1.. SPDX-License-Identifier: GPL-2.0 2 3================= 4Devlink Line card 5================= 6 7Background 8========== 9 10The ``devlink-linecard`` mechanism is targeted for manipulation of 11line cards that serve as a detachable PHY modules for modular switch 12system. Following operations are provided: 13 14 * Get a list of supported line card types. 15 * Provision of a slot with specific line card type. 16 * Get and monitor of line card state and its change. 17 * Get information about line card versions and devices. 18 19Line card according to the type may contain one or more gearboxes 20to mux the lanes with certain speed to multiple ports with lanes 21of different speed. Line card ensures N:M mapping between 22the switch ASIC modules and physical front panel ports. 23 24Overview 25======== 26 27Each line card devlink object is created by device driver, 28according to the physical line card slots available on the device. 29 30Similar to splitter cable, where the device might have no way 31of detection of the splitter cable geometry, the device 32might not have a way to detect line card type. For that devices, 33concept of provisioning is introduced. It allows the user to: 34 35 * Provision a line card slot with certain line card type 36 37 - Device driver would instruct the ASIC to prepare all 38 resources accordingly. The device driver would 39 create all instances, namely devlink port and netdevices 40 that reside on the line card, according to the line card type 41 * Manipulate of line card entities even without line card 42 being physically connected or powered-up 43 * Setup splitter cable on line card ports 44 45 - As on the ordinary ports, user may provision a splitter 46 cable of a certain type, without the need to 47 be physically connected to the port 48 * Configure devlink ports and netdevices 49 50Netdevice carrier is decided as follows: 51 52 * Line card is not inserted or powered-down 53 54 - The carrier is always down 55 * Line card is inserted and powered up 56 57 - The carrier is decided as for ordinary port netdevice 58 59Line card state 60=============== 61 62The ``devlink-linecard`` mechanism supports the following line card states: 63 64 * ``unprovisioned``: Line card is not provisioned on the slot. 65 * ``unprovisioning``: Line card slot is currently being unprovisioned. 66 * ``provisioning``: Line card slot is currently in a process of being provisioned 67 with a line card type. 68 * ``provisioning_failed``: Provisioning was not successful. 69 * ``provisioned``: Line card slot is provisioned with a type. 70 * ``active``: Line card is powered-up and active. 71 72The following diagram provides a general overview of ``devlink-linecard`` 73state transitions:: 74 75 +-------------------------+ 76 | | 77 +----------------------------------> unprovisioned | 78 | | | 79 | +--------|-------^--------+ 80 | | | 81 | | | 82 | +--------v-------|--------+ 83 | | | 84 | | provisioning | 85 | | | 86 | +------------|------------+ 87 | | 88 | +-----------------------------+ 89 | | | 90 | +------------v------------+ +------------v------------+ +-------------------------+ 91 | | | | ----> | 92 +----- provisioning_failed | | provisioned | | active | 93 | | | | <---- | 94 | +------------^------------+ +------------|------------+ +-------------------------+ 95 | | | 96 | | | 97 | | +------------v------------+ 98 | | | | 99 | | | unprovisioning | 100 | | | | 101 | | +------------|------------+ 102 | | | 103 | +-----------------------------+ 104 | | 105 +-----------------------------------------------+ 106 107 108Example usage 109============= 110 111.. code:: shell 112 113 $ devlink lc show [ DEV [ lc LC_INDEX ] ] 114 $ devlink lc set DEV lc LC_INDEX [ { type LC_TYPE | notype } ] 115 116 # Show current line card configuration and status for all slots: 117 $ devlink lc 118 119 # Set slot 8 to be provisioned with type "16x100G": 120 $ devlink lc set pci/0000:01:00.0 lc 8 type 16x100G 121 122 # Set slot 8 to be unprovisioned: 123 $ devlink lc set pci/0000:01:00.0 lc 8 notype 124 125 # Set info for slot 8: 126 $ devlink lc info pci/0000:01:00.0 lc 8 127