diff mbox series

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

Message ID 20201207221342.553976-1-parav@nvidia.com
State New
Headers show
Series [net-next,v5] devlink: Add devlink port documentation | expand

Commit Message

Parav Pandit Dec. 7, 2020, 10:13 p.m. UTC
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>
---
Changelog:
v4->v5:
 - described logically ingress and egress point of devlink port
 - removed networking from devlink port description
 - rephrased port type description
 - introdue PCI controller section and description
 - rephrased controller, device, function description
 - removed confusing eswitch to system wording
 - rephrased port function description
 - added example of mac address in port function attribute description
v3->v4:
 - changed 'exist' to 'exists'
 - added 'an' eswitch
 - changed 'can have one' to 'consists of'
 - changed 'who intents' to 'that intends'
 - removed unnecessary comma
 - rewrote description for the example diagram
 - changed 'controller consist of' to 'controller consists of'
v2->v3:
 - rephrased many lines
 - 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       | 116 ++++++++++++++++++
 Documentation/networking/devlink/index.rst    |   1 +
 2 files changed, 117 insertions(+)
 create mode 100644 Documentation/networking/devlink/devlink-port.rst

Comments

Randy Dunlap Dec. 8, 2020, 1:14 a.m. UTC | #1
Hi--

On 12/7/20 2:13 PM, Parav Pandit wrote:
> 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>

> ---

> Changelog:

> v4->v5:

>  - described logically ingress and egress point of devlink port

>  - removed networking from devlink port description

>  - rephrased port type description

>  - introdue PCI controller section and description


     introduce

>  - rephrased controller, device, function description

>  - removed confusing eswitch to system wording

>  - rephrased port function description

>  - added example of mac address in port function attribute description


> ---

>  .../networking/devlink/devlink-port.rst       | 116 ++++++++++++++++++

>  Documentation/networking/devlink/index.rst    |   1 +

>  2 files changed, 117 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..dce87d2c07ac

> --- /dev/null

> +++ b/Documentation/networking/devlink/devlink-port.rst

> @@ -0,0 +1,116 @@

> +.. SPDX-License-Identifier: GPL-2.0

> +

> +============

> +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 of one


                                                          port can be any one
   of many flavours.

> +among 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 networking 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 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.

> +

> +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 PCI device has only one controller. A controller consists of


either           PCI devices have
or               a PCI device has

> +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 complex or


                                                                complexes

> +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 may suppport ports of multiple controllers. 


                                    support

> +

> +An example view of two controller systems::


I think that this is

  An example view of a two-controller system::

instead of 2 controller systems.  ?

> +

> +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 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 | |

> +                 | ----------------------------------------------------- |

> +                 |                                                       |

> +                 |                                                       |

> +    -----------  |           --------- ---------         ------- ------- |

> +    | smartNIC|  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |

> +    | pci rc  |==| -------   ----/---- ---/----- ------- ---/--- ---/--- |

> +    | connect |  | | pf0 |______/________/       | pf1 |___/_______/     |

> +    -----------  | -------                       -------                 |

> +                 |                                                       |

> +                 |  local controller_num=0 (eswitch)                     |

> +                 ---------------------------------------------------------

> +

> +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.



-- 
~Randy
Parav Pandit Dec. 8, 2020, 5:59 a.m. UTC | #2
Hi Randy,

> From: Randy Dunlap <rdunlap@infradead.org>

> Sent: Tuesday, December 8, 2020 6:45 AM

> 

> > +An eswitch on the PCI device may suppport ports of multiple controllers.

> 

>                                     support

> 

> > +

> > +An example view of two controller systems::

> 

> I think that this is

> 

>   An example view of a two-controller system::

> 

> instead of 2 controller systems.  ?


Rephrasing it as "An example view of a system with two controllers" along with other comments.
Since Saeed is sending the sf patchset which also needs port documentation, I am sending v6 of this patch along with the change log in the subfunction patchset.
Parav Pandit Dec. 8, 2020, 6:51 a.m. UTC | #3
> From: Randy Dunlap <rdunlap@infradead.org>

> Sent: Tuesday, December 8, 2020 6:45 AM

> 

> Hi--

> 

> On 12/7/20 2:13 PM, Parav Pandit wrote:

> > 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>

> > ---

> > Changelog:

> > v4->v5:

> >  - described logically ingress and egress point of devlink port

> >  - removed networking from devlink port description

> >  - rephrased port type description

> >  - introdue PCI controller section and description

> 

>      introduce

> 

> >  - rephrased controller, device, function description

> >  - removed confusing eswitch to system wording

> >  - rephrased port function description

> >  - added example of mac address in port function attribute description

> 

> > ---

> >  .../networking/devlink/devlink-port.rst       | 116 ++++++++++++++++++

> >  Documentation/networking/devlink/index.rst    |   1 +

> >  2 files changed, 117 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..dce87d2c07ac

> > --- /dev/null

> > +++ b/Documentation/networking/devlink/devlink-port.rst

> > @@ -0,0 +1,116 @@

> > +.. SPDX-License-Identifier: GPL-2.0

> > +

> > +============

> > +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 of one

> 

>                                                           port can be any one

>    of many flavours.

> 

> > +among 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 networking 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 networking port of

> > +       PCI physical function (PF).

I forgot to remove 'networking' from the networking port here.
Will include this fix this in v6 in Saeed's subfunction patchset along with addressing Randy's comments.
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..dce87d2c07ac
--- /dev/null
+++ b/Documentation/networking/devlink/devlink-port.rst
@@ -0,0 +1,116 @@ 
+.. SPDX-License-Identifier: GPL-2.0
+
+============
+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 of one
+among 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 networking 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 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.
+
+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 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 complex 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 may suppport ports of multiple controllers. 
+
+An example view of two controller systems::
+
+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 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 | |
+                 | ----------------------------------------------------- |
+                 |                                                       |
+                 |                                                       |
+    -----------  |           --------- ---------         ------- ------- |
+    | smartNIC|  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
+    | pci rc  |==| -------   ----/---- ---/----- ------- ---/--- ---/--- |
+    | connect |  | | pf0 |______/________/       | pf1 |___/_______/     |
+    -----------  | -------                       -------                 |
+                 |                                                       |
+                 |  local controller_num=0 (eswitch)                     |
+                 ---------------------------------------------------------
+
+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