forked from Minki/linux
c4a67a21a6
This reverts commit5e927a9f4b, reversing changes made tocfc1d91a7d. The discussion is still ongoing so let's remove the uAPI until the discussion settles. Link: https://lore.kernel.org/all/20220425090021.32e9a98f@kernel.org/ Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20220504154037.539442-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
123 lines
5.1 KiB
ReStructuredText
123 lines
5.1 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
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=================
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Devlink Line card
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=================
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Background
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==========
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The ``devlink-linecard`` mechanism is targeted for manipulation of
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line cards that serve as a detachable PHY modules for modular switch
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system. Following operations are provided:
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* Get a list of supported line card types.
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* Provision of a slot with specific line card type.
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* Get and monitor of line card state and its change.
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Line card according to the type may contain one or more gearboxes
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to mux the lanes with certain speed to multiple ports with lanes
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of different speed. Line card ensures N:M mapping between
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the switch ASIC modules and physical front panel ports.
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Overview
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========
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Each line card devlink object is created by device driver,
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according to the physical line card slots available on the device.
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Similar to splitter cable, where the device might have no way
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of detection of the splitter cable geometry, the device
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might not have a way to detect line card type. For that devices,
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concept of provisioning is introduced. It allows the user to:
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* Provision a line card slot with certain line card type
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- Device driver would instruct the ASIC to prepare all
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resources accordingly. The device driver would
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create all instances, namely devlink port and netdevices
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that reside on the line card, according to the line card type
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* Manipulate of line card entities even without line card
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being physically connected or powered-up
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* Setup splitter cable on line card ports
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- As on the ordinary ports, user may provision a splitter
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cable of a certain type, without the need to
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be physically connected to the port
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* Configure devlink ports and netdevices
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Netdevice carrier is decided as follows:
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* Line card is not inserted or powered-down
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- The carrier is always down
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* Line card is inserted and powered up
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- The carrier is decided as for ordinary port netdevice
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Line card state
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===============
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The ``devlink-linecard`` mechanism supports the following line card states:
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* ``unprovisioned``: Line card is not provisioned on the slot.
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* ``unprovisioning``: Line card slot is currently being unprovisioned.
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* ``provisioning``: Line card slot is currently in a process of being provisioned
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with a line card type.
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* ``provisioning_failed``: Provisioning was not successful.
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* ``provisioned``: Line card slot is provisioned with a type.
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* ``active``: Line card is powered-up and active.
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The following diagram provides a general overview of ``devlink-linecard``
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state transitions::
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+-------------------------+
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+----------------------------------> unprovisioned |
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| +--------|-------^--------+
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| +--------v-------|--------+
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| | provisioning |
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| +------------|------------+
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| +-----------------------------+
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| +------------v------------+ +------------v------------+ +-------------------------+
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| | | | ----> |
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+----- provisioning_failed | | provisioned | | active |
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| | | | <---- |
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| +------------^------------+ +------------|------------+ +-------------------------+
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| | +------------v------------+
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| | | unprovisioning |
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| | +------------|------------+
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| +-----------------------------+
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+-----------------------------------------------+
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Example usage
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=============
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.. code:: shell
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$ devlink lc show [ DEV [ lc LC_INDEX ] ]
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$ devlink lc set DEV lc LC_INDEX [ { type LC_TYPE | notype } ]
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# Show current line card configuration and status for all slots:
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$ devlink lc
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# Set slot 8 to be provisioned with type "16x100G":
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$ devlink lc set pci/0000:01:00.0 lc 8 type 16x100G
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# Set slot 8 to be unprovisioned:
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$ devlink lc set pci/0000:01:00.0 lc 8 notype
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