Merge branch 'core/percpu' into stackprotector

Conflicts:
	arch/x86/include/asm/pda.h
	arch/x86/include/asm/system.h

Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

.mailmap

@@ -32,6 +32,7 @@ Christoph Hellwig <hch@lst.de>
 Corey Minyard <minyard@acm.org>
 David Brownell <david-b@pacbell.net>
 David Woodhouse <dwmw2@shinybook.infradead.org>
+Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
 Domen Puncer <domen@coderock.org>
 Douglas Gilbert <dougg@torque.net>
 Ed L. Cashin <ecashin@coraid.com>

CREDITS

@@ -369,10 +369,10 @@ P: 1024/8462A731 4C 55 86 34 44 59 A7 99  2B 97 88 4A 88 9A 0D 97
 D: sun4 port, Sparc hacker
 
 N: Hugh Blemings
-E: hugh@misc.nu
+E: hugh@blemings.org
-W: http://misc.nu/hugh/
+W: http://blemings.org/hugh
-D: Author and maintainer of the Keyspan USB to Serial drivers
+D: Original author of the Keyspan USB to serial drivers, random PowerPC hacker
-S: Po Box 234
+S: PO Box 234
 S: Belconnen ACT 2616
 S: Australia
 
@@ -464,6 +464,11 @@ S: 1200 Goldenrod Dr.
 S: Nampa, Idaho 83686
 S: USA
 
+N: Dirk J. Brandewie
+E: dirk.j.brandewie@intel.com
+E: linux-wimax@intel.com
+D: Intel Wireless WiMAX Connection 2400 SDIO driver
+
 N: Derrick J. Brashear
 E: shadow@dementia.org
 W: http://www.dementia.org/~shadow
@@ -1681,7 +1686,7 @@ E: ajoshi@shell.unixbox.com
 D: fbdev hacking
 
 N: Jesper Juhl
-E: jesper.juhl@gmail.com
+E: jj@chaosbits.net
 D: Various fixes, cleanups and minor features all over the tree.
 D: Wrote initial version of the hdaps driver (since passed on to others).
 S: Lemnosvej 1, 3.tv
@@ -2119,6 +2124,11 @@ N: H.J. Lu
 E: hjl@gnu.ai.mit.edu
 D: GCC + libraries hacker
 
+N: Yanir Lubetkin
+E: yanirx.lubatkin@intel.com
+E: linux-wimax@intel.com
+D: Intel Wireless WiMAX Connection 2400 driver
+
 N: Michal Ludvig
 E: michal@logix.cz
 E: michal.ludvig@asterisk.co.nz
@@ -2693,6 +2703,13 @@ S: RR #5, 497 Pole Line Road
 S: Thunder Bay, Ontario
 S: CANADA P7C 5M9
 
+N: Inaky Perez-Gonzalez
+E: inaky.perez-gonzalez@intel.com
+E: linux-wimax@intel.com
+E: inakypg@yahoo.com
+D: WiMAX stack
+D: Intel Wireless WiMAX Connection 2400 driver
+
 N: Yuri Per
 E: yuri@pts.mipt.ru
 D: Some smbfs fixes

Documentation/ABI/testing/sysfs-class-regulator

@@ -3,8 +3,9 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
-		state. This holds the regulator output state.
+		state. This reports the regulator enable status, for
+		regulators which can report that value.
 
 		This will be one of the following strings:
 
@@ -18,7 +19,8 @@ Description:
 		'disabled' means the regulator output is OFF and is not
 		supplying power to the system..
 
-		'unknown' means software cannot determine the state.
+		'unknown' means software cannot determine the state, or
+		the reported state is invalid.
 
 		NOTE: this field can be used in conjunction with microvolts
 		and microamps to determine regulator output levels.
@@ -53,9 +55,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		microvolts. This holds the regulator output voltage setting
-		measured in microvolts (i.e. E-6 Volts).
+		measured in microvolts (i.e. E-6 Volts), for regulators
+		which can report that voltage.
 
 		NOTE: This value should not be used to determine the regulator
 		output voltage level as this value is the same regardless of
@@ -67,9 +70,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		microamps. This holds the regulator output current limit
-		setting measured in microamps (i.e. E-6 Amps).
+		setting measured in microamps (i.e. E-6 Amps), for regulators
+		which can report that current.
 
 		NOTE: This value should not be used to determine the regulator
 		output current level as this value is the same regardless of
@@ -81,8 +85,9 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
-		opmode. This holds the regulator operating mode setting.
+		opmode. This holds the current regulator operating mode,
+		for regulators which can report it.
 
 		The opmode value can be one of the following strings:
 
@@ -92,7 +97,7 @@ Description:
 		'standby'
 		'unknown'
 
-		The modes are described in include/linux/regulator/regulator.h
+		The modes are described in include/linux/regulator/consumer.h
 
 		NOTE: This value should not be used to determine the regulator
 		output operating mode as this value is the same regardless of
@@ -104,9 +109,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		min_microvolts. This holds the minimum safe working regulator
-		output voltage setting for this domain measured in microvolts.
+		output voltage setting for this domain measured in microvolts,
+		for regulators which support voltage constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no min microvolts constraint defined by
@@ -118,9 +124,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		max_microvolts. This holds the maximum safe working regulator
-		output voltage setting for this domain measured in microvolts.
+		output voltage setting for this domain measured in microvolts,
+		for regulators which support voltage constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no max microvolts constraint defined by
@@ -132,10 +139,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		min_microamps. This holds the minimum safe working regulator
 		output current limit setting for this domain measured in
-		microamps.
+		microamps, for regulators which support current constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no min microamps constraint defined by
@@ -147,10 +154,10 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		max_microamps. This holds the maximum safe working regulator
 		output current limit setting for this domain measured in
-		microamps.
+		microamps, for regulators which support current constraints.
 
 		NOTE: this will return the string 'constraint not defined' if
 		the power domain has no max microamps constraint defined by
@@ -185,7 +192,7 @@ Date:		April 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		requested_microamps. This holds the total requested load
 		current in microamps for this regulator from all its consumer
 		devices.
@@ -204,125 +211,102 @@ Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_mem_microvolts. This holds the regulator output
 		voltage setting for this domain measured in microvolts when
-		the system is suspended to memory.
+		the system is suspended to memory, for voltage regulators
-
+		implementing suspend voltage configuration constraints.
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to memory voltage defined by
-		platform code.
 
 What:		/sys/class/regulator/.../suspend_disk_microvolts
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_disk_microvolts. This holds the regulator output
 		voltage setting for this domain measured in microvolts when
-		the system is suspended to disk.
+		the system is suspended to disk, for voltage regulators
-
+		implementing suspend voltage configuration constraints.
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to disk voltage defined by
-		platform code.
 
 What:		/sys/class/regulator/.../suspend_standby_microvolts
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_standby_microvolts. This holds the regulator output
 		voltage setting for this domain measured in microvolts when
-		the system is suspended to standby.
+		the system is suspended to standby, for voltage regulators
-
+		implementing suspend voltage configuration constraints.
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to standby voltage defined by
-		platform code.
 
 What:		/sys/class/regulator/.../suspend_mem_mode
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_mem_mode. This holds the regulator operating mode
 		setting for this domain when the system is suspended to
-		memory.
+		memory, for regulators implementing suspend mode
-
+		configuration constraints.
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to memory mode defined by
-		platform code.
 
 What:		/sys/class/regulator/.../suspend_disk_mode
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_disk_mode. This holds the regulator operating mode
-		setting for this domain when the system is suspended to disk.
+		setting for this domain when the system is suspended to disk,
-
+		for regulators implementing suspend mode configuration
-		NOTE: this will return the string 'not defined' if
+		constraints.
-		the power domain has no suspend to disk mode defined by
-		platform code.
 
 What:		/sys/class/regulator/.../suspend_standby_mode
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_standby_mode. This holds the regulator operating mode
 		setting for this domain when the system is suspended to
-		standby.
+		standby, for regulators implementing suspend mode
-
+		configuration constraints.
-		NOTE: this will return the string 'not defined' if
-		the power domain has no suspend to standby mode defined by
-		platform code.
 
 What:		/sys/class/regulator/.../suspend_mem_state
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_mem_state. This holds the regulator operating state
-		when suspended to memory.
+		when suspended to memory, for regulators implementing suspend
+		configuration constraints.
 
-		This will be one of the following strings:
+		This will be one of the same strings reported by
-
+		the "state" attribute.
-		'enabled'
-		'disabled'
-		'not defined'
 
 What:		/sys/class/regulator/.../suspend_disk_state
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_disk_state. This holds the regulator operating state
-		when suspended to disk.
+		when suspended to disk, for regulators implementing
+		suspend configuration constraints.
 
-		This will be one of the following strings:
+		This will be one of the same strings reported by
-
+		the "state" attribute.
-		'enabled'
-		'disabled'
-		'not defined'
 
 What:		/sys/class/regulator/.../suspend_standby_state
 Date:		May 2008
 KernelVersion:	2.6.26
 Contact:	Liam Girdwood <lrg@slimlogic.co.uk>
 Description:
-		Each regulator directory will contain a field called
+		Some regulator directories will contain a field called
 		suspend_standby_state. This holds the regulator operating
-		state when suspended to standby.
+		state when suspended to standby, for regulators implementing
+		suspend configuration constraints.
 
-		This will be one of the following strings:
+		This will be one of the same strings reported by
-
+		the "state" attribute.
-		'enabled'
-		'disabled'
-		'not defined'

Documentation/ABI/testing/sysfs-class-uwb_rc

@@ -32,14 +32,16 @@ Contact:        linux-usb@vger.kernel.org
 Description:
                 Write:
 
-                <channel> [<bpst offset>]
+                <channel>
 
-                to start beaconing on a specific channel, or stop
+                to force a specific channel to be used when beaconing,
-                beaconing if <channel> is -1.  Valid channels depends
+                or, if <channel> is -1, to prohibit beaconing.  If
-                on the radio controller's supported band groups.
+                <channel> is 0, then the default channel selection
+                algorithm will be used.  Valid channels depends on the
+                radio controller's supported band groups.
 
-                <bpst offset> may be used to try and join a specific
+                Reading returns the currently active channel, or -1 if
-                beacon group if more than one was found during a scan.
+                the radio controller is not beaconing.
 
 What:           /sys/class/uwb_rc/uwbN/scan
 Date:           July 2008

Documentation/ABI/testing/sysfs-devices-memory

@@ -6,7 +6,6 @@ Description:
 		internal state of the kernel memory blocks. Files could be
 		added or removed dynamically to represent hot-add/remove
 		operations.
-
 Users:		hotplug memory add/remove tools
 		https://w3.opensource.ibm.com/projects/powerpc-utils/
 
@@ -19,6 +18,56 @@ Description:
 		This is useful for a user-level agent to determine
 		identify removable sections of the memory before attempting
 		potentially expensive hot-remove memory operation
-
 Users:		hotplug memory remove tools
 		https://w3.opensource.ibm.com/projects/powerpc-utils/
+
+What:		/sys/devices/system/memory/memoryX/phys_device
+Date:		September 2008
+Contact:	Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+		The file /sys/devices/system/memory/memoryX/phys_device
+		is read-only and is designed to show the name of physical
+		memory device.  Implementation is currently incomplete.
+
+What:		/sys/devices/system/memory/memoryX/phys_index
+Date:		September 2008
+Contact:	Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+		The file /sys/devices/system/memory/memoryX/phys_index
+		is read-only and contains the section ID in hexadecimal
+		which is equivalent to decimal X contained in the
+		memory section directory name.
+
+What:		/sys/devices/system/memory/memoryX/state
+Date:		September 2008
+Contact:	Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+		The file /sys/devices/system/memory/memoryX/state
+		is read-write.  When read, it's contents show the
+		online/offline state of the memory section.  When written,
+		root can toggle the the online/offline state of a removable
+		memory section (see removable file description above)
+		using the following commands.
+		# echo online > /sys/devices/system/memory/memoryX/state
+		# echo offline > /sys/devices/system/memory/memoryX/state
+
+		For example, if /sys/devices/system/memory/memory22/removable
+		contains a value of 1 and
+		/sys/devices/system/memory/memory22/state contains the
+		string "online" the following command can be executed by
+		by root to offline that section.
+		# echo offline > /sys/devices/system/memory/memory22/state
+Users:		hotplug memory remove tools
+		https://w3.opensource.ibm.com/projects/powerpc-utils/
+
+What:		/sys/devices/system/node/nodeX/memoryY
+Date:		September 2008
+Contact:	Gary Hade <garyhade@us.ibm.com>
+Description:
+		When CONFIG_NUMA is enabled
+		/sys/devices/system/node/nodeX/memoryY is a symbolic link that
+		points to the corresponding /sys/devices/system/memory/memoryY
+		memory section directory.  For example, the following symbolic
+		link is created for memory section 9 on node0.
+		/sys/devices/system/node/node0/memory9 -> ../../memory/memory9
+

Documentation/DMA-mapping.txt

@@ -26,7 +26,7 @@ mapped only for the time they are actually used and unmapped after the DMA
 transfer.
 
 The following API will work of course even on platforms where no such
-hardware exists, see e.g. include/asm-i386/pci.h for how it is implemented on
+hardware exists, see e.g. arch/x86/include/asm/pci.h for how it is implemented on
 top of the virt_to_bus interface.
 
 First of all, you should make sure

Documentation/DocBook/Makefile

@@ -12,7 +12,7 @@ DOCBOOKS := z8530book.xml mcabook.xml \
 	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
 	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
 	    genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
-	    mac80211.xml debugobjects.xml sh.xml
+	    mac80211.xml debugobjects.xml sh.xml regulator.xml
 
 ###
 # The build process is as follows (targets):

Documentation/DocBook/networking.tmpl

@@ -74,6 +74,14 @@
 !Enet/sunrpc/rpcb_clnt.c
 !Enet/sunrpc/clnt.c
      </sect1>
+     <sect1><title>WiMAX</title>
+!Enet/wimax/op-msg.c
+!Enet/wimax/op-reset.c
+!Enet/wimax/op-rfkill.c
+!Enet/wimax/stack.c
+!Iinclude/net/wimax.h
+!Iinclude/linux/wimax.h
+     </sect1>
   </chapter>
 
   <chapter id="netdev">

Documentation/DocBook/regulator.tmpl

@@ -0,0 +1,304 @@
+<?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="regulator-api">
+ <bookinfo>
+  <title>Voltage and current regulator API</title>
+
+  <authorgroup>
+   <author>
+    <firstname>Liam</firstname>
+    <surname>Girdwood</surname>
+    <affiliation>
+     <address>
+      <email>lrg@slimlogic.co.uk</email>
+     </address>
+    </affiliation>
+   </author>
+   <author>
+    <firstname>Mark</firstname>
+    <surname>Brown</surname>
+    <affiliation>
+     <orgname>Wolfson Microelectronics</orgname>
+     <address>
+      <email>broonie@opensource.wolfsonmicro.com</email>
+     </address>
+    </affiliation>
+   </author>
+  </authorgroup>
+
+  <copyright>
+   <year>2007-2008</year>
+   <holder>Wolfson Microelectronics</holder>
+  </copyright>
+  <copyright>
+   <year>2008</year>
+   <holder>Liam Girdwood</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>
+	This framework is designed to provide a standard kernel
+	interface to control voltage and current regulators.
+    </para>
+    <para>
+	The intention is to allow systems to dynamically control
+	regulator power output in order to save power and prolong
+	battery life.  This applies to both voltage regulators (where
+	voltage output is controllable) and current sinks (where current
+	limit is controllable).
+    </para>
+    <para>
+	Note that additional (and currently more complete) documentation
+	is available in the Linux kernel source under
+	<filename>Documentation/power/regulator</filename>.
+    </para>
+
+    <sect1 id="glossary">
+       <title>Glossary</title>
+       <para>
+	The regulator API uses a number of terms which may not be
+	familiar:
+       </para>
+       <glossary>
+
+         <glossentry>
+	   <glossterm>Regulator</glossterm>
+	   <glossdef>
+	     <para>
+	Electronic device that supplies power to other devices.  Most
+	regulators can enable and disable their output and some can also
+	control their output voltage or current.
+	     </para>
+	   </glossdef>
+         </glossentry>
+
+	 <glossentry>
+	   <glossterm>Consumer</glossterm>
+	   <glossdef>
+	     <para>
+	Electronic device which consumes power provided by a regulator.
+	These may either be static, requiring only a fixed supply, or
+	dynamic, requiring active management of the regulator at
+	runtime.
+	     </para>
+	   </glossdef>
+	 </glossentry>
+
+	 <glossentry>
+	   <glossterm>Power Domain</glossterm>
+	   <glossdef>
+	     <para>
+	The electronic circuit supplied by a given regulator, including
+	the regulator and all consumer devices.  The configuration of
+	the regulator is shared between all the components in the
+	circuit.
+	     </para>
+	   </glossdef>
+	 </glossentry>
+
+	 <glossentry>
+	   <glossterm>Power Management Integrated Circuit</glossterm>
+	   <acronym>PMIC</acronym>
+	   <glossdef>
+	     <para>
+	An IC which contains numerous regulators and often also other
+	subsystems.  In an embedded system the primary PMIC is often
+	equivalent to a combination of the PSU and southbridge in a
+	desktop system.
+	     </para>
+	   </glossdef>
+	 </glossentry>
+	</glossary>
+     </sect1>
+  </chapter>
+
+  <chapter id="consumer">
+     <title>Consumer driver interface</title>
+     <para>
+       This offers a similar API to the kernel clock framework.
+       Consumer drivers use <link
+       linkend='API-regulator-get'>get</link> and <link
+       linkend='API-regulator-put'>put</link> operations to acquire and
+       release regulators.  Functions are
+       provided to <link linkend='API-regulator-enable'>enable</link>
+       and <link linkend='API-regulator-disable'>disable</link> the
+       reguator and to get and set the runtime parameters of the
+       regulator.
+     </para>
+     <para>
+       When requesting regulators consumers use symbolic names for their
+       supplies, such as "Vcc", which are mapped into actual regulator
+       devices by the machine interface.
+     </para>
+     <para>
+	A stub version of this API is provided when the regulator
+	framework is not in use in order to minimise the need to use
+	ifdefs.
+     </para>
+
+     <sect1 id="consumer-enable">
+       <title>Enabling and disabling</title>
+       <para>
+         The regulator API provides reference counted enabling and
+	 disabling of regulators. Consumer devices use the <function><link
+	 linkend='API-regulator-enable'>regulator_enable</link></function>
+	 and <function><link
+	 linkend='API-regulator-disable'>regulator_disable</link>
+	 </function> functions to enable and disable regulators.  Calls
+	 to the two functions must be balanced.
+       </para>
+       <para>
+         Note that since multiple consumers may be using a regulator and
+	 machine constraints may not allow the regulator to be disabled
+	 there is no guarantee that calling
+	 <function>regulator_disable</function> will actually cause the
+	 supply provided by the regulator to be disabled. Consumer
+	 drivers should assume that the regulator may be enabled at all
+	 times.
+       </para>
+     </sect1>
+
+     <sect1 id="consumer-config">
+       <title>Configuration</title>
+       <para>
+         Some consumer devices may need to be able to dynamically
+	 configure their supplies.  For example, MMC drivers may need to
+	 select the correct operating voltage for their cards.  This may
+	 be done while the regulator is enabled or disabled.
+       </para>
+       <para>
+	 The <function><link
+	 linkend='API-regulator-set-voltage'>regulator_set_voltage</link>
+	 </function> and <function><link
+	 linkend='API-regulator-set-current-limit'
+	 >regulator_set_current_limit</link>
+	 </function> functions provide the primary interface for this.
+	 Both take ranges of voltages and currents, supporting drivers
+	 that do not require a specific value (eg, CPU frequency scaling
+	 normally permits the CPU to use a wider range of supply
+	 voltages at lower frequencies but does not require that the
+	 supply voltage be lowered).  Where an exact value is required
+	 both minimum and maximum values should be identical.
+       </para>
+     </sect1>
+
+     <sect1 id="consumer-callback">
+       <title>Callbacks</title>
+       <para>
+	  Callbacks may also be <link
+	  linkend='API-regulator-register-notifier'>registered</link>
+	  for events such as regulation failures.
+       </para>
+     </sect1>
+   </chapter>
+
+   <chapter id="driver">
+     <title>Regulator driver interface</title>
+     <para>
+       Drivers for regulator chips <link
+       linkend='API-regulator-register'>register</link> the regulators
+       with the regulator core, providing operations structures to the
+       core.  A <link
+       linkend='API-regulator-notifier-call-chain'>notifier</link> interface
+       allows error conditions to be reported to the core.
+     </para>
+     <para>
+       Registration should be triggered by explicit setup done by the
+       platform, supplying a <link
+       linkend='API-struct-regulator-init-data'>struct
+       regulator_init_data</link> for the regulator containing
+       <link linkend='machine-constraint'>constraint</link> and
+       <link linkend='machine-supply'>supply</link> information.
+     </para>
+   </chapter>
+
+   <chapter id="machine">
+     <title>Machine interface</title>
+     <para>
+       This interface provides a way to define how regulators are
+       connected to consumers on a given system and what the valid
+       operating parameters are for the system.
+     </para>
+
+     <sect1 id="machine-supply">
+       <title>Supplies</title>
+       <para>
+         Regulator supplies are specified using <link
+	 linkend='API-struct-regulator-consumer-supply'>struct
+	 regulator_consumer_supply</link>.  This is done at
+	 <link linkend='driver'>driver registration
+	 time</link> as part of the machine constraints.
+       </para>
+     </sect1>
+
+     <sect1 id="machine-constraint">
+       <title>Constraints</title>
+       <para>
+	 As well as definining the connections the machine interface
+	 also provides constraints definining the operations that
+	 clients are allowed to perform and the parameters that may be
+	 set.  This is required since generally regulator devices will
+	 offer more flexibility than it is safe to use on a given
+	 system, for example supporting higher supply voltages than the
+	 consumers are rated for.
+       </para>
+       <para>
+	 This is done at <link linkend='driver'>driver
+	 registration time</link> by providing a <link
+	 linkend='API-struct-regulation-constraints'>struct
+	 regulation_constraints</link>.
+       </para>
+       <para>
+         The constraints may also specify an initial configuration for the
+         regulator in the constraints, which is particularly useful for
+         use with static consumers.
+       </para>
+     </sect1>
+  </chapter>
+
+  <chapter id="api">
+    <title>API reference</title>
+    <para>
+      Due to limitations of the kernel documentation framework and the
+      existing layout of the source code the entire regulator API is
+      documented here.
+    </para>
+!Iinclude/linux/regulator/consumer.h
+!Iinclude/linux/regulator/machine.h
+!Iinclude/linux/regulator/driver.h
+!Edrivers/regulator/core.c
+  </chapter>
+</book>

Documentation/DocBook/uio-howto.tmpl

@@ -41,6 +41,12 @@ GPL version 2.
 </abstract>
 
 <revhistory>
+	<revision>
+	<revnumber>0.6</revnumber>
+	<date>2008-12-05</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>Added description of portio sysfs attributes.</revremark>
+	</revision>
 	<revision>
 	<revnumber>0.5</revnumber>
 	<date>2008-05-22</date>
@@ -318,6 +324,54 @@ interested in translating it, please email me
 offset = N * getpagesize();
 </programlisting>
 
+<para>
+	Sometimes there is hardware with memory-like regions that can not be
+	mapped with the technique described here, but there are still ways to
+	access them from userspace. The most common example are x86 ioports.
+	On x86 systems, userspace can access these ioports using
+	<function>ioperm()</function>, <function>iopl()</function>,
+	<function>inb()</function>, <function>outb()</function>, and similar
+	functions.
+</para>
+<para>
+	Since these ioport regions can not be mapped, they will not appear under
+	<filename>/sys/class/uio/uioX/maps/</filename> like the normal memory
+	described above. Without information about the port regions a hardware
+	has to offer, it becomes difficult for the userspace part of the
+	driver to find out which ports belong to which UIO device.
+</para>
+<para>
+	To address this situation, the new directory
+	<filename>/sys/class/uio/uioX/portio/</filename> was added. It only
+	exists if the driver wants to pass information about one or more port
+	regions to userspace. If that is the case, subdirectories named
+	<filename>port0</filename>, <filename>port1</filename>, and so on,
+	will appear underneath
+	<filename>/sys/class/uio/uioX/portio/</filename>.
+</para>
+<para>
+	Each <filename>portX/</filename> directory contains three read-only
+	files that show start, size, and type of the port region:
+</para>
+<itemizedlist>
+<listitem>
+	<para>
+	<filename>start</filename>: The first port of this region.
+	</para>
+</listitem>
+<listitem>
+	<para>
+	<filename>size</filename>: The number of ports in this region.
+	</para>
+</listitem>
+<listitem>
+	<para>
+	<filename>porttype</filename>: A string describing the type of port.
+	</para>
+</listitem>
+</itemizedlist>
+
+
 </sect1>
 </chapter>
 
@@ -339,12 +393,12 @@ offset = N * getpagesize();
 
 <itemizedlist>
 <listitem><para>
-<varname>char *name</varname>: Required. The name of your driver as
+<varname>const char *name</varname>: Required. The name of your driver as
 it will appear in sysfs. I recommend using the name of your module for this.
 </para></listitem>
 
 <listitem><para>
-<varname>char *version</varname>: Required. This string appears in
+<varname>const char *version</varname>: Required. This string appears in
 <filename>/sys/class/uio/uioX/version</filename>.
 </para></listitem>
 
@@ -355,6 +409,13 @@ mapping you need to fill one of the <varname>uio_mem</varname> structures.
 See the description below for details.
 </para></listitem>
 
+<listitem><para>
+<varname>struct uio_port port[ MAX_UIO_PORTS_REGIONS ]</varname>: Required
+if you want to pass information about ioports to userspace. For each port
+region you need to fill one of the <varname>uio_port</varname> structures.
+See the description below for details.
+</para></listitem>
+
 <listitem><para>
 <varname>long irq</varname>: Required. If your hardware generates an
 interrupt, it's your modules task to determine the irq number during
@@ -448,6 +509,42 @@ Please do not touch the <varname>kobj</varname> element of
 <varname>struct uio_mem</varname>! It is used by the UIO framework
 to set up sysfs files for this mapping. Simply leave it alone.
 </para>
+
+<para>
+Sometimes, your device can have one or more port regions which can not be
+mapped to userspace. But if there are other possibilities for userspace to
+access these ports, it makes sense to make information about the ports
+available in sysfs. For each region, you have to set up a
+<varname>struct uio_port</varname> in the <varname>port[]</varname> array.
+Here's a description of the fields of <varname>struct uio_port</varname>:
+</para>
+
+<itemizedlist>
+<listitem><para>
+<varname>char *porttype</varname>: Required. Set this to one of the predefined
+constants. Use <varname>UIO_PORT_X86</varname> for the ioports found in x86
+architectures.
+</para></listitem>
+
+<listitem><para>
+<varname>unsigned long start</varname>: Required if the port region is used.
+Fill in the number of the first port of this region.
+</para></listitem>
+
+<listitem><para>
+<varname>unsigned long size</varname>: Fill in the number of ports in this
+region. If <varname>size</varname> is zero, the region is considered unused.
+Note that you <emphasis>must</emphasis> initialize <varname>size</varname>
+with zero for all unused regions.
+</para></listitem>
+</itemizedlist>
+
+<para>
+Please do not touch the <varname>portio</varname> element of
+<varname>struct uio_port</varname>! It is used internally by the UIO
+framework to set up sysfs files for this region. Simply leave it alone.
+</para>
+
 </sect1>
 
 <sect1 id="adding_irq_handler">

Documentation/PCI/pci.txt

@@ -294,7 +294,8 @@ NOTE: pci_enable_device() can fail! Check the return value.
 
 pci_set_master() will enable DMA by setting the bus master bit
 in the PCI_COMMAND register. It also fixes the latency timer value if
-it's set to something bogus by the BIOS.
+it's set to something bogus by the BIOS.  pci_clear_master() will
+disable DMA by clearing the bus master bit.
 
 If the PCI device can use the PCI Memory-Write-Invalidate transaction,
 call pci_set_mwi().  This enables the PCI_COMMAND bit for Mem-Wr-Inval

Documentation/RCU/00-INDEX

@@ -12,6 +12,8 @@ rcuref.txt
 	- Reference-count design for elements of lists/arrays protected by RCU
 rcu.txt
 	- RCU Concepts
+rcubarrier.txt
+	- Unloading modules that use RCU callbacks
 RTFP.txt
 	- List of RCU papers (bibliography) going back to 1980.
 torture.txt

Documentation/RCU/rcubarrier.txt

@@ -0,0 +1,304 @@
+RCU and Unloadable Modules
+
+[Originally published in LWN Jan. 14, 2007: http://lwn.net/Articles/217484/]
+
+RCU (read-copy update) is a synchronization mechanism that can be thought
+of as a replacement for read-writer locking (among other things), but with
+very low-overhead readers that are immune to deadlock, priority inversion,
+and unbounded latency. RCU read-side critical sections are delimited
+by rcu_read_lock() and rcu_read_unlock(), which, in non-CONFIG_PREEMPT
+kernels, generate no code whatsoever.
+
+This means that RCU writers are unaware of the presence of concurrent
+readers, so that RCU updates to shared data must be undertaken quite
+carefully, leaving an old version of the data structure in place until all
+pre-existing readers have finished. These old versions are needed because
+such readers might hold a reference to them. RCU updates can therefore be
+rather expensive, and RCU is thus best suited for read-mostly situations.
+
+How can an RCU writer possibly determine when all readers are finished,
+given that readers might well leave absolutely no trace of their
+presence? There is a synchronize_rcu() primitive that blocks until all
+pre-existing readers have completed. An updater wishing to delete an
+element p from a linked list might do the following, while holding an
+appropriate lock, of course:
+
+	list_del_rcu(p);
+	synchronize_rcu();
+	kfree(p);
+
+But the above code cannot be used in IRQ context -- the call_rcu()
+primitive must be used instead. This primitive takes a pointer to an
+rcu_head struct placed within the RCU-protected data structure and
+another pointer to a function that may be invoked later to free that
+structure. Code to delete an element p from the linked list from IRQ
+context might then be as follows:
+
+	list_del_rcu(p);
+	call_rcu(&p->rcu, p_callback);
+
+Since call_rcu() never blocks, this code can safely be used from within
+IRQ context. The function p_callback() might be defined as follows:
+
+	static void p_callback(struct rcu_head *rp)
+	{
+		struct pstruct *p = container_of(rp, struct pstruct, rcu);
+
+		kfree(p);
+	}
+
+
+Unloading Modules That Use call_rcu()
+
+But what if p_callback is defined in an unloadable module?
+
+If we unload the module while some RCU callbacks are pending,
+the CPUs executing these callbacks are going to be severely
+disappointed when they are later invoked, as fancifully depicted at
+http://lwn.net/images/ns/kernel/rcu-drop.jpg.
+
+We could try placing a synchronize_rcu() in the module-exit code path,
+but this is not sufficient. Although synchronize_rcu() does wait for a
+grace period to elapse, it does not wait for the callbacks to complete.
+
+One might be tempted to try several back-to-back synchronize_rcu()
+calls, but this is still not guaranteed to work. If there is a very
+heavy RCU-callback load, then some of the callbacks might be deferred
+in order to allow other processing to proceed. Such deferral is required
+in realtime kernels in order to avoid excessive scheduling latencies.
+
+
+rcu_barrier()
+
+We instead need the rcu_barrier() primitive. This primitive is similar
+to synchronize_rcu(), but instead of waiting solely for a grace
+period to elapse, it also waits for all outstanding RCU callbacks to
+complete. Pseudo-code using rcu_barrier() is as follows:
+
+   1. Prevent any new RCU callbacks from being posted.
+   2. Execute rcu_barrier().
+   3. Allow the module to be unloaded.
+
+Quick Quiz #1: Why is there no srcu_barrier()?
+
+The rcutorture module makes use of rcu_barrier in its exit function
+as follows:
+
+ 1 static void
+ 2 rcu_torture_cleanup(void)
+ 3 {
+ 4   int i;
+ 5
+ 6   fullstop = 1;
+ 7   if (shuffler_task != NULL) {
+ 8     VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
+ 9     kthread_stop(shuffler_task);
+10   }
+11   shuffler_task = NULL;
+12
+13   if (writer_task != NULL) {
+14     VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
+15     kthread_stop(writer_task);
+16   }
+17   writer_task = NULL;
+18
+19   if (reader_tasks != NULL) {
+20     for (i = 0; i < nrealreaders; i++) {
+21       if (reader_tasks[i] != NULL) {
+22         VERBOSE_PRINTK_STRING(
+23           "Stopping rcu_torture_reader task");
+24         kthread_stop(reader_tasks[i]);
+25       }
+26       reader_tasks[i] = NULL;
+27     }
+28     kfree(reader_tasks);
+29     reader_tasks = NULL;
+30   }
+31   rcu_torture_current = NULL;
+32
+33   if (fakewriter_tasks != NULL) {
+34     for (i = 0; i < nfakewriters; i++) {
+35       if (fakewriter_tasks[i] != NULL) {
+36         VERBOSE_PRINTK_STRING(
+37           "Stopping rcu_torture_fakewriter task");
+38         kthread_stop(fakewriter_tasks[i]);
+39       }
+40       fakewriter_tasks[i] = NULL;
+41     }
+42     kfree(fakewriter_tasks);
+43     fakewriter_tasks = NULL;
+44   }
+45
+46   if (stats_task != NULL) {
+47     VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
+48     kthread_stop(stats_task);
+49   }
+50   stats_task = NULL;
+51
+52   /* Wait for all RCU callbacks to fire. */
+53   rcu_barrier();
+54
+55   rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
+56
+57   if (cur_ops->cleanup != NULL)
+58     cur_ops->cleanup();
+59   if (atomic_read(&n_rcu_torture_error))
+60     rcu_torture_print_module_parms("End of test: FAILURE");
+61   else
+62     rcu_torture_print_module_parms("End of test: SUCCESS");
+63 }
+
+Line 6 sets a global variable that prevents any RCU callbacks from
+re-posting themselves. This will not be necessary in most cases, since
+RCU callbacks rarely include calls to call_rcu(). However, the rcutorture
+module is an exception to this rule, and therefore needs to set this
+global variable.
+
+Lines 7-50 stop all the kernel tasks associated with the rcutorture
+module. Therefore, once execution reaches line 53, no more rcutorture
+RCU callbacks will be posted. The rcu_barrier() call on line 53 waits
+for any pre-existing callbacks to complete.
+
+Then lines 55-62 print status and do operation-specific cleanup, and
+then return, permitting the module-unload operation to be completed.
+
+Quick Quiz #2: Is there any other situation where rcu_barrier() might
+	be required?
+
+Your module might have additional complications. For example, if your
+module invokes call_rcu() from timers, you will need to first cancel all
+the timers, and only then invoke rcu_barrier() to wait for any remaining
+RCU callbacks to complete.
+
+
+Implementing rcu_barrier()
+
+Dipankar Sarma's implementation of rcu_barrier() makes use of the fact
+that RCU callbacks are never reordered once queued on one of the per-CPU
+queues. His implementation queues an RCU callback on each of the per-CPU
+callback queues, and then waits until they have all started executing, at
+which point, all earlier RCU callbacks are guaranteed to have completed.
+
+The original code for rcu_barrier() was as follows:
+
+ 1 void rcu_barrier(void)
+ 2 {
+ 3   BUG_ON(in_interrupt());
+ 4   /* Take cpucontrol mutex to protect against CPU hotplug */
+ 5   mutex_lock(&rcu_barrier_mutex);
+ 6   init_completion(&rcu_barrier_completion);
+ 7   atomic_set(&rcu_barrier_cpu_count, 0);
+ 8   on_each_cpu(rcu_barrier_func, NULL, 0, 1);
+ 9   wait_for_completion(&rcu_barrier_completion);
+10   mutex_unlock(&rcu_barrier_mutex);
+11 }
+
+Line 3 verifies that the caller is in process context, and lines 5 and 10
+use rcu_barrier_mutex to ensure that only one rcu_barrier() is using the
+global completion and counters at a time, which are initialized on lines
+6 and 7. Line 8 causes each CPU to invoke rcu_barrier_func(), which is
+shown below. Note that the final "1" in on_each_cpu()'s argument list
+ensures that all the calls to rcu_barrier_func() will have completed
+before on_each_cpu() returns. Line 9 then waits for the completion.
+
+This code was rewritten in 2008 to support rcu_barrier_bh() and
+rcu_barrier_sched() in addition to the original rcu_barrier().
+
+The rcu_barrier_func() runs on each CPU, where it invokes call_rcu()
+to post an RCU callback, as follows:
+
+ 1 static void rcu_barrier_func(void *notused)
+ 2 {
+ 3 int cpu = smp_processor_id();
+ 4 struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
+ 5 struct rcu_head *head;
+ 6
+ 7 head = &rdp->barrier;
+ 8 atomic_inc(&rcu_barrier_cpu_count);
+ 9 call_rcu(head, rcu_barrier_callback);
+10 }
+
+Lines 3 and 4 locate RCU's internal per-CPU rcu_data structure,
+which contains the struct rcu_head that needed for the later call to
+call_rcu(). Line 7 picks up a pointer to this struct rcu_head, and line
+8 increments a global counter. This counter will later be decremented
+by the callback. Line 9 then registers the rcu_barrier_callback() on
+the current CPU's queue.
+
+The rcu_barrier_callback() function simply atomically decrements the
+rcu_barrier_cpu_count variable and finalizes the completion when it
+reaches zero, as follows:
+
+ 1 static void rcu_barrier_callback(struct rcu_head *notused)
+ 2 {
+ 3 if (atomic_dec_and_test(&rcu_barrier_cpu_count))
+ 4 complete(&rcu_barrier_completion);
+ 5 }
+
+Quick Quiz #3: What happens if CPU 0's rcu_barrier_func() executes
+	immediately (thus incrementing rcu_barrier_cpu_count to the
+	value one), but the other CPU's rcu_barrier_func() invocations
+	are delayed for a full grace period? Couldn't this result in
+	rcu_barrier() returning prematurely?
+
+
+rcu_barrier() Summary
+
+The rcu_barrier() primitive has seen relatively little use, since most
+code using RCU is in the core kernel rather than in modules. However, if
+you are using RCU from an unloadable module, you need to use rcu_barrier()
+so that your module may be safely unloaded.
+
+
+Answers to Quick Quizzes
+
+Quick Quiz #1: Why is there no srcu_barrier()?
+
+Answer: Since there is no call_srcu(), there can be no outstanding SRCU
+	callbacks. Therefore, there is no need to wait for them.
+
+Quick Quiz #2: Is there any other situation where rcu_barrier() might
+	be required?
+
+Answer: Interestingly enough, rcu_barrier() was not originally
+	implemented for module unloading. Nikita Danilov was using
+	RCU in a filesystem, which resulted in a similar situation at
+	filesystem-unmount time. Dipankar Sarma coded up rcu_barrier()
+	in response, so that Nikita could invoke it during the
+	filesystem-unmount process.
+
+	Much later, yours truly hit the RCU module-unload problem when
+	implementing rcutorture, and found that rcu_barrier() solves
+	this problem as well.
+
+Quick Quiz #3: What happens if CPU 0's rcu_barrier_func() executes
+	immediately (thus incrementing rcu_barrier_cpu_count to the
+	value one), but the other CPU's rcu_barrier_func() invocations
+	are delayed for a full grace period? Couldn't this result in
+	rcu_barrier() returning prematurely?
+
+Answer: This cannot happen. The reason is that on_each_cpu() has its last
+	argument, the wait flag, set to "1". This flag is passed through
+	to smp_call_function() and further to smp_call_function_on_cpu(),
+	causing this latter to spin until the cross-CPU invocation of
+	rcu_barrier_func() has completed. This by itself would prevent
+	a grace period from completing on non-CONFIG_PREEMPT kernels,
+	since each CPU must undergo a context switch (or other quiescent
+	state) before the grace period can complete. However, this is
+	of no use in CONFIG_PREEMPT kernels.
+
+	Therefore, on_each_cpu() disables preemption across its call
+	to smp_call_function() and also across the local call to
+	rcu_barrier_func(). This prevents the local CPU from context
+	switching, again preventing grace periods from completing. This
+	means that all CPUs have executed rcu_barrier_func() before
+	the first rcu_barrier_callback() can possibly execute, in turn
+	preventing rcu_barrier_cpu_count from prematurely reaching zero.
+
+	Currently, -rt implementations of RCU keep but a single global
+	queue for RCU callbacks, and thus do not suffer from this
+	problem. However, when the -rt RCU eventually does have per-CPU
+	callback queues, things will have to change. One simple change
+	is to add an rcu_read_lock() before line 8 of rcu_barrier()
+	and an rcu_read_unlock() after line 8 of this same function. If
+	you can think of a better change, please let me know!

Documentation/bad_memory.txt

@@ -0,0 +1,45 @@
+March 2008
+Jan-Simon Moeller, dl9pf@gmx.de
+
+
+How to deal with bad memory e.g. reported by memtest86+ ?
+#########################################################
+
+There are three possibilities I know of:
+
+1) Reinsert/swap the memory modules
+
+2) Buy new modules (best!) or try to exchange the memory
+   if you have spare-parts
+
+3) Use BadRAM or memmap
+
+This Howto is about number 3) .
+
+
+BadRAM
+######
+BadRAM is the actively developed and available as kernel-patch
+here:  http://rick.vanrein.org/linux/badram/
+
+For more details see the BadRAM documentation.
+
+memmap
+######
+
+memmap is already in the kernel and usable as kernel-parameter at
+boot-time.  Its syntax is slightly strange and you may need to
+calculate the values by yourself!
+
+Syntax to exclude a memory area (see kernel-parameters.txt for details):
+memmap=<size>$<address>
+
+Example: memtest86+ reported here errors at address 0x18691458, 0x18698424 and
+         some others. All had 0x1869xxxx in common, so I chose a pattern of
+         0x18690000,0xffff0000.
+
+With the numbers of the example above:
+memmap=64K$0x18690000
+ or
+memmap=0x10000$0x18690000
+

Documentation/blackfin/00-INDEX

@@ -9,3 +9,6 @@ cachefeatures.txt
 
 Filesystems
 	- Requirements for mounting the root file system.
+
+bfin-gpio-note.txt
+	- Notes in developing/using bfin-gpio driver.

Documentation/blackfin/bfin-gpio-notes.txt

@@ -0,0 +1,71 @@
+/*
+ * File:         Documentation/blackfin/bfin-gpio-note.txt
+ * Based on:
+ * Author:
+ *
+ * Created:      $Id: bfin-gpio-note.txt 2008-11-24 16:42 grafyang $
+ * Description:  This file contains the notes in developing/using bfin-gpio.
+ *
+ *
+ * Rev:
+ *
+ * Modified:
+ *               Copyright 2004-2008 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ */
+
+
+1. Blackfin GPIO introduction
+
+    There are many GPIO pins on Blackfin. Most of these pins are muxed to
+    multi-functions. They can be configured as peripheral, or just as GPIO,
+    configured to input with interrupt enabled, or output.
+
+    For detailed information, please see "arch/blackfin/kernel/bfin_gpio.c",
+    or the relevant HRM.
+
+
+2. Avoiding resource conflict
+
+    Followed function groups are used to avoiding resource conflict,
+    - Use the pin as peripheral,
+	int peripheral_request(unsigned short per, const char *label);
+	int peripheral_request_list(const unsigned short per[], const char *label);
+	void peripheral_free(unsigned short per);
+	void peripheral_free_list(const unsigned short per[]);
+    - Use the pin as GPIO,
+	int bfin_gpio_request(unsigned gpio, const char *label);
+	void bfin_gpio_free(unsigned gpio);
+    - Use the pin as GPIO interrupt,
+	int bfin_gpio_irq_request(unsigned gpio, const char *label);
+	void bfin_gpio_irq_free(unsigned gpio);
+
+    The request functions will record the function state for a certain pin,
+    the free functions will clear it's function state.
+    Once a pin is requested, it can't be requested again before it is freed by
+    previous caller, otherwise kernel will dump stacks, and the request
+    function fail.
+    These functions are wrapped by other functions, most of the users need not
+    care.
+
+
+3. But there are some exceptions
+    - Kernel permit the identical GPIO be requested both as GPIO and GPIO
+    interrut.
+    Some drivers, like gpio-keys, need this behavior. Kernel only print out
+    warning messages like,
+	bfin-gpio: GPIO 24 is already reserved by gpio-keys: BTN0, and you are
+configuring it as IRQ!
+
+        Note: Consider the case that, if there are two drivers need the
+	identical GPIO, one of them use it as GPIO, the other use it as
+	GPIO interrupt. This will really cause resource conflict. So if
+	there is any abnormal driver behavior, please check the bfin-gpio
+	warning messages.
+
+    - Kernel permit the identical GPIO be requested from the same driver twice.
+
+
+

Documentation/cgroups/cgroups.txt

@@ -227,7 +227,6 @@ Each cgroup is represented by a directory in the cgroup file system
 containing the following files describing that cgroup:
 
  - tasks: list of tasks (by pid) attached to that cgroup
- - releasable flag: cgroup currently removeable?
  - notify_on_release flag: run the release agent on exit?
  - release_agent: the path to use for release notifications (this file
    exists in the top cgroup only)
@@ -360,7 +359,7 @@ Now you want to do something with this cgroup.
 
 In this directory you can find several files:
 # ls
-notify_on_release releasable tasks
+notify_on_release tasks
 (plus whatever files added by the attached subsystems)
 
 Now attach your shell to this cgroup:
@@ -479,7 +478,6 @@ newly-created cgroup if an error occurs after this subsystem's
 create() method has been called for the new cgroup).
 
 void pre_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
-(cgroup_mutex held by caller)
 
 Called before checking the reference count on each subsystem. This may
 be useful for subsystems which have some extra references even if
@@ -498,6 +496,7 @@ remain valid while the caller holds cgroup_mutex.
 
 void attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
 	    struct cgroup *old_cgrp, struct task_struct *task)
+(cgroup_mutex held by caller)
 
 Called after the task has been attached to the cgroup, to allow any
 post-attachment activity that requires memory allocations or blocking.
@@ -511,6 +510,7 @@ void exit(struct cgroup_subsys *ss, struct task_struct *task)
 Called during task exit.
 
 int populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
+(cgroup_mutex held by caller)
 
 Called after creation of a cgroup to allow a subsystem to populate
 the cgroup directory with file entries.  The subsystem should make
@@ -520,6 +520,7 @@ method can return an error code, the error code is currently not
 always handled well.
 
 void post_clone(struct cgroup_subsys *ss, struct cgroup *cgrp)
+(cgroup_mutex held by caller)
 
 Called at the end of cgroup_clone() to do any paramater
 initialization which might be required before a task could attach.  For
@@ -527,7 +528,7 @@ example in cpusets, no task may attach before 'cpus' and 'mems' are set
 up.
 
 void bind(struct cgroup_subsys *ss, struct cgroup *root)
-(cgroup_mutex held by caller)
+(cgroup_mutex and ss->hierarchy_mutex held by caller)
 
 Called when a cgroup subsystem is rebound to a different hierarchy
 and root cgroup. Currently this will only involve movement between

Documentation/controllers/memcg_test.txt

@@ -0,0 +1,342 @@
+Memory Resource Controller(Memcg)  Implementation Memo.
+Last Updated: 2008/12/15
+Base Kernel Version: based on 2.6.28-rc8-mm.
+
+Because VM is getting complex (one of reasons is memcg...), memcg's behavior
+is complex. This is a document for memcg's internal behavior.
+Please note that implementation details can be changed.
+
+(*) Topics on API should be in Documentation/controllers/memory.txt)
+
+0. How to record usage ?
+   2 objects are used.
+
+   page_cgroup ....an object per page.
+	Allocated at boot or memory hotplug. Freed at memory hot removal.
+
+   swap_cgroup ... an entry per swp_entry.
+	Allocated at swapon(). Freed at swapoff().
+
+   The page_cgroup has USED bit and double count against a page_cgroup never
+   occurs. swap_cgroup is used only when a charged page is swapped-out.
+
+1. Charge
+
+   a page/swp_entry may be charged (usage += PAGE_SIZE) at
+
+	mem_cgroup_newpage_charge()
+	  Called at new page fault and Copy-On-Write.
+
+	mem_cgroup_try_charge_swapin()
+	  Called at do_swap_page() (page fault on swap entry) and swapoff.
+	  Followed by charge-commit-cancel protocol. (With swap accounting)
+	  At commit, a charge recorded in swap_cgroup is removed.
+
+	mem_cgroup_cache_charge()
+	  Called at add_to_page_cache()
+
+	mem_cgroup_cache_charge_swapin()
+	  Called at shmem's swapin.
+
+	mem_cgroup_prepare_migration()
+	  Called before migration. "extra" charge is done and followed by
+	  charge-commit-cancel protocol.
+	  At commit, charge against oldpage or newpage will be committed.
+
+2. Uncharge
+  a page/swp_entry may be uncharged (usage -= PAGE_SIZE) by
+
+	mem_cgroup_uncharge_page()
+	  Called when an anonymous page is fully unmapped. I.e., mapcount goes
+	  to 0. If the page is SwapCache, uncharge is delayed until
+	  mem_cgroup_uncharge_swapcache().
+
+	mem_cgroup_uncharge_cache_page()
+	  Called when a page-cache is deleted from radix-tree. If the page is
+	  SwapCache, uncharge is delayed until mem_cgroup_uncharge_swapcache().
+
+	mem_cgroup_uncharge_swapcache()
+	  Called when SwapCache is removed from radix-tree. The charge itself
+	  is moved to swap_cgroup. (If mem+swap controller is disabled, no
+	  charge to swap occurs.)
+
+	mem_cgroup_uncharge_swap()
+	  Called when swp_entry's refcnt goes down to 0. A charge against swap
+	  disappears.
+
+	mem_cgroup_end_migration(old, new)
+	At success of migration old is uncharged (if necessary), a charge
+	to new page is committed. At failure, charge to old page is committed.
+
+3. charge-commit-cancel
+	In some case, we can't know this "charge" is valid or not at charging
+	(because of races).
+	To handle such case, there are charge-commit-cancel functions.
+		mem_cgroup_try_charge_XXX
+		mem_cgroup_commit_charge_XXX
+		mem_cgroup_cancel_charge_XXX
+	these are used in swap-in and migration.
+
+	At try_charge(), there are no flags to say "this page is charged".
+	at this point, usage += PAGE_SIZE.
+
+	At commit(), the function checks the page should be charged or not
+	and set flags or avoid charging.(usage -= PAGE_SIZE)
+
+	At cancel(), simply usage -= PAGE_SIZE.
+
+Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y.
+
+4. Anonymous
+	Anonymous page is newly allocated at
+		  - page fault into MAP_ANONYMOUS mapping.
+		  - Copy-On-Write.
+ 	It is charged right after it's allocated before doing any page table
+	related operations. Of course, it's uncharged when another page is used
+	for the fault address.
+
+	At freeing anonymous page (by exit() or munmap()), zap_pte() is called
+	and pages for ptes are freed one by one.(see mm/memory.c). Uncharges
+	are done at page_remove_rmap() when page_mapcount() goes down to 0.
+
+	Another page freeing is by page-reclaim (vmscan.c) and anonymous
+	pages are swapped out. In this case, the page is marked as
+	PageSwapCache(). uncharge() routine doesn't uncharge the page marked
+	as SwapCache(). It's delayed until __delete_from_swap_cache().
+
+	4.1 Swap-in.
+	At swap-in, the page is taken from swap-cache. There are 2 cases.
+
+	(a) If the SwapCache is newly allocated and read, it has no charges.
+	(b) If the SwapCache has been mapped by processes, it has been
+	    charged already.
+
+	This swap-in is one of the most complicated work. In do_swap_page(),
+	following events occur when pte is unchanged.
+
+	(1) the page (SwapCache) is looked up.
+	(2) lock_page()
+	(3) try_charge_swapin()
+	(4) reuse_swap_page() (may call delete_swap_cache())
+	(5) commit_charge_swapin()
+	(6) swap_free().
+
+	Considering following situation for example.
+
+	(A) The page has not been charged before (2) and reuse_swap_page()
+	    doesn't call delete_from_swap_cache().
+	(B) The page has not been charged before (2) and reuse_swap_page()
+	    calls delete_from_swap_cache().
+	(C) The page has been charged before (2) and reuse_swap_page() doesn't
+	    call delete_from_swap_cache().
+	(D) The page has been charged before (2) and reuse_swap_page() calls
+	    delete_from_swap_cache().
+
+	    memory.usage/memsw.usage changes to this page/swp_entry will be
+	 Case          (A)      (B)       (C)     (D)
+         Event
+       Before (2)     0/ 1     0/ 1      1/ 1    1/ 1
+          ===========================================
+          (3)        +1/+1    +1/+1     +1/+1   +1/+1
+          (4)          -       0/ 0       -     -1/ 0
+          (5)         0/-1     0/ 0     -1/-1    0/ 0
+          (6)          -       0/-1       -      0/-1
+          ===========================================
+       Result         1/ 1     1/ 1      1/ 1    1/ 1
+
+       In any cases, charges to this page should be 1/ 1.
+
+	4.2 Swap-out.
+	At swap-out, typical state transition is below.
+
+	(a) add to swap cache. (marked as SwapCache)
+	    swp_entry's refcnt += 1.
+	(b) fully unmapped.
+	    swp_entry's refcnt += # of ptes.
+	(c) write back to swap.
+	(d) delete from swap cache. (remove from SwapCache)
+	    swp_entry's refcnt -= 1.
+
+
+	At (b), the page is marked as SwapCache and not uncharged.
+	At (d), the page is removed from SwapCache and a charge in page_cgroup
+	is moved to swap_cgroup.
+
+	Finally, at task exit,
+	(e) zap_pte() is called and swp_entry's refcnt -=1 -> 0.
+	Here, a charge in swap_cgroup disappears.
+
+5. Page Cache
+   	Page Cache is charged at
+	- add_to_page_cache_locked().
+
+	uncharged at
+	- __remove_from_page_cache().
+
+	The logic is very clear. (About migration, see below)
+	Note: __remove_from_page_cache() is called by remove_from_page_cache()
+	and __remove_mapping().
+
+6. Shmem(tmpfs) Page Cache
+	Memcg's charge/uncharge have special handlers of shmem. The best way
+	to understand shmem's page state transition is to read mm/shmem.c.
+	But brief explanation of the behavior of memcg around shmem will be
+	helpful to understand the logic.
+
+	Shmem's page (just leaf page, not direct/indirect block) can be on
+		- radix-tree of shmem's inode.
+		- SwapCache.
+		- Both on radix-tree and SwapCache. This happens at swap-in
+		  and swap-out,
+
+	It's charged when...
+	- A new page is added to shmem's radix-tree.
+	- A swp page is read. (move a charge from swap_cgroup to page_cgroup)
+	It's uncharged when
+	- A page is removed from radix-tree and not SwapCache.
+	- When SwapCache is removed, a charge is moved to swap_cgroup.
+	- When swp_entry's refcnt goes down to 0, a charge in swap_cgroup
+	  disappears.
+
+7. Page Migration
+   	One of the most complicated functions is page-migration-handler.
+	Memcg has 2 routines. Assume that we are migrating a page's contents
+	from OLDPAGE to NEWPAGE.
+
+	Usual migration logic is..
+	(a) remove the page from LRU.
+	(b) allocate NEWPAGE (migration target)
+	(c) lock by lock_page().
+	(d) unmap all mappings.
+	(e-1) If necessary, replace entry in radix-tree.
+	(e-2) move contents of a page.
+	(f) map all mappings again.
+	(g) pushback the page to LRU.
+	(-) OLDPAGE will be freed.
+
+	Before (g), memcg should complete all necessary charge/uncharge to
+	NEWPAGE/OLDPAGE.
+
+	The point is....
+	- If OLDPAGE is anonymous, all charges will be dropped at (d) because
+          try_to_unmap() drops all mapcount and the page will not be
+	  SwapCache.
+
+	- If OLDPAGE is SwapCache, charges will be kept at (g) because
+	  __delete_from_swap_cache() isn't called at (e-1)
+
+	- If OLDPAGE is page-cache, charges will be kept at (g) because
+	  remove_from_swap_cache() isn't called at (e-1)
+
+	memcg provides following hooks.
+
+	- mem_cgroup_prepare_migration(OLDPAGE)
+	  Called after (b) to account a charge (usage += PAGE_SIZE) against
+	  memcg which OLDPAGE belongs to.
+
+        - mem_cgroup_end_migration(OLDPAGE, NEWPAGE)
+	  Called after (f) before (g).
+	  If OLDPAGE is used, commit OLDPAGE again. If OLDPAGE is already
+	  charged, a charge by prepare_migration() is automatically canceled.
+	  If NEWPAGE is used, commit NEWPAGE and uncharge OLDPAGE.
+
+	  But zap_pte() (by exit or munmap) can be called while migration,
+	  we have to check if OLDPAGE/NEWPAGE is a valid page after commit().
+
+8. LRU
+        Each memcg has its own private LRU. Now, it's handling is under global
+	VM's control (means that it's handled under global zone->lru_lock).
+	Almost all routines around memcg's LRU is called by global LRU's
+	list management functions under zone->lru_lock().
+
+	A special function is mem_cgroup_isolate_pages(). This scans
+	memcg's private LRU and call __isolate_lru_page() to extract a page
+	from LRU.
+	(By __isolate_lru_page(), the page is removed from both of global and
+	 private LRU.)
+
+
+9. Typical Tests.
+
+ Tests for racy cases.
+
+ 9.1 Small limit to memcg.
+	When you do test to do racy case, it's good test to set memcg's limit
+	to be very small rather than GB. Many races found in the test under
+	xKB or xxMB limits.
+	(Memory behavior under GB and Memory behavior under MB shows very
+	 different situation.)
+
+ 9.2 Shmem
+	Historically, memcg's shmem handling was poor and we saw some amount
+	of troubles here. This is because shmem is page-cache but can be
+	SwapCache. Test with shmem/tmpfs is always good test.
+
+ 9.3 Migration
+	For NUMA, migration is an another special case. To do easy test, cpuset
+	is useful. Following is a sample script to do migration.
+
+	mount -t cgroup -o cpuset none /opt/cpuset
+
+	mkdir /opt/cpuset/01
+	echo 1 > /opt/cpuset/01/cpuset.cpus
+	echo 0 > /opt/cpuset/01/cpuset.mems
+	echo 1 > /opt/cpuset/01/cpuset.memory_migrate
+	mkdir /opt/cpuset/02
+	echo 1 > /opt/cpuset/02/cpuset.cpus
+	echo 1 > /opt/cpuset/02/cpuset.mems
+	echo 1 > /opt/cpuset/02/cpuset.memory_migrate
+
+	In above set, when you moves a task from 01 to 02, page migration to
+	node 0 to node 1 will occur. Following is a script to migrate all
+	under cpuset.
+	--
+	move_task()
+	{
+	for pid in $1
+        do
+                /bin/echo $pid >$2/tasks 2>/dev/null
+		echo -n $pid
+		echo -n " "
+        done
+	echo END
+	}
+
+	G1_TASK=`cat ${G1}/tasks`
+	G2_TASK=`cat ${G2}/tasks`
+	move_task "${G1_TASK}" ${G2} &
+	--
+ 9.4 Memory hotplug.
+	memory hotplug test is one of good test.
+	to offline memory, do following.
+	# echo offline > /sys/devices/system/memory/memoryXXX/state
+	(XXX is the place of memory)
+	This is an easy way to test page migration, too.
+
+ 9.5 mkdir/rmdir
+	When using hierarchy, mkdir/rmdir test should be done.
+	Use tests like the following.
+
+	echo 1 >/opt/cgroup/01/memory/use_hierarchy
+	mkdir /opt/cgroup/01/child_a
+	mkdir /opt/cgroup/01/child_b
+
+	set limit to 01.
+	add limit to 01/child_b
+	run jobs under child_a and child_b
+
+	create/delete following groups at random while jobs are running.
+	/opt/cgroup/01/child_a/child_aa
+	/opt/cgroup/01/child_b/child_bb
+	/opt/cgroup/01/child_c
+
+	running new jobs in new group is also good.
+
+ 9.6 Mount with other subsystems.
+	Mounting with other subsystems is a good test because there is a
+	race and lock dependency with other cgroup subsystems.
+
+	example)
+	# mount -t cgroup none /cgroup -t cpuset,memory,cpu,devices
+
+	and do task move, mkdir, rmdir etc...under this.

Documentation/controllers/memory.txt

@@ -137,7 +137,32 @@ behind this approach is that a cgroup that aggressively uses a shared
 page will eventually get charged for it (once it is uncharged from
 the cgroup that brought it in -- this will happen on memory pressure).
 
-2.4 Reclaim
+Exception: If CONFIG_CGROUP_CGROUP_MEM_RES_CTLR_SWAP is not used..
+When you do swapoff and make swapped-out pages of shmem(tmpfs) to
+be backed into memory in force, charges for pages are accounted against the
+caller of swapoff rather than the users of shmem.
+
+
+2.4 Swap Extension (CONFIG_CGROUP_MEM_RES_CTLR_SWAP)
+Swap Extension allows you to record charge for swap. A swapped-in page is
+charged back to original page allocator if possible.
+
+When swap is accounted, following files are added.
+ - memory.memsw.usage_in_bytes.
+ - memory.memsw.limit_in_bytes.
+
+usage of mem+swap is limited by memsw.limit_in_bytes.
+
+Note: why 'mem+swap' rather than swap.
+The global LRU(kswapd) can swap out arbitrary pages. Swap-out means
+to move account from memory to swap...there is no change in usage of
+mem+swap.
+
+In other words, when we want to limit the usage of swap without affecting
+global LRU, mem+swap limit is better than just limiting swap from OS point
+of view.
+
+2.5 Reclaim
 
 Each cgroup maintains a per cgroup LRU that consists of an active
 and inactive list. When a cgroup goes over its limit, we first try
@@ -207,12 +232,6 @@ exceeded.
 The memory.stat file gives accounting information. Now, the number of
 caches, RSS and Active pages/Inactive pages are shown.
 
-The memory.force_empty gives an interface to drop *all* charges by force.
-
-# echo 1 > memory.force_empty
-
-will drop all charges in cgroup. Currently, this is maintained for test.
-
 4. Testing
 
 Balbir posted lmbench, AIM9, LTP and vmmstress results [10] and [11].
@@ -242,10 +261,106 @@ reclaimed.
 
 A cgroup can be removed by rmdir, but as discussed in sections 4.1 and 4.2, a
 cgroup might have some charge associated with it, even though all
-tasks have migrated away from it. Such charges are automatically dropped at
+tasks have migrated away from it.
-rmdir() if there are no tasks.
+Such charges are freed(at default) or moved to its parent. When moved,
+both of RSS and CACHES are moved to parent.
+If both of them are busy, rmdir() returns -EBUSY. See 5.1 Also.
 
-5. TODO
+Charges recorded in swap information is not updated at removal of cgroup.
+Recorded information is discarded and a cgroup which uses swap (swapcache)
+will be charged as a new owner of it.
+
+
+5. Misc. interfaces.
+
+5.1 force_empty
+  memory.force_empty interface is provided to make cgroup's memory usage empty.
+  You can use this interface only when the cgroup has no tasks.
+  When writing anything to this
+
+  # echo 0 > memory.force_empty
+
+  Almost all pages tracked by this memcg will be unmapped and freed. Some of
+  pages cannot be freed because it's locked or in-use. Such pages are moved
+  to parent and this cgroup will be empty. But this may return -EBUSY in
+  some too busy case.
+
+  Typical use case of this interface is that calling this before rmdir().
+  Because rmdir() moves all pages to parent, some out-of-use page caches can be
+  moved to the parent. If you want to avoid that, force_empty will be useful.
+
+5.2 stat file
+  memory.stat file includes following statistics (now)
+	cache			- # of pages from page-cache and shmem.
+	rss			- # of pages from anonymous memory.
+	pgpgin			- # of event of charging
+	pgpgout			- # of event of uncharging
+	active_anon		- # of pages on active lru of anon, shmem.
+	inactive_anon 		- # of pages on active lru of anon, shmem
+	active_file		- # of pages on active lru of file-cache
+	inactive_file		- # of pages on inactive lru of file cache
+	unevictable		- # of pages cannot be reclaimed.(mlocked etc)
+
+	Below is depend on CONFIG_DEBUG_VM.
+	inactive_ratio		- VM inernal parameter. (see mm/page_alloc.c)
+	recent_rotated_anon	- VM internal parameter. (see mm/vmscan.c)
+	recent_rotated_file	- VM internal parameter. (see mm/vmscan.c)
+	recent_scanned_anon 	- VM internal parameter. (see mm/vmscan.c)
+	recent_scanned_file 	- VM internal parameter. (see mm/vmscan.c)
+
+  Memo:
+	recent_rotated means recent frequency of lru rotation.
+	recent_scanned means recent # of scans to lru.
+	showing for better debug please see the code for meanings.
+
+
+5.3 swappiness
+  Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only.
+
+  Following cgroup's swapiness can't be changed.
+  - root cgroup (uses /proc/sys/vm/swappiness).
+  - a cgroup which uses hierarchy and it has child cgroup.
+  - a cgroup which uses hierarchy and not the root of hierarchy.
+
+
+6. Hierarchy support
+
+The memory controller supports a deep hierarchy and hierarchical accounting.
+The hierarchy is created by creating the appropriate cgroups in the
+cgroup filesystem. Consider for example, the following cgroup filesystem
+hierarchy
+
+		root
+	     /  |   \
+           /	|    \
+	  a	b	c
+			| \
+			|  \
+			d   e
+
+In the diagram above, with hierarchical accounting enabled, all memory
+usage of e, is accounted to its ancestors up until the root (i.e, c and root),
+that has memory.use_hierarchy enabled.  If one of the ancestors goes over its
+limit, the reclaim algorithm reclaims from the tasks in the ancestor and the
+children of the ancestor.
+
+6.1 Enabling hierarchical accounting and reclaim
+
+The memory controller by default disables the hierarchy feature. Support
+can be enabled by writing 1 to memory.use_hierarchy file of the root cgroup
+
+# echo 1 > memory.use_hierarchy
+
+The feature can be disabled by
+
+# echo 0 > memory.use_hierarchy
+
+NOTE1: Enabling/disabling will fail if the cgroup already has other
+cgroups created below it.
+
+NOTE2: This feature can be enabled/disabled per subtree.
+
+7. TODO
 
 1. Add support for accounting huge pages (as a separate controller)
 2. Make per-cgroup scanner reclaim not-shared pages first

Documentation/cpu-hotplug.txt

@@ -50,16 +50,17 @@ additional_cpus=n (*)	Use this to limit hotpluggable cpus. This option sets
   			cpu_possible_map = cpu_present_map + additional_cpus
 
 (*) Option valid only for following architectures
-- x86_64, ia64
+- ia64
 
-ia64 and x86_64 use the number of disabled local apics in ACPI tables MADT
+ia64 uses the number of disabled local apics in ACPI tables MADT to
-to determine the number of potentially hot-pluggable cpus. The implementation
+determine the number of potentially hot-pluggable cpus. The implementation
-should only rely on this to count the # of cpus, but *MUST* not rely on the
+should only rely on this to count the # of cpus, but *MUST* not rely
-apicid values in those tables for disabled apics. In the event BIOS doesn't
+on the apicid values in those tables for disabled apics. In the event
-mark such hot-pluggable cpus as disabled entries, one could use this
+BIOS doesn't mark such hot-pluggable cpus as disabled entries, one could
-parameter "additional_cpus=x" to represent those cpus in the cpu_possible_map.
+use this parameter "additional_cpus=x" to represent those cpus in the
+cpu_possible_map.
 
-possible_cpus=n		[s390 only] use this to set hotpluggable cpus.
+possible_cpus=n		[s390,x86_64] use this to set hotpluggable cpus.
 			This option sets possible_cpus bits in
 			cpu_possible_map. Thus keeping the numbers of bits set
 			constant even if the machine gets rebooted.