Merge branch 'origin'

CREDITS

@@ -3101,7 +3101,7 @@ S: Minto, NSW, 2566
 S: Australia
 
 N: Stephen Smalley
-E: sds@epoch.ncsc.mil
+E: sds@tycho.nsa.gov
 D: portions of the Linux Security Module (LSM) framework and security modules
 
 N: Chris Smith

Documentation/RCU/RTFP.txt

@@ -90,16 +90,20 @@ at OLS.  The resulting abundance of RCU patches was presented the
 following year [McKenney02a], and use of RCU in dcache was first
 described that same year [Linder02a].
 
-Also in 2002, Michael [Michael02b,Michael02a] presented techniques
-that defer the destruction of data structures to simplify non-blocking
-synchronization (wait-free synchronization, lock-free synchronization,
-and obstruction-free synchronization are all examples of non-blocking
-synchronization).  In particular, this technique eliminates locking,
-reduces contention, reduces memory latency for readers, and parallelizes
-pipeline stalls and memory latency for writers.  However, these
-techniques still impose significant read-side overhead in the form of
-memory barriers.  Researchers at Sun worked along similar lines in the
-same timeframe [HerlihyLM02,HerlihyLMS03].
+Also in 2002, Michael [Michael02b,Michael02a] presented "hazard-pointer"
+techniques that defer the destruction of data structures to simplify
+non-blocking synchronization (wait-free synchronization, lock-free
+synchronization, and obstruction-free synchronization are all examples of
+non-blocking synchronization).  In particular, this technique eliminates
+locking, reduces contention, reduces memory latency for readers, and
+parallelizes pipeline stalls and memory latency for writers.  However,
+these techniques still impose significant read-side overhead in the
+form of memory barriers.  Researchers at Sun worked along similar lines
+in the same timeframe [HerlihyLM02,HerlihyLMS03].  These techniques
+can be thought of as inside-out reference counts, where the count is
+represented by the number of hazard pointers referencing a given data
+structure (rather than the more conventional counter field within the
+data structure itself).
 
 In 2003, the K42 group described how RCU could be used to create
 hot-pluggable implementations of operating-system functions.  Later that
@@ -113,7 +117,6 @@ number of operating-system kernels [PaulEdwardMcKenneyPhD], a paper
 describing how to make RCU safe for soft-realtime applications [Sarma04c],
 and a paper describing SELinux performance with RCU [JamesMorris04b].
 
-
 2005 has seen further adaptation of RCU to realtime use, permitting
 preemption of RCU realtime critical sections [PaulMcKenney05a,
 PaulMcKenney05b].

Documentation/RCU/checklist.txt

@@ -177,3 +177,9 @@ over a rather long period of time, but improvements are always welcome!
 
 	If you want to wait for some of these other things, you might
 	instead need to use synchronize_irq() or synchronize_sched().
+
+12.	Any lock acquired by an RCU callback must be acquired elsewhere
+	with irq disabled, e.g., via spin_lock_irqsave().  Failing to
+	disable irq on a given acquisition of that lock will result in
+	deadlock as soon as the RCU callback happens to interrupt that
+	acquisition's critical section.

Documentation/RCU/listRCU.txt

@@ -232,7 +232,7 @@ entry does not exist.  For this to be helpful, the search function must
 return holding the per-entry spinlock, as ipc_lock() does in fact do.
 
 Quick Quiz:  Why does the search function need to return holding the
-per-entry lock for this deleted-flag technique to be helpful?
+	per-entry lock for this deleted-flag technique to be helpful?
 
 If the system-call audit module were to ever need to reject stale data,
 one way to accomplish this would be to add a "deleted" flag and a "lock"
@@ -275,8 +275,8 @@ flag under the spinlock as follows:
 	{
 		struct audit_entry  *e;
 
-		/* Do not use the _rcu iterator here, since this is the only
-		 * deletion routine. */
+		/* Do not need to use the _rcu iterator here, since this
+		 * is the only deletion routine. */
 		list_for_each_entry(e, list, list) {
 			if (!audit_compare_rule(rule, &e->rule)) {
 				spin_lock(&e->lock);
@@ -304,9 +304,12 @@ function to reject newly deleted data.
 
 
 Answer to Quick Quiz
+	Why does the search function need to return holding the per-entry
+	lock for this deleted-flag technique to be helpful?
 
-If the search function drops the per-entry lock before returning, then
-the caller will be processing stale data in any case.  If it is really
-OK to be processing stale data, then you don't need a "deleted" flag.
-If processing stale data really is a problem, then you need to hold the
-per-entry lock across all of the code that uses the value looked up.
+	If the search function drops the per-entry lock before returning,
+	then the caller will be processing stale data in any case.  If it
+	is really OK to be processing stale data, then you don't need a
+	"deleted" flag.  If processing stale data really is a problem,
+	then you need to hold the per-entry lock across all of the code
+	that uses the value that was returned.

Documentation/RCU/rcu.txt

@@ -111,6 +111,11 @@ o	What are all these files in this directory?
 
 		You are reading it!
 
+	rcuref.txt
+
+		Describes how to combine use of reference counts
+		with RCU.
+
 	whatisRCU.txt
 
 		Overview of how the RCU implementation works.  Along

Documentation/RCU/rcuref.txt

@@ -1,7 +1,7 @@
-Refcounter design for elements of lists/arrays protected by RCU.
+Reference-count design for elements of lists/arrays protected by RCU.
 
-Refcounting on elements of  lists which are protected by traditional
-reader/writer spinlocks or semaphores are straight forward as in:
+Reference counting on elements of lists which are protected by traditional
+reader/writer spinlocks or semaphores are straightforward:
 
 1.				2.
 add()				search_and_reference()
@@ -28,12 +28,12 @@ release_referenced()			delete()
 					    ...
 					}
 
-If this list/array is made lock free using rcu as in changing the
-write_lock in add() and delete() to spin_lock and changing read_lock
+If this list/array is made lock free using RCU as in changing the
+write_lock() in add() and delete() to spin_lock and changing read_lock
 in search_and_reference to rcu_read_lock(), the atomic_get in
 search_and_reference could potentially hold reference to an element which
-has already been deleted from the list/array.  atomic_inc_not_zero takes
-care of this scenario. search_and_reference should look as;
+has already been deleted from the list/array.  Use atomic_inc_not_zero()
+in this scenario as follows:
 
 1.					2.
 add()					search_and_reference()
@@ -51,17 +51,16 @@ add()					search_and_reference()
 release_referenced()			delete()
 {					{
     ...					    write_lock(&list_lock);
-    atomic_dec(&el->rc, relfunc)	    ...
-    ...					    delete_element
-}					    write_unlock(&list_lock);
- 					    ...
+    if (atomic_dec_and_test(&el->rc))       ...
+        call_rcu(&el->head, el_free);       delete_element
+    ...                                     write_unlock(&list_lock);
+} 					    ...
 					    if (atomic_dec_and_test(&el->rc))
 					        call_rcu(&el->head, el_free);
 					    ...
 					}
 
-Sometimes, reference to the element need to be obtained in the
-update (write) stream.  In such cases, atomic_inc_not_zero might be an
-overkill since the spinlock serialising list updates are held. atomic_inc
-is to be used in such cases.
-
+Sometimes, a reference to the element needs to be obtained in the
+update (write) stream.  In such cases, atomic_inc_not_zero() might be
+overkill, since we hold the update-side spinlock.  One might instead
+use atomic_inc() in such cases.

Documentation/RCU/whatisRCU.txt

@@ -200,10 +200,11 @@ rcu_assign_pointer()
 	the new value, and also executes any memory-barrier instructions
 	required for a given CPU architecture.
 
-	Perhaps more important, it serves to document which pointers
-	are protected by RCU.  That said, rcu_assign_pointer() is most
-	frequently used indirectly, via the _rcu list-manipulation
-	primitives such as list_add_rcu().
+	Perhaps just as important, it serves to document (1) which
+	pointers are protected by RCU and (2) the point at which a
+	given structure becomes accessible to other CPUs.  That said,
+	rcu_assign_pointer() is most frequently used indirectly, via
+	the _rcu list-manipulation primitives such as list_add_rcu().
 
 rcu_dereference()
 
@@ -258,9 +259,11 @@ rcu_dereference()
 	locking.
 
 	As with rcu_assign_pointer(), an important function of
-	rcu_dereference() is to document which pointers are protected
-	by RCU.  And, again like rcu_assign_pointer(), rcu_dereference()
-	is typically used indirectly, via the _rcu list-manipulation
+	rcu_dereference() is to document which pointers are protected by
+	RCU, in particular, flagging a pointer that is subject to changing
+	at any time, including immediately after the rcu_dereference().
+	And, again like rcu_assign_pointer(), rcu_dereference() is
+	typically used indirectly, via the _rcu list-manipulation
 	primitives, such as list_for_each_entry_rcu().
 
 The following diagram shows how each API communicates among the
@@ -327,7 +330,7 @@ for specialized uses, but are relatively uncommon.
 3.  WHAT ARE SOME EXAMPLE USES OF CORE RCU API?
 
 This section shows a simple use of the core RCU API to protect a
-global pointer to a dynamically allocated structure.  More typical
+global pointer to a dynamically allocated structure.  More-typical
 uses of RCU may be found in listRCU.txt, arrayRCU.txt, and NMI-RCU.txt.
 
 	struct foo {
@@ -410,6 +413,8 @@ o	Use synchronize_rcu() -after- removing a data element from an
 	data item.
 
 See checklist.txt for additional rules to follow when using RCU.
+And again, more-typical uses of RCU may be found in listRCU.txt,
+arrayRCU.txt, and NMI-RCU.txt.
 
 
 4.  WHAT IF MY UPDATING THREAD CANNOT BLOCK?
@@ -513,7 +518,7 @@ production-quality implementation, and see:
 
 for papers describing the Linux kernel RCU implementation.  The OLS'01
 and OLS'02 papers are a good introduction, and the dissertation provides
-more details on the current implementation.
+more details on the current implementation as of early 2004.
 
 
 5A.  "TOY" IMPLEMENTATION #1: LOCKING
@@ -768,7 +773,6 @@ RCU pointer/list traversal:
 	rcu_dereference
 	list_for_each_rcu		(to be deprecated in favor of
 					 list_for_each_entry_rcu)
-	list_for_each_safe_rcu		(deprecated, not used)
 	list_for_each_entry_rcu
 	list_for_each_continue_rcu	(to be deprecated in favor of new
 					 list_for_each_entry_continue_rcu)
@@ -807,7 +811,8 @@ Quick Quiz #1:	Why is this argument naive?  How could a deadlock
 Answer:		Consider the following sequence of events:
 
 		1.	CPU 0 acquires some unrelated lock, call it
-			"problematic_lock".
+			"problematic_lock", disabling irq via
+			spin_lock_irqsave().
 
 		2.	CPU 1 enters synchronize_rcu(), write-acquiring
 			rcu_gp_mutex.
@@ -894,7 +899,7 @@ Answer:		Just as PREEMPT_RT permits preemption of spinlock
 ACKNOWLEDGEMENTS
 
 My thanks to the people who helped make this human-readable, including
-Jon Walpole, Josh Triplett, Serge Hallyn, and Suzanne Wood.
+Jon Walpole, Josh Triplett, Serge Hallyn, Suzanne Wood, and Alan Stern.
 
 
 For more information, see http://www.rdrop.com/users/paulmck/RCU.

Documentation/cputopology.txt

@@ -0,0 +1,41 @@
+
+Export cpu topology info by sysfs. Items (attributes) are similar
+to /proc/cpuinfo.
+
+1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
+represent the physical package id of  cpu X;
+2) /sys/devices/system/cpu/cpuX/topology/core_id:
+represent the cpu core id to cpu X;
+3) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
+represent the thread siblings to cpu X in the same core;
+4) /sys/devices/system/cpu/cpuX/topology/core_siblings:
+represent the thread siblings to cpu X in the same physical package;
+
+To implement it in an architecture-neutral way, a new source file,
+driver/base/topology.c, is to export the 5 attributes.
+
+If one architecture wants to support this feature, it just needs to
+implement 4 defines, typically in file include/asm-XXX/topology.h.
+The 4 defines are:
+#define topology_physical_package_id(cpu)
+#define topology_core_id(cpu)
+#define topology_thread_siblings(cpu)
+#define topology_core_siblings(cpu)
+
+The type of **_id is int.
+The type of siblings is cpumask_t.
+
+To be consistent on all architectures, the 4 attributes should have
+deafult values if their values are unavailable. Below is the rule.
+1) physical_package_id: If cpu has no physical package id, -1 is the
+default value.
+2) core_id: If cpu doesn't support multi-core, its core id is 0.
+3) thread_siblings: Just include itself, if the cpu doesn't support
+HT/multi-thread.
+4) core_siblings: Just include itself, if the cpu doesn't support
+multi-core and HT/Multi-thread.
+
+So be careful when declaring the 4 defines in include/asm-XXX/topology.h.
+
+If an attribute isn't defined on an architecture, it won't be exported.
+

Documentation/driver-model/overview.txt

@@ -1,50 +1,43 @@
 The Linux Kernel Device Model
 
-Patrick Mochel	<mochel@osdl.org>
+Patrick Mochel	<mochel@digitalimplant.org>
 
-26 August 2002
+Drafted 26 August 2002
+Updated 31 January 2006
 
 
 Overview
 ~~~~~~~~
 
-This driver model is a unification of all the current, disparate driver models
-that are currently in the kernel. It is intended to augment the
+The Linux Kernel Driver Model is a unification of all the disparate driver
+models that were previously used in the kernel. It is intended to augment the
 bus-specific drivers for bridges and devices by consolidating a set of data
 and operations into globally accessible data structures.
 
-Current driver models implement some sort of tree-like structure (sometimes
-just a list) for the devices they control. But, there is no linkage between
-the different bus types.
+Traditional driver models implemented some sort of tree-like structure
+(sometimes just a list) for the devices they control. There wasn't any
+uniformity across the different bus types.
 
-A common data structure can provide this linkage with little overhead: when a
-bus driver discovers a particular device, it can insert it into the global
-tree as well as its local tree. In fact, the local tree becomes just a subset
-of the global tree.
-
-Common data fields can also be moved out of the local bus models into the
-global model. Some of the manipulations of these fields can also be
-consolidated. Most likely, manipulation functions will become a set
-of helper functions, which the bus drivers wrap around to include any
-bus-specific items.
-
-The common device and bridge interface currently reflects the goals of the
-modern PC: namely the ability to do seamless Plug and Play, power management,
-and hot plug. (The model dictated by Intel and Microsoft (read: ACPI) ensures
-us that any device in the system may fit any of these criteria.)
-
-In reality, not every bus will be able to support such operations. But, most
-buses will support a majority of those operations, and all future buses will.
-In other words, a bus that doesn't support an operation is the exception,
-instead of the other way around.
+The current driver model provides a comon, uniform data model for describing
+a bus and the devices that can appear under the bus. The unified bus
+model includes a set of common attributes which all busses carry, and a set
+of common callbacks, such as device discovery during bus probing, bus
+shutdown, bus power management, etc.
 
+The common device and bridge interface reflects the goals of the modern
+computer: namely the ability to do seamless device "plug and play", power
+management, and hot plug. In particular, the model dictated by Intel and
+Microsoft (namely ACPI) ensures that almost every device on almost any bus
+on an x86-compatible system can work within this paradigm.  Of course,
+not every bus is able to support all such operations, although most
+buses support a most of those operations.
 
 
 Downstream Access
 ~~~~~~~~~~~~~~~~~
 
 Common data fields have been moved out of individual bus layers into a common
-data structure. But, these fields must still be accessed by the bus layers,
+data structure. These fields must still be accessed by the bus layers,
 and sometimes by the device-specific drivers.
 
 Other bus layers are encouraged to do what has been done for the PCI layer.
@@ -53,7 +46,7 @@ struct pci_dev now looks like this:
 struct pci_dev {
 	...
 
-	struct device device;
+	struct device dev;
 };
 
 Note first that it is statically allocated. This means only one allocation on
@@ -64,9 +57,9 @@ the two.
 
 The PCI bus layer freely accesses the fields of struct device. It knows about
 the structure of struct pci_dev, and it should know the structure of struct
-device. PCI devices that have been converted generally do not touch the fields
-of struct device. More precisely, device-specific drivers should not touch
-fields of struct device unless there is a strong compelling reason to do so.
+device. Individual PCI device drivers that have been converted the the current
+driver model generally do not and should not touch the fields of struct device,
+unless there is a strong compelling reason to do so.
 
 This abstraction is prevention of unnecessary pain during transitional phases.
 If the name of the field changes or is removed, then every downstream driver

Documentation/feature-removal-schedule.txt

@@ -148,3 +148,17 @@ Why:	The 8250 serial driver now has the ability to deal with the differences
 	brother on Alchemy SOCs.  The loss of features is not considered an
 	issue.
 Who:	Ralf Baechle <ralf@linux-mips.org>
+
+---------------------------
+
+What:	Legacy /proc/pci interface (PCI_LEGACY_PROC)
+When:	March 2006
+Why:	deprecated since 2.5.53 in favor of lspci(8)
+Who:	Adrian Bunk <bunk@stusta.de>
+
+---------------------------
+
+What:	pci_module_init(driver)
+When:	January 2007
+Why:	Is replaced by pci_register_driver(pci_driver).
+Who:	Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>

Documentation/filesystems/configfs/configfs_example.c

@@ -320,6 +320,7 @@ static struct config_item_type simple_children_type = {
 	.ct_item_ops	= &simple_children_item_ops,
 	.ct_group_ops	= &simple_children_group_ops,
 	.ct_attrs	= simple_children_attrs,
+	.ct_owner	= THIS_MODULE,
 };
 
 static struct configfs_subsystem simple_children_subsys = {
@@ -403,6 +404,7 @@ static struct config_item_type group_children_type = {
 	.ct_item_ops	= &group_children_item_ops,
 	.ct_group_ops	= &group_children_group_ops,
 	.ct_attrs	= group_children_attrs,
+	.ct_owner	= THIS_MODULE,
 };
 
 static struct configfs_subsystem group_children_subsys = {

Documentation/filesystems/ocfs2.txt

@@ -35,6 +35,7 @@ Features which OCFS2 does not support yet:
 	  be cluster coherent.
 	- quotas
 	- cluster aware flock
+	- cluster aware lockf
 	- Directory change notification (F_NOTIFY)
 	- Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
 	- POSIX ACLs

Documentation/kernel-doc-nano-HOWTO.txt

@@ -45,10 +45,10 @@ How to extract the documentation
 
 If you just want to read the ready-made books on the various
 subsystems (see Documentation/DocBook/*.tmpl), just type 'make
-psdocs', or 'make pdfdocs', or 'make htmldocs', depending on your 
-preference.  If you would rather read a different format, you can type 
-'make sgmldocs' and then use DocBook tools to convert 
-Documentation/DocBook/*.sgml to a format of your choice (for example, 
+psdocs', or 'make pdfdocs', or 'make htmldocs', depending on your
+preference.  If you would rather read a different format, you can type
+'make sgmldocs' and then use DocBook tools to convert
+Documentation/DocBook/*.sgml to a format of your choice (for example,
 'db2html ...' if 'make htmldocs' was not defined).
 
 If you want to see man pages instead, you can do this:
@@ -124,6 +124,36 @@ patterns, which are highlighted appropriately.
 Take a look around the source tree for examples.
 
 
+kernel-doc for structs, unions, enums, and typedefs
+---------------------------------------------------
+
+Beside functions you can also write documentation for structs, unions,
+enums and typedefs. Instead of the function name you must write the name
+of the declaration;  the struct/union/enum/typedef must always precede
+the name. Nesting of declarations is not supported.
+Use the argument mechanism to document members or constants.
+
+Inside a struct description, you can use the "private:" and "public:"
+comment tags.  Structure fields that are inside a "private:" area
+are not listed in the generated output documentation.
+
+Example:
+
+/**
+ * struct my_struct - short description
+ * @a: first member
+ * @b: second member
+ *
+ * Longer description
+ */
+struct my_struct {
+    int a;
+    int b;
+/* private: */
+    int c;
+};
+
+
 How to make new SGML template files
 -----------------------------------
 
@@ -147,4 +177,3 @@ documentation, in <filename>, for the functions listed.
 
 Tim.
 */ <twaugh@redhat.com>
-

Documentation/kernel-parameters.txt

@@ -452,6 +452,11 @@ running once the system is up.
 
 	eata=		[HW,SCSI]
 
+	ec_intr=	[HW,ACPI] ACPI Embedded Controller interrupt mode
+			Format: <int>
+			0: polling mode
+			non-0: interrupt mode (default)
+
 	eda=		[HW,PS2]
 
 	edb=		[HW,PS2]

Documentation/networking/ip-sysctl.txt

@@ -427,6 +427,23 @@ icmp_ignore_bogus_error_responses - BOOLEAN
 	will avoid log file clutter.
 	Default: FALSE
 
+icmp_errors_use_inbound_ifaddr - BOOLEAN
+
+	If zero, icmp error messages are sent with the primary address of
+	the exiting interface.
+ 
+	If non-zero, the message will be sent with the primary address of
+	the interface that received the packet that caused the icmp error.
+	This is the behaviour network many administrators will expect from
+	a router. And it can make debugging complicated network layouts
+	much easier. 
+
+	Note that if no primary address exists for the interface selected,
+	then the primary address of the first non-loopback interface that
+	has one will be used regarldess of this setting.
+
+	Default: 0
+
 igmp_max_memberships - INTEGER
 	Change the maximum number of multicast groups we can subscribe to.
 	Default: 20

Documentation/parport-lowlevel.txt

@@ -1068,7 +1068,7 @@ SYNOPSIS
 
 struct parport_operations {
 	...
-	void (*write_status) (struct parport *port, unsigned char s);
+	void (*write_control) (struct parport *port, unsigned char s);
 	...
 };
 
@@ -1097,9 +1097,9 @@ SYNOPSIS
 
 struct parport_operations {
 	...
-	void (*frob_control) (struct parport *port,
-	                      unsigned char mask,
-			      unsigned char val);
+	unsigned char (*frob_control) (struct parport *port,
+				       unsigned char mask,
+				       unsigned char val);
 	...
 };
 

Documentation/power/interface.txt

@@ -44,7 +44,7 @@ it.
 /sys/power/image_size controls the size of the image created by
 the suspend-to-disk mechanism.  It can be written a string
 representing a non-negative integer that will be used as an upper
-limit of the image size, in megabytes.  The suspend-to-disk mechanism will
+limit of the image size, in bytes.  The suspend-to-disk mechanism will
 do its best to ensure the image size will not exceed that number.  However,
 if this turns out to be impossible, it will try to suspend anyway using the
 smallest image possible.  In particular, if "0" is written to this file, the

Documentation/power/swsusp.txt

@@ -27,7 +27,7 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state
 
 echo platform > /sys/power/disk; echo disk > /sys/power/state
 
-If you want to limit the suspend image size to N megabytes, do
+If you want to limit the suspend image size to N bytes, do
 
 echo N > /sys/power/image_size