Unified changelog, 80 columns rule, and address form fix.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Currently CMCI mask of hot-added CPU is always disabled after CPU hotplug.
We should adjust this mask depending on CMC polling state.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NSatoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

When the CPE handler encounters too many CPEs (such as a solid single
bit memory error), it sets up a polling timer and disables the CPE
interrupt (to avoid excessive overhead logging the stream of single
bit errors).  disable_irq_nosync() calls chip->disable() to provide
a chipset specifiec interface for disabling the interrupt.  This patch
adds the Altix specific support to disable and re-enable the CPE interrupt.

Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: NTony Luck <tony.luck@intel.com>

Additional testing uncovered a situation where the MCA recovery code could
hang due to a race condition.

According to the SAL spec, SAL sends a rendezvous interrupt to all but the first
CPU that goes into MCA.  This includes other CPUs that go into MCA at the same
time.  Those other CPUs will go into the linux MCA handler (rather than the
slave loop) with the rendezvous interrupt pending.  When all the CPUs have
completed MCA processing and the last monarch completes, freeing all the CPUs,
the CPUs with the pended rendezvous interrupt then go into the
ia64_mca_rendez_int_handler().  In ia64_mca_rendez_int_handler() the CPUs
get marked as rendezvoused, but then leave the handler (due to no MCA).
That leaves the CPUs marked as rendezvoused _before_ the next MCA event.

When the next MCA hits, the monarch will mistakenly believe that all the CPUs
are rendezvoused when they are not, opening up a window where a CPU can get
stuck in the slave loop.

This patch avoids leaving CPUs marked as rendezvoused when they are not.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

While testing the MCA recovery code, noticed that some machines would have a
five second delay rendezvousing cpus.  What was happening is that
ia64_wait_for_slaves() would check to see if all the slave CPUs had
rendezvoused.  If any had not, it would wait 1 millisecond then check again.
If any CPUs had still not rendezvoused, it would wait 5 seconds before
checking again.

On some configs the rendezvous takes more than 1 millisecond, causing the code
to wait the full 5 seconds, even though the last CPU rendezvoused after only
a few milliseconds.

The fix is to check every 1 millisecond to see if all the cpus have
rendezvoused.  After 5 seconds the code concludes the CPUs will never
rendezvous (same as before).

The MCA code is, by definition, not performance critical, but a needless
delay of 5 seconds is senseless.  The 5 seconds also adds up quickly
when running the error injection code in a loop.

This patch both simplifies the code and removes the needless delay.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Use local_vector_to_irq() instead of looping through all NR_IRQS.
This avoids registering the CPE handler on multiple irqs.  Only
register if the irq is valid.  If no valid irq is found, print an
error message and set up polling.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Fix the following section mismatch warnings:

WARNING: vmlinux.o(.text+0x41902): Section mismatch: reference to .init.text:__alloc_bootmem (between 'ia64_mca_cpu_init' and 'ia64_do_tlb_purge')
WARNING: vmlinux.o(.text+0x49222): Section mismatch: reference to .init.text:__alloc_bootmem (between 'register_intr' and 'iosapic_register_intr')
WARNING: vmlinux.o(.text+0x62beb2): Section mismatch: reference to .init.text:__alloc_bootmem_node (between 'hubdev_init_node' and 'cnodeid_get_geoid')
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Linux does not gracefully deal with multiple processors going
through OS_MCA aa part of the same MCA event.  The first cpu
into OS_MCA grabs the ia64_mca_serialize lock.  Subsequent
cpus wait for that lock, preventing them from reporting in as
rendezvoused.  The first cpu waits 5 seconds then complains
that all the cpus have not rendezvoused.  The first cpu then
handles its MCA and frees up all the rendezvoused cpus and
releases the ia64_mca_serialize lock.  One of the subsequent
cpus going thought OS_MCA then gets the ia64_mca_serialize
lock, waits another 5 seconds and then complains that none of
the other cpus have rendezvoused.

This patch allows multiple CPUs to gracefully go through OS_MCA.

The first CPU into ia64_mca_handler() grabs a mca_count lock.
Subsequent CPUs into ia64_mca_handler() are added to a list of cpus
that need to go through OS_MCA (a bit set in mca_cpu), and report
in as rendezvoused, and but spin waiting their turn.

The first CPU sees everyone rendezvous, handles his MCA, wakes up
one of the other CPUs waiting to process their MCA (by clearing
one mca_cpu bit), and then waits for the other cpus to complete
their MCA handling.  The next CPU handles his MCA and the process
repeats until all the CPUs have handled their MCA.  When the last
CPU has handled it's MCA, it sets monarch_cpu to -1, releasing all
the CPUs.

In testing this works more reliably and faster.

Thanks to Keith Owens for suggesting numerous improvements
to this code.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Building with GCC 4.2, I get the following error:

  CC      arch/ia64/kernel/mca.o
arch/ia64/kernel/mca.c:275: error: __ksymtab_ia64_mlogbuf_finish causes a
section type conflict

This is because ia64_mlogbuf_finish is both declared static and exported.
Fix by removing the export (which is unneeded now).
Signed-off-by: NMartin Michlmayr <tbm@cyrius.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The current implementation of kdump on INIT events would enter
kdump processing on DIE_INIT_MONARCH_ENTER and DIE_INIT_SLAVE_ENTER
events. Thus, the monarch cpu would go ahead and boot up the kdump

On SN shub2 systems, this out-of-sync situation causes some slave
cpus on different nodes to enter POD.

This patch moves kdump entry points to DIE_INIT_MONARCH_LEAVE and
DIE_INIT_SLAVE_LEAVE. It also sets kdump_in_progress variable in
the DIE_INIT_MONARCH_PROCESS event to not dump all active stack
traces to the console in the case of kdump.

I have tested this patch on an SN machine and a HP RX2600.
Signed-off-by: NJay Lan <jlan@sgi.com>
Acked-by: NZou Nan hai <nanhai.zou@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Only shows up while building sim_defconfig because CONFIG_ACPI=n
there, and all of the uses of cpe_poll_timer are inside #ifdef CONFIG_ACPI.
Signed-off-by: NTony Luck <tony.luck@intel.com>

This finally renames the thread_info field in task structure to stack, so that
the assumptions about this field are gone and archs have more freedom about
placing the thread_info structure.

Nonbroken archs which have a proper thread pointer can do the access to both
current thread and task structure via a single pointer.

It'll allow for a few more cleanups of the fork code, from which e.g.  ia64
could benefit.
Signed-off-by: NRoman Zippel <zippel@linux-m68k.org>
[akpm@linux-foundation.org: build fix]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Andi Kleen <ak@muc.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch moves the die notifier handling to common code.  Previous
various architectures had exactly the same code for it.  Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)

arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at.  avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Jack Steiner noticed that duplicate TLB DTC entries do not cause a
linux panic.  See discussion:

http://www.gelato.unsw.edu.au/archives/linux-ia64/0307/6108.html

The current TLB recovery code is recovering from the duplicate itr.d
dropins, masking the underlying problem.  This change modifies
the MCA recovery code to look for the TLB check signature of the
duplicate TLB entry and panic in that case.

Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: NTony Luck <tony.luck@intel.com>

Actually, on reflection I think that there is a good case for
keeping the options separate. I am thinking particularly of people
who want a very small crashdump kernel and thus don't want to compile
in kexec.

The patch below should fix things up so that all valid combinations of
KEXEC, CRASH_DUMP and VMCORE compile cleanly - VMCORE depends on
CRASH_DUMP which is why I said valid combinations. In a nutshell
it just untangles unrelated code and switches around a few defines.

Please note that it creats a new file, arch/ia64/kernel/crash_dump.c
This is in keeping with the i386 implementation.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Changes and updates.

1. Remove fake rendz path and related code according to discuss with Khalid Aziz.
2. fc.i offset fix in relocate_kernel.S.
3. iospic shutdown code eoi and mask race fix from Fujitsu.
4. Warm boot hook in machine_kexec to SN SAL code from Jack Steiner.
5. Send slave to SAL slave loop patch from Jay Lan.
6. Kdump on non-recoverable MCA event patch from Jay Lan
7. Use CTL_UNNUMBERED in kdump_on_init sysctl.
Signed-off-by: NZou Nan hai <nanhai.zou@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Fix up arch-specific work items where possible to use the new work_struct and
delayed_work structs.

Three places that enqueue bits of their stack and then return have been marked
with #error as this is not permitted.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

Convert various spin_lock_irqsave() callers to correctly use `unsigned long'.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch reverses the order of fetching log from SAL and
checking poll threshold. This will fix following trivial issues:

- If SAL_GET_SATE_INFO is unbelievably slow (due to huge system
   or just its silly implementation) and if it takes more than
   1/5 sec, CMCI/CPEI will never switch to CMCP/CPEP.
- Assuming terrible flood of interrupt (continuous corrected
   errors let all CPUs enter to handler at once and bind them
   in it), CPUs will be serialized by IA64_LOG_LOCK(*).
   Now we check the poll threshold after the lock and log fetch,
   so we need to call SAL_GET_STATE_INFO (num_online_cpus() + 4)
   times in the worst case.
   if we can check the threshold before the lock, we can shut up
   interrupts quickly without waiting preceding log fetches, and
   the number of times will be reduced to (num_online_cpus()) in
   the same situation.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Printing message to console from MCA/INIT handler is useful,
however doing oops_in_progress = 1 in them exactly makes
something in kernel wrong. Especially it sounds ugly if
system goes wrong after returning from recoverable MCA.

This patch adds ia64_mca_printk() function that collects
messages into temporary-not-so-large message buffer during
in MCA/INIT environment and print them out later, after
returning to normal context or when handlers determine to
down the system.

Also this print function is exported for use in extensional
MCA handler. It would be useful to describe detail about
recovery.

NOTE:
I don't think it is sane thing if temporary message buffer
is enlarged enough to hold whole stack dumps from INIT, so
buffering is disabled during stack dump from INIT-monarch
(= default_monarch_init_process). please fix it in future.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

cleanup: remove task_t and convert all the uses to struct task_struct. I
introduced it for the scheduler anno and it was a mistake.

Conversion was mostly scripted, the result was reviewed and all
secondary whitespace and style impact (if any) was fixed up by hand.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use the new IRQF_ constants and remove the SA_INTERRUPT define
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Cleanup: remove irq_descp() - explicit use of irq_desc[] is shorter and more
readable.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ia64_wait_for_slaves() was changed in 2.6.17-rc1 to report the slave
state.  It incorrectly assumes that all slaves are for MCA, but
ia64_wait_for_slaves() is also called from the INIT monarch handler.
The existing message is very misleading, so correct it.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The MCA/INIT handlers maintain important state in the SAL to OS (sos)
area and in the monarch_cpu flag.  Kernel debuggers (such as KDB) need
this data, and may need to adjust the monarch_cpu field so make the
data available to the notify_die hooks.  Define two more events for
calling the functions on the notify_die chain.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

__set_bit() --> cpu_set() cleanup
Signed-off-by: NAkinobu Mita <mita@miraclelinux.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Memory errors encountered by user applications may surface
when the CPU is running in kernel context.  The current code
will not attempt recovery if the MCA surfaces in kernel
context (privilage mode 0).  This patch adds a check for cases
where the user initiated the load that surfaces in kernel
interrupt code.

An example is a user process lauching a load from memory
and the data in memory had bad ECC.  Before the bad data
gets to the CPU register, and interrupt comes in.  The
code jumps to the IVT interrupt entry point and begins
execution in kernel context.  The process of saving the
user registers (SAVE_REST) causes the bad data to be loaded
into a CPU register, triggering the MCA.  The MCA surfaces in
kernel context, even though the load was initiated from
user context.

As suggested by David and Tony, this patch uses an exception
table like approach, puting the tagged recovery addresses in
a searchable table.  One difference from the exception table
is that MCAs do not surface in precise places (such as with
a TLB miss), so instead of tagging specific instructions,
address ranges are registers.  A single macro is used to do
the tagging, with the input parameter being the label
of the starting address and the macro being the ending
address.  This limits clutter in the code.

This patch only tags one spot, the interrupt ivt entry.
Testing showed that spot to be a "heavy hitter" with
MCAs surfacing while saving user registers.  Other spots
can be added as needed by adding a single macro.

Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: NTony Luck <tony.luck@intel.com>

Mark init related variable and functions with appropriate
__init* declaration to mca functions.
Signed-off-by: NKen Chen <kenneth.w.chen@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

No platform in the community tree uses PLATFORM_MCA_HANDLERS, remove
the references.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Update the comm field on the MCA handler for user tasks as well as for
verified kernel tasks.  This helps to identify the task that was
running when the MCA occurred.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Print a message identifying the monarch MCA handler.  Print a summary
of the status of the slave MCA cpus.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

on ia64 thread_info is at the constant offset from task_struct and stack
is embedded into the same beast.  Set __HAVE_THREAD_FUNCTIONS, made
task_thread_info() just add a constant.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

here is the BSP removal support for IA64. Its pretty much the same thing that
was released a while back, but has your feedback incorporated.

- Removed CONFIG_BSP_REMOVE_WORKAROUND and associated cmdline param
- Fixed compile issue with sn2/zx1 due to a undefined fix_b0_for_bsp
- some formatting nits (whitespace etc)

This has been tested on tiger and long back by alex on hp systems as well.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

notify_die() added for MCA_{MONARCH,SLAVE,RENDEZVOUS}_{ENTER,PROCESS,LEAVE} and
INIT_{MONARCH,SLAVE}_{ENTER,PROCESS,LEAVE}.  We need multiple
notification points for these events because they can take many seconds
to run which has nasty effects on the behaviour of the rest of the
system.

DIE_SS replaced by a generic DIE_FAULT which checks the vector number,
to allow interception of faults other than SS.

DIE_MACHINE_{HALT,RESTART} added to allow last minute close down
processing, especially when the halt/restart routines are called from
error handlers.

DIE_OOPS added.

The check for kprobe's break numbers has been moved from traps.c to
kprobes.c, allowing DIE_BREAK to be used for any additional break
numbers, i.e. it is no longer kprobes specific.

Hooks for kernel debuggers and kernel dumpers added, ENTER and LEAVE.
Both of these disable the system for long periods which impact on
watchdogs and heartbeat systems in general.  More patches to come that
use these events to reset watchdogs and heartbeats.

unregister_die_notifier() added and both routines exported.  Requested
by Dean Nelson.

Lock removed from {un,}register_die_notifier.  notifier_chain_register()
already takes a lock.  Also the generic notifier chain locking is being
reworked to distinguish between callbacks that can block and those that
cannot, the lock in {un,}register_die_notifier would interfere with
that change.  http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

Leading white space removed from arch/ia64/kernel/kprobes.c.

Typo in mca.c in original version of this patch found & fixed by Dean
Nelson.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Acked-by: NDean Nelson <dcn@sgi.com>
Acked-by: NAnil Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

In arch/ia64 change the explicit use of a for-loop using NR_CPUS into the
general for_each_online_cpu() construct.  This widens the scope of potential
future optimizations of the general constructs, as well as takes advantage
of the existing optimizations of first_cpu() and next_cpu(), which is
advantageous when the true CPU count is much smaller than NR_CPUS.
Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

I've noticed a kernel hang during a storm of CMC interrupts, which was
tracked down to the continual execution of the interrupt handler.

There's code in the CMC handler that's supposed to disable CMC
interrupts and switch to polling mode when it sees a bunch of CMCs.
Because disabling CMCs across all CPUs isn't safe in interrupt context,
the disable is done with a schedule_work().  But with continual CMC
interrupts, the schedule_work() never gets executed.

The following patch immediately disables CMC interrupts for the current
CPU.  This then allows (at least) one CPU to ignore CMC interrupts,
execute the schedule_work() code, and disable CMC interrupts on the rest
of the CPUs.
Acked-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NBryan Sutula <Bryan.Sutula@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The bulk of the change.  Use per cpu MCA/INIT stacks.  Change the SAL
to OS state (sos) to be per process.  Do all the assembler work on the
MCA/INIT stacks, leaving the original stack alone.  Pass per cpu state
data to the C handlers for MCA and INIT, which also means changing the
mca_drv interfaces slightly.  Lots of verification on whether the
original stack is usable before converting it to a sleeping process.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>