commit 11ad47a0edbd62bfc0547cfcdf227a911433f207 upstream.

In the old times, the whole idle task was considered
as an RCU quiescent state. But as RCU became more and
more successful overtime, some RCU read side critical
section have been added even in the code of some
architectures idle tasks, for tracing for example.

So nowadays, rcu_idle_enter() and rcu_idle_exit() must
be called by the architecture to tell RCU about the part
in the idle loop that doesn't make use of rcu read side
critical sections, typically the part that puts the CPU
in low power mode.

This is necessary for RCU to find the quiescent states in
idle in order to complete grace periods.

Add this missing pair of calls in the xtensa's idle loop.

Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit e520c410854bab763be24e0fce7ba89dc252efee

    "xtensa: convert to asm-generic/hardirq.h"

converted over to using the asm-generic parts, but it also
added the sentinel

	#define ack_bad_irq ack_bad_irq

which tells asm-generic to _not_ use the common ack_bad_irq.

Since e520c41 deleted the duplicated code from the arch specific
file, we _do_ want the asm-generic one in scope.  So delete
the trigger define above which hides it.  In doing so we'll
realize that we've got to delete the almost-duplicate prototype
as well to avoid "static declaration ... follows non-static".

Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

Caused by commit 6c03438edeb5c359af35f060ea016ca65671c269

    kernel.h: doesn't explicitly use bug.h, so don't include it.

This header uses bug.h so explicitly include it now that the
implicit presence was removed by 6c03438ed.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

Caused by commit 3785006ac3c8941feb63097c416de92114a6bc39

    "xtensa: don't mask signals if we fail to setup signal stack"

It assigns a return value to "ret", but there is no such variable
anywhere in scope.  Create one.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

Pull x32 support for x86-64 from Ingo Molnar:
 "This tree introduces the X32 binary format and execution mode for x86:
  32-bit data space binaries using 64-bit instructions and 64-bit kernel
  syscalls.

  This allows applications whose working set fits into a 32 bits address
  space to make use of 64-bit instructions while using a 32-bit address
  space with shorter pointers, more compressed data structures, etc."

Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c}

* 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  x32: Fix alignment fail in struct compat_siginfo
  x32: Fix stupid ia32/x32 inversion in the siginfo format
  x32: Add ptrace for x32
  x32: Switch to a 64-bit clock_t
  x32: Provide separate is_ia32_task() and is_x32_task() predicates
  x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls
  x86/x32: Fix the binutils auto-detect
  x32: Warn and disable rather than error if binutils too old
  x32: Only clear TIF_X32 flag once
  x32: Make sure TS_COMPAT is cleared for x32 tasks
  fs: Remove missed ->fds_bits from cessation use of fd_set structs internally
  fs: Fix close_on_exec pointer in alloc_fdtable
  x32: Drop non-__vdso weak symbols from the x32 VDSO
  x32: Fix coding style violations in the x32 VDSO code
  x32: Add x32 VDSO support
  x32: Allow x32 to be configured
  x32: If configured, add x32 system calls to system call tables
  x32: Handle process creation
  x32: Signal-related system calls
  x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h>
  ...

Pull x86 updates from Ingo Molnar.

This touches some non-x86 files due to the sanitized INLINE_SPIN_UNLOCK
config usage.

Fixed up trivial conflicts due to just header include changes (removing
headers due to cpu_idle() merge clashing with the <asm/system.h> split).

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic/amd: Be more verbose about LVT offset assignments
  x86, tls: Off by one limit check
  x86/ioapic: Add io_apic_ops driver layer to allow interception
  x86/olpc: Add debugfs interface for EC commands
  x86: Merge the x86_32 and x86_64 cpu_idle() functions
  x86/kconfig: Remove CONFIG_TR=y from the defconfigs
  x86: Stop recursive fault in print_context_stack after stack overflow
  x86/io_apic: Move and reenable irq only when CONFIG_GENERIC_PENDING_IRQ=y
  x86/apic: Add separate apic_id_valid() functions for selected apic drivers
  locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage
  x86/kconfig: Update defconfigs
  x86: Fix excessive MSR print out when show_msr is not specified

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...

Delete all instances of asm/system.h as they should be redundant by this
point.

Signed-off-by: David Howells <dhowells@redhat.com>

Disintegrate asm/system.h for Xtensa.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chris Zankel <chris@zankel.net>

Merge second batch of patches from Andrew Morton:
 - various misc things
 - core kernel changes to prctl, exit, exec, init, etc.
 - kernel/watchdog.c updates
 - get_maintainer
 - MAINTAINERS
 - the backlight driver queue
 - core bitops code cleanups
 - the led driver queue
 - some core prio_tree work
 - checkpatch udpates
 - largeish crc32 update
 - a new poll() feature for the v4l guys
 - the rtc driver queue
 - fatfs
 - ptrace
 - signals
 - kmod/usermodehelper updates
 - coredump
 - procfs updates

* emailed from Andrew Morton <akpm@linux-foundation.org>: (141 commits)
  seq_file: add seq_set_overflow(), seq_overflow()
  proc-ns: use d_set_d_op() API to set dentry ops in proc_ns_instantiate().
  procfs: speed up /proc/pid/stat, statm
  procfs: add num_to_str() to speed up /proc/stat
  proc: speed up /proc/stat handling
  fs/proc/kcore.c: make get_sparsemem_vmemmap_info() static
  coredump: add VM_NODUMP, MADV_NODUMP, MADV_CLEAR_NODUMP
  coredump: remove VM_ALWAYSDUMP flag
  kmod: make __request_module() killable
  kmod: introduce call_modprobe() helper
  usermodehelper: ____call_usermodehelper() doesn't need do_exit()
  usermodehelper: kill umh_wait, renumber UMH_* constants
  usermodehelper: implement UMH_KILLABLE
  usermodehelper: introduce umh_complete(sub_info)
  usermodehelper: use UMH_WAIT_PROC consistently
  signal: zap_pid_ns_processes: s/SEND_SIG_NOINFO/SEND_SIG_FORCED/
  signal: oom_kill_task: use SEND_SIG_FORCED instead of force_sig()
  signal: cosmetic, s/from_ancestor_ns/force/ in prepare_signal() paths
  signal: give SEND_SIG_FORCED more power to beat SIGNAL_UNKILLABLE
  Hexagon: use set_current_blocked() and block_sigmask()
  ...