLINK_PARAM_GENERIC_ID_##_id,				\

include/uapi/linux/devlink.h

@@ -163,6 +163,11 @@ enum devlink_param_cmode {
 	DEVLINK_PARAM_CMODE_MAX = __DEVLINK_PARAM_CMODE_MAX - 1
 };
 
+enum devlink_param_fw_load_policy_value {
+	DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_DRIVER,
+	DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_FLASH,
+};
+
 enum devlink_attr {
 	/* don't change the order or add anything between, this is ABI! */
 	DEVLINK_ATTR_UNSPEC,

net/core/devlink.c

@@ -2692,6 +2692,11 @@ static const struct devlink_param devlink_param_generic[] = {
 		.name = DEVLINK_PARAM_GENERIC_MSIX_VEC_PER_PF_MIN_NAME,
 		.type = DEVLINK_PARAM_GENERIC_MSIX_VEC_PER_PF_MIN_TYPE,
 	},
+	{
+		.id = DEVLINK_PARAM_GENERIC_ID_FW_LOAD_POLICY,
+		.name = DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_NAME,
+		.type = DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_TYPE,
+	},
 };
 
 static int devlink_param_generic_verify(const struct devlink_param *param)