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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/infiniband
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'Documentation/infiniband')
-rw-r--r--Documentation/infiniband/ipoib.txt56
-rw-r--r--Documentation/infiniband/sysfs.txt66
-rw-r--r--Documentation/infiniband/user_mad.txt99
3 files changed, 221 insertions, 0 deletions
diff --git a/Documentation/infiniband/ipoib.txt b/Documentation/infiniband/ipoib.txt
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+++ b/Documentation/infiniband/ipoib.txt
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1IP OVER INFINIBAND
2
3 The ib_ipoib driver is an implementation of the IP over InfiniBand
4 protocol as specified by the latest Internet-Drafts issued by the
5 IETF ipoib working group. It is a "native" implementation in the
6 sense of setting the interface type to ARPHRD_INFINIBAND and the
7 hardware address length to 20 (earlier proprietary implementations
8 masqueraded to the kernel as ethernet interfaces).
9
10Partitions and P_Keys
11
12 When the IPoIB driver is loaded, it creates one interface for each
13 port using the P_Key at index 0. To create an interface with a
14 different P_Key, write the desired P_Key into the main interface's
15 /sys/class/net/<intf name>/create_child file. For example:
16
17 echo 0x8001 > /sys/class/net/ib0/create_child
18
19 This will create an interface named ib0.8001 with P_Key 0x8001. To
20 remove a subinterface, use the "delete_child" file:
21
22 echo 0x8001 > /sys/class/net/ib0/delete_child
23
24 The P_Key for any interface is given by the "pkey" file, and the
25 main interface for a subinterface is in "parent."
26
27Debugging Information
28
29 By compiling the IPoIB driver with CONFIG_INFINIBAND_IPOIB_DEBUG set
30 to 'y', tracing messages are compiled into the driver. They are
31 turned on by setting the module parameters debug_level and
32 mcast_debug_level to 1. These parameters can be controlled at
33 runtime through files in /sys/module/ib_ipoib/.
34
35 CONFIG_INFINIBAND_IPOIB_DEBUG also enables the "ipoib_debugfs"
36 virtual filesystem. By mounting this filesystem, for example with
37
38 mkdir -p /ipoib_debugfs
39 mount -t ipoib_debugfs none /ipoib_debufs
40
41 it is possible to get statistics about multicast groups from the
42 files /ipoib_debugfs/ib0_mcg and so on.
43
44 The performance impact of this option is negligible, so it
45 is safe to enable this option with debug_level set to 0 for normal
46 operation.
47
48 CONFIG_INFINIBAND_IPOIB_DEBUG_DATA enables even more debug output in
49 the data path when data_debug_level is set to 1. However, even with
50 the output disabled, enabling this configuration option will affect
51 performance, because it adds tests to the fast path.
52
53References
54
55 IETF IP over InfiniBand (ipoib) Working Group
56 http://ietf.org/html.charters/ipoib-charter.html
diff --git a/Documentation/infiniband/sysfs.txt b/Documentation/infiniband/sysfs.txt
new file mode 100644
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1SYSFS FILES
2
3 For each InfiniBand device, the InfiniBand drivers create the
4 following files under /sys/class/infiniband/<device name>:
5
6 node_type - Node type (CA, switch or router)
7 node_guid - Node GUID
8 sys_image_guid - System image GUID
9
10 In addition, there is a "ports" subdirectory, with one subdirectory
11 for each port. For example, if mthca0 is a 2-port HCA, there will
12 be two directories:
13
14 /sys/class/infiniband/mthca0/ports/1
15 /sys/class/infiniband/mthca0/ports/2
16
17 (A switch will only have a single "0" subdirectory for switch port
18 0; no subdirectory is created for normal switch ports)
19
20 In each port subdirectory, the following files are created:
21
22 cap_mask - Port capability mask
23 lid - Port LID
24 lid_mask_count - Port LID mask count
25 rate - Port data rate (active width * active speed)
26 sm_lid - Subnet manager LID for port's subnet
27 sm_sl - Subnet manager SL for port's subnet
28 state - Port state (DOWN, INIT, ARMED, ACTIVE or ACTIVE_DEFER)
29 phys_state - Port physical state (Sleep, Polling, LinkUp, etc)
30
31 There is also a "counters" subdirectory, with files
32
33 VL15_dropped
34 excessive_buffer_overrun_errors
35 link_downed
36 link_error_recovery
37 local_link_integrity_errors
38 port_rcv_constraint_errors
39 port_rcv_data
40 port_rcv_errors
41 port_rcv_packets
42 port_rcv_remote_physical_errors
43 port_rcv_switch_relay_errors
44 port_xmit_constraint_errors
45 port_xmit_data
46 port_xmit_discards
47 port_xmit_packets
48 symbol_error
49
50 Each of these files contains the corresponding value from the port's
51 Performance Management PortCounters attribute, as described in
52 section 16.1.3.5 of the InfiniBand Architecture Specification.
53
54 The "pkeys" and "gids" subdirectories contain one file for each
55 entry in the port's P_Key or GID table respectively. For example,
56 ports/1/pkeys/10 contains the value at index 10 in port 1's P_Key
57 table.
58
59MTHCA
60
61 The Mellanox HCA driver also creates the files:
62
63 hw_rev - Hardware revision number
64 fw_ver - Firmware version
65 hca_type - HCA type: "MT23108", "MT25208 (MT23108 compat mode)",
66 or "MT25208"
diff --git a/Documentation/infiniband/user_mad.txt b/Documentation/infiniband/user_mad.txt
new file mode 100644
index 000000000000..cae0c83f1ee9
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1USERSPACE MAD ACCESS
2
3Device files
4
5 Each port of each InfiniBand device has a "umad" device and an
6 "issm" device attached. For example, a two-port HCA will have two
7 umad devices and two issm devices, while a switch will have one
8 device of each type (for switch port 0).
9
10Creating MAD agents
11
12 A MAD agent can be created by filling in a struct ib_user_mad_reg_req
13 and then calling the IB_USER_MAD_REGISTER_AGENT ioctl on a file
14 descriptor for the appropriate device file. If the registration
15 request succeeds, a 32-bit id will be returned in the structure.
16 For example:
17
18 struct ib_user_mad_reg_req req = { /* ... */ };
19 ret = ioctl(fd, IB_USER_MAD_REGISTER_AGENT, (char *) &req);
20 if (!ret)
21 my_agent = req.id;
22 else
23 perror("agent register");
24
25 Agents can be unregistered with the IB_USER_MAD_UNREGISTER_AGENT
26 ioctl. Also, all agents registered through a file descriptor will
27 be unregistered when the descriptor is closed.
28
29Receiving MADs
30
31 MADs are received using read(). The buffer passed to read() must be
32 large enough to hold at least one struct ib_user_mad. For example:
33
34 struct ib_user_mad mad;
35 ret = read(fd, &mad, sizeof mad);
36 if (ret != sizeof mad)
37 perror("read");
38
39 In addition to the actual MAD contents, the other struct ib_user_mad
40 fields will be filled in with information on the received MAD. For
41 example, the remote LID will be in mad.lid.
42
43 If a send times out, a receive will be generated with mad.status set
44 to ETIMEDOUT. Otherwise when a MAD has been successfully received,
45 mad.status will be 0.
46
47 poll()/select() may be used to wait until a MAD can be read.
48
49Sending MADs
50
51 MADs are sent using write(). The agent ID for sending should be
52 filled into the id field of the MAD, the destination LID should be
53 filled into the lid field, and so on. For example:
54
55 struct ib_user_mad mad;
56
57 /* fill in mad.data */
58
59 mad.id = my_agent; /* req.id from agent registration */
60 mad.lid = my_dest; /* in network byte order... */
61 /* etc. */
62
63 ret = write(fd, &mad, sizeof mad);
64 if (ret != sizeof mad)
65 perror("write");
66
67Setting IsSM Capability Bit
68
69 To set the IsSM capability bit for a port, simply open the
70 corresponding issm device file. If the IsSM bit is already set,
71 then the open call will block until the bit is cleared (or return
72 immediately with errno set to EAGAIN if the O_NONBLOCK flag is
73 passed to open()). The IsSM bit will be cleared when the issm file
74 is closed. No read, write or other operations can be performed on
75 the issm file.
76
77/dev files
78
79 To create the appropriate character device files automatically with
80 udev, a rule like
81
82 KERNEL="umad*", NAME="infiniband/%k"
83 KERNEL="issm*", NAME="infiniband/%k"
84
85 can be used. This will create device nodes named
86
87 /dev/infiniband/umad0
88 /dev/infiniband/issm0
89
90 for the first port, and so on. The InfiniBand device and port
91 associated with these devices can be determined from the files
92
93 /sys/class/infiniband_mad/umad0/ibdev
94 /sys/class/infiniband_mad/umad0/port
95
96 and
97
98 /sys/class/infiniband_mad/issm0/ibdev
99 /sys/class/infiniband_mad/issm0/port