1 .. SPDX-License-Identifier: GPL-2.0
2
3 =======================================
4 Configuring PCI Endpoint Using CONFIGFS
5 =======================================
6
7 :Author: Kishon Vijay Abraham I <kishon@ti.com>
8
9 The PCI Endpoint Core exposes configfs entry (
10 PCI endpoint function and to bind the endpoint
11 with the endpoint controller. (For introducing
12 configure the PCI Endpoint Function refer to [
13
14 Mounting configfs
15 =================
16
17 The PCI Endpoint Core layer creates pci_ep dir
18 directory. configfs can be mounted using the f
19
20 mount -t configfs none /sys/kernel/con
21
22 Directory Structure
23 ===================
24
25 The pci_ep configfs has two directories at its
26 functions. Every EPC device present in the sys
27 the *controllers* directory and every EPF driv
28 will have an entry in the *functions* director
29 ::
30
31 /sys/kernel/config/pci_ep/
32 .. controllers/
33 .. functions/
34
35 Creating EPF Device
36 ===================
37
38 Every registered EPF driver will be listed in
39 entries corresponding to EPF driver will be cr
40 ::
41
42 /sys/kernel/config/pci_ep/functions/
43 .. <EPF Driver1>/
44 ... <EPF Device 11>/
45 ... <EPF Device 21>/
46 ... <EPF Device 31>/
47 .. <EPF Driver2>/
48 ... <EPF Device 12>/
49 ... <EPF Device 22>/
50
51 In order to create a <EPF device> of the type
52 user has to create a directory inside <EPF Dri
53
54 Every <EPF device> directory consists of the f
55 used to configure the standard configuration h
56 (These entries are created by the framework wh
57 created)
58 ::
59
60 .. <EPF Driver1>/
61 ... <EPF Device 11>/
62 ... vendorid
63 ... deviceid
64 ... revid
65 ... progif_cod
66 ... subclass_c
67 ... baseclass_
68 ... cache_line
69 ... subsys_ven
70 ... subsys_id
71 ... interrupt_
72 ... <Symlink E
73 ... primary/
74 ... <S
75 ... secondary/
76 ... <S
77
78 If an EPF device has to be associated with 2 E
79 Non-transparent bridge), symlink of endpoint c
80 interface should be added in 'primary' directo
81 controller connected to secondary interface sh
82 directory.
83
84 The <EPF Device> directory can have a list of
85 (<Symlink EPF Device 31>) to other <EPF Device
86 be created by the user to represent the virtua
87 the physical function. In the above directory
88 physical function and <EPF Device 31> is a vir
89 it's linked to another EPF device, cannot be l
90
91 EPC Device
92 ==========
93
94 Every registered EPC device will be listed in
95 entries corresponding to EPC device will be cr
96 ::
97
98 /sys/kernel/config/pci_ep/controllers/
99 .. <EPC Device1>/
100 ... <Symlink EPF Devic
101 ... <Symlink EPF Devic
102 ... start
103 .. <EPC Device2>/
104 ... <Symlink EPF Devic
105 ... <Symlink EPF Devic
106 ... start
107
108 The <EPC Device> directory will have a list of
109 <EPF Device>. These symbolic links should be c
110 represent the functions present in the endpoin
111 that represents a physical function can be lin
112
113 The <EPC Device> directory will also have a *s
114 "1" is written to this field, the endpoint dev
115 establish the link with the host. This is usua
116 all the EPF devices are created and linked wit
117 ::
118
119 | controllers/
120 | <Directory:
121 | <Sym
122 | star
123 | functions/
124 | <Directory:
125 | <Dir
126
127
128
129
130
131
132
133
134
135
136
137
138 [1] Documentation/PCI/endpoint/pci-endpoint.rs
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.