Add specification for the PCI vNTB function device. The endpoint function
driver and the host PCI driver should be created based on this
specification.
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
Change from v1:
- Add virtual pci ntb driver config
Documentation/PCI/endpoint/index.rst | 2 +
.../PCI/endpoint/pci-vntb-function.rst | 126 +++++++++++++
Documentation/PCI/endpoint/pci-vntb-howto.rst | 167 ++++++++++++++++++
3 files changed, 295 insertions(+)
create mode 100644 Documentation/PCI/endpoint/pci-vntb-function.rst
create mode 100644 Documentation/PCI/endpoint/pci-vntb-howto.rst
diff --git a/Documentation/PCI/endpoint/index.rst b/Documentation/PCI/endpoint/index.rst
index 38ea1f604b6d3..4d2333e7ae067 100644
--- a/Documentation/PCI/endpoint/index.rst
+++ b/Documentation/PCI/endpoint/index.rst
@@ -13,6 +13,8 @@ PCI Endpoint Framework
pci-test-howto
pci-ntb-function
pci-ntb-howto
+ pci-vntb-function
+ pci-vntb-howto
function/binding/pci-test
function/binding/pci-ntb
diff --git a/Documentation/PCI/endpoint/pci-vntb-function.rst b/Documentation/PCI/endpoint/pci-vntb-function.rst
new file mode 100644
index 0000000000000..cad8013e88390
--- /dev/null
+++ b/Documentation/PCI/endpoint/pci-vntb-function.rst
@@ -0,0 +1,126 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+PCI vNTB Function
+=================
+
+:Author: Frank Li <Frank.Li@xxxxxxx>
+
+The difference between PCI NTB function and PCI vNTB function is
+
+PCI NTB function need at two endpoint instances and connect HOST1
+and HOST2.
+
+PCI vNTB function only use one host and one endpoint(EP), use NTB
+connect EP and PCI host
+
+.. code-block:: text
+
+
+ +------------+ +---------------------------------------+
+ | | | |
+ +------------+ | +--------------+
+ | NTB | | | NTB |
+ | NetDev | | | NetDev |
+ +------------+ | +--------------+
+ | NTB | | | NTB |
+ | Transfer | | | Transfer |
+ +------------+ | +--------------+
+ | | | | |
+ | PCI NTB | | | |
+ | EPF | | | |
+ | Driver | | | PCI Virtual |
+ | | +---------------+ | NTB Driver |
+ | | | PCI EP NTB |<------>| |
+ | | | FN Driver | | |
+ +------------+ +---------------+ +--------------+
+ | | | | | |
+ | PCI BUS | <-----> | PCI EP BUS | | Virtual PCI |
+ | | PCI | | | BUS |
+ +------------+ +---------------+--------+--------------+
+ PCI RC PCI EP
+
+Constructs used for Implementing vNTB
+=====================================
+
+ 1) Config Region
+ 2) Self Scratchpad Registers
+ 3) Peer Scratchpad Registers
+ 4) Doorbell (DB) Registers
+ 5) Memory Window (MW)
+
+
+Config Region:
+--------------
+
+It is same as PCI NTB Function driver
+
+Scratchpad Registers:
+---------------------
+
+ It is appended after Config region.
+
+ +--------------------------------------------------+ Base
+ | |
+ | |
+ | |
+ | Common Config Register |
+ | |
+ | |
+ | |
+ +-----------------------+--------------------------+ Base + span_offset
+ | | |
+ | Peer Span Space | Span Space |
+ | | |
+ | | |
+ +-----------------------+--------------------------+ Base + span_offset
+ | | | + span_count * 4
+ | | |
+ | Span Space | Peer Span Space |
+ | | |
+ +-----------------------+--------------------------+
+ Virtual PCI Pcie Endpoint
+ NTB Driver NTB Driver
+
+
+Doorbell Registers:
+-------------------
+
+ Doorbell Registers are used by the hosts to interrupt each other.
+
+Memory Window:
+--------------
+
+ Actual transfer of data between the two hosts will happen using the
+ memory window.
+
+Modeling Constructs:
+====================
+
+32-bit BARs.
+
+====== ===============
+BAR NO CONSTRUCTS USED
+====== ===============
+BAR0 Config Region
+BAR1 Doorbell
+BAR2 Memory Window 1
+BAR3 Memory Window 2
+BAR4 Memory Window 3
+BAR5 Memory Window 4
+====== ===============
+
+64-bit BARs.
+
+====== ===============================
+BAR NO CONSTRUCTS USED
+====== ===============================
+BAR0 Config Region + Scratchpad
+BAR1
+BAR2 Doorbell
+BAR3
+BAR4 Memory Window 1
+BAR5
+====== ===============================
+
+
diff --git a/Documentation/PCI/endpoint/pci-vntb-howto.rst b/Documentation/PCI/endpoint/pci-vntb-howto.rst
new file mode 100644
index 0000000000000..524cd487e1840
--- /dev/null
+++ b/Documentation/PCI/endpoint/pci-vntb-howto.rst
@@ -0,0 +1,167 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================================================================
+PCI Non-Transparent Bridge (NTB) Endpoint Function (EPF) User Guide
+===================================================================
+
+:Author: Frank Li <Frank.Li@xxxxxxx>
+
+This document is a guide to help users use pci-epf-vntb function driver
+and ntb_hw_epf host driver for NTB functionality. The list of steps to
+be followed in the host side and EP side is given below. For the hardware
+configuration and internals of NTB using configurable endpoints see
+Documentation/PCI/endpoint/pci-vntb-function.rst
+
+Endpoint Device
+===============
+
+Endpoint Controller Devices
+---------------------------
+
+To find the list of endpoint controller devices in the system::
+
+ # ls /sys/class/pci_epc/
+ 5f010000.pcie_ep
+
+If PCI_ENDPOINT_CONFIGFS is enabled::
+
+ # ls /sys/kernel/config/pci_ep/controllers
+ 5f010000.pcie_ep
+
+Endpoint Function Drivers
+-------------------------
+
+To find the list of endpoint function drivers in the system::
+
+ # ls /sys/bus/pci-epf/drivers
+ pci_epf_ntb pci_epf_test pci_epf_vntb
+
+If PCI_ENDPOINT_CONFIGFS is enabled::
+
+ # ls /sys/kernel/config/pci_ep/functions
+ pci_epf_ntb pci_epf_test pci_epf_vntb
+
+
+Creating pci-epf-vntb Device
+----------------------------
+
+PCI endpoint function device can be created using the configfs. To create
+pci-epf-vntb device, the following commands can be used::
+
+ # mount -t configfs none /sys/kernel/config
+ # cd /sys/kernel/config/pci_ep/
+ # mkdir functions/pci_epf_vntb/func1
+
+The "mkdir func1" above creates the pci-epf-ntb function device that will
+be probed by pci_epf_vntb driver.
+
+The PCI endpoint framework populates the directory with the following
+configurable fields::
+
+ # ls functions/pci_epf_ntb/func1
+ baseclass_code deviceid msi_interrupts pci-epf-ntb.0
+ progif_code secondary subsys_id vendorid
+ cache_line_size interrupt_pin msix_interrupts primary
+ revid subclass_code subsys_vendor_id
+
+The PCI endpoint function driver populates these entries with default values
+when the device is bound to the driver. The pci-epf-vntb driver populates
+vendorid with 0xffff and interrupt_pin with 0x0001::
+
+ # cat functions/pci_epf_vntb/func1/vendorid
+ 0xffff
+ # cat functions/pci_epf_vntb/func1/interrupt_pin
+ 0x0001
+
+
+Configuring pci-epf-vntb Device
+-------------------------------
+
+The user can configure the pci-epf-vntb device using its configfs entry. In order
+to change the vendorid and the deviceid, the following
+commands can be used::
+
+ # echo 0x1957 > functions/pci_epf_vntb/func1/vendorid
+ # echo 0x0809 > functions/pci_epf_vntb/func1/deviceid
+
+In order to configure NTB specific attributes, a new sub-directory to func1
+should be created::
+
+ # mkdir functions/pci_epf_vntb/func1/pci_epf_vntb.0/
+
+The NTB function driver will populate this directory with various attributes
+that can be configured by the user::
+
+ # ls functions/pci_epf_vntb/func1/pci_epf_vntb.0/
+ db_count mw1 mw2 mw3 mw4 num_mws
+ spad_count
+
+A sample configuration for NTB function is given below::
+
+ # echo 4 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/db_count
+ # echo 128 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/spad_count
+ # echo 1 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/num_mws
+ # echo 0x100000 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/mw1
+
+A sample configuration for virtual NTB driver for virutal PCI bus::
+
+ # echo 0x1957 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vntb_vid
+ # echo 0x080A > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vntb_pid
+ # echo 0x10 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vbus_number
+
+Binding pci-epf-ntb Device to EP Controller
+--------------------------------------------
+
+NTB function device should be attached to PCI endpoint controllers
+connected to the host.
+
+ # ln -s controllers/5f010000.pcie_ep functions/pci-epf-ntb/func1/primary
+
+Once the above step is completed, the PCI endpoint controllers are ready to
+establish a link with the host.
+
+
+Start the Link
+--------------
+
+In order for the endpoint device to establish a link with the host, the _start_
+field should be populated with '1'. For NTB, both the PCI endpoint controllers
+should establish link with the host (imx8 don't need this steps)::
+
+ # echo 1 > controllers/5f010000.pcie_ep/start
+
+RootComplex Device
+==================
+
+lspci Output at Host side
+------------------------
+
+Note that the devices listed here correspond to the values populated in
+"Creating pci-epf-ntb Device" section above::
+
+ # lspci
+ 00:00.0 PCI bridge: Freescale Semiconductor Inc Device 0000 (rev 01)
+ 01:00.0 RAM memory: Freescale Semiconductor Inc Device 0809
+
+Endpoint Device / Virtual PCI bus
+=================================
+
+lspci Output at EP Side / Virtual PCI bus
+-----------------------------------------
+
+Note that the devices listed here correspond to the values populated in
+"Creating pci-epf-ntb Device" section above::
+
+ # lspci
+ 10:00.0 Unassigned class [ffff]: Dawicontrol Computersysteme GmbH Device 1234 (rev ff)
+
+Using ntb_hw_epf Device
+-----------------------
+
+The host side software follows the standard NTB software architecture in Linux.
+All the existing client side NTB utilities like NTB Transport Client and NTB
+Netdev, NTB Ping Pong Test Client and NTB Tool Test Client can be used with NTB
+function device.
+
+For more information on NTB see
+:doc:`Non-Transparent Bridge <../../driver-api/ntb>`
--
2.24.0.rc1
