If a rescuer and stop_machine() bringing down a CPU race with each
other, they may deadlock on non-preemptive kernel.  The CPU won't
accept a new task, so the rescuer can't migrate to the target CPU,
while stop_machine() can't proceed because the rescuer is holding one
of the CPU retrying migration.  GCWQ_DISASSOCIATED is never cleared
and worker_maybe_bind_and_lock() retries indefinitely.

This problem can be reproduced semi reliably while the system is
entering suspend.

 http://thread.gmane.org/gmane.linux.kernel/1122051

A lot of kudos to Thilo-Alexander for reporting this tricky issue and
painstaking testing.

stable: This affects all kernels with cmwq, so all kernels since and
        including v2.6.36 need this fix.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Thilo-Alexander Ginkel <thilo@ginkel.com>
Tested-by: Thilo-Alexander Ginkel <thilo@ginkel.com>
Cc: stable@kernel.org

It is not obvious how to debug run-away workers.

These are some tips given by Tejun on lkml.
Signed-off-by: Florian Mickler <florian@mickler.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  avr32: Fix missing irq namespace conversion
  powerpc: qe_ic: Rename get_irq_desc_data and get_irq_desc_chip
  genirq: Remove the now obsolete config options and select statements
  arm: versatile : Fix typo introduced in irq namespace cleanup
  sound: Fixup the last user of the old irq functions
  genirq: Remove obsolete comment
  genirq: Remove now obsolete set_irq_wake()
  sh: Fix irq cleanup fallout
  x86: apb_timer: Fixup genirq fallout
  genirq: Fix misnamed label in handle_edge_eoi_irq

Fix up crazy conflict in arch/powerpc/include/asm/qe_ic.h:

 - commit eead4d5c ("powerpc: qe_ic: Rename get_irq_desc_data and
   get_irq_desc_chip") made the helper functions use
   irq_desc_get_handler_data() instead of the legacy (and no longer
   existing) get_irq_desc_data.

 - commit d4db35e8 ("powerpc/qe_ic: Fix another breakage from the
   irq_data conversion") used irq_desc_get_chip_data() instead.

According to Thomas, the former is the correct direct conversion, but it
does look like both should work (arch/powerpc/sysdev/qe_lib/qe_ic.c
seems to initialize both to the same thing), and the chip data in some
ways is the more logical.  Somebody should really decide on one of the
other.

This merge picks irq_desc_get_handler_data() as the straightforward pure
conversion to new names, as per Thomas.

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/qe_ic: Fix another breakage from the irq_data conversion
  powerpc/8xx: Fix another breakage from the irq_data conversion
  powerpc/cell: Use handle_edge_eoi_irq for real
  powerpc/pseries: Enable Chelsio network and iWARP drivers
  powerpc/mm: Move the STAB0 location to 0x8000 to make room in low memory
  powerpc: Fix accounting of softirq time when idle
  powerpc/pseries/smp: query-cpu-stopped-state support won't change
  powerpc/xics: Use hwirq for xics domain irq number
  powerpc/xics: Fix numberspace mismatch from irq_desc conversion
  powerpc: Wire up new syscalls
  powerpc/booke: Correct the SPRN_MAS5 definition.
  powerpc: ARCH_PFN_OFFSET should be unsigned long
  powerpc: Implement dma_mmap_coherent()
  powerpc/nvram: Don't overwrite oops/panic report on normal shutdown
  powerpc: Restore some misc devices to our configs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin:
  Blackfin: bitops: fix include order after little endian inclusion
  Blackfin: defconfigs: update after misc devices defaulted to N
  Blackfin: use more standard pr_fmt in the module loader

* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (65 commits)
  ARM: 6826/1: Merge v6 and v7 DEBUG_LL DCC support
  ARM: 6838/1: etm: fix section mismatch warning
  ARM: 6837/1: remove unused pci_fixup_prpmc1100
  ARM: 6836/1: kprobes/fix emulation of LDR/STR instruction when Rn == PC
  Fix the broken build for Marvell Dove platform.
  ARM: 6835/1: perf: ensure overflows aren't missed due to IRQ latency
  ARM: 6834/1: perf: reset counters on all CPUs during initialisation
  ARM: 6833/1: perf: add required isbs() to ARMv7 backend
  ARM: 6825/1: kernel/sleep.S: fix Thumb2 compilation issues
  ARM: 6807/1: realview: Fix secondary GIC initialisation for EB with MPCore tile
  arm: mach-mx3: pcm043: add write-protect and card-detect for SD1
  eukrea_mbimxsd51: add SD Card detect
  eukrea_mbimxsd25-baseboard: add SD card detect
  mx3/eukrea_mbimxsd-baseboard: add SD card detect support
  mx3/eukrea_mbimxsd-baseboard: fix gpio request
  ARM: mxs/mx28evk: add mmc device
  ARM: mxs/mx23evk: add mmc device
  ARM: mxs: dynamically allocate mmc device
  ARM: mx51_efika: update platform data for new mfd changes
  mx2/iomux: Set direction for CSPI2 pins
  ...

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

These two functions disappeared in commit

    0c6f8a8b
    "genirq: Remove compat code"

but they still exist in qe_ic.h.
This patch renames the function to their new names.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Lennert Buytenhek <buytenh@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <20110330132504.GA31832@riccoc20.at.omicron.at>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Commit 6845664(arm: Cleanup the irq namespace) introduces a typo
causing a build failure for the versatile platform.

[ tglx: Sorry, my bad. Have no idea how I fatfingered that ]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
LKML-Reference: <20110330060229.27397.7628.stgit@ponder>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fixes these errors:

  kernel/irq/chip.c: In function 'handle_edge_eoi_irq':
  kernel/irq/chip.c:517: warning: label 'out_unlock' defined but not used
  kernel/irq/chip.c:503: error: label 'out_eoi' used but not defined
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Missed one instance when moving that to the core code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: michael@ellerman.id.au
Cc: mingo@elte.hu
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Ensure the Chelsio T3/T4 network drivers and iWARP drivers are
enabled in the pseries config.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Recent upstream builds with allmodconfig fail due to lack of space
between 0x3000 and 0x6000. We have a hard block at 0x7000 but we can
spare a page by moving the STAB0 from 0x6000 to 0x8000.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

commit cf9efce0 (powerpc: Account time using timebase rather
than PURR) used in_irq() to detect if the time was spent in
interrupt processing. This only catches hardirq context so if we
are in softirq context and in the idle loop we end up accounting it
as idle time. If we instead use in_interrupt() we catch both softirq
and hardirq time.

The issue was found when running a network intensive workload. top
showed the following:

0.0%us,  1.1%sy,  0.0%ni, 85.7%id,  0.0%wa,  9.9%hi,  3.3%si,  0.0%st

85.7% idle. But this was wildly different to the perf events data.
To confirm the suspicion I ran something to keep the core busy:

# yes > /dev/null &

8.2%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa, 10.3%hi, 81.4%si,  0.0%st

We only got 8.2% of the CPU for the userspace task and softirq has
shot up to 81.4%.

With the patch below top shows the correct stats:

0.0%us,  0.0%sy,  0.0%ni,  5.3%id,  0.0%wa, 13.3%hi, 81.3%si,  0.0%st
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

If a given firmware doesn't have a token to support query-cpu-stopped-state,
its not likely to change during the lifetime of the kernel.

Only print this information once, not once per secondary thread.

While here, make the line wrap grep friendly.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

To try to avoid future confusion, rename irq to hwirq when it refers
to a xics domain number instead of a linux irq number.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

commit 79f26c26 (powerpc:
platforms/pseries irq_data conversion) pushed irq_desc down into many
functions, dererencing the descriptor irq field as late as possible.

But it incorrectly passed a linix virtural irq number to RTAS,
resulting in the interrupt not being disabled and possibly
other bad things, such as another interrupt being disabled and/or
a checkstop.

In addition this missed the point of xics_mask_unknown_vec and
the seperation of xics_mask_real_irq from xics_mask_irq.  When
xics_mask_unknown_vec is called it's because the hardware delivered an
irq source for which we have no linux irq allocated, and thefore we can
not have an irq_desc allocated.

Revert xics_mask_real_irq to its prior version, naming the argument
hwirq to highlight the difference.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

These syscalls have been added recently:
	name_to_handle_at
	open_by_handle_at
	clock_adjtime
	syncfs
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

339 is the SPR number for MAS5 documented by Power ISA 2.06, and
implemented by e500mc.  It is not yet used anywhere in the kernel,
so nothing should be relying on the wrong number.
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

pfns are unsigned long, but MEMORY_START is phys_addr_t.  This leads
to page_to_pfn() returning phys_addr_t, and thus type mismatches in a few
print statements.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This is used by Alsa to mmap buffers allocated with dma_alloc_coherent()
into userspace. We need a special variant to handle machines with
non-coherent DMAs as those buffers have "special" virt addresses and
require non-cachable mappings
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

For normal halt, reboot, and poweroff events, refrain from overwriting
the lnx,oops-log partition.  Also, don't save the dmesg buffer on an
emergency-restart event if we've already saved it earlier in panic().
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Uwe Kleine-König reported:

	while working on an defconfig (arm/mx27) I noticed that just updating
	it[1] results in removing CONFIG_EEPROM_AT24=y.  The reason is that
	since commit

		v2.6.36-5965-g5f2365d8 (misc devices: do not enable by default)

	MISC_DEVICES isn't enabled anymore by default.  So all defconfigs that
	have CONFIG_SOME_SYMBOL=y (or =m) (with SOME_SYMBOL depending on
	MISC_DEVICES) but not CONFIG_MISC_DEVICES=y suffer from the same
	problem.

This restores those misc devices to the powerpc defconfigs.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: Uwe Kleine-König
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

I had seen that before, but now that I removed set_irq_wake it broke.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Missed that one in the big compat remval patch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

I missed that coccinelle does not fix up header files by default.
Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: <lethal@linux-sh.org>

The lonely user of the internal interface was not in the coccinelle
script.
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Reported-by: michael@ellerman.id.au
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: (26 commits)
  mmc: SDHI should depend on SUPERH || ARCH_SHMOBILE
  mmc: tmio_mmc: Move some defines into a shared header
  mmc: tmio: support aggressive clock gating
  mmc: tmio: fix power-mode interpretation
  mmc: tmio: remove work-around for unmasked SDIO interrupts
  sh: fix SDHI IO address-range
  ARM: mach-shmobile: fix SDHI IO address-range
  mmc: tmio: only access registers above 0xff, if available
  mfd: remove now redundant sh_mobile_sdhi.h header
  sh: convert boards to use linux/mmc/sh_mobile_sdhi.h
  ARM: mach-shmobile: convert boards to use linux/mmc/sh_mobile_sdhi.h
  mmc: tmio: convert the SDHI MMC driver from MFD to a platform driver
  sh: ecovec: use the CONFIG_MMC_TMIO symbols instead of MFD
  mmc: tmio: split core functionality, DMA and MFD glue
  mmc: tmio: use PIO for short transfers
  mmc: tmio-mmc: Improve DMA stability on sh-mobile
  mmc: fix mmc_app_send_scr() for dma transfer
  mmc: sdhci-esdhc: enable esdhc on imx53
  mmc: sdhci-esdhc: use writel/readl as general APIs
  mmc: sdhci: add the abort CMDTYPE bits definition
  ...

* 'frv' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-frv:
  FRV: Use generic show_interrupts()
  FRV: Convert genirq namespace
  frv: Select GENERIC_HARDIRQS_NO_DEPRECATED
  frv: Convert cpu irq_chip to new functions
  frv: Convert mb93493 irq_chip to new functions
  frv: Convert mb93093 irq_chip to new function
  frv: Convert mb93091 irq_chip to new functions
  frv: Fix typo from __do_IRQ overhaul
  frv: Remove stale irq_chip.end
  FRV: Do some cleanups
  FRV: Missing node arg in alloc_thread_info_node() macro
  NOMMU: implement access_remote_vm
  NOMMU: support SMP dynamic percpu_alloc
  NOMMU: percpu should use is_vmalloc_addr().

* 'stable/bug-fixes-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: Use new irq_move functions
  xen: Convert genirq namespace
  xen: fix p2m section mismatches
  xen/p2m: Allocate p2m tracking pages on override
  xen-gntdev: unlock on error path in gntdev_mmap()
  xen-gntdev: return -EFAULT on copy_to_user failure

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  watchdog: softdog.c: enhancement to optionally invoke panic instead of reboot on timer expiry
  watchdog: fix nv_tco section mismatch
  watchdog: sp5100_tco.c: Check if firmware has set correct value in tcobase.
  watchdog: Convert release_resource to release_region/release_mem_region
  watchdog: s3c2410_wdt.c: Convert release_resource to release_region/release_mem_region

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  amd64_edac: Fix potential memleak