[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <BY5PR12MB43222477EECDCC3D90FD6A84DCF20@BY5PR12MB4322.namprd12.prod.outlook.com>
Date: Thu, 3 Dec 2020 05:06:50 +0000
From: Parav Pandit <parav@...dia.com>
To: Randy Dunlap <rdunlap@...radead.org>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
"davem@...emloft.net" <davem@...emloft.net>,
"kuba@...nel.org" <kuba@...nel.org>
CC: "jacob.e.keller@...el.com" <jacob.e.keller@...el.com>,
Jiri Pirko <jiri@...dia.com>
Subject: RE: [PATCH net-next v3] devlink: Add devlink port documentation
> From: Randy Dunlap <rdunlap@...radead.org>
> Sent: Thursday, December 3, 2020 7:57 AM
>
> Hi--
>
> On 12/2/20 5:53 AM, Parav Pandit wrote:
> > Added documentation for devlink port and port function related commands.
> >
> > Signed-off-by: Parav Pandit <parav@...dia.com>
> > Reviewed-by: Jiri Pirko <jiri@...dia.com>
> > Reviewed-by: Jacob Keller <jacob.e.keller@...el.com>
> > ---
> > Changelog:
> > v2->v3:
> > - rephased many lines
>
> rephrased
>
> > - first paragraph now describe devlink port
> > - instead of saying PCI device/function, using PCI function every
> > where
> > - changed 'physical link layer' to 'link layer'
> > - made devlink port type description more clear
> > - made devlink port flavour description more clear
> > - moved devlink port type table after port flavour
> > - added description for the example diagram
> > - describe CPU port that its linked to DSA
> > - made devlink port description for eswitch port more clear
> > v1->v2:
> > - Removed duplicate table entries for DEVLINK_PORT_FLAVOUR_VIRTUAL.
> > - replaced 'consist of' to 'consisting'
> > - changed 'can be' to 'can be of'
> > ---
> > .../networking/devlink/devlink-port.rst | 111 ++++++++++++++++++
> > Documentation/networking/devlink/index.rst | 1 +
> > 2 files changed, 112 insertions(+)
> > create mode 100644 Documentation/networking/devlink/devlink-port.rst
> >
> > diff --git a/Documentation/networking/devlink/devlink-port.rst
> > b/Documentation/networking/devlink/devlink-port.rst
> > new file mode 100644
> > index 000000000000..8407bbe9ce88
> > --- /dev/null
> > +++ b/Documentation/networking/devlink/devlink-port.rst
> > @@ -0,0 +1,111 @@
> > +.. SPDX-License-Identifier: GPL-2.0
> > +
> > +============
> > +Devlink Port
> > +============
> > +
> > +``devlink-port`` is a port that exist on the device. A devlink port
> > +can
>
> exists
>
> > +be of one among many flavours. A devlink port flavour along with port
> > +attributes describe what a port represents.
> > +
> > +A device driver who intents to publish a devlink port, sets the
>
> that intends ^no comma
>
> > +devlink port attributes and registers the devlink port.
> > +
> > +Devlink port flavours are described below.
> > +
> > +.. list-table:: List of devlink port flavours
> > + :widths: 33 90
> > +
> > + * - Flavour
> > + - Description
> > + * - ``DEVLINK_PORT_FLAVOUR_PHYSICAL``
> > + - Any kind of physical networking port. This can be a eswitch
> > + physical
>
> an
>
> > + port or any other physical port on the device.
> > + * - ``DEVLINK_PORT_FLAVOUR_DSA``
> > + - This indicates a DSA interconnect port.
> > + * - ``DEVLINK_PORT_FLAVOUR_CPU``
> > + - This indicates a CPU port applicable only to DSA.
> > + * - ``DEVLINK_PORT_FLAVOUR_PCI_PF``
> > + - This indicates an eswitch port representing a networking port of
> > + PCI physical function (PF).
> > + * - ``DEVLINK_PORT_FLAVOUR_PCI_VF``
> > + - This indicates an eswitch port representing a networking port of
> > + PCI virtual function (VF).
> > + * - ``DEVLINK_PORT_FLAVOUR_VIRTUAL``
> > + - This indicates a virtual port for the virtual PCI device such as PCI VF.
> > +
> > +A devlink port types are described below.
>
> The devlink port types
>
> > +
> > +.. list-table:: List of devlink port types
> > + :widths: 23 90
> > +
> > + * - Type
> > + - Description
> > + * - ``DEVLINK_PORT_TYPE_ETH``
> > + - Driver should set this port type when a link layer of the port is Ethernet.
> > + * - ``DEVLINK_PORT_TYPE_IB``
> > + - Driver should set this port type when a link layer of the port is InfiniBand.
> > + * - ``DEVLINK_PORT_TYPE_AUTO``
> > + - This type is indicated by the user when user prefers to set the port type
> > + to be automatically detected by the device driver.
> > +
> > +A controller consist of one or more PCI functions. Such PCI function
> > +can have one
>
> consists
>
> > +or more networking ports. A networking port of such PCI function is
> > +represented by the eswitch devlink port. A devlink instance holds
> > +ports of two types of controllers.
> > +
> > +(1) controller discovered on same system where eswitch resides:
> > +This is the case where PCI PF/VF of a controller and devlink eswitch
> > +instance both are located on a single system.
> > +
> > +(2) controller located on external host system.
> > +This is the case where a controller is located in one system and its
> > +devlink eswitch ports are located in a different system. Such
> > +controller is called external controller.
> > +
> > +An example view of two controller systems::
> > +
> > +In this example a controller which contains the eswitch is local
> > +controller with controller number = 0. The second is a external
> > +controller having controller number = 1. Eswitch devlink instance has
> > +representor devlink ports for the PCI functions of both the controllers.
>
> I find that sentence confusing but I don't know how to fix it.
>
Will rewrite it as below and also address above comments.
In this example, external controller (identified by controller number = 1) doesn't have eswitch.
Local controller (identified by controller number = 0) has the eswitch. Devlink instance on local
Controller has eswitch devlink ports representing networking ports for both the controllers.
> > +
> > + ---------------------------------------------------------
> > + | |
> > + | --------- --------- ------- ------- |
> > + ----------- | | vf(s) | | sf(s) | |vf(s)| |sf(s)| |
> > + | server | | ------- ----/---- ---/----- ------- ---/--- ---/--- |
> > + | pci rc |=== | pf0 |______/________/ | pf1 |___/_______/ |
> > + | connect | | ------- ------- |
> > + ----------- | | controller_num=1 (no eswitch) |
> > + ------|--------------------------------------------------
> > + (internal wire)
> > + |
> > + ---------------------------------------------------------
> > + | devlink eswitch ports and reps |
> > + | ----------------------------------------------------- |
> > + | |ctrl-0 | ctrl-0 | ctrl-0 | ctrl-0 | ctrl-0 |ctrl-0 | |
> > + | |pf0 | pf0vfN | pf0sfN | pf1 | pf1vfN |pf1sfN | |
> > + | ----------------------------------------------------- |
> > + | |ctrl-1 | ctrl-1 | ctrl-1 | ctrl-1 | ctrl-1 |ctrl-1 | |
> > + | |pf0 | pf0vfN | pf0sfN | pf1 | pf1vfN |pf1sfN | |
> > + | ----------------------------------------------------- |
> > + | |
> > + | |
> > + | --------- --------- ------- ------- |
> > + | | vf(s) | | sf(s) | |vf(s)| |sf(s)| |
> > + | ------- ----/---- ---/----- ------- ---/--- ---/--- |
> > + | | pf0 |______/________/ | pf1 |___/_______/ |
> > + | ------- ------- |
> > + | |
> > + | local controller_num=0 (eswitch) |
> > +
> > + ---------------------------------------------------------
> > +
> > +Port function configuration
> > +===========================
> > +
> > +When a port flavor is ``DEVLINK_PORT_FLAVOUR_PCI_PF`` or
> > +``DEVLINK_PORT_FLAVOUR_PCI_VF``, it represents the networking port of
> > +a PCI function. A user can configure the port function attributes
> > +before enumerating the function. For example user may set the
> > +hardware address of the function represented by the devlink port function.
>
> thanks.
Thanks for the review Randy.
> --
> ~Randy
Powered by blists - more mailing lists