1 .. SPDX-License-Identifier: GPL-2.0
3 ===================================================================
4 PCI Non-Transparent Bridge (NTB) Endpoint Function (EPF) User Guide
5 ===================================================================
7 :Author: Frank Li <Frank.Li@nxp.com>
9 This document is a guide to help users use pci-epf-vntb function driver
10 and ntb_hw_epf host driver for NTB functionality. The list of steps to
11 be followed in the host side and EP side is given below. For the hardware
12 configuration and internals of NTB using configurable endpoints see
13 Documentation/PCI/endpoint/pci-vntb-function.rst
18 Endpoint Controller Devices
19 ---------------------------
21 To find the list of endpoint controller devices in the system::
23 # ls /sys/class/pci_epc/
26 If PCI_ENDPOINT_CONFIGFS is enabled::
28 # ls /sys/kernel/config/pci_ep/controllers
31 Endpoint Function Drivers
32 -------------------------
34 To find the list of endpoint function drivers in the system::
36 # ls /sys/bus/pci-epf/drivers
37 pci_epf_ntb pci_epf_test pci_epf_vntb
39 If PCI_ENDPOINT_CONFIGFS is enabled::
41 # ls /sys/kernel/config/pci_ep/functions
42 pci_epf_ntb pci_epf_test pci_epf_vntb
45 Creating pci-epf-vntb Device
46 ----------------------------
48 PCI endpoint function device can be created using the configfs. To create
49 pci-epf-vntb device, the following commands can be used::
51 # mount -t configfs none /sys/kernel/config
52 # cd /sys/kernel/config/pci_ep/
53 # mkdir functions/pci_epf_vntb/func1
55 The "mkdir func1" above creates the pci-epf-ntb function device that will
56 be probed by pci_epf_vntb driver.
58 The PCI endpoint framework populates the directory with the following
61 # ls functions/pci_epf_ntb/func1
62 baseclass_code deviceid msi_interrupts pci-epf-ntb.0
63 progif_code secondary subsys_id vendorid
64 cache_line_size interrupt_pin msix_interrupts primary
65 revid subclass_code subsys_vendor_id
67 The PCI endpoint function driver populates these entries with default values
68 when the device is bound to the driver. The pci-epf-vntb driver populates
69 vendorid with 0xffff and interrupt_pin with 0x0001::
71 # cat functions/pci_epf_vntb/func1/vendorid
73 # cat functions/pci_epf_vntb/func1/interrupt_pin
77 Configuring pci-epf-vntb Device
78 -------------------------------
80 The user can configure the pci-epf-vntb device using its configfs entry. In order
81 to change the vendorid and the deviceid, the following
82 commands can be used::
84 # echo 0x1957 > functions/pci_epf_vntb/func1/vendorid
85 # echo 0x0809 > functions/pci_epf_vntb/func1/deviceid
87 The PCI endpoint framework also automatically creates a sub-directory in the
88 function attribute directory. This sub-directory has the same name as the name
89 of the function device and is populated with the following NTB specific
90 attributes that can be configured by the user::
92 # ls functions/pci_epf_vntb/func1/pci_epf_vntb.0/
93 db_count mw1 mw2 mw3 mw4 num_mws
96 A sample configuration for NTB function is given below::
98 # echo 4 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/db_count
99 # echo 128 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/spad_count
100 # echo 1 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/num_mws
101 # echo 0x100000 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/mw1
103 A sample configuration for virtual NTB driver for virtual PCI bus::
105 # echo 0x1957 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vntb_vid
106 # echo 0x080A > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vntb_pid
107 # echo 0x10 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vbus_number
109 Binding pci-epf-ntb Device to EP Controller
110 --------------------------------------------
112 NTB function device should be attached to PCI endpoint controllers
113 connected to the host.
115 # ln -s controllers/5f010000.pcie_ep functions/pci-epf-ntb/func1/primary
117 Once the above step is completed, the PCI endpoint controllers are ready to
118 establish a link with the host.
124 In order for the endpoint device to establish a link with the host, the _start_
125 field should be populated with '1'. For NTB, both the PCI endpoint controllers
126 should establish link with the host (imx8 don't need this steps)::
128 # echo 1 > controllers/5f010000.pcie_ep/start
133 lspci Output at Host side
134 -------------------------
136 Note that the devices listed here correspond to the values populated in
137 "Creating pci-epf-ntb Device" section above::
140 00:00.0 PCI bridge: Freescale Semiconductor Inc Device 0000 (rev 01)
141 01:00.0 RAM memory: Freescale Semiconductor Inc Device 0809
143 Endpoint Device / Virtual PCI bus
144 =================================
146 lspci Output at EP Side / Virtual PCI bus
147 -----------------------------------------
149 Note that the devices listed here correspond to the values populated in
150 "Creating pci-epf-ntb Device" section above::
153 10:00.0 Unassigned class [ffff]: Dawicontrol Computersysteme GmbH Device 1234 (rev ff)
155 Using ntb_hw_epf Device
156 -----------------------
158 The host side software follows the standard NTB software architecture in Linux.
159 All the existing client side NTB utilities like NTB Transport Client and NTB
160 Netdev, NTB Ping Pong Test Client and NTB Tool Test Client can be used with NTB
163 For more information on NTB see
164 :doc:`Non-Transparent Bridge <../../driver-api/ntb>`