.. SPDX-License-Identifier: GPL-2.0 ==============Devlink Params============== ``devlink`` provides capability for a driver to expose device parameters for lowlevel device functionality. Since devlink can operate at the device-widelevel, it can be used to provide configuration that may affect multipleports on a single device. This document describes a number of generic parameters that are supportedacross multiple drivers. Each driver is also free to add their ownparameters. Each driver must document the specific parameters they support,whether generic or not. Configuration modes=================== Parameters may be set in different configuration modes. .. list-table:: Possible configuration modes   :widths: 5 90    * - Name     - Description   * - ``runtime``     - set while the driver is running, and takes effect immediately. No       reset is required.   * - ``driverinit``     - applied while the driver initializes. Requires the user to restart       the driver using the ``devlink`` reload command.   * - ``permanent``     - written to the device's non-volatile memory. A hard reset is required       for it to take effect. Reloading--------- In order for ``driverinit`` parameters to take effect, the driver mustsupport reloading via the ``devlink-reload`` command. This command willrequest a reload of the device driver. .. _devlink_params_generic: Generic configuration parameters================================The following is a list of generic configuration parameters that drivers mayadd. Use of generic parameters is preferred over each driver creating theirown name. .. list-table:: List of generic parameters   :widths: 5 5 90    * - Name     - Type     - Description   * - ``enable_sriov``     - Boolean     - Enable Single Root I/O Virtualization (SRIOV) in the device.   * - ``ignore_ari``     - Boolean     - Ignore Alternative Routing-ID Interpretation (ARI) capability. If       enabled, the adapter will ignore ARI capability even when the       platform has support enabled. The device will create the same number       of partitions as when the platform does not support ARI.   * - ``msix_vec_per_pf_max``     - u32     - Provides the maximum number of MSI-X interrupts that a device can       create. Value is the same across all physical functions (PFs) in the       device.   * - ``msix_vec_per_pf_min``     - u32     - Provides the minimum number of MSI-X interrupts required for the       device to initialize. Value is the same across all physical functions       (PFs) in the device.   * - ``fw_load_policy``     - u8     - Control the device's firmware loading policy.        - ``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.        - ``DEVLINK_PARAM_FW_LOAD_POLICY_VALUE_DISK`` (2)          Load firmware currently available on host's disk.   * - ``reset_dev_on_drv_probe``     - u8     - Controls the device's reset policy on driver probe.        - ``DEVLINK_PARAM_RESET_DEV_ON_DRV_PROBE_VALUE_UNKNOWN`` (0)          Unknown or invalid value.        - ``DEVLINK_PARAM_RESET_DEV_ON_DRV_PROBE_VALUE_ALWAYS`` (1)          Always reset device on driver probe.        - ``DEVLINK_PARAM_RESET_DEV_ON_DRV_PROBE_VALUE_NEVER`` (2)          Never reset device on driver probe.        - ``DEVLINK_PARAM_RESET_DEV_ON_DRV_PROBE_VALUE_DISK`` (3)          Reset the device only if firmware can be found in the filesystem.   * - ``enable_roce``     - Boolean     - Enable handling of RoCE traffic in the device.   * - ``enable_eth``     - Boolean     - When enabled, the device driver will instantiate Ethernet specific       auxiliary device of the devlink device.   * - ``enable_rdma``     - Boolean     - When enabled, the device driver will instantiate RDMA specific       auxiliary device of the devlink device.   * - ``enable_vnet``     - Boolean     - When enabled, the device driver will instantiate VDPA networking       specific auxiliary device of the devlink device.   * - ``enable_iwarp``     - Boolean     - Enable handling of iWARP traffic in the device.   * - ``internal_err_reset``     - Boolean     - When enabled, the device driver will reset the device on internal       errors.   * - ``max_macs``     - u32     - Typically macvlan, vlan net devices mac are also programmed in their       parent netdevice's Function rx filter. This parameter limit the       maximum number of unicast mac address filters to receive traffic from       per ethernet port of this device.   * - ``region_snapshot_enable``     - Boolean     - Enable capture of ``devlink-region`` snapshots.   * - ``enable_remote_dev_reset``     - Boolean     - Enable device reset by remote host. When cleared, the device driver       will NACK any attempt of other host to reset the device. This parameter       is useful for setups where a device is shared by different hosts, such       as multi-host setup.   * - ``io_eq_size``     - u32     - Control the size of I/O completion EQs.   * - ``event_eq_size``     - u32     - Control the size of asynchronous control events EQ.   * - ``enable_phc``     - Boolean     - Enable PHC (PTP Hardware Clock) functionality in the device.   * - ``clock_id``     - u64     - Clock ID used by the device for registering DPLL devices and pins.   * - ``total_vfs``     - u32     - The max number of Virtual Functions (VFs) exposed by the PF.       after reboot/pci reset, 'sriov_totalvfs' entry under the device's sysfs       directory will report this value.   * - ``num_doorbells``     - u32     - Controls the number of doorbells used by the device.