[PATCH 17/57] docs: infiniband: convert it to ReST format

Mauro Carvalho Chehab
2019-04-16T02:59:38Z

The InfiniBand docs are plain text with no markups.
So, all we needed to do were to add the title markups and
some markup sequences in order to properly parse tables,
lists and literal blocks.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
Documentation/infiniband/core_locking.txt | 64 +++++++------
Documentation/infiniband/ipoib.txt | 24 +++--
Documentation/infiniband/opa_vnic.txt | 108 ++++++++++++----------
Documentation/infiniband/sysfs.txt | 4 +-
Documentation/infiniband/tag_matching.txt | 5 +
Documentation/infiniband/user_mad.txt | 33 +++++--
Documentation/infiniband/user_verbs.txt | 12 ++-
7 files changed, 149 insertions(+), 101 deletions(-)

diff --git a/Documentation/infiniband/core_locking.txt b/Documentation/infiniband/core_locking.txt
index 4b1f36b6ada0..f34669beb4fe 100644
--- a/Documentation/infiniband/core_locking.txt
+++ b/Documentation/infiniband/core_locking.txt
@@ -1,4 +1,6 @@
-INFINIBAND MIDLAYER LOCKING
+===========================
+InfiniBand Midlayer Locking
+===========================

This guide is an attempt to make explicit the locking assumptions
made by the InfiniBand midlayer. It describes the requirements on
@@ -6,45 +8,47 @@ INFINIBAND MIDLAYER LOCKING
protocols that use the midlayer.

Sleeping and interrupt context
+==============================

With the following exceptions, a low-level driver implementation of
all of the methods in struct ib_device may sleep. The exceptions
are any methods from the list:

- create_ah
- modify_ah
- query_ah
- destroy_ah
- post_send
- post_recv
- poll_cq
- req_notify_cq
- map_phys_fmr
+ - create_ah
+ - modify_ah
+ - query_ah
+ - destroy_ah
+ - post_send
+ - post_recv
+ - poll_cq
+ - req_notify_cq
+ - map_phys_fmr

which may not sleep and must be callable from any context.

The corresponding functions exported to upper level protocol
consumers:

- ib_create_ah
- ib_modify_ah
- ib_query_ah
- ib_destroy_ah
- ib_post_send
- ib_post_recv
- ib_req_notify_cq
- ib_map_phys_fmr
+ - ib_create_ah
+ - ib_modify_ah
+ - ib_query_ah
+ - ib_destroy_ah
+ - ib_post_send
+ - ib_post_recv
+ - ib_req_notify_cq
+ - ib_map_phys_fmr

are therefore safe to call from any context.

In addition, the function

- ib_dispatch_event
+ - ib_dispatch_event

used by low-level drivers to dispatch asynchronous events through
the midlayer is also safe to call from any context.

Reentrancy
+----------

All of the methods in struct ib_device exported by a low-level
driver must be fully reentrant. The low-level driver is required to
@@ -62,6 +66,7 @@ Reentrancy
information between different calls of ib_poll_cq() is not defined.

Callbacks
+---------

A low-level driver must not perform a callback directly from the
same callchain as an ib_device method call. For example, it is not
@@ -74,18 +79,18 @@ Callbacks
completion event handlers for the same CQ are not called
simultaneously. The driver must guarantee that only one CQ event
handler for a given CQ is running at a time. In other words, the
- following situation is not allowed:
+ following situation is not allowed::

- CPU1 CPU2
+ CPU1 CPU2

- low-level driver ->
- consumer CQ event callback:
- /* ... */
- ib_req_notify_cq(cq, ...);
- low-level driver ->
- /* ... */ consumer CQ event callback:
- /* ... */
- return from CQ event handler
+ low-level driver ->
+ consumer CQ event callback:
+ /* ... */
+ ib_req_notify_cq(cq, ...);
+ low-level driver ->
+ /* ... */ consumer CQ event callback:
+ /* ... */
+ return from CQ event handler

The context in which completion event and asynchronous event
callbacks run is not defined. Depending on the low-level driver, it
@@ -93,6 +98,7 @@ Callbacks
Upper level protocol consumers may not sleep in a callback.

Hot-plug
+--------

A low-level driver announces that a device is ready for use by
consumers when it calls ib_register_device(), all initialization
diff --git a/Documentation/infiniband/ipoib.txt b/Documentation/infiniband/ipoib.txt
index 47c1dd9818f2..0dd36154c0c9 100644
--- a/Documentation/infiniband/ipoib.txt
+++ b/Documentation/infiniband/ipoib.txt
@@ -1,4 +1,6 @@
-IP OVER INFINIBAND
+==================
+IP over InfiniBand
+==================

The ib_ipoib driver is an implementation of the IP over InfiniBand
protocol as specified by RFC 4391 and 4392, issued by the IETF ipoib
@@ -8,16 +10,17 @@ IP OVER INFINIBAND
masqueraded to the kernel as ethernet interfaces).

Partitions and P_Keys
+=====================

When the IPoIB driver is loaded, it creates one interface for each
port using the P_Key at index 0. To create an interface with a
different P_Key, write the desired P_Key into the main interface's
- /sys/class/net/<intf name>/create_child file. For example:
+ /sys/class/net/<intf name>/create_child file. For example::

echo 0x8001 > /sys/class/net/ib0/create_child

This will create an interface named ib0.8001 with P_Key 0x8001. To
- remove a subinterface, use the "delete_child" file:
+ remove a subinterface, use the "delete_child" file::

echo 0x8001 > /sys/class/net/ib0/delete_child

@@ -28,6 +31,7 @@ Partitions and P_Keys
rtnl_link_ops, where children created using either way behave the same.

Datagram vs Connected modes
+===========================

The IPoIB driver supports two modes of operation: datagram and
connected. The mode is set and read through an interface's
@@ -51,6 +55,7 @@ Datagram vs Connected modes
networking stack to use the smaller UD MTU for these neighbours.

Stateless offloads
+==================

If the IB HW supports IPoIB stateless offloads, IPoIB advertises
TCP/IP checksum and/or Large Send (LSO) offloading capability to the
@@ -60,9 +65,10 @@ Stateless offloads
on/off using ethtool calls. Currently LRO is supported only for
checksum offload capable devices.

- Stateless offloads are supported only in datagram mode.
+ Stateless offloads are supported only in datagram mode.

Interrupt moderation
+====================

If the underlying IB device supports CQ event moderation, one can
use ethtool to set interrupt mitigation parameters and thus reduce
@@ -71,6 +77,7 @@ Interrupt moderation
moderation is supported.

Debugging Information
+=====================

By compiling the IPoIB driver with CONFIG_INFINIBAND_IPOIB_DEBUG set
to 'y', tracing messages are compiled into the driver. They are
@@ -79,7 +86,7 @@ Debugging Information
runtime through files in /sys/module/ib_ipoib/.

CONFIG_INFINIBAND_IPOIB_DEBUG also enables files in the debugfs
- virtual filesystem. By mounting this filesystem, for example with
+ virtual filesystem. By mounting this filesystem, for example with::

mount -t debugfs none /sys/kernel/debug

@@ -96,10 +103,13 @@ Debugging Information
performance, because it adds tests to the fast path.

References
+==========

Transmission of IP over InfiniBand (IPoIB) (RFC 4391)
- http://ietf.org/rfc/rfc4391.txt
+ http://ietf.org/rfc/rfc4391.txt
+
IP over InfiniBand (IPoIB) Architecture (RFC 4392)
- http://ietf.org/rfc/rfc4392.txt
+ http://ietf.org/rfc/rfc4392.txt
+
IP over InfiniBand: Connected Mode (RFC 4755)
http://ietf.org/rfc/rfc4755.txt
diff --git a/Documentation/infiniband/opa_vnic.txt b/Documentation/infiniband/opa_vnic.txt
index 282e17be798a..2f888d9ffec0 100644
--- a/Documentation/infiniband/opa_vnic.txt
+++ b/Documentation/infiniband/opa_vnic.txt
@@ -1,3 +1,7 @@
+=================================================================
+Intel Omni-Path (OPA) Virtual Network Interface Controller (VNIC)
+=================================================================
+
Intel Omni-Path (OPA) Virtual Network Interface Controller (VNIC) feature
supports Ethernet functionality over Omni-Path fabric by encapsulating
the Ethernet packets between HFI nodes.
@@ -17,70 +21,72 @@ an independent Ethernet network. The configuration is performed by an
Ethernet Manager (EM) which is part of the trusted Fabric Manager (FM)
application. HFI nodes can have multiple VNICs each connected to a
different virtual Ethernet switch. The below diagram presents a case
-of two virtual Ethernet switches with two HFI nodes.
+of two virtual Ethernet switches with two HFI nodes::

- +-------------------+
- | Subnet/ |
- | Ethernet |
- | Manager |
- +-------------------+
- / /
- / /
- / /
- / /
-+-----------------------------+ +------------------------------+
-| Virtual Ethernet Switch | | Virtual Ethernet Switch |
-| +---------+ +---------+ | | +---------+ +---------+ |
-| | VPORT | | VPORT | | | | VPORT | | VPORT | |
-+--+---------+----+---------+-+ +-+---------+----+---------+---+
- | \ / |
- | \ / |
- | \/ |
- | / \ |
- | / \ |
- +-----------+------------+ +-----------+------------+
- | VNIC | VNIC | | VNIC | VNIC |
- +-----------+------------+ +-----------+------------+
- | HFI | | HFI |
- +------------------------+ +------------------------+
+ +-------------------+
+ | Subnet/ |
+ | Ethernet |
+ | Manager |
+ +-------------------+
+ / /
+ / /
+ / /
+ / /
+ +-----------------------------+ +------------------------------+
+ | Virtual Ethernet Switch | | Virtual Ethernet Switch |
+ | +---------+ +---------+ | | +---------+ +---------+ |
+ | | VPORT | | VPORT | | | | VPORT | | VPORT | |
+ +--+---------+----+---------+-+ +-+---------+----+---------+---+
+ | \ / |
+ | \ / |
+ | \/ |
+ | / \ |
+ | / \ |
+ +-----------+------------+ +-----------+------------+
+ | VNIC | VNIC | | VNIC | VNIC |
+ +-----------+------------+ +-----------+------------+
+ | HFI | | HFI |
+ +------------------------+ +------------------------+

The Omni-Path encapsulated Ethernet packet format is as described below.

-Bits Field
-------------------------------------
+==================== ================================
+Bits Field
+==================== ================================
Quad Word 0:
-0-19 SLID (lower 20 bits)
-20-30 Length (in Quad Words)
-31 BECN bit
-32-51 DLID (lower 20 bits)
-52-56 SC (Service Class)
-57-59 RC (Routing Control)
-60 FECN bit
-61-62 L2 (=10, 16B format)
-63 LT (=1, Link Transfer Head Flit)
+0-19 SLID (lower 20 bits)
+20-30 Length (in Quad Words)
+31 BECN bit
+32-51 DLID (lower 20 bits)
+52-56 SC (Service Class)
+57-59 RC (Routing Control)
+60 FECN bit
+61-62 L2 (=10, 16B format)
+63 LT (=1, Link Transfer Head Flit)

Quad Word 1:
-0-7 L4 type (=0x78 ETHERNET)
-8-11 SLID[23:20]
-12-15 DLID[23:20]
-16-31 PKEY
-32-47 Entropy
-48-63 Reserved
+0-7 L4 type (=0x78 ETHERNET)
+8-11 SLID[23:20]
+12-15 DLID[23:20]
+16-31 PKEY
+32-47 Entropy
+48-63 Reserved

Quad Word 2:
-0-15 Reserved
-16-31 L4 header
-32-63 Ethernet Packet
+0-15 Reserved
+16-31 L4 header
+32-63 Ethernet Packet

Quad Words 3 to N-1:
-0-63 Ethernet packet (pad extended)
+0-63 Ethernet packet (pad extended)

Quad Word N (last):
-0-23 Ethernet packet (pad extended)
-24-55 ICRC
-56-61 Tail
-62-63 LT (=01, Link Transfer Tail Flit)
+0-23 Ethernet packet (pad extended)
+24-55 ICRC
+56-61 Tail
+62-63 LT (=01, Link Transfer Tail Flit)
+==================== ================================

Ethernet packet is padded on the transmit side to ensure that the VNIC OPA
packet is quad word aligned. The 'Tail' field contains the number of bytes
@@ -123,7 +129,7 @@ operation. It also handles the encapsulation of Ethernet packets with an
Omni-Path header in the transmit path. For each VNIC interface, the
information required for encapsulation is configured by the EM via VEMA MAD
interface. It also passes any control information to the HW dependent driver
-by invoking the RDMA netdev control operations.
+by invoking the RDMA netdev control operations::

+-------------------+ +----------------------+
| | | Linux |
diff --git a/Documentation/infiniband/sysfs.txt b/Documentation/infiniband/sysfs.txt
index 9fab5062f84b..f0abd6fa48f4 100644
--- a/Documentation/infiniband/sysfs.txt
+++ b/Documentation/infiniband/sysfs.txt
@@ -1,4 +1,6 @@
-SYSFS FILES
+===========
+Sysfs files
+===========

The sysfs interface has moved to
Documentation/ABI/stable/sysfs-class-infiniband.
diff --git a/Documentation/infiniband/tag_matching.txt b/Documentation/infiniband/tag_matching.txt
index d2a3bf819226..ef56ea585f92 100644
--- a/Documentation/infiniband/tag_matching.txt
+++ b/Documentation/infiniband/tag_matching.txt
@@ -1,12 +1,16 @@
+==================
Tag matching logic
+==================

The MPI standard defines a set of rules, known as tag-matching, for matching
source send operations to destination receives. The following parameters must
match the following source and destination parameters:
+
* Communicator
* User tag - wild card may be specified by the receiver
* Source rank – wild car may be specified by the receiver
* Destination rank – wild
+
The ordering rules require that when more than one pair of send and receive
message envelopes may match, the pair that includes the earliest posted-send
and the earliest posted-receive is the pair that must be used to satisfy the
@@ -35,6 +39,7 @@ the header to initiate an RDMA READ operation directly to the matching buffer.
A fin message needs to be received in order for the buffer to be reused.

Tag matching implementation
+===========================

There are two types of matching objects used, the posted receive list and the
unexpected message list. The application posts receive buffers through calls
diff --git a/Documentation/infiniband/user_mad.txt b/Documentation/infiniband/user_mad.txt
index 7aca13a54a3a..d88abfc0e370 100644
--- a/Documentation/infiniband/user_mad.txt
+++ b/Documentation/infiniband/user_mad.txt
@@ -1,6 +1,9 @@
-USERSPACE MAD ACCESS
+====================
+Userspace MAD access
+====================

Device files
+============

Each port of each InfiniBand device has a "umad" device and an
"issm" device attached. For example, a two-port HCA will have two
@@ -8,12 +11,13 @@ Device files
device of each type (for switch port 0).

Creating MAD agents
+===================

A MAD agent can be created by filling in a struct ib_user_mad_reg_req
and then calling the IB_USER_MAD_REGISTER_AGENT ioctl on a file
descriptor for the appropriate device file. If the registration
request succeeds, a 32-bit id will be returned in the structure.
- For example:
+ For example::

struct ib_user_mad_reg_req req = { /* ... */ };
ret = ioctl(fd, IB_USER_MAD_REGISTER_AGENT, (char *) &req);
@@ -26,12 +30,14 @@ Creating MAD agents
ioctl. Also, all agents registered through a file descriptor will
be unregistered when the descriptor is closed.

- 2014 -- a new registration ioctl is now provided which allows additional
+ 2014
+ a new registration ioctl is now provided which allows additional
fields to be provided during registration.
Users of this registration call are implicitly setting the use of
pkey_index (see below).

Receiving MADs
+==============

MADs are received using read(). The receive side now supports
RMPP. The buffer passed to read() must be at least one
@@ -41,7 +47,8 @@ Receiving MADs
MAD (RMPP), the errno is set to ENOSPC and the length of the
buffer needed is set in mad.length.

- Example for normal MAD (non RMPP) reads:
+ Example for normal MAD (non RMPP) reads::
+
struct ib_user_mad *mad;
mad = malloc(sizeof *mad + 256);
ret = read(fd, mad, sizeof *mad + 256);
@@ -50,7 +57,8 @@ Receiving MADs
free(mad);
}

- Example for RMPP reads:
+ Example for RMPP reads::
+
struct ib_user_mad *mad;
mad = malloc(sizeof *mad + 256);
ret = read(fd, mad, sizeof *mad + 256);
@@ -76,11 +84,12 @@ Receiving MADs
poll()/select() may be used to wait until a MAD can be read.

Sending MADs
+============

MADs are sent using write(). The agent ID for sending should be
filled into the id field of the MAD, the destination LID should be
filled into the lid field, and so on. The send side does support
- RMPP so arbitrary length MAD can be sent. For example:
+ RMPP so arbitrary length MAD can be sent. For example::

struct ib_user_mad *mad;

@@ -97,6 +106,7 @@ Sending MADs
perror("write");

Transaction IDs
+===============

Users of the umad devices can use the lower 32 bits of the
transaction ID field (that is, the least significant half of the
@@ -105,6 +115,7 @@ Transaction IDs
the kernel and will be overwritten before a MAD is sent.

P_Key Index Handling
+====================

The old ib_umad interface did not allow setting the P_Key index for
MADs that are sent and did not provide a way for obtaining the P_Key
@@ -119,6 +130,7 @@ P_Key Index Handling
default, and the IB_USER_MAD_ENABLE_PKEY ioctl will be removed.

Setting IsSM Capability Bit
+===========================

To set the IsSM capability bit for a port, simply open the
corresponding issm device file. If the IsSM bit is already set,
@@ -129,25 +141,26 @@ Setting IsSM Capability Bit
the issm file.

/dev files
+==========

To create the appropriate character device files automatically with
- udev, a rule like
+ udev, a rule like::

KERNEL=="umad*", NAME="infiniband/%k"
KERNEL=="issm*", NAME="infiniband/%k"

- can be used. This will create device nodes named
+ can be used. This will create device nodes named::

/dev/infiniband/umad0
/dev/infiniband/issm0

for the first port, and so on. The InfiniBand device and port
- associated with these devices can be determined from the files
+ associated with these devices can be determined from the files::

/sys/class/infiniband_mad/umad0/ibdev
/sys/class/infiniband_mad/umad0/port

- and
+ and::

/sys/class/infiniband_mad/issm0/ibdev
/sys/class/infiniband_mad/issm0/port
diff --git a/Documentation/infiniband/user_verbs.txt b/Documentation/infiniband/user_verbs.txt
index 47ebf2f80b2b..8ddc4b1cfef2 100644
--- a/Documentation/infiniband/user_verbs.txt
+++ b/Documentation/infiniband/user_verbs.txt
@@ -1,4 +1,6 @@
-USERSPACE VERBS ACCESS
+======================
+Userspace verbs access
+======================

The ib_uverbs module, built by enabling CONFIG_INFINIBAND_USER_VERBS,
enables direct userspace access to IB hardware via "verbs," as
@@ -13,6 +15,7 @@ USERSPACE VERBS ACCESS
libmthca userspace driver be installed.

User-kernel communication
+=========================

Userspace communicates with the kernel for slow path, resource
management operations via the /dev/infiniband/uverbsN character
@@ -28,6 +31,7 @@ User-kernel communication
system call.

Resource management
+===================

Since creation and destruction of all IB resources is done by
commands passed through a file descriptor, the kernel can keep track
@@ -41,6 +45,7 @@ Resource management
prevent one process from touching another process's resources.

Memory pinning
+==============

Direct userspace I/O requires that memory regions that are potential
I/O targets be kept resident at the same physical address. The
@@ -54,13 +59,14 @@ Memory pinning
number of pages pinned by a process.

/dev files
+==========

To create the appropriate character device files automatically with
- udev, a rule like
+ udev, a rule like::

KERNEL=="uverbs*", NAME="infiniband/%k"

- can be used. This will create device nodes named
+ can be used. This will create device nodes named::

/dev/infiniband/uverbs0

--
2.20.1