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[net-next,v5,13/15] devlink: Add devlink port documentation

Message ID 20201215090358.240365-14-saeed@kernel.org (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series Add mlx5 subfunction support | expand

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Commit Message

Saeed Mahameed Dec. 15, 2020, 9:03 a.m. UTC
From: Parav Pandit <parav@nvidia.com>

Added documentation for devlink port and port function related commands.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
 .../networking/devlink/devlink-port.rst       | 118 ++++++++++++++++++
 Documentation/networking/devlink/index.rst    |   1 +
 2 files changed, 119 insertions(+)
 create mode 100644 Documentation/networking/devlink/devlink-port.rst

Comments

Jakub Kicinski Dec. 16, 2020, 12:57 a.m. UTC | #1
On Tue, 15 Dec 2020 01:03:56 -0800 Saeed Mahameed wrote:
> +PCI controllers
> +---------------
> +In most cases a PCI device has only one controller. A controller consists of
> +potentially multiple physical and virtual functions. Such PCI function consists
> +of one or more ports.

s/Such//

you say consists in two consecutive sentences.

> This port of the function is represented by the devlink eswitch port.

"This port of the function"? Why not just "Each port"?

> +A PCI Device connected to multiple CPUs or multiple PCI root complexes or

Why is device capitalized all of the sudden?

> +SmartNIC, however, may have multiple controllers. For a device with multiple

a SmartNIC or SmartNICs

> +controllers, each controller is distinguished by a unique controller number.
> +An eswitch on the PCI device support ports of multiple controllers.

eswitch is on a PCI device?

> +An example view of a system with two 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 | |
> +                 | ----------------------------------------------------- |
> +                 |                                                       |
> +                 |                                                       |
> +    -----------  |           --------- ---------         ------- ------- |
> +    | smartNIC|  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
> +    | pci rc  |==| -------   ----/---- ---/----- ------- ---/--- ---/--- |
> +    | connect |  | | pf0 |______/________/       | pf1 |___/_______/     |
> +    -----------  | -------                       -------                 |
> +                 |                                                       |
> +                 |  local controller_num=0 (eswitch)                     |
> +                 ---------------------------------------------------------
> +
> +In above 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 ports for both the controllers.
> +
> +Port function configuration
> +===========================
> +
> +A user can configure the port function attribute before enumerating the

s/A user/User/

/port function attribute/$something_meaningful/

> +PCI function. Usually it means, user should configure port function attribute

attributes, plural

> +before a bus specific device for the function is created. However, when
> +SRIOV is enabled, virtual function devices are created on the PCI bus.
> +Hence, function attribute should be configured before binding virtual
> +function device to the driver.
> +
> +User may set the hardware address of the function represented by the devlink
> +port function. For Ethernet port function this means a MAC address.
Parav Pandit Dec. 16, 2020, 5:40 a.m. UTC | #2
> From: Jakub Kicinski <kuba@kernel.org>
> Sent: Wednesday, December 16, 2020 6:28 AM
> 
> On Tue, 15 Dec 2020 01:03:56 -0800 Saeed Mahameed wrote:
> > +PCI controllers
> > +---------------
> > +In most cases a PCI device has only one controller. A controller
> > +consists of potentially multiple physical and virtual functions. Such
> > +PCI function consists of one or more ports.
> 
> s/Such//
>
Ack.
 
> you say consists in two consecutive sentences.
> 
> > This port of the function is represented by the devlink eswitch port.
> 
First sentence describe controller. Second sentence describe function.
So what is wrong in that?

> "This port of the function"? Why not just "Each port"?
> 
That's fine too. Will simplify.

> > +A PCI Device connected to multiple CPUs or multiple PCI root
> > +complexes or
> 
> Why is device capitalized all of the sudden?
>
Will fix.
 
> > +SmartNIC, however, may have multiple controllers. For a device with
> > +multiple
> 
> a SmartNIC or SmartNICs
> 
> > +controllers, each controller is distinguished by a unique controller
> number.
> > +An eswitch on the PCI device support ports of multiple controllers.
> 
> eswitch is on a PCI device?
>
Will change.
 
> > +An example view of a system with two 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 | |
> > +                 | ----------------------------------------------------- |
> > +                 |                                                       |
> > +                 |                                                       |
> > +    -----------  |           --------- ---------         ------- ------- |
> > +    | smartNIC|  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
> > +    | pci rc  |==| -------   ----/---- ---/----- ------- ---/--- ---/--- |
> > +    | connect |  | | pf0 |______/________/       | pf1 |___/_______/     |
> > +    -----------  | -------                       -------                 |
> > +                 |                                                       |
> > +                 |  local controller_num=0 (eswitch)                     |
> > +
> > + ---------------------------------------------------------
> > +
> > +In above 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 ports for both the
> controllers.
> > +
> > +Port function configuration
> > +===========================
> > +
> > +A user can configure the port function attribute before enumerating
> > +the
> 
> s/A user/User/
> 
> /port function attribute/$something_meaningful/
> 
May be just say function attribute?

> > +PCI function. Usually it means, user should configure port function
> > +attribute
> 
> attributes, plural
> 
Yes, but at present there is only one i.e. mac address, so didn't use plural.
diff mbox series

Patch

diff --git a/Documentation/networking/devlink/devlink-port.rst b/Documentation/networking/devlink/devlink-port.rst
new file mode 100644
index 000000000000..4c910dbb01ca
--- /dev/null
+++ b/Documentation/networking/devlink/devlink-port.rst
@@ -0,0 +1,118 @@ 
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _devlink_port:
+
+============
+Devlink Port
+============
+
+``devlink-port`` is a port that exists on the device. It has a logically
+separate ingress/egress point of the device. A devlink port can be any one
+of many flavours. A devlink port flavour along with port attributes
+describe what a port represents.
+
+A device driver that intends to publish a devlink port sets the
+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 port. This can be an eswitch physical 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 port of PCI
+       physical function (PF).
+   * - ``DEVLINK_PORT_FLAVOUR_PCI_VF``
+     - This indicates an eswitch port representing a port of PCI
+       virtual function (VF).
+   * - ``DEVLINK_PORT_FLAVOUR_VIRTUAL``
+     - This indicates a virtual port for the PCI virtual function.
+
+Devlink port can have a different type based on the link layer described below.
+
+.. 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 driver should detect the port
+       type automatically.
+
+PCI controllers
+---------------
+In most cases a PCI device has only one controller. A controller consists of
+potentially multiple physical and virtual functions. Such PCI function consists
+of one or more ports. This port of the function is represented by the devlink
+eswitch port.
+
+A PCI Device connected to multiple CPUs or multiple PCI root complexes or
+SmartNIC, however, may have multiple controllers. For a device with multiple
+controllers, each controller is distinguished by a unique controller number.
+An eswitch on the PCI device support ports of multiple controllers.
+
+An example view of a system with two 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 | |
+                 | ----------------------------------------------------- |
+                 |                                                       |
+                 |                                                       |
+    -----------  |           --------- ---------         ------- ------- |
+    | smartNIC|  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
+    | pci rc  |==| -------   ----/---- ---/----- ------- ---/--- ---/--- |
+    | connect |  | | pf0 |______/________/       | pf1 |___/_______/     |
+    -----------  | -------                       -------                 |
+                 |                                                       |
+                 |  local controller_num=0 (eswitch)                     |
+                 ---------------------------------------------------------
+
+In above 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 ports for both the controllers.
+
+Port function configuration
+===========================
+
+A user can configure the port function attribute before enumerating the
+PCI function. Usually it means, user should configure port function attribute
+before a bus specific device for the function is created. However, when
+SRIOV is enabled, virtual function devices are created on the PCI bus.
+Hence, function attribute should be configured before binding virtual
+function device to the driver.
+
+User may set the hardware address of the function represented by the devlink
+port function. For Ethernet port function this means a MAC address.
diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst
index d82874760ae2..aab79667f97b 100644
--- a/Documentation/networking/devlink/index.rst
+++ b/Documentation/networking/devlink/index.rst
@@ -18,6 +18,7 @@  general.
    devlink-info
    devlink-flash
    devlink-params
+   devlink-port
    devlink-region
    devlink-resource
    devlink-reload