1.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2 3============ 4Devlink Info 5============ 6 7The ``devlink-info`` mechanism enables device drivers to report device 8(hardware and firmware) information in a standard, extensible fashion. 9 10The original motivation for the ``devlink-info`` API was twofold: 11 12 - making it possible to automate device and firmware management in a fleet 13 of machines in a vendor-independent fashion (see also 14 :ref:`Documentation/networking/devlink/devlink-flash.rst <devlink_flash>`); 15 - name the per component FW versions (as opposed to the crowded ethtool 16 version string). 17 18``devlink-info`` supports reporting multiple types of objects. Reporting driver 19versions is generally discouraged - here, and via any other Linux API. 20 21.. list-table:: List of top level info objects 22 :widths: 5 95 23 24 * - Name 25 - Description 26 * - ``driver`` 27 - Name of the currently used device driver, also available through sysfs. 28 29 * - ``serial_number`` 30 - Serial number of the device. 31 32 This is usually the serial number of the ASIC, also often available 33 in PCI config space of the device in the *Device Serial Number* 34 capability. 35 36 The serial number should be unique per physical device. 37 Sometimes the serial number of the device is only 48 bits long (the 38 length of the Ethernet MAC address), and since PCI DSN is 64 bits long 39 devices pad or encode additional information into the serial number. 40 One example is adding port ID or PCI interface ID in the extra two bytes. 41 Drivers should make sure to strip or normalize any such padding 42 or interface ID, and report only the part of the serial number 43 which uniquely identifies the hardware. In other words serial number 44 reported for two ports of the same device or on two hosts of 45 a multi-host device should be identical. 46 47 * - ``board.serial_number`` 48 - Board serial number of the device. 49 50 This is usually the serial number of the board, often available in 51 PCI *Vital Product Data*. 52 53 * - ``fixed`` 54 - Group for hardware identifiers, and versions of components 55 which are not field-updatable. 56 57 Versions in this section identify the device design. For example, 58 component identifiers or the board version reported in the PCI VPD. 59 Data in ``devlink-info`` should be broken into the smallest logical 60 components, e.g. PCI VPD may concatenate various information 61 to form the Part Number string, while in ``devlink-info`` all parts 62 should be reported as separate items. 63 64 This group must not contain any frequently changing identifiers, 65 such as serial numbers. See 66 :ref:`Documentation/networking/devlink/devlink-flash.rst <devlink_flash>` 67 to understand why. 68 69 * - ``running`` 70 - Group for information about currently running software/firmware. 71 These versions often only update after a reboot, sometimes device reset. 72 73 * - ``stored`` 74 - Group for software/firmware versions in device flash. 75 76 Stored values must update to reflect changes in the flash even 77 if reboot has not yet occurred. If device is not capable of updating 78 ``stored`` versions when new software is flashed, it must not report 79 them. 80 81Each version can be reported at most once in each version group. Firmware 82components stored on the flash should feature in both the ``running`` and 83``stored`` sections, if device is capable of reporting ``stored`` versions 84(see :ref:`Documentation/networking/devlink/devlink-flash.rst <devlink_flash>`). 85In case software/firmware components are loaded from the disk (e.g. 86``/lib/firmware``) only the running version should be reported via 87the kernel API. 88 89Generic Versions 90================ 91 92It is expected that drivers use the following generic names for exporting 93version information. If a generic name for a given component doesn't exist yet, 94driver authors should consult existing driver-specific versions and attempt 95reuse. As last resort, if a component is truly unique, using driver-specific 96names is allowed, but these should be documented in the driver-specific file. 97 98All versions should try to use the following terminology: 99 100.. list-table:: List of common version suffixes 101 :widths: 10 90 102 103 * - Name 104 - Description 105 * - ``id``, ``revision`` 106 - Identifiers of designs and revision, mostly used for hardware versions. 107 108 * - ``api`` 109 - Version of API between components. API items are usually of limited 110 value to the user, and can be inferred from other versions by the vendor, 111 so adding API versions is generally discouraged as noise. 112 113 * - ``bundle_id`` 114 - Identifier of a distribution package which was flashed onto the device. 115 This is an attribute of a firmware package which covers multiple versions 116 for ease of managing firmware images (see 117 :ref:`Documentation/networking/devlink/devlink-flash.rst <devlink_flash>`). 118 119 ``bundle_id`` can appear in both ``running`` and ``stored`` versions, 120 but it must not be reported if any of the components covered by the 121 ``bundle_id`` was changed and no longer matches the version from 122 the bundle. 123 124board.id 125-------- 126 127Unique identifier of the board design. 128 129board.rev 130--------- 131 132Board design revision. 133 134asic.id 135------- 136 137ASIC design identifier. 138 139asic.rev 140-------- 141 142ASIC design revision/stepping. 143 144board.manufacture 145----------------- 146 147An identifier of the company or the facility which produced the part. 148 149fw 150-- 151 152Overall firmware version, often representing the collection of 153fw.mgmt, fw.app, etc. 154 155fw.mgmt 156------- 157 158Control unit firmware version. This firmware is responsible for house 159keeping tasks, PHY control etc. but not the packet-by-packet data path 160operation. 161 162fw.mgmt.api 163----------- 164 165Firmware interface specification version of the software interfaces between 166driver and firmware. 167 168fw.app 169------ 170 171Data path microcode controlling high-speed packet processing. 172 173fw.undi 174------- 175 176UNDI software, may include the UEFI driver, firmware or both. 177 178fw.ncsi 179------- 180 181Version of the software responsible for supporting/handling the 182Network Controller Sideband Interface. 183 184fw.psid 185------- 186 187Unique identifier of the firmware parameter set. These are usually 188parameters of a particular board, defined at manufacturing time. 189 190fw.roce 191------- 192 193RoCE firmware version which is responsible for handling roce 194management. 195 196fw.bundle_id 197------------ 198 199Unique identifier of the entire firmware bundle. 200 201fw.bootloader 202------------- 203 204Version of the bootloader. 205 206Future work 207=========== 208 209The following extensions could be useful: 210 211 - on-disk firmware file names - drivers list the file names of firmware they 212 may need to load onto devices via the ``MODULE_FIRMWARE()`` macro. These, 213 however, are per module, rather than per device. It'd be useful to list 214 the names of firmware files the driver will try to load for a given device, 215 in order of priority. 216