tick: Cure broadcast false positive pending bit warning

commit 26517f3e (tick: Avoid programming the local cpu timer if
broadcast pending) added a warning if the cpu enters broadcast mode
again while the pending bit is still set. Meelis reported that the
warning triggers. There are two corner cases which have been not
considered:

1) cpuidle calls clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
   twice. That can result in the following scenario

   CPU0                    CPU1
                           cpuidle_idle_call()
                             clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
                               set cpu in tick_broadcast_oneshot_mask

   broadcast interrupt
     event expired for cpu1
     set pending bit

                             acpi_idle_enter_simple()
                               clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
                                 WARN_ON(pending bit)

  Move the WARN_ON into the section where we enter broadcast mode so
  it wont provide false positives on the second call.

2) safe_halt() enables interrupts, so a broadcast interrupt can be
   delivered befor the broadcast mode is disabled. That sets the
   pending bit for the CPU which receives the broadcast
   interrupt. Though the interrupt is delivered right away from the
   broadcast handler and leaves the pending bit stale.

   Clear the pending bit for the current cpu in the broadcast handler.

Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Cc: Len Brown <lenb@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305271841130.4220@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
posix-timers: Show clock ID in proc file

Expand information about posix-timers in /proc/<pid>/timers by adding
info about clock, with which the timer was created. I.e. in the forth
line of timer info after "notify:" line go "ClockID: <clock_id>".

Signed-off-by: Pavel Tikhomirov <snorcht@gmail.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Link: http://lkml.kernel.org/r/1368742323-46949-2-git-send-email-snorcht@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ntp: Remove unused variable flags in __hardpps

kernel/time/ntp.c: In function ‘__hardpps’:
kernel/time/ntp.c:877: warning: unused variable ‘flags’

commit a076b2146fabb0894cae5e0189a8ba3f1502d737 ("ntp: Remove ntp_lock,
using the timekeeping locks to protect ntp state") removed its users,
but not the actual variable.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
timekeeping: Correct run-time detection of persistent_clock.

Since commit 31ade30692dc9680bfc95700d794818fa3f754ac, timekeeping_init()
checks for presence of persistent clock by attempting to read a non-zero
time value. This is an issue on platforms where persistent_clock (instead
is implemented as a free-running counter (instead of an RTC) starting
from zero on each boot and running during suspend. Examples are some ARM
platforms (e.g. PandaBoard).

An attempt to read such a clock during timekeeping_init() may return zero
value and falsely declare persistent clock as missing. Additionally, in
the above case suspend times may be accounted twice (once from
timekeeping_resume() and once from rtc_resume()), resulting in a gradual
drift of system time.

This patch does a run-time correction of the issue by doing the same check
during timekeeping_suspend().

A better long-term solution would have to return error when trying to read
non-existing clock and zero when trying to read an uninitialized clock, but
that would require changing all persistent_clock implementations.

This patch addresses the immediate breakage, for now.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
[jstultz: Tweaked commit message and subject]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Merge branch 'fortglx/3.10/time' of git://git.linaro.org/people/jstultz/linux into timers/urgent
irqdomain: export irq_domain_add_simple

All other irq_domain_add_* functions are exported already, and apparently
this one got left out by mistake, which causes build errors for ARM
allmodconfig kernels:

ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-rcar.ko] undefined!
ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-em.ko] undefined!

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
kernel/irq/irqdomain.c: before use 'irq_data', need check it whether valid.

Since irq_data may be NULL, if so, we WARN_ON(), and continue, 'hwirq'
which related with 'irq_data' has to initialize later, or it will cause
issue.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
irqdomain: document the simple domain first_irq

The first_irq needs to be zero to get a linear domain and that
comes with special semantics. We want to simplify this going
forward but some documentation never hurts.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
irqchip: Return -EPERM for reserved IRQs

The irqdomain core will report a log message for any attempted map call
that fails unless the error code is -EPERM. This patch changes the
Versatile irq controller drivers to use -EPERM because it is normal for
a subset of the IRQ inputs to be marked as reserved on the various
Versatile platforms.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux

Pull irqdomain bug fixes from Grant Likely:
 "This branch contains a set of straight forward bug fixes to the
  irqdomain code and to a couple of drivers that make use of it."

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux:
  irqchip: Return -EPERM for reserved IRQs
  irqdomain: document the simple domain first_irq
  kernel/irq/irqdomain.c: before use 'irq_data', need check it whether valid.
  irqdomain: export irq_domain_add_simple
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:

 - Trivial: unused variable removal

 - Posix-timers: Add the clock ID to the new proc interface to make it
   useful.  The interface is new and should be functional when we reach
   the final 3.10 release.

 - Cure a false positive warning in the tick code introduced by the
   overhaul in 3.10

 - Fix for a persistent clock detection regression introduced in this
   cycle

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Correct run-time detection of persistent_clock.
  ntp: Remove unused variable flags in __hardpps
  posix-timers: Show clock ID in proc file
  tick: Cure broadcast false positive pending bit warning
hpfs: fix warnings when the filesystem fills up

This patch fixes warnings due to missing lock on write error path.

  WARNING: at fs/hpfs/hpfs_fn.h:353 hpfs_truncate+0x75/0x80 [hpfs]()
  Hardware name: empty
  Pid: 26563, comm: dd Tainted: P           O 3.9.4 #12
  Call Trace:
    hpfs_truncate+0x75/0x80 [hpfs]
    hpfs_write_begin+0x84/0x90 [hpfs]
    _hpfs_bmap+0x10/0x10 [hpfs]
    generic_file_buffered_write+0x121/0x2c0
    __generic_file_aio_write+0x1c7/0x3f0
    generic_file_aio_write+0x7c/0x100
    do_sync_write+0x98/0xd0
    hpfs_file_write+0xd/0x50 [hpfs]
    vfs_write+0xa2/0x160
    sys_write+0x51/0xa0
    page_fault+0x22/0x30
    system_call_fastpath+0x1a/0x1f

Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@kernel.org  # 2.6.39+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux 3.10-rc5