When testing cpu hotplug code on 32-bit we kept hitting the "CPU%d:
Stuck ??" message due to multiple cores concurrently accessing the
cpu_callin_mask, among others.

Since these codepaths are not protected from concurrent access due to
the fact that there's no sane reason for making an already complex
code unnecessarily more complex - we hit the issue only when insanely
switching cores off- and online - serialize hotplugging cores on the
sysfs level and be done with it.

[ v2.1: fix !HOTPLUG_CPU build ]

Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100819181029.GC17171@aftab>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Fix dummy inline stubs for trampoline-related functions when no
trampolines exist (until we get rid of the no-trampoline case
entirely.)
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <4C6C294D.3030404@zytor.com>

This patch fixes machine crashes which occur when heavily exercising the
CPU hotplug codepaths on a 32-bit kernel. These crashes are caused by
AMD Erratum 383 and result in a fatal machine check exception. Here's
the scenario:

1. On 32-bit, the swapper_pg_dir page table is used as the initial page
table for booting a secondary CPU.

2. To make this work, swapper_pg_dir needs a direct mapping of physical
memory in it (the low mappings). By adding those low, large page (2M)
mappings (PAE kernel), we create the necessary conditions for Erratum
383 to occur.

3. Other CPUs which do not participate in the off- and onlining game may
use swapper_pg_dir while the low mappings are present (when leave_mm is
called). For all steps below, the CPU referred to is a CPU that is using
swapper_pg_dir, and not the CPU which is being onlined.

4. The presence of the low mappings in swapper_pg_dir can result
in TLB entries for addresses below __PAGE_OFFSET to be established
speculatively. These TLB entries are marked global and large.

5. When the CPU with such TLB entry switches to another page table, this
TLB entry remains because it is global.

6. The process then generates an access to an address covered by the
above TLB entry but there is a permission mismatch - the TLB entry
covers a large global page not accessible to userspace.

7. Due to this permission mismatch a new 4kb, user TLB entry gets
established. Further, Erratum 383 provides for a small window of time
where both TLB entries are present. This results in an uncorrectable
machine check exception signalling a TLB multimatch which panics the
machine.

There are two ways to fix this issue:

        1. Always do a global TLB flush when a new cr3 is loaded and the
        old page table was swapper_pg_dir. I consider this a hack hard
        to understand and with performance implications

        2. Do not use swapper_pg_dir to boot secondary CPUs like 64-bit
        does.

This patch implements solution 2. It introduces a trampoline_pg_dir
which has the same layout as swapper_pg_dir with low_mappings. This page
table is used as the initial page table of the booting CPU. Later in the
bringup process, it switches to swapper_pg_dir and does a global TLB
flush. This fixes the crashes in our test cases.

-v2: switch to swapper_pg_dir right after entering start_secondary() so
that we are able to access percpu data which might not be mapped in the
trampoline page table.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20100816123833.GB28147@aftab>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

A bug in the family-model-stepping matching code caused the presence of
errata to go undetected when OSVW was not used. This causes hangs on
some K8 systems because the E400 workaround is not enabled.
Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1282141190-930137-1-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  gcc-4.6: ACPI: fix unused but set variables in ACPI
  ACPI thermal: make procfs I/F depend on CONFIG_ACPI_PROCFS
  ACPI video: make procfs I/F depend on CONFIG_ACPI_PROCFS
  ACPI processor: remove deprecated ACPI procfs I/F
  ACPI power_resource: remove unused procfs I/F
  ACPI: remove deprecated ACPI procfs I/F
  ACPI: introduce drivers/acpi/sysfs.c
  ACPI: introduce module parameter acpi.aml_debug_output
  ACPI: introduce drivers/acpi/debugfs.c
  ACPI, APEI, ERST debug support
  ACPI, APEI, Manage GHES as platform devices
  ACPI, APEI, Rename CPER and GHES severity constants
  ACPI, APEI, Fix a typo of error path of apei_resources_request
  ACPI / ACPICA: Fix reference counting problems with GPE handlers
  ACPI: Add the check of ADR flag in course of finding ACPI handle for PCI device
  ACPI / Sleep: Drop acpi_suspend_finish()
  ACPI / Sleep: Consolidate suspend and hibernation routines
  ACPI / Wakeup: Simplify enabling of wakeup devices
  ACPI / Sleep: Rework enabling wakeup devices
  ACPI / Sleep: Free NVS copy if suspending of devices fails

Fixed up totally buggered "ACPI: fix unused but set variables in ACPI"
patch that doesn't even compile in the merge.

Thanks to Sedat Dilek <sedat.dilek@googlemail.com> for noticing the
breakage before I even pulled.  And a big "Grrr.." at Len for not even
bothering to compile the tree before asking me to pull.

* git://git.infradead.org/iommu-2.6:
  intel-iommu: Fix 32-bit build warning with __cmpxchg()
  intr-remap: allow disabling source id checking

* git://git.infradead.org/mtd-2.6:
  mtd/nand_ids: Fix buswidth
  mtd/m25p80: fix test for end of loop
  mtd/m25p80: retlen is never NULL
  MIPS: Fix gen_nand probe structures contents
  gen_nand: Test if nr_chips field is valid
  BFIN: Fix gen_nand probe structures contents
  nand/denali: move all hardware initialization work to denali_hw_init
  nand/denali: Add a page check in denali_read_page & denali_read_page_raw
  nand/denali: use cpu_relax() while waiting for hardware interrupt
  nand/denali: change read_status function method
  nand/denali: Fixed check patch warnings
  ARM: Fix gen_nand probe structures contents
  mtd/nand_base: fix kernel-doc warnings & typos
  nand/denali: use dev_xx debug function to replace nand_dbg_print and some printk
  nand/denali: Fixed handle ECC error bugs
  nand/denali: use iowrite32() to replace denali_write32()
  nand/denali: Fixed probe function bugs

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: don't validate CROSS_COMPILE needlessly
  arch/tile: export only COMMAND_LINE_SIZE to userspace.
  arch/tile: rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN
  arch/tile: Rename the hweight() implementations to __arch_hweight()
  arch/tile: extend syscall ABI to set r1 on return as well.
  arch/tile: Various cleanups.
  arch/tile: support backtracing on TILE-Gx
  arch/tile: Fix a couple of issues with the COMPAT code for TILE-Gx.
  arch/tile: Use separate, better minsec values for clocksource and sched_clock.
  arch/tile: correct a bug in freeing bootmem by VA for the optional second initrd.
  arch: tile: mm: pgtable.c: Removed duplicated #include
  arch: tile: kernel/proc.c Removed duplicated #include
  Add fanotify syscalls to <asm-generic/unistd.h>.
  arch/tile: support new kunmap_atomic() naming convention.
  tile: remove unused ISA_DMA_THRESHOLD define

Conflicts in arch/tile/configs/tile_defconfig (pick the mainline version
with the reduced defconfig).

With this change, the arch/tile Makefile will only check for a valid
combination of CROSS_COMPILE vs "uname -m" for a few common targets
that are typically the ones we get wrong (vmlinux, all, and modules).
The change handles the case of an empty "make" goal like "make all".
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

This commit makes the stack guard page somewhat less visible to user
space. It does this by:

 - not showing the guard page in /proc/<pid>/maps

   It looks like lvm-tools will actually read /proc/self/maps to figure
   out where all its mappings are, and effectively do a specialized
   "mlockall()" in user space.  By not showing the guard page as part of
   the mapping (by just adding PAGE_SIZE to the start for grows-up
   pages), lvm-tools ends up not being aware of it.

 - by also teaching the _real_ mlock() functionality not to try to lock
   the guard page.

   That would just expand the mapping down to create a new guard page,
   so there really is no point in trying to lock it in place.

It would perhaps be nice to show the guard page specially in
/proc/<pid>/maps (or at least mark grow-down segments some way), but
let's not open ourselves up to more breakage by user space from programs
that depends on the exact deails of the 'maps' file.

Special thanks to Henrique de Moraes Holschuh for diving into lvm-tools
source code to see what was going on with the whole new warning.

Reported-and-tested-by: François Valenduc <francois.valenduc@tvcablenet.be
Reported-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: sound/usb/format: silence uninitialized variable warnings
  MAINTAINERS: Add Ian Lartey as comaintaner for Wolfson devices
  MAINTAINERS: Make Wolfson entry also cover CODEC drivers
  ASoC: Only tweak WM8994 chip configuration on devices up to rev D
  ASoC: Optimise DSP performance for WM8994
  ALSA: hda - Fix dynamic ADC change working again
  ALSA: hda - Restrict PCM parameters per ELD information over HDMI
  sound: oss: sh_dac_audio.c removed duplicated #include

* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
  intel_idle: recognize Lincroft Atom Processor
  intel_idle: no longer EXPERIMENTAL
  intel_idle: disable module support
  intel_idle: add support for Westmere-EX
  intel_idle: delete power_policy modparam, and choose substate functions
  intel_idle: delete substates DEBUG modparam

This fixes a failure in "make headers_check" for tile.
I hadn't realized this file was exported to userspace by default.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

See commit a6eb9fe1.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

Gcc complains that ret might be used uninitialized:

sound/usb/format.c: In function ‘snd_usb_parse_audio_format’:
sound/usb/format.c:354: warning: ‘ret’ may be used uninitialized in this function
sound/usb/format.c:354: note: ‘ret’ was declared here
sound/usb/format.c:414: warning: ‘ret’ may be used uninitialized in this function
sound/usb/format.c:414: note: ‘ret’ was declared here

I suppose it could be uninitialized if there is ever a UAC_VERSION_3
released. Anyway this patch is worthwhile if only to silence the gcc
warning.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Conflicts:
	drivers/acpi/debug.c
Signed-off-by: Len Brown <len.brown@intel.com>

Some minor improvements in error handling, but overall it was mostly dead
code.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

Mark the ACPI thermal procfs I/F deprecated, because /sys/class/thermal/
is already available and has been working for years w/o any problem.

The ACPI thermal procfs I/F will be removed in 2.6.37.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Mark ACPI video driver procfs I/F deprecated, including:
/proc/acpi/video/*/info
/proc/acpi/video/*/DOS
/proc/acpi/video/*/ROM
/proc/acpi/video/*/POST
/proc/acpi/video/*/POST_info
/proc/acpi/video/*/*/info
/proc/acpi/video/*/*/state
/proc/acpi/video/*/*/EDID
and
/proc/acpi/video/*/*/brightness, because
1. we already have the sysfs I/F /sysclass/backlight/ as the replacement
of /proc/acpi/video/*/*/brightness.
2. the other procfs I/F is not useful for userspace.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Remove deprecated ACPI processor procfs I/F, including:
/proc/acpi/processor/CPUX/power
/proc/acpi/processor/CPUX/limit
/proc/acpi/processor/CPUX/info

/proc/acpi/processor/CPUX/throttling still exists,
as we don't have sysfs I/F available for now.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Remove unused ACPI power procfs I/F.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Rmove deprecated ACPI procfs I/F, including
/proc/acpi/debug_layer
/proc/acpi/debug_level
/proc/acpi/info
/proc/acpi/dsdt
/proc/acpi/fadt
/proc/acpi/sleep

because the sysfs I/F is already available
and has been working well for years.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Introduce drivers/acpi/sysfs.c.

code for ACPI sysfs I/F, including
#ifdef ACPI_DEBUG
/sys/module/acpi/parameters/debug_layer
/sys/module/acpi/parameters/debug_level
/sys/module/acpi/parameters/trace_method_name
/sys/module/acpi/parameters/trace_debug_layer
/sys/module/acpi/parameters/trace_debug_level
/sys/module/acpi/parameters/trace_state
#endif
/sys/module/acpi/parameters/acpica_version
/sys/firmware/acpi/tables/
/sys/firmware/acpi/interrupts/
is moved to this file.

No function change in this patch.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Introduce module parameter acpi.aml_debug_output.

With acpi.aml_debug_output set, we can get AML debug object output
(Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared.

Together with the runtime custom method mechanism,
we can debug AML code problems without rebuilding the kernel.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Introduce drivers/acpi/debugfs.c.

Code for ACPI debugfs I/F,
i.e. /sys/kernel/debug/acpi/custom_method,
is moved to this file.

And make ACPI debugfs always built in,
even if CONFIG_ACPI_DEBUG is cleared.

BTW:this adds about 400bytes code to ACPI, when
CONFIG_ACPI_DEBUG is cleared.

[uaccess.h build fix from Andrew Morton <akpm@linux-foundation.org>]
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

This patch adds debugging/testing support to ERST. A misc device is
implemented to export raw ERST read/write/clear etc operations to user
space. With this patch, we can add ERST testing support to
linuxfirmwarekit ISO (linuxfirmwarekit.org) to verify the kernel
support and the firmware implementation.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/sam/cleanup:
  defconfig reduction
  kbuild: drop unifdef-y support
  archs: replace unifdef-y with header-y
  include: replace unifdef-y with header-y

Fix fusion missing kernel-doc:

  Warning(drivers/message/fusion/mptbase.c:649): No description found for parameter 'func_name'
  Warning(drivers/message/fusion/mptbase.c:8010): No description found for parameter 'cb_idx'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix parameter name in kernel-doc notation (causes a warning).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix comment begin notation not to look like kernel-doc
since it's not.  Removes kernel-doc warnings.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Remove leading /** from non-kernel-doc function comments to prevent
kernel-doc warnings.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>