Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Adding support for Dream Cheeky DL1800B Friend Alert device.
Signed-off-by: NDan Delaney <drdelaney@loclhst.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The USB HID Usage Tables spec defines page 6 for Generic Device Controls, the
most useful of which (to me) is Battery Strength.
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

HID 1.11 specification, section 5.10 tells us:

	HID class devices support the ability to ignore selected fields in a
	report at run- time. This is accomplished by declaring bit field in a
	report that is capable of containing a range of values larger than
	those actually generated by the control. If the host or the device
	receives an out-of-range value then the current value for the
	respective control will not be modified.

So we shouldn't be restricted to EV_ABS only.
Reported-by: NDenilson Figueiredo de Sá <denilsonsa@gmail.com>
Tested-by: NDenilson Figueiredo de Sá <denilsonsa@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Linux should ignore values outside logical min/max range, as they are not
meaningful. This is what at least some of other OSes do, and it also makes
sense (currently the value gets misinterpreted larger up the stack).
Reported-by: NDenilson Figueiredo de Sá <denilsonsa@gmail.com>
Tested-by: NDenilson Figueiredo de Sá <denilsonsa@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This allows the latest N-Trig devices to function properly.

BugLink: https://bugs.launchpad.net/bugs/724831

Cc: stable@vger.kernel.org
Signed-off-by: NChase Douglas <chase.douglas@canonical.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Casting (void *) value returned by kmalloc is useless
as mentioned in Documentation/CodingStyle, Chap 14.

The semantic patch that makes this change is available
in scripts/coccinelle/api/alloc/drop_kmalloc_cast.cocci.
Signed-off-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  Revert "HID: multitouch: decide if hid-multitouch needs to handle mt devices"
  HID: drivers/hid/hid-roccat.c: eliminate a null pointer dereference
  HID: hid-apple: add device ID of another wireless aluminium
  HID: Add device IDs for Macbook Pro 8 keyboards

This reverts commit 144060fe.

It causes a resume regression for Andi on his Acer Aspire 1830T post
3.1.  The screen just stays black after wakeup.

Also, it really looks like the wrong way to suspend and resume perf
events: I think they should be done as part of the CPU suspend and
resume, rather than as a notifier that does smp_call_function().
Reported-by: NAndi Kleen <andi@firstfloor.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/linux-dm:
  dm: raid fix device status indicator when array initializing
  dm log userspace: add log device dependency
  dm log userspace: fix comment hyphens
  dm: add thin provisioning target
  dm: add persistent data library
  dm: add bufio
  dm: export dm get md
  dm table: add immutable feature
  dm table: add always writeable feature
  dm table: add singleton feature
  dm kcopyd: add dm_kcopyd_zero to zero an area
  dm: remove superfluous smp_mb
  dm: use local printk ratelimit
  dm table: propagate non rotational flag

* 'for-linus' of git://git.selinuxproject.org/~jmorris/linux-security:
  TOMOYO: Fix interactive judgment functionality.

* 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac: (21 commits)
  MAINTAINERS: add an entry for Edac Sandy Bridge driver
  edac: tag sb_edac as EXPERIMENTAL, as it requires more testing
  EDAC: Fix incorrect edac mode reporting in sb_edac
  edac: sb_edac: Add it to the building system
  edac: Add an experimental new driver to support Sandy Bridge CPU's
  i7300_edac: Fix error cleanup logic
  i7core_edac: Initialize memory name with cpu, channel, bank
  i7core_edac: Fix compilation on 32 bits arch
  i7core_edac: scrubbing fixups
  EDAC: Correct Kconfig dependencies
  i7core_edac: return -ENODEV if no MC is found
  i7core_edac: use edac's own way to print errors
  MAINTAINERS: remove dropped edac_mce.* from the file
  i7core_edac: Drop the edac_mce facility
  x86, MCE: Use notifier chain only for MCE decoding
  EDAC i7core: Use mce socketid for better compatibility
  i7core_edac: Don't enable memory scrubbing for Xeon 35xx
  i7core_edac: Add scrubbing support
  edac: Move edac main structs to include/linux/edac.h
  i7core_edac: Fix oops when trying to inject errors
  ...

* 'for-3.2' of git://linux-nfs.org/~bfields/linux:
  nfsd4: typo logical vs bitwise negate in nfsd4_decode_share_access

* 'misc-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  MAINTAINERS: Update entry for IA64
  [IA64] gpio: GENERIC_GPIO default must be n
  [IA64[ add CONFIG_NET_VENDOR_INTEL=y to default config files where needed
  [IA64] agp/hp-agp: Allow binding user memory to the AGP GART
  [IA64] sn2: add missing put_cpu()

Says Andrew:

 "60 patches.  That's good enough for -rc1 I guess.  I have quite a lot
  of detritus to be rechecked, work through maintainers, etc.

 - most of the remains of MM
 - rtc
 - various misc
 - cgroups
 - memcg
 - cpusets
 - procfs
 - ipc
 - rapidio
 - sysctl
 - pps
 - w1
 - drivers/misc
 - aio"

* akpm: (60 commits)
  memcg: replace ss->id_lock with a rwlock
  aio: allocate kiocbs in batches
  drivers/misc/vmw_balloon.c: fix typo in code comment
  drivers/misc/vmw_balloon.c: determine page allocation flag can_sleep outside loop
  w1: disable irqs in critical section
  drivers/w1/w1_int.c: multiple masters used same init_name
  drivers/power/ds2780_battery.c: fix deadlock upon insertion and removal
  drivers/power/ds2780_battery.c: add a nolock function to w1 interface
  drivers/power/ds2780_battery.c: create central point for calling w1 interface
  w1: ds2760 and ds2780, use ida for id and ida_simple_get() to get it
  pps gpio client: add missing dependency
  pps: new client driver using GPIO
  pps: default echo function
  include/linux/dma-mapping.h: add dma_zalloc_coherent()
  sysctl: make CONFIG_SYSCTL_SYSCALL default to n
  sysctl: add support for poll()
  RapidIO: documentation update
  drivers/net/rionet.c: fix ethernet address macros for LE platforms
  RapidIO: fix potential null deref in rio_setup_device()
  RapidIO: add mport driver for Tsi721 bridge
  ...

While back-porting Johannes Weiner's patch "mm: memcg-aware global
reclaim" for an internal effort, we noticed a significant performance
regression during page-reclaim heavy workloads due to high contention of
the ss->id_lock.  This lock protects idr map, and serializes calls to
idr_get_next() in css_get_next() (which is used during the memcg hierarchy
walk).

Since idr_get_next() is just doing a look up, we need only serialize it
with respect to idr_remove()/idr_get_new().  By making the ss->id_lock a
rwlock, contention is greatly reduced and performance improves.

Tested: cat a 256m file from a ramdisk in a 128m container 50 times on
each core (one file + container per core) in parallel on a NUMA machine.
Result is the time for the test to complete in 1 of the containers.
Both kernels included Johannes' memcg-aware global reclaim patches.

Before rwlock patch: 1710.778s
After rwlock patch: 152.227s
Signed-off-by: NAndrew Bresticker <abrestic@google.com>
Cc: Paul Menage <menage@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In testing aio on a fast storage device, I found that the context lock
takes up a fair amount of cpu time in the I/O submission path.  The reason
is that we take it for every I/O submitted (see __aio_get_req).  Since we
know how many I/Os are passed to io_submit, we can preallocate the kiocbs
in batches, reducing the number of times we take and release the lock.

In my testing, I was able to reduce the amount of time spent in
_raw_spin_lock_irq by .56% (average of 3 runs).  The command I used to
test this was:

   aio-stress -O -o 2 -o 3 -r 8 -d 128 -b 32 -i 32 -s 16384 <dev>

I also tested the patch with various numbers of events passed to
io_submit, and I ran the xfstests aio group of tests to ensure I didn't
break anything.
Signed-off-by: NJeff Moyer <jmoyer@redhat.com>
Cc: Daniel Ehrenberg <dehrenberg@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix typo in code comment.
Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com>
Acked-by: NDmitry Torokhov <dtor@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In vmballoon_reserve_page(), flags has been passed from the callee
function (vmballoon_inflate here).  So, we can determine can_sleep outside
the loop.
Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com>
Acked-by: NDmitry Torokhov <dtor@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Interrupting w1_delay() in w1_read_bit() results in missing the low level
on the w1 line and receiving "1" instead of "0".

Add local_irq_save()/local_irq_restore() around the critical section
Signed-off-by: NJan Weitzel <j.weitzel@phytec.de>
Acked-by: NEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When using multiple masters, w1_int.c would use the .init_name from w1.c
for all entities, which will fail when creating a corresponding sysfs
entry.  This patch uses the unique name previously generated.

  WARNING: at fs/sysfs/dir.c:451 sysfs_add_one+0x48/0x64()
  sysfs: cannot create duplicate filename '/devices/w1 bus master'
  Modules linked in:
  Call trace:
   [<9001a604>] warn_slowpath_common+0x34/0x44
   [<9001a64c>] warn_slowpath_fmt+0x14/0x18
   [<90078020>] sysfs_add_one+0x48/0x64
   [<900784ec>] create_dir+0x40/0x68
   [<9007857a>] sysfs_create_dir+0x66/0x78
   [<900c1a8a>] kobject_add_internal+0x6e/0x104
   [<900c1bc0>] kobject_add_varg+0x20/0x2c
   [<900c1c1c>] kobject_add+0x30/0x3c
   [<900dbd66>] device_add+0x6a/0x378
   [<900dbb4a>] device_initialize+0x12/0x48
   [<900dc080>] device_register+0xc/0x10
   [<900f99be>] w1_add_master_device+0x162/0x274
   [<90008e7a>] w1_gpio_probe+0x66/0xb4
   [<9000030c>] kernel_init+0x0/0xe8
   [<900dde54>] platform_drv_probe+0xc/0xe
   [<9000030c>] kernel_init+0x0/0xe8
   [<900dd4f8>] driver_probe_device+0x6c/0xdc
   [<900dd5fc>] __driver_attach+0x34/0x48
   [<900dcce8>] bus_for_each_dev+0x2c/0x48
   [<900dd5c8>] __driver_attach+0x0/0x48
   [<900dd38c>] driver_attach+0x10/0x14
   [<900dd16a>] bus_add_driver+0x6a/0x18c
   [<900dd768>] driver_register+0x60/0xb8
   [<90011594>] __initcall_w1_therm_init6+0x0/0x4
   [<90008e00>] w1_gpio_init+0x0/0x14
   [<9000030c>] kernel_init+0x0/0xe8
   [<900ddf48>] platform_driver_register+0x30/0x38
   [<90011594>] __initcall_w1_therm_init6+0x0/0x4
   [<90008e00>] w1_gpio_init+0x0/0x14
   [<9000030c>] kernel_init+0x0/0xe8
   [<900ddf5e>] platform_driver_probe+0xe/0x3c
   [<90008e0c>] w1_gpio_init+0xc/0x14
   [<90011594>] __initcall_w1_therm_init6+0x0/0x4
   [<90008e00>] w1_gpio_init+0x0/0x14
   [<900126d4>] do_one_initcall+0x34/0x130
   [<90000372>] kernel_init+0x66/0xe8
   [<90011594>] __initcall_w1_therm_init6+0x0/0x4
   [<9001ca3e>] do_exit+0x0/0x3a6
   [<9000030c>] kernel_init+0x0/0xe8
   [<9001ca3e>] do_exit+0x0/0x3a6

  ---[ end trace 5a9233884fead918 ]---
  kobject_add_internal failed for w1 bus master with -EEXIST, don't try to register things with the same name in the same directory.
Signed-off-by: NFlorian Faber <faber@faberman.de>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes the deadlock when inserting and removing the ds2780.
Signed-off-by: NClifton Barnes <cabarnes@indesign-llc.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Adds a nolock function to the w1 interface to avoid locking the
mutex if needed.
Signed-off-by: NClifton Barnes <cabarnes@indesign-llc.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simply creates one point to call the w1 interface.
Signed-off-by: NClifton Barnes <cabarnes@indesign-llc.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Straightforward.  As an aside, the ida_init calls are not needed as far as
I can see needed.  (DEFINE_IDA does the same already).
Signed-off-by: NJonathan Cameron <jic23@cam.ac.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: NClifton Barnes <cabarnes@indesign-llc.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add "depends on GENERIC_HARDIRQS" to avoid compile breakage on s390:

drivers/built-in.o: In function `pps_gpio_remove':
linux-next/drivers/pps/clients/pps-gpio.c:189: undefined reference to `free_irq'
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Nuss <jamesnuss@nanometrics.ca>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This client driver allows you to use a GPIO pin as a source for PPS
signals.  Platform data [1] are used to specify the GPIO pin number,
label, assert event edge type, and whether clear events are captured.

This driver is based on the work by Ricardo Martins who submitted an
initial implementation [2] of a PPS IRQ client driver to the linuxpps
mailing-list on Dec 3 2010.

[1] include/linux/pps-gpio.h
[2] http://ml.enneenne.com/pipermail/linuxpps/2010-December/004155.html

[akpm@linux-foundation.org: remove unneeded cast of void*]
Signed-off-by: NJames Nuss <jamesnuss@nanometrics.ca>
Cc: Ricardo Martins <rasm@fe.up.pt>
Acked-by: NRodolfo Giometti <giometti@linux.it>
Signed-off-by: NRicardo Martins <rasm@fe.up.pt>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Igor Plyatov <plyatov@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A default echo function has been provided so it is no longer an error when
you specify PPS_ECHOASSERT or PPS_ECHOCLEAR without an explicit echo
function.  This allows some code re-use and also makes it easier to write
client drivers since the default echo function does not normally need to
change.
Signed-off-by: NJames Nuss <jamesnuss@nanometrics.ca>
Reviewed-by: NBen Gardiner <bengardiner@nanometrics.ca>
Acked-by: NRodolfo Giometti <giometti@linux.it>
Cc: Ricardo Martins <rasm@fe.up.pt>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Igor Plyatov <plyatov@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Lots of driver code does a dma_alloc_coherent() and then zeroes out the
memory with a memset.  Make it easy for them.

Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When I tried to send a patch to remove it, Andi told me we still need to
keep compabitlies for old libc, so we can't remove this completely.  Then
just make it default to n and remove the doc from
feature-removal-schedule.txt.
Signed-off-by: NWANG Cong <amwang@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Adding support for poll() in sysctl fs allows userspace to receive
notifications of changes in sysctl entries.  This adds a infrastructure to
allow files in sysctl fs to be pollable and implements it for hostname and
domainname.

[akpm@linux-foundation.org: s/declare/define/ for definitions]
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Greg KH <gregkh@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update rapidio.txt to reflect changes from recent patch.
See http://marc.info/?l=linux-kernel&m=131285620113589&w=2 for details.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Liu Gang <Gang.Liu@freescale.com>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Modify Ethernet addess macros to be compatible with BE/LE platforms
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Chul Kim <chul.kim@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: <stable@kernel.org>		[2.6.39+]
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "goto cleanup" path can deference "rswitch" when it is NULL.
Reported-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Chul Kim <chul.kim@idt.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add RapidIO mport driver for IDT TSI721 PCI Express-to-SRIO bridge device.
 The driver provides full set of callback functions defined for mport
devices in RapidIO subsystem.  It also is compatible with current version
of RIONET driver (Ethernet over RapidIO messaging services).

This patch is applicable to kernel versions starting from 2.6.39.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: NChul Kim <chul.kim@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/sysdev/fsl_rio.c: release rapidio port I/O region resource if port failed to initialize

The "struct rio_mport" contains a member of master port I/O memory
resource structure "struct resource iores".  This resource will be read
from device tree and be used for rapidio R/W transaction memory space.
Rapidio requests the port I/O memory resource under the root resource
"iomem_resource".

			struct rio_mport *port;
			port = kzalloc(sizeof(struct rio_mport), GFP_KERNEL);

			request_resource(&iomem_resource, &port->iores);

When port failed to initialize, allocated "rio_mport" structure memory
will be freed, and the port I/O memory resource structure pointer
"&port->iores" will be invalid.  If other requests resource under
"iomem_resource", "&port->iores" node may be operated in the child
resources list and this will cause the system to crash.

So the requested port I/O memory resource should be released before
freeing allocated "rio_mport" structure.
Signed-off-by: NLiu Gang <Gang.Liu@freescale.com>
Acked-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The discovered bit in PGCCSR register indicates if the device has been
discovered by system host.  In Rapidio systems, some agent devices can also
be master devices.  They can issue requests into the system.
Signed-off-by: NLiu Gang <Gang.Liu@freescale.com>
Acked-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Expand root=PARTUUID=UUID syntax to support selecting a root partition by
integer offset from a known, unique partition.  This approach provides
similar properties to specifying a device and partition number, but using
the UUID as the unique path prior to evaluating the offset.

For example,
  root=PARTUUID=99DE9194-FC15-4223-9192-FC243948F88B/PARTNROFF=1
selects the partition with UUID 99DE.. then select the next
partition.

This change is motivated by a particular usecase in Chromium OS where the
bootloader can easily determine what partition it is on (by UUID) but
doesn't perform general partition table walking.

That said, support for this model provides a direct mechanism for the user
to modify the root partition to boot without specifically needing to
extract each UUID or update the bootloader explicitly when the root
partition UUID is changed (if it is recreated to be larger, for instance).
 Pinning to a /boot-style partition UUID allows the arbitrary root
partition reconfiguration/modifications with slightly less ambiguity than
just [dev][partition] and less stringency than the specific root partition
UUID.

[sfr@canb.auug.org.au: fix init sections warning]
Signed-off-by: NWill Drewry <wad@chromium.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>