Merge branch 'linus' into x86/x2apic

Conflicts:

	drivers/pci/dmar.c

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

CREDITS

@@ -317,6 +317,14 @@ S: 2322 37th Ave SW
 S: Seattle, Washington 98126-2010
 S: USA
 
+N: Muli Ben-Yehuda
+E: mulix@mulix.org
+E: muli@il.ibm.com
+W: http://www.mulix.org
+D: trident OSS sound driver, x86-64 dma-ops and Calgary IOMMU,
+D: KVM and Xen bits and other misc. hackery.
+S: Haifa, Israel
+
 N: Johannes Berg
 E: johannes@sipsolutions.net
 W: http://johannes.sipsolutions.net/

Documentation/ABI/testing/sysfs-dev

@@ -0,0 +1,20 @@
+What:		/sys/dev
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Dan Williams <dan.j.williams@intel.com>
+Description:	The /sys/dev tree provides a method to look up the sysfs
+		path for a device using the information returned from
+		stat(2).  There are two directories, 'block' and 'char',
+		beneath /sys/dev containing symbolic links with names of
+		the form "<major>:<minor>".  These links point to the
+		corresponding sysfs path for the given device.
+
+		Example:
+		$ readlink /sys/dev/block/8:32
+		../../block/sdc
+
+		Entries in /sys/dev/char and /sys/dev/block will be
+		dynamically created and destroyed as devices enter and
+		leave the system.
+
+Users:		mdadm <linux-raid@vger.kernel.org>

Documentation/ABI/testing/sysfs-devices-memory

@@ -0,0 +1,24 @@
+What:		/sys/devices/system/memory
+Date:		June 2008
+Contact:	Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+		The /sys/devices/system/memory contains a snapshot of the
+		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/
+
+What:		/sys/devices/system/memory/memoryX/removable
+Date:		June 2008
+Contact:	Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+		The file /sys/devices/system/memory/memoryX/removable
+		indicates whether this memory block is removable or not.
+		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/

Documentation/ABI/testing/sysfs-kernel-mm

@@ -0,0 +1,6 @@
+What:		/sys/kernel/mm
+Date:		July 2008
+Contact:	Nishanth Aravamudan <nacc@us.ibm.com>, VM maintainers
+Description:
+		/sys/kernel/mm/ should contain any and all VM
+		related information in /sys/kernel/.

Documentation/ABI/testing/sysfs-kernel-mm-hugepages

@@ -0,0 +1,15 @@
+What:		/sys/kernel/mm/hugepages/
+Date:		June 2008
+Contact:	Nishanth Aravamudan <nacc@us.ibm.com>, hugetlb maintainers
+Description:
+		/sys/kernel/mm/hugepages/ contains a number of subdirectories
+		of the form hugepages-<size>kB, where <size> is the page size
+		of the hugepages supported by the kernel/CPU combination.
+
+		Under these directories are a number of files:
+			nr_hugepages
+			nr_overcommit_hugepages
+			free_hugepages
+			surplus_hugepages
+			resv_hugepages
+		See Documentation/vm/hugetlbpage.txt for details.

Documentation/DMA-attributes.txt

@@ -22,3 +22,12 @@ ready and available in memory.  The DMA of the "completion indication"
 could race with data DMA.  Mapping the memory used for completion
 indications with DMA_ATTR_WRITE_BARRIER would prevent the race.
 
+DMA_ATTR_WEAK_ORDERING
+----------------------
+
+DMA_ATTR_WEAK_ORDERING specifies that reads and writes to the mapping
+may be weakly ordered, that is that reads and writes may pass each other.
+
+Since it is optional for platforms to implement DMA_ATTR_WEAK_ORDERING,
+those that do not will simply ignore the attribute and exhibit default
+behavior.

Documentation/DocBook/kernel-locking.tmpl

@@ -219,10 +219,10 @@
    </para>
 
    <sect1 id="lock-intro">
-   <title>Three Main Types of Kernel Locks: Spinlocks, Mutexes and Semaphores</title>
+   <title>Two Main Types of Kernel Locks: Spinlocks and Mutexes</title>
 
    <para>
-     There are three main types of kernel locks.  The fundamental type
+     There are two main types of kernel locks.  The fundamental type
      is the spinlock 
      (<filename class="headerfile">include/asm/spinlock.h</filename>),
      which is a very simple single-holder lock: if you can't get the 
@@ -239,14 +239,6 @@
      can't sleep (see <xref linkend="sleeping-things"/>), and so have to
      use a spinlock instead.
    </para>
-   <para>
-     The third type is a semaphore
-     (<filename class="headerfile">include/linux/semaphore.h</filename>): it
-     can have more than one holder at any time (the number decided at
-     initialization time), although it is most commonly used as a
-     single-holder lock (a mutex).  If you can't get a semaphore, your
-     task will be suspended and later on woken up - just like for mutexes.
-   </para>
    <para>
      Neither type of lock is recursive: see
      <xref linkend="deadlock"/>.
@@ -278,7 +270,7 @@
     </para>
 
     <para>
-      Semaphores still exist, because they are required for
+      Mutexes still exist, because they are required for
       synchronization between <firstterm linkend="gloss-usercontext">user 
       contexts</firstterm>, as we will see below.
     </para>
@@ -289,18 +281,17 @@
 
      <para>
        If you have a data structure which is only ever accessed from
-       user context, then you can use a simple semaphore
-       (<filename>linux/linux/semaphore.h</filename>) to protect it.  This
-       is the most trivial case: you initialize the semaphore to the number 
-       of resources available (usually 1), and call
-       <function>down_interruptible()</function> to grab the semaphore, and 
-       <function>up()</function> to release it.  There is also a 
-       <function>down()</function>, which should be avoided, because it 
+       user context, then you can use a simple mutex
+       (<filename>include/linux/mutex.h</filename>) to protect it.  This
+       is the most trivial case: you initialize the mutex.  Then you can
+       call <function>mutex_lock_interruptible()</function> to grab the mutex,
+       and <function>mutex_unlock()</function> to release it.  There is also a 
+       <function>mutex_lock()</function>, which should be avoided, because it 
        will not return if a signal is received.
      </para>
 
      <para>
-       Example: <filename>linux/net/core/netfilter.c</filename> allows 
+       Example: <filename>net/netfilter/nf_sockopt.c</filename> allows 
        registration of new <function>setsockopt()</function> and 
        <function>getsockopt()</function> calls, with
        <function>nf_register_sockopt()</function>.  Registration and 
@@ -515,7 +506,7 @@
       <listitem>
 	<para>
           If you are in a process context (any syscall) and want to
-	lock other process out, use a semaphore.  You can take a semaphore
+	lock other process out, use a mutex.  You can take a mutex
 	and sleep (<function>copy_from_user*(</function> or
 	<function>kmalloc(x,GFP_KERNEL)</function>).
       </para>
@@ -662,7 +653,7 @@
 <entry>SLBH</entry>
 <entry>SLBH</entry>
 <entry>SLBH</entry>
-<entry>DI</entry>
+<entry>MLI</entry>
 <entry>None</entry>
 </row>
 
@@ -692,8 +683,8 @@
 <entry>spin_lock_bh</entry>
 </row>
 <row>
-<entry>DI</entry>
-<entry>down_interruptible</entry>
+<entry>MLI</entry>
+<entry>mutex_lock_interruptible</entry>
 </row>
 
 </tbody>
@@ -1310,7 +1301,7 @@ as Alan Cox says, <quote>Lock data, not code</quote>.
     <para>
       There is a coding bug where a piece of code tries to grab a
       spinlock twice: it will spin forever, waiting for the lock to
-      be released (spinlocks, rwlocks and semaphores are not
+      be released (spinlocks, rwlocks and mutexes are not
       recursive in Linux).  This is trivial to diagnose: not a
       stay-up-five-nights-talk-to-fluffy-code-bunnies kind of
       problem.
@@ -1335,7 +1326,7 @@ as Alan Cox says, <quote>Lock data, not code</quote>.
 
     <para>
       This complete lockup is easy to diagnose: on SMP boxes the
-      watchdog timer or compiling with <symbol>DEBUG_SPINLOCKS</symbol> set
+      watchdog timer or compiling with <symbol>DEBUG_SPINLOCK</symbol> set
       (<filename>include/linux/spinlock.h</filename>) will show this up 
       immediately when it happens.
     </para>
@@ -1558,7 +1549,7 @@ the amount of locking which needs to be done.
    <title>Read/Write Lock Variants</title>
 
    <para>
-      Both spinlocks and semaphores have read/write variants:
+      Both spinlocks and mutexes have read/write variants:
       <type>rwlock_t</type> and <structname>struct rw_semaphore</structname>.
       These divide users into two classes: the readers and the writers.  If
       you are only reading the data, you can get a read lock, but to write to
@@ -1681,7 +1672,7 @@ the amount of locking which needs to be done.
  #include &lt;linux/slab.h&gt;
  #include &lt;linux/string.h&gt;
 +#include &lt;linux/rcupdate.h&gt;
- #include &lt;linux/semaphore.h&gt;
+ #include &lt;linux/mutex.h&gt;
  #include &lt;asm/errno.h&gt;
 
  struct object
@@ -1913,7 +1904,7 @@ machines due to caching.
        </listitem>
        <listitem>
         <para>
-          <function> put_user()</function>
+          <function>put_user()</function>
         </para>
        </listitem>
       </itemizedlist>
@@ -1927,13 +1918,13 @@ machines due to caching.
 
      <listitem>
       <para>
-      <function>down_interruptible()</function> and
-      <function>down()</function>
+      <function>mutex_lock_interruptible()</function> and
+      <function>mutex_lock()</function>
       </para>
       <para>
-       There is a <function>down_trylock()</function> which can be
+       There is a <function>mutex_trylock()</function> which can be
        used inside interrupt context, as it will not sleep.
-       <function>up()</function> will also never sleep.
+       <function>mutex_unlock()</function> will also never sleep.
       </para>
      </listitem>
     </itemizedlist>
@@ -2023,7 +2014,7 @@ machines due to caching.
       <para>
         Prior to 2.5, or when <symbol>CONFIG_PREEMPT</symbol> is
         unset, processes in user context inside the kernel would not
-        preempt each other (ie. you had that CPU until you have it up,
+        preempt each other (ie. you had that CPU until you gave it up,
         except for interrupts).  With the addition of
         <symbol>CONFIG_PREEMPT</symbol> in 2.5.4, this changed: when
         in user context, higher priority tasks can "cut in": spinlocks

Documentation/DocBook/uio-howto.tmpl

@@ -21,6 +21,18 @@
     </affiliation>
 </author>
 
+<copyright>
+	<year>2006-2008</year>
+	<holder>Hans-Jürgen Koch.</holder>
+</copyright>
+
+<legalnotice>
+<para>
+This documentation is Free Software licensed under the terms of the
+GPL version 2.
+</para>
+</legalnotice>
+
 <pubdate>2006-12-11</pubdate>
 
 <abstract>
@@ -29,6 +41,12 @@
 </abstract>
 
 <revhistory>
+	<revision>
+	<revnumber>0.5</revnumber>
+	<date>2008-05-22</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>Added description of write() function.</revremark>
+	</revision>
 	<revision>
 	<revnumber>0.4</revnumber>
 	<date>2007-11-26</date>
@@ -57,20 +75,9 @@
 </bookinfo>
 
 <chapter id="aboutthisdoc">
-<?dbhtml filename="about.html"?>
+<?dbhtml filename="aboutthis.html"?>
 <title>About this document</title>
 
-<sect1 id="copyright">
-<?dbhtml filename="copyright.html"?>
-<title>Copyright and License</title>
-<para>
-      Copyright (c) 2006 by Hans-Jürgen Koch.</para>
-<para>
-This documentation is Free Software licensed under the terms of the
-GPL version 2.
-</para>
-</sect1>
-
 <sect1 id="translations">
 <?dbhtml filename="translations.html"?>
 <title>Translations</title>
@@ -189,6 +196,30 @@ interested in translating it, please email me
 	represents the total interrupt count. You can use this number
 	to figure out if you missed some interrupts.
 	</para>
+	<para>
+	For some hardware that has more than one interrupt source internally,
+	but not separate IRQ mask and status registers, there might be
+	situations where userspace cannot determine what the interrupt source
+	was if the kernel handler disables them by writing to the chip's IRQ
+	register. In such a case, the kernel has to disable the IRQ completely
+	to leave the chip's register untouched. Now the userspace part can
+	determine the cause of the interrupt, but it cannot re-enable
+	interrupts. Another cornercase is chips where re-enabling interrupts
+	is a read-modify-write operation to a combined IRQ status/acknowledge
+	register. This would be racy if a new interrupt occurred
+	simultaneously.
+	</para>
+	<para>
+	To address these problems, UIO also implements a write() function. It
+	is normally not used and can be ignored for hardware that has only a
+	single interrupt source or has separate IRQ mask and status registers.
+	If you need it, however, a write to <filename>/dev/uioX</filename>
+	will call the <function>irqcontrol()</function> function implemented
+	by the driver. You have to write a 32-bit value that is usually either
+	0 or 1 to disable or enable interrupts. If a driver does not implement
+	<function>irqcontrol()</function>, <function>write()</function> will
+	return with <varname>-ENOSYS</varname>.
+	</para>
 
 	<para>
 	To handle interrupts properly, your custom kernel module can
@@ -362,6 +393,14 @@ device is actually used.
 <function>open()</function>, you will probably also want a custom
 <function>release()</function> function.
 </para></listitem>
+
+<listitem><para>
+<varname>int (*irqcontrol)(struct uio_info *info, s32 irq_on)
+</varname>: Optional. If you need to be able to enable or disable
+interrupts from userspace by writing to <filename>/dev/uioX</filename>,
+you can implement this function. The parameter <varname>irq_on</varname>
+will be 0 to disable interrupts and 1 to enable them.
+</para></listitem>
 </itemizedlist>
 
 <para>

Documentation/HOWTO

@@ -358,7 +358,7 @@ Here is a list of some of the different kernel trees available:
     - pcmcia, Dominik Brodowski <linux@dominikbrodowski.net>
 	git.kernel.org:/pub/scm/linux/kernel/git/brodo/pcmcia-2.6.git
 
-    - SCSI, James Bottomley <James.Bottomley@SteelEye.com>
+    - SCSI, James Bottomley <James.Bottomley@hansenpartnership.com>
 	git.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6.git
 
     - x86, Ingo Molnar <mingo@elte.hu>