aboutsummaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2009-04-13 14:41:05 -0700
committerDavid S. Miller <davem@davemloft.net>2009-04-13 14:41:05 -0700
commit83400207a07584539366f6859362db6872809a12 (patch)
treefad187f8b3bebf1b387ec42ef8143e6f4e49a256 /Documentation
parent0d489ffb76de0fe804cf06a9d4d11fa7342d74b9 (diff)
parent80a04d3f2f94fb68b5df05e3ac6697130bc3467a (diff)
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts: MAINTAINERS
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DocBook/Makefile11
-rw-r--r--Documentation/cgroups/cpuacct.txt18
-rw-r--r--Documentation/feature-removal-schedule.txt9
-rw-r--r--Documentation/infiniband/ipoib.txt45
-rw-r--r--Documentation/input/rotary-encoder.txt101
-rw-r--r--Documentation/kbuild/makefiles.txt83
-rw-r--r--Documentation/sparse.txt8
-rw-r--r--Documentation/trace/ftrace.txt (renamed from Documentation/ftrace.txt)0
-rw-r--r--Documentation/trace/kmemtrace.txt (renamed from Documentation/vm/kmemtrace.txt)0
-rw-r--r--Documentation/trace/mmiotrace.txt (renamed from Documentation/tracers/mmiotrace.txt)0
-rw-r--r--Documentation/trace/tracepoints.txt (renamed from Documentation/tracepoints.txt)0
11 files changed, 264 insertions, 11 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index a3a83d38f96..8918a32c6b3 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -31,7 +31,7 @@ PS_METHOD = $(prefer-db2x)
###
# The targets that may be used.
-PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs
+PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs
BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))
xmldocs: $(BOOKS)
@@ -213,11 +213,12 @@ silent_gen_xml = :
dochelp:
@echo ' Linux kernel internal documentation in different formats:'
@echo ' htmldocs - HTML'
- @echo ' installmandocs - install man pages generated by mandocs'
- @echo ' mandocs - man pages'
@echo ' pdfdocs - PDF'
@echo ' psdocs - Postscript'
@echo ' xmldocs - XML DocBook'
+ @echo ' mandocs - man pages'
+ @echo ' installmandocs - install man pages generated by mandocs'
+ @echo ' cleandocs - clean all generated DocBook files'
###
# Temporary files left by various tools
@@ -235,6 +236,10 @@ clean-files := $(DOCBOOKS) \
clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) man
+cleandocs:
+ $(Q)rm -f $(call objectify, $(clean-files))
+ $(Q)rm -rf $(call objectify, $(clean-dirs))
+
# Declare the contents of the .PHONY variable as phony. We keep that
# information in a variable se we can use it in if_changed and friends.
diff --git a/Documentation/cgroups/cpuacct.txt b/Documentation/cgroups/cpuacct.txt
index bb775fbe43d..8b930946c52 100644
--- a/Documentation/cgroups/cpuacct.txt
+++ b/Documentation/cgroups/cpuacct.txt
@@ -30,3 +30,21 @@ The above steps create a new group g1 and move the current shell
process (bash) into it. CPU time consumed by this bash and its children
can be obtained from g1/cpuacct.usage and the same is accumulated in
/cgroups/cpuacct.usage also.
+
+cpuacct.stat file lists a few statistics which further divide the
+CPU time obtained by the cgroup into user and system times. Currently
+the following statistics are supported:
+
+user: Time spent by tasks of the cgroup in user mode.
+system: Time spent by tasks of the cgroup in kernel mode.
+
+user and system are in USER_HZ unit.
+
+cpuacct controller uses percpu_counter interface to collect user and
+system times. This has two side effects:
+
+- It is theoretically possible to see wrong values for user and system times.
+ This is because percpu_counter_read() on 32bit systems isn't safe
+ against concurrent writes.
+- It is possible to see slightly outdated values for user and system times
+ due to the batch processing nature of percpu_counter.
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 7e2af10e826..de491a3e231 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -428,3 +428,12 @@ Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
After a reasonable transition period, we will remove the legacy
fakephp interface.
Who: Alex Chiang <achiang@hp.com>
+
+---------------------------
+
+What: i2c-voodoo3 driver
+When: October 2009
+Why: Superseded by tdfxfb. I2C/DDC support used to live in a separate
+ driver but this caused driver conflicts.
+Who: Jean Delvare <khali@linux-fr.org>
+ Krzysztof Helt <krzysztof.h1@wp.pl>
diff --git a/Documentation/infiniband/ipoib.txt b/Documentation/infiniband/ipoib.txt
index 864ff328378..6d40f00b358 100644
--- a/Documentation/infiniband/ipoib.txt
+++ b/Documentation/infiniband/ipoib.txt
@@ -24,6 +24,49 @@ Partitions and P_Keys
The P_Key for any interface is given by the "pkey" file, and the
main interface for a subinterface is in "parent."
+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
+ /sys/class/net/<intf name>/mode file.
+
+ In datagram mode, the IB UD (Unreliable Datagram) transport is used
+ and so the interface MTU has is equal to the IB L2 MTU minus the
+ IPoIB encapsulation header (4 bytes). For example, in a typical IB
+ fabric with a 2K MTU, the IPoIB MTU will be 2048 - 4 = 2044 bytes.
+
+ In connected mode, the IB RC (Reliable Connected) transport is used.
+ Connected mode is to takes advantage of the connected nature of the
+ IB transport and allows an MTU up to the maximal IP packet size of
+ 64K, which reduces the number of IP packets needed for handling
+ large UDP datagrams, TCP segments, etc and increases the performance
+ for large messages.
+
+ In connected mode, the interface's UD QP is still used for multicast
+ and communication with peers that don't support connected mode. In
+ this case, RX emulation of ICMP PMTU packets is used to cause the
+ 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
+ network stack.
+
+ Large Receive (LRO) offloading is also implemented and may be turned
+ on/off using ethtool calls. Currently LRO is supported only for
+ checksum offload capable devices.
+
+ 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
+ the overhead incurred by handling interrupts. The main code path of
+ IPoIB doesn't use events for TX completion signaling so only RX
+ moderation is supported.
+
Debugging Information
By compiling the IPoIB driver with CONFIG_INFINIBAND_IPOIB_DEBUG set
@@ -55,3 +98,5 @@ References
http://ietf.org/rfc/rfc4391.txt
IP over InfiniBand (IPoIB) Architecture (RFC 4392)
http://ietf.org/rfc/rfc4392.txt
+ IP over InfiniBand: Connected Mode (RFC 4755)
+ http://ietf.org/rfc/rfc4755.txt
diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt
new file mode 100644
index 00000000000..435102a26d9
--- /dev/null
+++ b/Documentation/input/rotary-encoder.txt
@@ -0,0 +1,101 @@
+rotary-encoder - a generic driver for GPIO connected devices
+Daniel Mack <daniel@caiaq.de>, Feb 2009
+
+0. Function
+-----------
+
+Rotary encoders are devices which are connected to the CPU or other
+peripherals with two wires. The outputs are phase-shifted by 90 degrees
+and by triggering on falling and rising edges, the turn direction can
+be determined.
+
+The phase diagram of these two outputs look like this:
+
+ _____ _____ _____
+ | | | | | |
+ Channel A ____| |_____| |_____| |____
+
+ : : : : : : : : : : : :
+ __ _____ _____ _____
+ | | | | | | |
+ Channel B |_____| |_____| |_____| |__
+
+ : : : : : : : : : : : :
+ Event a b c d a b c d a b c d
+
+ |<-------->|
+ one step
+
+
+For more information, please see
+ http://en.wikipedia.org/wiki/Rotary_encoder
+
+
+1. Events / state machine
+-------------------------
+
+a) Rising edge on channel A, channel B in low state
+ This state is used to recognize a clockwise turn
+
+b) Rising edge on channel B, channel A in high state
+ When entering this state, the encoder is put into 'armed' state,
+ meaning that there it has seen half the way of a one-step transition.
+
+c) Falling edge on channel A, channel B in high state
+ This state is used to recognize a counter-clockwise turn
+
+d) Falling edge on channel B, channel A in low state
+ Parking position. If the encoder enters this state, a full transition
+ should have happend, unless it flipped back on half the way. The
+ 'armed' state tells us about that.
+
+2. Platform requirements
+------------------------
+
+As there is no hardware dependent call in this driver, the platform it is
+used with must support gpiolib. Another requirement is that IRQs must be
+able to fire on both edges.
+
+
+3. Board integration
+--------------------
+
+To use this driver in your system, register a platform_device with the
+name 'rotary-encoder' and associate the IRQs and some specific platform
+data with it.
+
+struct rotary_encoder_platform_data is declared in
+include/linux/rotary-encoder.h and needs to be filled with the number of
+steps the encoder has and can carry information about externally inverted
+signals (because of used invertig buffer or other reasons).
+
+Because GPIO to IRQ mapping is platform specific, this information must
+be given in seperately to the driver. See the example below.
+
+---------<snip>---------
+
+/* board support file example */
+
+#include <linux/input.h>
+#include <linux/rotary_encoder.h>
+
+#define GPIO_ROTARY_A 1
+#define GPIO_ROTARY_B 2
+
+static struct rotary_encoder_platform_data my_rotary_encoder_info = {
+ .steps = 24,
+ .axis = ABS_X,
+ .gpio_a = GPIO_ROTARY_A,
+ .gpio_b = GPIO_ROTARY_B,
+ .inverted_a = 0,
+ .inverted_b = 0,
+};
+
+static struct platform_device rotary_encoder_device = {
+ .name = "rotary-encoder",
+ .id = 0,
+ .dev = {
+ .platform_data = &my_rotary_encoder_info,
+ }
+};
+
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 51104f9194a..d4b05672f9f 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -40,10 +40,16 @@ This document describes the Linux kernel Makefiles.
--- 6.7 Custom kbuild commands
--- 6.8 Preprocessing linker scripts
- === 7 Kbuild Variables
- === 8 Makefile language
- === 9 Credits
- === 10 TODO
+ === 7 Kbuild syntax for exported headers
+ --- 7.1 header-y
+ --- 7.2 objhdr-y
+ --- 7.3 destination-y
+ --- 7.4 unifdef-y (deprecated)
+
+ === 8 Kbuild Variables
+ === 9 Makefile language
+ === 10 Credits
+ === 11 TODO
=== 1 Overview
@@ -1143,8 +1149,69 @@ When kbuild executes, the following steps are followed (roughly):
The kbuild infrastructure for *lds file are used in several
architecture-specific files.
+=== 7 Kbuild syntax for exported headers
+
+The kernel include a set of headers that is exported to userspace.
+Many headers can be exported as-is but other headers requires a
+minimal pre-processing before they are ready for user-space.
+The pre-processing does:
+- drop kernel specific annotations
+- drop include of compiler.h
+- drop all sections that is kernel internat (guarded by ifdef __KERNEL__)
+
+Each relevant directory contain a file name "Kbuild" which specify the
+headers to be exported.
+See subsequent chapter for the syntax of the Kbuild file.
+
+ --- 7.1 header-y
+
+ header-y specify header files to be exported.
+
+ Example:
+ #include/linux/Kbuild
+ header-y += usb/
+ header-y += aio_abi.h
+
+ The convention is to list one file per line and
+ preferably in alphabetic order.
+
+ header-y also specify which subdirectories to visit.
+ A subdirectory is identified by a trailing '/' which
+ can be seen in the example above for the usb subdirectory.
+
+ Subdirectories are visited before their parent directories.
+
+ --- 7.2 objhdr-y
+
+ objhdr-y specifies generated files to be exported.
+ Generated files are special as they need to be looked
+ up in another directory when doing 'make O=...' builds.
+
+ Example:
+ #include/linux/Kbuild
+ objhdr-y += version.h
+
+ --- 7.3 destination-y
+
+ When an architecture have a set of exported headers that needs to be
+ exported to a different directory destination-y is used.
+ destination-y specify the destination directory for all exported
+ headers in the file where it is present.
+
+ Example:
+ #arch/xtensa/platforms/s6105/include/platform/Kbuild
+ destination-y := include/linux
+
+ In the example above all exported headers in the Kbuild file
+ will be located in the directory "include/linux" when exported.
+
+
+ --- 7.4 unifdef-y (deprecated)
+
+ unifdef-y is deprecated. A direct replacement is header-y.
+
-=== 7 Kbuild Variables
+=== 8 Kbuild Variables
The top Makefile exports the following variables:
@@ -1206,7 +1273,7 @@ The top Makefile exports the following variables:
INSTALL_MOD_STRIP will used as the option(s) to the strip command.
-=== 8 Makefile language
+=== 9 Makefile language
The kernel Makefiles are designed to be run with GNU Make. The Makefiles
use only the documented features of GNU Make, but they do use many
@@ -1225,14 +1292,14 @@ time the left-hand side is used.
There are some cases where "=" is appropriate. Usually, though, ":="
is the right choice.
-=== 9 Credits
+=== 10 Credits
Original version made by Michael Elizabeth Chastain, <mailto:mec@shout.net>
Updates by Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de>
Updates by Sam Ravnborg <sam@ravnborg.org>
Language QA by Jan Engelhardt <jengelh@gmx.de>
-=== 10 TODO
+=== 11 TODO
- Describe how kbuild supports shipped files with _shipped.
- Generating offset header files.
diff --git a/Documentation/sparse.txt b/Documentation/sparse.txt
index 42f43fa59f2..34c76a55bc0 100644
--- a/Documentation/sparse.txt
+++ b/Documentation/sparse.txt
@@ -42,6 +42,14 @@ sure that bitwise types don't get mixed up (little-endian vs big-endian
vs cpu-endian vs whatever), and there the constant "0" really _is_
special.
+__bitwise__ - to be used for relatively compact stuff (gfp_t, etc.) that
+is mostly warning-free and is supposed to stay that way. Warnings will
+be generated without __CHECK_ENDIAN__.
+
+__bitwise - noisy stuff; in particular, __le*/__be* are that. We really
+don't want to drown in noise unless we'd explicitly asked for it.
+
+
Getting sparse
~~~~~~~~~~~~~~
diff --git a/Documentation/ftrace.txt b/Documentation/trace/ftrace.txt
index fd9a3e69381..fd9a3e69381 100644
--- a/Documentation/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
diff --git a/Documentation/vm/kmemtrace.txt b/Documentation/trace/kmemtrace.txt
index a956d9b7f94..a956d9b7f94 100644
--- a/Documentation/vm/kmemtrace.txt
+++ b/Documentation/trace/kmemtrace.txt
diff --git a/Documentation/tracers/mmiotrace.txt b/Documentation/trace/mmiotrace.txt
index 5731c67abc5..5731c67abc5 100644
--- a/Documentation/tracers/mmiotrace.txt
+++ b/Documentation/trace/mmiotrace.txt
diff --git a/Documentation/tracepoints.txt b/Documentation/trace/tracepoints.txt
index c0e1ceed75a..c0e1ceed75a 100644
--- a/Documentation/tracepoints.txt
+++ b/Documentation/trace/tracepoints.txt