pds_vdpa: pds_vdps.rst and Kconfig

Add the documentation and Kconfig entry for pds_vdpa driver.

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230519215632.12343-12-shannon.nelson@amd.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 86 insertions, 0 deletions

diff --git a/Documentation/networking/device_drivers/ethernet/amd/pds_vdpa.rst b/Documentation/networking/device_drivers/ethernet/amd/pds_vdpa.rst
new file mode 100644
index 000000000000..587927d3de92
--- /dev/null
+++ b/Documentation/networking/device_drivers/ethernet/amd/pds_vdpa.rst
@@ -0,0 +1,85 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. note: can be edited and viewed with /usr/bin/formiko-vim
+
+==========================================================
+PCI vDPA driver for the AMD/Pensando(R) DSC adapter family
+==========================================================
+
+AMD/Pensando vDPA VF Device Driver
+
+Copyright(c) 2023 Advanced Micro Devices, Inc
+
+Overview
+========
+
+The ``pds_vdpa`` driver is an auxiliary bus driver that supplies
+a vDPA device for use by the virtio network stack.  It is used with
+the Pensando Virtual Function devices that offer vDPA and virtio queue
+services.  It depends on the ``pds_core`` driver and hardware for the PF
+and VF PCI handling as well as for device configuration services.
+
+Using the device
+================
+
+The ``pds_vdpa`` device is enabled via multiple configuration steps and
+depends on the ``pds_core`` driver to create and enable SR-IOV Virtual
+Function devices.  After the VFs are enabled, we enable the vDPA service
+in the ``pds_core`` device to create the auxiliary devices used by pds_vdpa.
+
+Example steps:
+
+.. code-block:: bash
+
+  #!/bin/bash
+
+  modprobe pds_core
+  modprobe vdpa
+  modprobe pds_vdpa
+
+  PF_BDF=`ls /sys/module/pds_core/drivers/pci\:pds_core/*/sriov_numvfs | awk -F / '{print $7}'`
+
+  # Enable vDPA VF auxiliary device(s) in the PF
+  devlink dev param set pci/$PF_BDF name enable_vnet cmode runtime value true
+
+  # Create a VF for vDPA use
+  echo 1 > /sys/bus/pci/drivers/pds_core/$PF_BDF/sriov_numvfs
+
+  # Find the vDPA services/devices available
+  PDS_VDPA_MGMT=`vdpa mgmtdev show | grep vDPA | head -1 | cut -d: -f1`
+
+  # Create a vDPA device for use in virtio network configurations
+  vdpa dev add name vdpa1 mgmtdev $PDS_VDPA_MGMT mac 00:11:22:33:44:55
+
+  # Set up an ethernet interface on the vdpa device
+  modprobe virtio_vdpa
+
+
+
+Enabling the driver
+===================
+
+The driver is enabled via the standard kernel configuration system,
+using the make command::
+
+  make oldconfig/menuconfig/etc.
+
+The driver is located in the menu structure at:
+
+  -> Device Drivers
+    -> Network device support (NETDEVICES [=y])
+      -> Ethernet driver support
+        -> Pensando devices
+          -> Pensando Ethernet PDS_VDPA Support
+
+Support
+=======
+
+For general Linux networking support, please use the netdev mailing
+list, which is monitored by Pensando personnel::
+
+  netdev@vger.kernel.org
+
+For more specific support needs, please use the Pensando driver support
+email::
+
+  drivers@pensando.io
diff --git a/Documentation/networking/device_drivers/ethernet/index.rst b/Documentation/networking/device_drivers/ethernet/index.rst
index 417ca514a4d0..94ecb67c0885 100644
--- a/Documentation/networking/device_drivers/ethernet/index.rst
+++ b/Documentation/networking/device_drivers/ethernet/index.rst
@@ -15,6 +15,7 @@ Contents:
    amazon/ena
    altera/altera_tse
    amd/pds_core
+   amd/pds_vdpa
    aquantia/atlantic
    chelsio/cxgb
    cirrus/cs89x0