From: Parav Pandit <parav@xxxxxxxxxx>
Added documentation for devlink port and port function related commands.
Signed-off-by: Parav Pandit <parav@xxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>
Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx>
---
.../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
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
--
2.26.2
