1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 ============================================== 3 ===================================================================
4 PCI Non-Transparent Bridge (NTB) Endpoint Func 4 PCI Non-Transparent Bridge (NTB) Endpoint Function (EPF) User Guide
5 ============================================== 5 ===================================================================
6 6
7 :Author: Kishon Vijay Abraham I <kishon@ti.com> 7 :Author: Kishon Vijay Abraham I <kishon@ti.com>
8 8
9 This document is a guide to help users use pci 9 This document is a guide to help users use pci-epf-ntb function driver
10 and ntb_hw_epf host driver for NTB functionali 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 gi 11 be followed in the host side and EP side is given below. For the hardware
12 configuration and internals of NTB using confi 12 configuration and internals of NTB using configurable endpoints see
13 Documentation/PCI/endpoint/pci-ntb-function.rs 13 Documentation/PCI/endpoint/pci-ntb-function.rst
14 14
15 Endpoint Device 15 Endpoint Device
16 =============== 16 ===============
17 17
18 Endpoint Controller Devices 18 Endpoint Controller Devices
19 --------------------------- 19 ---------------------------
20 20
21 For implementing NTB functionality at least tw 21 For implementing NTB functionality at least two endpoint controller devices
22 are required. 22 are required.
23 23
24 To find the list of endpoint controller device 24 To find the list of endpoint controller devices in the system::
25 25
26 # ls /sys/class/pci_epc/ 26 # ls /sys/class/pci_epc/
27 2900000.pcie-ep 2910000.pcie-ep 27 2900000.pcie-ep 2910000.pcie-ep
28 28
29 If PCI_ENDPOINT_CONFIGFS is enabled:: 29 If PCI_ENDPOINT_CONFIGFS is enabled::
30 30
31 # ls /sys/kernel/config/pci_ep/control 31 # ls /sys/kernel/config/pci_ep/controllers
32 2900000.pcie-ep 2910000.pcie-ep 32 2900000.pcie-ep 2910000.pcie-ep
33 33
34 34
35 Endpoint Function Drivers 35 Endpoint Function Drivers
36 ------------------------- 36 -------------------------
37 37
38 To find the list of endpoint function drivers 38 To find the list of endpoint function drivers in the system::
39 39
40 # ls /sys/bus/pci-epf/drivers 40 # ls /sys/bus/pci-epf/drivers
41 pci_epf_ntb pci_epf_ntb 41 pci_epf_ntb pci_epf_ntb
42 42
43 If PCI_ENDPOINT_CONFIGFS is enabled:: 43 If PCI_ENDPOINT_CONFIGFS is enabled::
44 44
45 # ls /sys/kernel/config/pci_ep/functio 45 # ls /sys/kernel/config/pci_ep/functions
46 pci_epf_ntb pci_epf_ntb 46 pci_epf_ntb pci_epf_ntb
47 47
48 48
49 Creating pci-epf-ntb Device 49 Creating pci-epf-ntb Device
50 ---------------------------- 50 ----------------------------
51 51
52 PCI endpoint function device can be created us 52 PCI endpoint function device can be created using the configfs. To create
53 pci-epf-ntb device, the following commands can 53 pci-epf-ntb device, the following commands can be used::
54 54
55 # mount -t configfs none /sys/kernel/c 55 # mount -t configfs none /sys/kernel/config
56 # cd /sys/kernel/config/pci_ep/ 56 # cd /sys/kernel/config/pci_ep/
57 # mkdir functions/pci_epf_ntb/func1 57 # mkdir functions/pci_epf_ntb/func1
58 58
59 The "mkdir func1" above creates the pci-epf-nt 59 The "mkdir func1" above creates the pci-epf-ntb function device that will
60 be probed by pci_epf_ntb driver. 60 be probed by pci_epf_ntb driver.
61 61
62 The PCI endpoint framework populates the direc 62 The PCI endpoint framework populates the directory with the following
63 configurable fields:: 63 configurable fields::
64 64
65 # ls functions/pci_epf_ntb/func1 65 # ls functions/pci_epf_ntb/func1
66 baseclass_code deviceid ms 66 baseclass_code deviceid msi_interrupts pci-epf-ntb.0
67 progif_code secondary su 67 progif_code secondary subsys_id vendorid
68 cache_line_size interrupt_pin ms 68 cache_line_size interrupt_pin msix_interrupts primary
69 revid subclass_code su 69 revid subclass_code subsys_vendor_id
70 70
71 The PCI endpoint function driver populates the 71 The PCI endpoint function driver populates these entries with default values
72 when the device is bound to the driver. The pc 72 when the device is bound to the driver. The pci-epf-ntb driver populates
73 vendorid with 0xffff and interrupt_pin with 0x 73 vendorid with 0xffff and interrupt_pin with 0x0001::
74 74
75 # cat functions/pci_epf_ntb/func1/vend 75 # cat functions/pci_epf_ntb/func1/vendorid
76 0xffff 76 0xffff
77 # cat functions/pci_epf_ntb/func1/inte 77 # cat functions/pci_epf_ntb/func1/interrupt_pin
78 0x0001 78 0x0001
79 79
80 80
81 Configuring pci-epf-ntb Device 81 Configuring pci-epf-ntb Device
82 ------------------------------- 82 -------------------------------
83 83
84 The user can configure the pci-epf-ntb device 84 The user can configure the pci-epf-ntb device using its configfs entry. In order
85 to change the vendorid and the deviceid, the f 85 to change the vendorid and the deviceid, the following
86 commands can be used:: 86 commands can be used::
87 87
88 # echo 0x104c > functions/pci_epf_ntb/ 88 # echo 0x104c > functions/pci_epf_ntb/func1/vendorid
89 # echo 0xb00d > functions/pci_epf_ntb/ 89 # echo 0xb00d > functions/pci_epf_ntb/func1/deviceid
90 90
91 The PCI endpoint framework also automatically 91 The PCI endpoint framework also automatically creates a sub-directory in the
92 function attribute directory. This sub-directo 92 function attribute directory. This sub-directory has the same name as the name
93 of the function device and is populated with t 93 of the function device and is populated with the following NTB specific
94 attributes that can be configured by the user: 94 attributes that can be configured by the user::
95 95
96 # ls functions/pci_epf_ntb/func1/pci_e 96 # ls functions/pci_epf_ntb/func1/pci_epf_ntb.0/
97 db_count mw1 mw2 mw 97 db_count mw1 mw2 mw3 mw4 num_mws
98 spad_count 98 spad_count
99 99
100 A sample configuration for NTB function is giv 100 A sample configuration for NTB function is given below::
101 101
102 # echo 4 > functions/pci_epf_ntb/func1 102 # echo 4 > functions/pci_epf_ntb/func1/pci_epf_ntb.0/db_count
103 # echo 128 > functions/pci_epf_ntb/fun 103 # echo 128 > functions/pci_epf_ntb/func1/pci_epf_ntb.0/spad_count
104 # echo 2 > functions/pci_epf_ntb/func1 104 # echo 2 > functions/pci_epf_ntb/func1/pci_epf_ntb.0/num_mws
105 # echo 0x100000 > functions/pci_epf_nt 105 # echo 0x100000 > functions/pci_epf_ntb/func1/pci_epf_ntb.0/mw1
106 # echo 0x100000 > functions/pci_epf_nt 106 # echo 0x100000 > functions/pci_epf_ntb/func1/pci_epf_ntb.0/mw2
107 107
108 Binding pci-epf-ntb Device to EP Controller 108 Binding pci-epf-ntb Device to EP Controller
109 -------------------------------------------- 109 --------------------------------------------
110 110
111 NTB function device should be attached to two 111 NTB function device should be attached to two PCI endpoint controllers
112 connected to the two hosts. Use the 'primary' 112 connected to the two hosts. Use the 'primary' and 'secondary' entries
113 inside NTB function device to attach one PCI e 113 inside NTB function device to attach one PCI endpoint controller to
114 primary interface and the other PCI endpoint c 114 primary interface and the other PCI endpoint controller to the secondary
115 interface:: 115 interface::
116 116
117 # ln -s controllers/2900000.pcie-ep/ f 117 # ln -s controllers/2900000.pcie-ep/ functions/pci-epf-ntb/func1/primary
118 # ln -s controllers/2910000.pcie-ep/ f 118 # ln -s controllers/2910000.pcie-ep/ functions/pci-epf-ntb/func1/secondary
119 119
120 Once the above step is completed, both the PCI 120 Once the above step is completed, both the PCI endpoint controllers are ready to
121 establish a link with the host. 121 establish a link with the host.
122 122
123 123
124 Start the Link 124 Start the Link
125 -------------- 125 --------------
126 126
127 In order for the endpoint device to establish 127 In order for the endpoint device to establish a link with the host, the _start_
128 field should be populated with '1'. For NTB, b 128 field should be populated with '1'. For NTB, both the PCI endpoint controllers
129 should establish link with the host:: 129 should establish link with the host::
130 130
131 # echo 1 > controllers/2900000.pcie-ep 131 # echo 1 > controllers/2900000.pcie-ep/start
132 # echo 1 > controllers/2910000.pcie-ep 132 # echo 1 > controllers/2910000.pcie-ep/start
133 133
134 134
135 RootComplex Device 135 RootComplex Device
136 ================== 136 ==================
137 137
138 lspci Output 138 lspci Output
139 ------------ 139 ------------
140 140
141 Note that the devices listed here correspond t 141 Note that the devices listed here correspond to the values populated in
142 "Creating pci-epf-ntb Device" section above:: 142 "Creating pci-epf-ntb Device" section above::
143 143
144 # lspci 144 # lspci
145 0000:00:00.0 PCI bridge: Texas Instrum 145 0000:00:00.0 PCI bridge: Texas Instruments Device b00d
146 0000:01:00.0 RAM memory: Texas Instrum 146 0000:01:00.0 RAM memory: Texas Instruments Device b00d
147 147
148 148
149 Using ntb_hw_epf Device 149 Using ntb_hw_epf Device
150 ----------------------- 150 -----------------------
151 151
152 The host side software follows the standard NT 152 The host side software follows the standard NTB software architecture in Linux.
153 All the existing client side NTB utilities lik 153 All the existing client side NTB utilities like NTB Transport Client and NTB
154 Netdev, NTB Ping Pong Test Client and NTB Tool 154 Netdev, NTB Ping Pong Test Client and NTB Tool Test Client can be used with NTB
155 function device. 155 function device.
156 156
157 For more information on NTB see 157 For more information on NTB see
158 :doc:`Non-Transparent Bridge <../../driver-api 158 :doc:`Non-Transparent Bridge <../../driver-api/ntb>`
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