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merge linus into release branch

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Conflicts:

	drivers/acpi/acpi_memhotplug.c
This commit is contained in:
Len Brown
2006-06-29 19:57:46 -04:00
parent 9dce0e950d bf7e851108
commit d120cfb544
1387 changed files with 50185 additions and 18084 deletions
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CREDITS
+2 -2
View File
@@ -3401,10 +3401,10 @@ S: Czech Republic
N: Thibaut Varene
E: T-Bone@parisc-linux.org
W: http://www.parisc-linux.org/
W: http://www.parisc-linux.org/~varenet/
P: 1024D/B7D2F063 E67C 0D43 A75E 12A5 BB1C FA2F 1E32 C3DA B7D2 F063
D: PA-RISC port minion, PDC and GSCPS2 drivers, debuglocks and other bits
D: Some bits in an ARM port, S1D13XXX FB driver, random patches here and there
D: Some ARM at91rm9200 bits, S1D13XXX FB driver, random patches here and there
D: AD1889 sound driver
S: Paris, France
Documentation/Changes
+6 -9
View File
@@ -181,8 +181,8 @@ Intel IA32 microcode
--------------------
A driver has been added to allow updating of Intel IA32 microcode,
accessible as both a devfs regular file and as a normal (misc)
character device. If you are not using devfs you may need to:
accessible as a normal (misc) character device. If you are not using
udev you may need to:
mkdir /dev/cpu
mknod /dev/cpu/microcode c 10 184
@@ -201,7 +201,9 @@ with programs using shared memory.
udev
----
udev is a userspace application for populating /dev dynamically with
only entries for devices actually present. udev replaces devfs.
only entries for devices actually present. udev replaces the basic
functionality of devfs, while allowing persistant device naming for
devices.
FUSE
----
@@ -231,18 +233,13 @@ The PPP driver has been restructured to support multilink and to
enable it to operate over diverse media layers. If you use PPP,
upgrade pppd to at least 2.4.0.
If you are not using devfs, you must have the device file /dev/ppp
If you are not using udev, you must have the device file /dev/ppp
which can be made by:
mknod /dev/ppp c 108 0
as root.
If you use devfsd and build ppp support as modules, you will need
the following in your /etc/devfsd.conf file:
LOOKUP PPP MODLOAD
Isdn4k-utils
------------
Documentation/DocBook/Makefile
+2 -1
View File
@@ -10,7 +10,8 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
procfs-guide.xml writing_usb_driver.xml \
kernel-api.xml journal-api.xml lsm.xml usb.xml \
gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml
gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
genericirq.xml
###
# The build process is as follows (targets):
Documentation/DocBook/genericirq.tmpl
+474
View File
@@ -0,0 +1,474 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
<book id="Generic-IRQ-Guide">
<bookinfo>
<title>Linux generic IRQ handling</title>
<authorgroup>
<author>
<firstname>Thomas</firstname>
<surname>Gleixner</surname>
<affiliation>
<address>
<email>tglx@linutronix.de</email>
</address>
</affiliation>
</author>
<author>
<firstname>Ingo</firstname>
<surname>Molnar</surname>
<affiliation>
<address>
<email>mingo@elte.hu</email>
</address>
</affiliation>
</author>
</authorgroup>
<copyright>
<year>2005-2006</year>
<holder>Thomas Gleixner</holder>
</copyright>
<copyright>
<year>2005-2006</year>
<holder>Ingo Molnar</holder>
</copyright>
<legalnotice>
<para>
This documentation is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public
License version 2 as published by the Free Software Foundation.
</para>
<para>
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
</para>
<para>
You should have received a copy of the GNU General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
</para>
<para>
For more details see the file COPYING in the source
distribution of Linux.
</para>
</legalnotice>
</bookinfo>
<toc></toc>
<chapter id="intro">
<title>Introduction</title>
<para>
The generic interrupt handling layer is designed to provide a
complete abstraction of interrupt handling for device drivers.
It is able to handle all the different types of interrupt controller
hardware. Device drivers use generic API functions to request, enable,
disable and free interrupts. The drivers do not have to know anything
about interrupt hardware details, so they can be used on different
platforms without code changes.
</para>
<para>
This documentation is provided to developers who want to implement
an interrupt subsystem based for their architecture, with the help
of the generic IRQ handling layer.
</para>
</chapter>
<chapter id="rationale">
<title>Rationale</title>
<para>
The original implementation of interrupt handling in Linux is using
the __do_IRQ() super-handler, which is able to deal with every
type of interrupt logic.
</para>
<para>
Originally, Russell King identified different types of handlers to
build a quite universal set for the ARM interrupt handler
implementation in Linux 2.5/2.6. He distinguished between:
<itemizedlist>
<listitem><para>Level type</para></listitem>
<listitem><para>Edge type</para></listitem>
<listitem><para>Simple type</para></listitem>
</itemizedlist>
In the SMP world of the __do_IRQ() super-handler another type
was identified:
<itemizedlist>
<listitem><para>Per CPU type</para></listitem>
</itemizedlist>
</para>
<para>
This split implementation of highlevel IRQ handlers allows us to
optimize the flow of the interrupt handling for each specific
interrupt type. This reduces complexity in that particular codepath
and allows the optimized handling of a given type.
</para>
<para>
The original general IRQ implementation used hw_interrupt_type
structures and their ->ack(), ->end() [etc.] callbacks to
differentiate the flow control in the super-handler. This leads to
a mix of flow logic and lowlevel hardware logic, and it also leads
to unnecessary code duplication: for example in i386, there is a
ioapic_level_irq and a ioapic_edge_irq irq-type which share many
of the lowlevel details but have different flow handling.
</para>
<para>
A more natural abstraction is the clean separation of the
'irq flow' and the 'chip details'.
</para>
<para>
Analysing a couple of architecture's IRQ subsystem implementations
reveals that most of them can use a generic set of 'irq flow'
methods and only need to add the chip level specific code.
The separation is also valuable for (sub)architectures
which need specific quirks in the irq flow itself but not in the
chip-details - and thus provides a more transparent IRQ subsystem
design.
</para>
<para>
Each interrupt descriptor is assigned its own highlevel flow
handler, which is normally one of the generic
implementations. (This highlevel flow handler implementation also
makes it simple to provide demultiplexing handlers which can be
found in embedded platforms on various architectures.)
</para>
<para>
The separation makes the generic interrupt handling layer more
flexible and extensible. For example, an (sub)architecture can
use a generic irq-flow implementation for 'level type' interrupts
and add a (sub)architecture specific 'edge type' implementation.
</para>
<para>
To make the transition to the new model easier and prevent the
breakage of existing implementations, the __do_IRQ() super-handler
is still available. This leads to a kind of duality for the time
being. Over time the new model should be used in more and more
architectures, as it enables smaller and cleaner IRQ subsystems.
</para>
</chapter>
<chapter id="bugs">
<title>Known Bugs And Assumptions</title>
<para>
None (knock on wood).
</para>
</chapter>
<chapter id="Abstraction">
<title>Abstraction layers</title>
<para>
There are three main levels of abstraction in the interrupt code:
<orderedlist>
<listitem><para>Highlevel driver API</para></listitem>
<listitem><para>Highlevel IRQ flow handlers</para></listitem>
<listitem><para>Chiplevel hardware encapsulation</para></listitem>
</orderedlist>
</para>
<sect1>
<title>Interrupt control flow</title>
<para>
Each interrupt is described by an interrupt descriptor structure
irq_desc. The interrupt is referenced by an 'unsigned int' numeric
value which selects the corresponding interrupt decription structure
in the descriptor structures array.
The descriptor structure contains status information and pointers
to the interrupt flow method and the interrupt chip structure
which are assigned to this interrupt.
</para>
<para>
Whenever an interrupt triggers, the lowlevel arch code calls into
the generic interrupt code by calling desc->handle_irq().
This highlevel IRQ handling function only uses desc->chip primitives
referenced by the assigned chip descriptor structure.
</para>
</sect1>
<sect1>
<title>Highlevel Driver API</title>
<para>
The highlevel Driver API consists of following functions:
<itemizedlist>
<listitem><para>request_irq()</para></listitem>
<listitem><para>free_irq()</para></listitem>
<listitem><para>disable_irq()</para></listitem>
<listitem><para>enable_irq()</para></listitem>
<listitem><para>disable_irq_nosync() (SMP only)</para></listitem>
<listitem><para>synchronize_irq() (SMP only)</para></listitem>
<listitem><para>set_irq_type()</para></listitem>
<listitem><para>set_irq_wake()</para></listitem>
<listitem><para>set_irq_data()</para></listitem>
<listitem><para>set_irq_chip()</para></listitem>
<listitem><para>set_irq_chip_data()</para></listitem>
</itemizedlist>
See the autogenerated function documentation for details.
</para>
</sect1>
<sect1>
<title>Highlevel IRQ flow handlers</title>
<para>
The generic layer provides a set of pre-defined irq-flow methods:
<itemizedlist>
<listitem><para>handle_level_irq</para></listitem>
<listitem><para>handle_edge_irq</para></listitem>
<listitem><para>handle_simple_irq</para></listitem>
<listitem><para>handle_percpu_irq</para></listitem>
</itemizedlist>
The interrupt flow handlers (either predefined or architecture
specific) are assigned to specific interrupts by the architecture
either during bootup or during device initialization.
</para>
<sect2>
<title>Default flow implementations</title>
<sect3>
<title>Helper functions</title>
<para>
The helper functions call the chip primitives and
are used by the default flow implementations.
The following helper functions are implemented (simplified excerpt):
<programlisting>
default_enable(irq)
{
desc->chip->unmask(irq);
}
default_disable(irq)
{
if (!delay_disable(irq))
desc->chip->mask(irq);
}
default_ack(irq)
{
chip->ack(irq);
}
default_mask_ack(irq)
{
if (chip->mask_ack) {
chip->mask_ack(irq);
} else {
chip->mask(irq);
chip->ack(irq);
}
}
noop(irq)
{
}
</programlisting>
</para>
</sect3>
</sect2>
<sect2>
<title>Default flow handler implementations</title>
<sect3>
<title>Default Level IRQ flow handler</title>
<para>
handle_level_irq provides a generic implementation
for level-triggered interrupts.
</para>
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
desc->chip->start();
handle_IRQ_event(desc->action);
desc->chip->end();
</programlisting>
</para>
</sect3>
<sect3>
<title>Default Edge IRQ flow handler</title>
<para>
handle_edge_irq provides a generic implementation
for edge-triggered interrupts.
</para>
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
if (desc->status &amp; running) {
desc->chip->hold();
desc->status |= pending | masked;
return;
}
desc->chip->start();
desc->status |= running;
do {
if (desc->status &amp; masked)
desc->chip->enable();
desc-status &amp;= ~pending;
handle_IRQ_event(desc->action);
} while (status &amp; pending);
desc-status &amp;= ~running;
desc->chip->end();
</programlisting>
</para>
</sect3>
<sect3>
<title>Default simple IRQ flow handler</title>
<para>
handle_simple_irq provides a generic implementation
for simple interrupts.
</para>
<para>
Note: The simple flow handler does not call any
handler/chip primitives.
</para>
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
handle_IRQ_event(desc->action);
</programlisting>
</para>
</sect3>
<sect3>
<title>Default per CPU flow handler</title>
<para>
handle_percpu_irq provides a generic implementation
for per CPU interrupts.
</para>
<para>
Per CPU interrupts are only available on SMP and
the handler provides a simplified version without
locking.
</para>
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
desc->chip->start();
handle_IRQ_event(desc->action);
desc->chip->end();
</programlisting>
</para>
</sect3>
</sect2>
<sect2>
<title>Quirks and optimizations</title>
<para>
The generic functions are intended for 'clean' architectures and chips,
which have no platform-specific IRQ handling quirks. If an architecture
needs to implement quirks on the 'flow' level then it can do so by
overriding the highlevel irq-flow handler.
</para>
</sect2>
<sect2>
<title>Delayed interrupt disable</title>
<para>
This per interrupt selectable feature, which was introduced by Russell
King in the ARM interrupt implementation, does not mask an interrupt
at the hardware level when disable_irq() is called. The interrupt is
kept enabled and is masked in the flow handler when an interrupt event
happens. This prevents losing edge interrupts on hardware which does
not store an edge interrupt event while the interrupt is disabled at
the hardware level. When an interrupt arrives while the IRQ_DISABLED
flag is set, then the interrupt is masked at the hardware level and
the IRQ_PENDING bit is set. When the interrupt is re-enabled by
enable_irq() the pending bit is checked and if it is set, the
interrupt is resent either via hardware or by a software resend
mechanism. (It's necessary to enable CONFIG_HARDIRQS_SW_RESEND when
you want to use the delayed interrupt disable feature and your
hardware is not capable of retriggering an interrupt.)
The delayed interrupt disable can be runtime enabled, per interrupt,
by setting the IRQ_DELAYED_DISABLE flag in the irq_desc status field.
</para>
</sect2>
</sect1>
<sect1>
<title>Chiplevel hardware encapsulation</title>
<para>
The chip level hardware descriptor structure irq_chip
contains all the direct chip relevant functions, which
can be utilized by the irq flow implementations.
<itemizedlist>
<listitem><para>ack()</para></listitem>
<listitem><para>mask_ack() - Optional, recommended for performance</para></listitem>
<listitem><para>mask()</para></listitem>
<listitem><para>unmask()</para></listitem>
<listitem><para>retrigger() - Optional</para></listitem>
<listitem><para>set_type() - Optional</para></listitem>
<listitem><para>set_wake() - Optional</para></listitem>
</itemizedlist>
These primitives are strictly intended to mean what they say: ack means
ACK, masking means masking of an IRQ line, etc. It is up to the flow
handler(s) to use these basic units of lowlevel functionality.
</para>
</sect1>
</chapter>
<chapter id="doirq">
<title>__do_IRQ entry point</title>
<para>
The original implementation __do_IRQ() is an alternative entry
point for all types of interrupts.
</para>
<para>
This handler turned out to be not suitable for all
interrupt hardware and was therefore reimplemented with split
functionality for egde/level/simple/percpu interrupts. This is not
only a functional optimization. It also shortens code paths for
interrupts.
</para>
<para>
To make use of the split implementation, replace the call to
__do_IRQ by a call to desc->chip->handle_irq() and associate
the appropriate handler function to desc->chip->handle_irq().
In most cases the generic handler implementations should
be sufficient.
</para>
</chapter>
<chapter id="locking">
<title>Locking on SMP</title>
<para>
The locking of chip registers is up to the architecture that
defines the chip primitives. There is a chip->lock field that can be used
for serialization, but the generic layer does not touch it. The per-irq
structure is protected via desc->lock, by the generic layer.
</para>
</chapter>
<chapter id="structs">
<title>Structures</title>
<para>
This chapter contains the autogenerated documentation of the structures which are
used in the generic IRQ layer.
</para>
!Iinclude/linux/irq.h
</chapter>
<chapter id="pubfunctions">
<title>Public Functions Provided</title>
<para>
This chapter contains the autogenerated documentation of the kernel API functions
which are exported.
</para>
!Ekernel/irq/manage.c
!Ekernel/irq/chip.c
</chapter>
<chapter id="intfunctions">
<title>Internal Functions Provided</title>
<para>
This chapter contains the autogenerated documentation of the internal functions.
</para>
!Ikernel/irq/handle.c
!Ikernel/irq/chip.c
</chapter>
<chapter id="credits">
<title>Credits</title>
<para>
The following people have contributed to this document:
<orderedlist>
<listitem><para>Thomas Gleixner<email>tglx@linutronix.de</email></para></listitem>
<listitem><para>Ingo Molnar<email>mingo@elte.hu</email></para></listitem>
</orderedlist>
</para>
</chapter>
</book>
Documentation/DocBook/kernel-api.tmpl
-5
View File
@@ -348,11 +348,6 @@ X!Earch/i386/kernel/mca.c
</sect1>
</chapter>
<chapter id="devfs">
<title>The Device File System</title>
!Efs/devfs/base.c
</chapter>
<chapter id="sysfs">
<title>The Filesystem for Exporting Kernel Objects</title>
!Efs/sysfs/file.c
Documentation/IRQ.txt
+22
View File
@@ -0,0 +1,22 @@
What is an IRQ?
An IRQ is an interrupt request from a device.
Currently they can come in over a pin, or over a packet.
Several devices may be connected to the same pin thus
sharing an IRQ.
An IRQ number is a kernel identifier used to talk about a hardware
interrupt source. Typically this is an index into the global irq_desc
array, but except for what linux/interrupt.h implements the details
are architecture specific.
An IRQ number is an enumeration of the possible interrupt sources on a
machine. Typically what is enumerated is the number of input pins on
all of the interrupt controller in the system. In the case of ISA
what is enumerated are the 16 input pins on the two i8259 interrupt
controllers.
Architectures can assign additional meaning to the IRQ numbers, and
are encouraged to in the case where there is any manual configuration
of the hardware involved. The ISA IRQs are a classic example of
assigning this kind of additional meaning.
Documentation/RCU/torture.txt
+24 -10
View File
@@ -7,7 +7,7 @@ The CONFIG_RCU_TORTURE_TEST config option is available for all RCU
implementations. It creates an rcutorture kernel module that can
be loaded to run a torture test. The test periodically outputs
status messages via printk(), which can be examined via the dmesg
command (perhaps grepping for "rcutorture"). The test is started
command (perhaps grepping for "torture"). The test is started
when the module is loaded, and stops when the module is unloaded.
However, actually setting this config option to "y" results in the system
@@ -35,6 +35,19 @@ stat_interval The number of seconds between output of torture
be printed -only- when the module is unloaded, and this
is the default.
shuffle_interval
The number of seconds to keep the test threads affinitied
to a particular subset of the CPUs. Used in conjunction
with test_no_idle_hz.
test_no_idle_hz Whether or not to test the ability of RCU to operate in
a kernel that disables the scheduling-clock interrupt to
idle CPUs. Boolean parameter, "1" to test, "0" otherwise.
torture_type The type of RCU to test: "rcu" for the rcu_read_lock()
API, "rcu_bh" for the rcu_read_lock_bh() API, and "srcu"
for the "srcu_read_lock()" API.
verbose Enable debug printk()s. Default is disabled.
@@ -42,14 +55,14 @@ OUTPUT
The statistics output is as follows:
rcutorture: --- Start of test: nreaders=16 stat_interval=0 verbose=0
rcutorture: rtc: 0000000000000000 ver: 1916 tfle: 0 rta: 1916 rtaf: 0 rtf: 1915
rcutorture: Reader Pipe: 1466408 9747 0 0 0 0 0 0 0 0 0
rcutorture: Reader Batch: 1464477 11678 0 0 0 0 0 0 0 0
rcutorture: Free-Block Circulation: 1915 1915 1915 1915 1915 1915 1915 1915 1915 1915 0
rcutorture: --- End of test
rcu-torture: --- Start of test: nreaders=16 stat_interval=0 verbose=0
rcu-torture: rtc: 0000000000000000 ver: 1916 tfle: 0 rta: 1916 rtaf: 0 rtf: 1915
rcu-torture: Reader Pipe: 1466408 9747 0 0 0 0 0 0 0 0 0
rcu-torture: Reader Batch: 1464477 11678 0 0 0 0 0 0 0 0
rcu-torture: Free-Block Circulation: 1915 1915 1915 1915 1915 1915 1915 1915 1915 1915 0
rcu-torture: --- End of test
The command "dmesg | grep rcutorture:" will extract this information on
The command "dmesg | grep torture:" will extract this information on
most systems. On more esoteric configurations, it may be necessary to
use other commands to access the output of the printk()s used by
the RCU torture test. The printk()s use KERN_ALERT, so they should
@@ -115,8 +128,9 @@ The following script may be used to torture RCU:
modprobe rcutorture
sleep 100
rmmod rcutorture
dmesg | grep rcutorture:
dmesg | grep torture:
The output can be manually inspected for the error flag of "!!!".
One could of course create a more elaborate script that automatically
checked for such errors.
checked for such errors. The "rmmod" command forces a "SUCCESS" or
"FAILURE" indication to be printk()ed.
Documentation/README.DAC960
+3 -3
View File
@@ -78,9 +78,9 @@ also known as "System Drives", and Drive Groups are also called "Packs". Both
terms are in use in the Mylex documentation; I have chosen to standardize on
the more generic "Logical Drive" and "Drive Group".
DAC960 RAID disk devices are named in the style of the Device File System
(DEVFS). The device corresponding to Logical Drive D on Controller C is
referred to as /dev/rd/cCdD, and the partitions are called /dev/rd/cCdDp1
DAC960 RAID disk devices are named in the style of the obsolete Device File
System (DEVFS). The device corresponding to Logical Drive D on Controller C
is referred to as /dev/rd/cCdD, and the partitions are called /dev/rd/cCdDp1
through /dev/rd/cCdDp7. For example, partition 3 of Logical Drive 5 on
Controller 2 is referred to as /dev/rd/c2d5p3. Note that unlike with SCSI
disks the device names will not change in the event of a disk drive failure.
Documentation/feature-removal-schedule.txt
+54 -21
View File
@@ -6,17 +6,6 @@ be removed from this file.
---------------------------
What: devfs
When: July 2005
Files: fs/devfs/*, include/linux/devfs_fs*.h and assorted devfs
function calls throughout the kernel tree
Why: It has been unmaintained for a number of years, has unfixable
races, contains a naming policy within the kernel that is
against the LSB, and can be replaced by using udev.
Who: Greg Kroah-Hartman <greg@kroah.com>
---------------------------
What: RAW driver (CONFIG_RAW_DRIVER)
When: December 2005
Why: declared obsolete since kernel 2.6.3
@@ -132,16 +121,6 @@ Who: NeilBrown <neilb@suse.de>
---------------------------
What: au1x00_uart driver
When: January 2006
Why: The 8250 serial driver now has the ability to deal with the differences
between the standard 8250 family of UARTs and their slightly strange
brother on Alchemy SOCs. The loss of features is not considered an
issue.
Who: Ralf Baechle <ralf@linux-mips.org>
---------------------------
What: eepro100 network driver
When: January 2007
Why: replaced by the e100 driver
@@ -177,6 +156,16 @@ Who: Jean Delvare <khali@linux-fr.org>
---------------------------
What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
(temporary transition config option provided until then)
The transition config option will also be removed at the same time.
When: before 2.6.19
Why: Unused symbols are both increasing the size of the kernel binary
and are often a sign of "wrong API"
Who: Arjan van de Ven <arjan@linux.intel.com>
---------------------------
What: remove EXPORT_SYMBOL(tasklist_lock)
When: August 2006
Files: kernel/fork.c
@@ -224,3 +213,47 @@ Why: The interface no longer has any callers left in the kernel. It
Who: Nick Piggin <npiggin@suse.de>
---------------------------
What: Support for the MIPS EV96100 evaluation board
When: September 2006
Why: Does no longer build since at least November 15, 2003, apparently
no userbase left.
Who: Ralf Baechle <ralf@linux-mips.org>
---------------------------
What: Support for the Momentum / PMC-Sierra Jaguar ATX evaluation board
When: September 2006
Why: Does no longer build since quite some time, and was never popular,
due to the platform being replaced by successor models. Apparently
no user base left. It also is one of the last users of
WANT_PAGE_VIRTUAL.
Who: Ralf Baechle <ralf@linux-mips.org>
---------------------------
What: Support for the Momentum Ocelot, Ocelot 3, Ocelot C and Ocelot G
When: September 2006
Why: Some do no longer build and apparently there is no user base left
for these platforms.
Who: Ralf Baechle <ralf@linux-mips.org>
---------------------------
What: Support for MIPS Technologies' Altas and SEAD evaluation board
When: September 2006
Why: Some do no longer build and apparently there is no user base left
for these platforms. Hardware out of production since several years.
Who: Ralf Baechle <ralf@linux-mips.org>
---------------------------
What: Support for the IT8172-based platforms, ITE 8172G and Globespan IVR
When: September 2006
Why: Code does no longer build since at least 2.6.0, apparently there is
no user base left for these platforms. Hardware out of production
since several years and hardly a trace of the manufacturer left on
the net.
Who: Ralf Baechle <ralf@linux-mips.org>
---------------------------
Documentation/filesystems/devfs/ChangeLog
-1977
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Documentation/filesystems/devfs/README
-1959
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Documentation/filesystems/devfs/ToDo
-40
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@@ -1,40 +0,0 @@
Device File System (devfs) ToDo List
Richard Gooch <rgooch@atnf.csiro.au>
3-JUL-2000
This is a list of things to be done for better devfs support in the
Linux kernel. If you'd like to contribute to the devfs, please have a
look at this list for anything that is unallocated. Also, if there are
items missing (surely), please contact me so I can add them to the
list (preferably with your name attached to them:-).
- >256 ptys
Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
- Amiga floppy driver (drivers/block/amiflop.c)
- Atari floppy driver (drivers/block/ataflop.c)
- SWIM3 (Super Woz Integrated Machine 3) floppy driver (drivers/block/swim3.c)
- Amiga ZorroII ramdisc driver (drivers/block/z2ram.c)
- Parallel port ATAPI CD-ROM (drivers/block/paride/pcd.c)
- Parallel port ATAPI floppy (drivers/block/paride/pf.c)
- AP1000 block driver (drivers/ap1000/ap.c, drivers/ap1000/ddv.c)
- Archimedes floppy (drivers/acorn/block/fd1772.c)
- MFM hard drive (drivers/acorn/block/mfmhd.c)
- I2O block device (drivers/message/i2o/i2o_block.c)
- ST-RAM device (arch/m68k/atari/stram.c)
- Raw devices
Documentation/filesystems/devfs/boot-options
-65
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@@ -1,65 +0,0 @@
/* -*- auto-fill -*- */
Device File System (devfs) Boot Options
Richard Gooch <rgooch@atnf.csiro.au>
18-AUG-2001
When CONFIG_DEVFS_DEBUG is enabled, you can pass several boot options
to the kernel to debug devfs. The boot options are prefixed by
"devfs=", and are separated by commas. Spaces are not allowed. The
syntax looks like this:
devfs=<option1>,<option2>,<option3>
and so on. For example, if you wanted to turn on debugging for module
load requests and device registration, you would do:
devfs=dmod,dreg
You may prefix "no" to any option. This will invert the option.
Debugging Options
=================
These requires CONFIG_DEVFS_DEBUG to be enabled.
Note that all debugging options have 'd' as the first character. By
default all options are off. All debugging output is sent to the
kernel logs. The debugging options do not take effect until the devfs
version message appears (just prior to the root filesystem being
mounted).
These are the options:
dmod print module load requests to <request_module>
dreg print device register requests to <devfs_register>
dunreg print device unregister requests to <devfs_unregister>
dchange print device change requests to <devfs_set_flags>
dilookup print inode lookup requests
diget print VFS inode allocations
diunlink print inode unlinks
dichange print inode changes
dimknod print calls to mknod(2)
dall some debugging turned on
Other Options
=============
These control the default behaviour of devfs. The options are:
mount mount devfs onto /dev at boot time
only disable non-devfs device nodes for devfs-capable drivers
Documentation/initrd.txt
+8 -16
View File
@@ -67,8 +67,7 @@ initrd adds the following new options:
as the last process has closed it, all data is freed and /dev/initrd
can't be opened anymore.
root=/dev/ram0 (without devfs)
root=/dev/rd/0 (with devfs)
root=/dev/ram0
initrd is mounted as root, and the normal boot procedure is followed,
with the RAM disk still mounted as root.
@@ -90,8 +89,7 @@ you're building an install floppy), the root file system creation
procedure should create the /initrd directory.
If initrd will not be mounted in some cases, its content is still
accessible if the following device has been created (note that this
does not work if using devfs):
accessible if the following device has been created:
# mknod /dev/initrd b 1 250
# chmod 400 /dev/initrd
@@ -119,8 +117,7 @@ We'll describe the loopback device method:
(if space is critical, you may want to use the Minix FS instead of Ext2)
3) mount the file system, e.g.
# mount -t ext2 -o loop initrd /mnt
4) create the console device (not necessary if using devfs, but it can't
hurt to do it anyway):
4) create the console device:
# mkdir /mnt/dev
# mknod /mnt/dev/console c 5 1
5) copy all the files that are needed to properly use the initrd
@@ -152,12 +149,7 @@ have to be given:
root=/dev/ram0 init=/linuxrc rw
if not using devfs, or
root=/dev/rd/0 init=/linuxrc rw
if using devfs. (rw is only necessary if writing to the initrd file
system.)
(rw is only necessary if writing to the initrd file system.)
With LOADLIN, you simply execute
@@ -217,9 +209,9 @@ following command:
# exec chroot . what-follows <dev/console >dev/console 2>&1
Where what-follows is a program under the new root, e.g. /sbin/init
If the new root file system will be used with devfs and has no valid
/dev directory, devfs must be mounted before invoking chroot in order to
provide /dev/console.
If the new root file system will be used with udev and has no valid
/dev directory, udev must be initialized before invoking chroot in order
to provide /dev/console.
Note: implementation details of pivot_root may change with time. In order
to ensure compatibility, the following points should be observed:
@@ -236,7 +228,7 @@ Now, the initrd can be unmounted and the memory allocated by the RAM
disk can be freed:
# umount /initrd
# blockdev --flushbufs /dev/ram0 # /dev/rd/0 if using devfs
# blockdev --flushbufs /dev/ram0
It is also possible to use initrd with an NFS-mounted root, see the
pivot_root(8) man page for details.
Documentation/ioctl-number.txt
-1
View File
@@ -119,7 +119,6 @@ Code Seq# Include File Comments
'c' 00-7F linux/comstats.h conflict!
'c' 00-7F linux/coda.h conflict!
'd' 00-FF linux/char/drm/drm/h conflict!
'd' 00-1F linux/devfs_fs.h conflict!
'd' 00-DF linux/video_decoder.h conflict!
'd' F0-FF linux/digi1.h
'e' all linux/digi1.h conflict!
Documentation/kernel-parameters.txt
+11 -6
View File
@@ -35,7 +35,6 @@ parameter is applicable:
APM Advanced Power Management support is enabled.
AX25 Appropriate AX.25 support is enabled.
CD Appropriate CD support is enabled.
DEVFS devfs support is enabled.
DRM Direct Rendering Management support is enabled.
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
@@ -440,9 +439,6 @@ running once the system is up.
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
devfs= [DEVFS]
See Documentation/filesystems/devfs/boot-options.
dhash_entries= [KNL]
Set number of hash buckets for dentry cache.
@@ -1669,6 +1665,10 @@ running once the system is up.
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.
vdso= [IA-32]
vdso=1: enable VDSO (default)
vdso=0: disable VDSO mapping
video= [FB] Frame buffer configuration
See Documentation/fb/modedb.txt.
@@ -1685,9 +1685,14 @@ running once the system is up.
decrease the size and leave more room for directly
mapped kernel RAM.
vmhalt= [KNL,S390]
vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
Format: <command>
vmpoff= [KNL,S390]
vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
Format: <command>
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
waveartist= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>
Documentation/keys-request-key.txt
+31 -13
View File
@@ -3,16 +3,23 @@
===================
The key request service is part of the key retention service (refer to
Documentation/keys.txt). This document explains more fully how that the
requesting algorithm works.
Documentation/keys.txt). This document explains more fully how the requesting
algorithm works.
The process starts by either the kernel requesting a service by calling
request_key():
request_key*():
struct key *request_key(const struct key_type *type,
const char *description,
const char *callout_string);
or:
struct key *request_key_with_auxdata(const struct key_type *type,
const char *description,
const char *callout_string,
void *aux);
Or by userspace invoking the request_key system call:
key_serial_t request_key(const char *type,
@@ -20,16 +27,26 @@ Or by userspace invoking the request_key system call:
const char *callout_info,
key_serial_t dest_keyring);
The main difference between the two access points is that the in-kernel
interface does not need to link the key to a keyring to prevent it from being
immediately destroyed. The kernel interface returns a pointer directly to the
key, and it's up to the caller to destroy the key.
The main difference between the access points is that the in-kernel interface
does not need to link the key to a keyring to prevent it from being immediately
destroyed. The kernel interface returns a pointer directly to the key, and
it's up to the caller to destroy the key.
The request_key_with_auxdata() call is like the in-kernel request_key() call,
except that it permits auxiliary data to be passed to the upcaller (the default
is NULL). This is only useful for those key types that define their own upcall
mechanism rather than using /sbin/request-key.
The userspace interface links the key to a keyring associated with the process
to prevent the key from going away, and returns the serial number of the key to
the caller.
The following example assumes that the key types involved don't define their
own upcall mechanisms. If they do, then those should be substituted for the
forking and execution of /sbin/request-key.
===========
THE PROCESS
===========
@@ -40,8 +57,8 @@ A request proceeds in the following manner:
interface].
(2) request_key() searches the process's subscribed keyrings to see if there's
a suitable key there. If there is, it returns the key. If there isn't, and
callout_info is not set, an error is returned. Otherwise the process
a suitable key there. If there is, it returns the key. If there isn't,
and callout_info is not set, an error is returned. Otherwise the process
proceeds to the next step.
(3) request_key() sees that A doesn't have the desired key yet, so it creates
@@ -79,10 +96,11 @@ A request proceeds in the following manner:
(10) The program then exits 0 and request_key() deletes key V and returns key
U to the caller.
This also extends further. If key W (step 7 above) didn't exist, key W would be
created uninstantiated, another auth key (X) would be created (as per step 3)
and another copy of /sbin/request-key spawned (as per step 4); but the context
specified by auth key X will still be process A, as it was in auth key V.
This also extends further. If key W (step 7 above) didn't exist, key W would
be created uninstantiated, another auth key (X) would be created (as per step
3) and another copy of /sbin/request-key spawned (as per step 4); but the
context specified by auth key X will still be process A, as it was in auth key
V.
This is because process A's keyrings can't simply be attached to
/sbin/request-key at the appropriate places because (a) execve will discard two
Documentation/keys.txt
+29
View File
@@ -780,6 +780,17 @@ payload contents" for more information.
See also Documentation/keys-request-key.txt.
(*) To search for a key, passing auxiliary data to the upcaller, call:
struct key *request_key_with_auxdata(const struct key_type *type,
const char *description,
const char *callout_string,
void *aux);
This is identical to request_key(), except that the auxiliary data is
passed to the key_type->request_key() op if it exists.
(*) When it is no longer required, the key should be released using:
void key_put(struct key *key);
@@ -1031,6 +1042,24 @@ The structure has a number of fields, some of which are mandatory:
as might happen when the userspace buffer is accessed.
(*) int (*request_key)(struct key *key, struct key *authkey, const char *op,
void *aux);
This method is optional. If provided, request_key() and
request_key_with_auxdata() will invoke this function rather than
upcalling to /sbin/request-key to operate upon a key of this type.
The aux parameter is as passed to request_key_with_auxdata() or is NULL
otherwise. Also passed are the key to be operated upon, the
authorisation key for this operation and the operation type (currently
only "create").
This function should return only when the upcall is complete. Upon return
the authorisation key will be revoked, and the target key will be
negatively instantiated if it is still uninstantiated. The error will be
returned to the caller of request_key*().
============================
REQUEST-KEY CALLBACK SERVICE
============================
Documentation/pi-futex.txt
+121
View File
@@ -0,0 +1,121 @@
Lightweight PI-futexes
----------------------
We are calling them lightweight for 3 reasons:
- in the user-space fastpath a PI-enabled futex involves no kernel work
(or any other PI complexity) at all. No registration, no extra kernel
calls - just pure fast atomic ops in userspace.
- even in the slowpath, the system call and scheduling pattern is very
similar to normal futexes.
- the in-kernel PI implementation is streamlined around the mutex
abstraction, with strict rules that keep the implementation
relatively simple: only a single owner may own a lock (i.e. no
read-write lock support), only the owner may unlock a lock, no
recursive locking, etc.
Priority Inheritance - why?
---------------------------
The short reply: user-space PI helps achieving/improving determinism for
user-space applications. In the best-case, it can help achieve
determinism and well-bound latencies. Even in the worst-case, PI will
improve the statistical distribution of locking related application
delays.
The longer reply:
-----------------
Firstly, sharing locks between multiple tasks is a common programming
technique that often cannot be replaced with lockless algorithms. As we
can see it in the kernel [which is a quite complex program in itself],
lockless structures are rather the exception than the norm - the current
ratio of lockless vs. locky code for shared data structures is somewhere
between 1:10 and 1:100. Lockless is hard, and the complexity of lockless
algorithms often endangers to ability to do robust reviews of said code.
I.e. critical RT apps often choose lock structures to protect critical
data structures, instead of lockless algorithms. Furthermore, there are
cases (like shared hardware, or other resource limits) where lockless
access is mathematically impossible.
Media players (such as Jack) are an example of reasonable application
design with multiple tasks (with multiple priority levels) sharing
short-held locks: for example, a highprio audio playback thread is
combined with medium-prio construct-audio-data threads and low-prio
display-colory-stuff threads. Add video and decoding to the mix and
we've got even more priority levels.
So once we accept that synchronization objects (locks) are an
unavoidable fact of life, and once we accept that multi-task userspace
apps have a very fair expectation of being able to use locks, we've got
to think about how to offer the option of a deterministic locking
implementation to user-space.
Most of the technical counter-arguments against doing priority
inheritance only apply to kernel-space locks. But user-space locks are
different, there we cannot disable interrupts or make the task
non-preemptible in a critical section, so the 'use spinlocks' argument
does not apply (user-space spinlocks have the same priority inversion
problems as other user-space locking constructs). Fact is, pretty much
the only technique that currently enables good determinism for userspace
locks (such as futex-based pthread mutexes) is priority inheritance:
Currently (without PI), if a high-prio and a low-prio task shares a lock
[this is a quite common scenario for most non-trivial RT applications],
even if all critical sections are coded carefully to be deterministic
(i.e. all critical sections are short in duration and only execute a
limited number of instructions), the kernel cannot guarantee any
deterministic execution of the high-prio task: any medium-priority task
could preempt the low-prio task while it holds the shared lock and
executes the critical section, and could delay it indefinitely.
Implementation:
---------------
As mentioned before, the userspace fastpath of PI-enabled pthread
mutexes involves no kernel work at all - they behave quite similarly to
normal futex-based locks: a 0 value means unlocked, and a value==TID
means locked. (This is the same method as used by list-based robust
futexes.) Userspace uses atomic ops to lock/unlock these mutexes without
entering the kernel.
To handle the slowpath, we have added two new futex ops:
FUTEX_LOCK_PI
FUTEX_UNLOCK_PI
If the lock-acquire fastpath fails, [i.e. an atomic transition from 0 to
TID fails], then FUTEX_LOCK_PI is called. The kernel does all the
remaining work: if there is no futex-queue attached to the futex address
yet then the code looks up the task that owns the futex [it has put its
own TID into the futex value], and attaches a 'PI state' structure to
the futex-queue. The pi_state includes an rt-mutex, which is a PI-aware,
kernel-based synchronization object. The 'other' task is made the owner
of the rt-mutex, and the FUTEX_WAITERS bit is atomically set in the
futex value. Then this task tries to lock the rt-mutex, on which it
blocks. Once it returns, it has the mutex acquired, and it sets the
futex value to its own TID and returns. Userspace has no other work to
perform - it now owns the lock, and futex value contains
FUTEX_WAITERS|TID.
If the unlock side fastpath succeeds, [i.e. userspace manages to do a
TID -> 0 atomic transition of the futex value], then no kernel work is
triggered.
If the unlock fastpath fails (because the FUTEX_WAITERS bit is set),
then FUTEX_UNLOCK_PI is called, and the kernel unlocks the futex on the
behalf of userspace - and it also unlocks the attached
pi_state->rt_mutex and thus wakes up any potential waiters.
Note that under this approach, contrary to previous PI-futex approaches,
there is no prior 'registration' of a PI-futex. [which is not quite
possible anyway, due to existing ABI properties of pthread mutexes.]
Also, under this scheme, 'robustness' and 'PI' are two orthogonal
properties of futexes, and all four combinations are possible: futex,
robust-futex, PI-futex, robust+PI-futex.
More details about priority inheritance can be found in
Documentation/rtmutex.txt.
Documentation/robust-futexes.txt
+1 -1
View File
@@ -95,7 +95,7 @@ comparison. If the thread has registered a list, then normally the list
is empty. If the thread/process crashed or terminated in some incorrect
way then the list might be non-empty: in this case the kernel carefully
walks the list [not trusting it], and marks all locks that are owned by
this thread with the FUTEX_OWNER_DEAD bit, and wakes up one waiter (if
this thread with the FUTEX_OWNER_DIED bit, and wakes up one waiter (if
any).
The list is guaranteed to be private and per-thread at do_exit() time,

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