Commit d435d862
("cpu hotplug: mce: fix cpu hotplug error handling")
changed the error handling in mce_cpu_callback.

In cases where not all CPUs are brought up during
boot (e.g. using maxcpus and additional_cpus parameters)
mce_cpu_callback now returns NOTFIY_BAD because
for such CPUs cpu_data is not completely filled when
the notifier is called. Thus mce_create_device fails right
at its beginning:

        if (!mce_available(&cpu_data[cpu]))
                return -EIO;

As a quick fix I suggest to check boot_cpu_data for MCE.

To reproduce this regression:

(1) boot with maxcpus=2 addtional_cpus=2 on a 4 CPU x86-64 system
(2) # echo 1 >/sys/devices/system/cpu/cpu2/online
  -bash: echo: write error: Invalid argument

dmesg shows:

_cpu_up: attempt to bring up CPU 2 failed
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Fix regression introduced with d435d862
("cpu hotplug: mce: fix cpu hotplug error handling").

A CPU which was not brought up during boot (using maxcpus and
additional_cpus parameters) couldn't be onlined anymore.  For such a CPU it
seemed that MCE was not supported during CPU_UP_PREPARE-time which caused
mce_cpu_callback to return NOTIFY_BAD to notifier_call_chain.  To fix this
we:

 - call mce_create_device for CPU_ONLINE event (instead of CPU_UP_PREPARE),
 - avoid mce_remove_device() for the CPU that is not correctly initialized
   by mce_create_device() failure,
 - make mce_cpu_callback always return NOTIFY_OK for CPU_ONLINE event.
   Because CPU_ONLINE callback return value is always ignored.

[akinobu.mita@gmail.com: avoid mce_remove_device() for not initialized device]
[akinobu.mita@gmail.com: make mce_cpu_callback always return NOTIFY_OK]
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The x86_64 arch/x86/kernel/Makefile uses references into 
arch/x86/kernel/cpu/... to use code from there.

Unifiy it with the nicely structured i386 way and reuse the existing
subdirectory make rules.

Also move the machine check related source into ...kernel/cpu/mcheck,
where the other machine check related code is.

No code change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move mce.c to mce_32.c to allow the later move of the x86_64 mce.c
from arch/x86/kernel/ to ...kernel/cpu/mcheck

No code change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Prepare the makefiles in x86/kernel/cpu and x86/kernel/cpu/mcheck to
be used by the x86_64 build as well.

No code change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Do thermal_throttle_add_dev() in CPU_UP_PREPARE instead of CPU_ONLINE.

Cc: Dmitriy Zavin <dmitriyz@google.com>
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Andi Kleen <ak@suse.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add missing IRQs and IRQ descriptions to /proc/interrupts.

/proc/interrupts is most useful when it displays every IRQ vector in use by
the system, not just those somebody thought would be interesting.

This patch inserts the following vector displays to the i386 and x86_64
platforms, as appropriate:

	rescheduling interrupts
	TLB flush interrupts
	function call interrupts
	thermal event interrupts
	threshold interrupts
	spurious interrupts

A threshold interrupt occurs when ECC memory correction is occuring at too
high a frequency.  Thresholds are used by the ECC hardware as occasional
ECC failures are part of normal operation, but long sequences of ECC
failures usually indicate a memory chip that is about to fail.

Thermal event interrupts occur when a temperature threshold has been
exceeded for some CPU chip.  IIRC, a thermal interrupt is also generated
when the temperature drops back to a normal level.

A spurious interrupt is an interrupt that was raised then lowered by the
device before it could be fully processed by the APIC.  Hence the apic sees
the interrupt but does not know what device it came from.  For this case
the APIC hardware will assume a vector of 0xff.

Rescheduling, call, and TLB flush interrupts are sent from one CPU to
another per the needs of the OS.  Typically, their statistics would be used
to discover if an interrupt flood of the given type has been occuring.

AK: merged v2 and v4 which had some more tweaks
AK: replace Local interrupts with Local timer interrupts
AK: Fixed description of interrupt types.

[ tglx: arch/x86 adaptation ]
[ mingo: small cleanup ]
Signed-off-by: NJoe Korty <joe.korty@ccur.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Tim Hockin <thockin@hockin.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Fix bugzilla #8679

WARNING: arch/i386/kernel/built-in.o(.data+0x2148): Section mismatch: reference
to .init.text: (between 'thermal_throttle_cpu_notifier' and 'mtrr_mutex')

comes because struct notifier_block thermal_throttle_cpu_notifier in
arch/i386/kernel/cpu/mcheck/therm_throt.c goes in .data section but the
notifier callback function itself has been marked __cpuinit which becomes
__init == .init.text when HOTPLUG_CPU=n.  The warning is bogus because the
callback will never be called out if HOTPLUG_CPU=n in the first place (as
one can see from kernel/cpu.c, the cpu_chain itself is __cpuinitdata :-)

So, let's mark thermal_throttle_cpu_notifier as __cpuinitdata to fix
the section mismatch warning.

[ tglx: arch/x86 adaptation ]
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>