Use knowledge about EFLAGS layout (bits 22:63 are always 0) to distingush
EFLAGS word and kernel address in the spin lock stack frame.
Signed-off-by: NAndi Kleen <ak@suse.de>

This ports the algorithm from x86-64 (with improvements) to i386.
Previously this only worked for frame pointer enabled kernels.
But spinlocks have a very simple stack frame that can be manually
analyzed. Do this.
Signed-off-by: NAndi Kleen <ak@suse.de>

Based on patch from Frank van Maarseveen <frankvm@frankvm.com>, but
extended.
Signed-off-by: NAndi Kleen <ak@suse.de>

A few trivial spelling and grammar mistakes picked up in
"arch/x86_64/aperture.c", "arch/x86_64/crash.c" and
"arch/x86_64/apic.c". I think all are correct fixes but am ever aware
of my fallibility :o) This is my first patch submission so all
feedback is appreciated, esp. WRT CCing to Linus, Andi and
trivial@kernel.org, is this correct? And which is the most appropriate
kernel version to diff against? If any.

Should apply cleanly to 2.6.18-rc1
Signed-off-by: NAdam Henley <adamazing@gmail.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

-  adam

Hello,

Following my discussion with Andi. Here is a patch that introduces
two new TIF flags to simplify the context switch code in __switch_to().
The idea is to minimize the number of cache lines accessed in the common
case, i.e., when neither the debug registers nor the I/O bitmap are used.

This patch covers the x86-64 modifications. A patch for i386 follows.

Changelog:
	- add TIF_DEBUG to track when debug registers are active
	- add TIF_IO_BITMAP to track when I/O bitmap is used
	- modify __switch_to() to use the new TIF flags

<signed-off-by>: eranian@hpl.hp.com
Signed-off-by: NAndi Kleen <ak@suse.de>

No need to include it from entry.S
Drop all the #ifdef __ASSEMBLY__
Signed-off-by: NAndi Kleen <ak@suse.de>

For NUMA optimization and some other algorithms it is useful to have a fast
to get the current CPU and node numbers in user space.

x86-64 added a fast way to do this in a vsyscall. This adds a generic
syscall for other architectures to make it a generic portable facility.

I expect some of them will also implement it as a faster vsyscall.

The cache is an optimization for the x86-64 vsyscall optimization. Since
what the syscall returns is an approximation anyways and user space
often wants very fast results it can be cached for some time.  The norma
methods to get this information in user space are relatively slow

The vsyscall is in a better position to manage the cache because it has direct
access to a fast time stamp (jiffies). For the generic syscall optimization
it doesn't help much, but enforce a valid argument to keep programs
portable

I only added an i386 syscall entry for now. Other architectures can follow
as needed.

AK: Also added some cleanups from Andrew Morton
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch adds a vgetcpu vsyscall, which depending on the CPU RDTSCP
capability uses either the RDTSCP or CPUID to obtain a CPU and node
numbers and pass them to the program.

AK: Lots of changes over Vojtech's original code:
Better prototype for vgetcpu()
It's better to pass the cpu / node numbers as separate arguments
to avoid mistakes when going from SMP to NUMA.
Also add a fast time stamp based cache using a user supplied
argument to speed things more up.
Use fast method from Chuck Ebbert to retrieve node/cpu from
GDT limit instead of CPUID
Made sure RDTSCP init is always executed after node is known.
Drop printk
Signed-off-by: NVojtech Pavlik <vojtech@suse.cz>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch adds initalization of the RDTSCP auxilliary values to CPU numbers
to time.c. If RDTSCP is available, the MSRs are written with the respective
values. It can be later used to initalize per-cpu timekeeping variables.

AK: Some cleanups. Move externs into headers and fix CPU hotplug.
Signed-off-by: NVojtech Pavlik <vojtech@suse.cz>
Signed-off-by: NAndi Kleen <ak@suse.de>

AK: This redoes the changes I temporarily reverted.

Intel now has support for Architectural Performance Monitoring Counters
( Refer to IA-32 Intel Architecture Software Developer's Manual
http://www.intel.com/design/pentium4/manuals/253669.htm ). This
feature is present starting from Intel Core Duo and Intel Core Solo processors.

What this means is, the performance monitoring counters and some performance
monitoring events are now defined in an architectural way (using cpuid).
And there will be no need to check for family/model etc for these architectural
events.

Below is the patch to use this performance counters in nmi watchdog driver.
Patch handles both i386 and x86-64 kernels.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

I've had good experiences with having this on by default on x86-64.
It turns nasty hangs into easier to debug oopses.

Enable the local APIC wdog by default for systems newer than 2004.

This comes from a strange compromise: according to arjan the reason
it was off by default was some old IBM systems that corrupted
registered when NMI happened in SMI. Can't remember more specific,
but >= 2004 should avoid these. It's probably overly broad
because most older systems should be ok (and the really old systems
won't be supported by the local apic watchdog anyways)
Signed-off-by: NAndi Kleen <ak@suse.de>

After a crash we should wait for NMI IPI event and not for external NMI or
NMI watchdog tick.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

After a crash we should wait for NMI IPI event and not for external NMI or
NMI watchdog tick.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

This patch makes the following needlessly global functions static:
- nmi_int.c: profile_exceptions_notify()
- nmi_timer_int.c: profile_timer_exceptions_notify()
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>

When a unknown NMI happened the panic would claim a NMI watchdog timeout.
Also it would check the variable set by nmi_watchdog=panic and panic then.

Fix up the panic message to be generic
Unconditionally panic on unknown NMI when panic on unknown nmi is enabled.

Noticed by Jan Beulich

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

Making NMI suspend/resume work with SMP. We use CPU hotplug to offline
APs in SMP suspend/resume. Only BSP executes sysdev's .suspend/.resume
method. APs should follow CPU hotplug code path.

And:

+From: Don Zickus <dzickus@redhat.com>

Makes the start/stop paths of nmi watchdog more robust to handle the
suspend/resume cases more gracefully.

AK: I merged the two patches together
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Clean up some of the output messages on the nmi error paths to make more
sense when they are displayed.  This is mainly a cosmetic fix and
shouldn't impact any normal code path.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

To quote Alan Cox:

The default Linux behaviour on an NMI of either memory or unknown is to
continue operation. For many environments such as scientific computing
it is preferable that the box is taken out and the error dealt with than
an uncorrected parity/ECC error get propogated.

A small number of systems do generate NMI's for bizarre random reasons
such as power management so the default is unchanged. In other respects
the new proc/sys entry works like the existing panic controls already in
that directory.

This is separate to the edac support - EDAC allows supported chipsets to
handle ECC errors well, this change allows unsupported cases to at least
panic rather than cause problems further down the line.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Adds a new /proc/sys/kernel/nmi_watchdog call that will enable/disable the
nmi watchdog.

By entering a non-zero value here, a user can enable the nmi watchdog to
monitor the online cpus in the system.  By entering a zero value here, a
user can disable the nmi watchdog and free up a performance counter which
could then be utilized by the oprofile subsystem, otherwise oprofile may be
short a counter when in use.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Adds a new /proc/sys/kernel/nmi call that will enable/disable the nmi
watchdog.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Removes the un/set_nmi_callback and reserve/release_lapic_nmi functions as
they are no longer needed.  The various subsystems are modified to register
with the die_notifier instead.

Also includes compile fixes by Andrew Morton.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Needed TIF_RESTORE_SIGMASK first
Signed-off-by: NAndi Kleen <ak@suse.de>

We need TIF_RESTORE_SIGMASK in order to support ppoll() and pselect()
system calls. This patch originally came from Andi, and was based
heavily on David Howells' implementation of same on i386. I fixed a typo
which was causing do_signal() to use the wrong signal mask.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch cleans up the NMI interrupt path.  Instead of being gated by if
the 'nmi callback' is set, the interrupt handler now calls everyone who is
registered on the die_chain and additionally checks the nmi watchdog,
reseting it if enabled.  This allows more subsystems to hook into the NMI if
they need to (without being block by set_nmi_callback).
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch includes the changes to make the nmi watchdog on i386 SMP aware.
A bunch of code was moved around to make it simpler to read.  In addition,
it is now possible to determine if a particular NMI was the result of the
watchdog or not.  This feature allows the kernel to filter out unknown NMIs
easier.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch includes the changes to make the nmi watchdog on x86_64 SMP
aware.  A bunch of code was moved around to make it simpler to read.  In
addition, it is now possible to determine if a particular NMI was the result
of the watchdog or not.  This feature allows the kernel to filter out
unknown NMIs easier.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Incorporates the new performance counter reservation system in oprofile.
Also cleans up a lot of the initialization code.  The code original zero'd
out every register associated with performance counters regardless if those
registers were used or not.  This causes issues with the nmi watchdog.
Now oprofile tries to reserve registers and gives up if it can't get them.

Cc: levon@movementarian.org
Cc: oprofile-list@lists.sf.net
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Adds basic infrastructure to allow subsystems to reserve performance
counters on the x86 chips.  Only UP kernels are supported in this patch to
make reviewing easier.  The SMP portion makes a lot more changes.

Think of this as a locking mechanism where each bit represents a different
counter.  In addition, each subsystem should also reserve an appropriate
event selection register that will correspond to the performance counter it
will be using (this is mainly neccessary for the Pentium 4 chips as they
break the 1:1 relationship to performance counters).

This will help prevent subsystems like oprofile from interfering with the
nmi watchdog.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This makes merging easier.  They are readded a few patches later.
Signed-off-by: NAndi Kleen <ak@suse.de>

There are some machines around (large xSeries or Unisys ES7000) that
need physical IO-APIC destination mode to access all of their IO
devices. This currently doesn't work in UP kernels as used in
distribution installers.

This patch allows to compile even UP kernels as GENERICARCH which
allows to use physical or clustered APIC mode.
Signed-off-by: NAndi Kleen <ak@suse.de>

This is based on the x86-64 defconfig which works on a wide range of systems.
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAndi Kleen <ak@suse.de>

If there is only 1 node in the system cpus should think they are apart of
some other node.

If cases where a real numa system boots the Flat numa option make sure the
cpus don't claim to be apart on a non-existent node.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Assume that a cpu is *physically* offlined at boot time...

Because smpboot.c::smp_boot_cpu_map() canoot find cpu's sapicid,
numa.c::build_cpu_to_node_map() cannot build cpu<->node map for
offlined cpu.

For such cpus, cpu_to_node map should be fixed at cpu-hot-add.
This mapping should be done before cpu onlining.

This patch also handles cpu hotremove case.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Problem description:

  We have additional_cpus= option for allocating possible_cpus.  But nid
  for possible cpus are not fixed at boot time.  cpus which is offlined at
  boot or cpus which is not on SRAT is not tied to its node.  This will
  cause panic at cpu onlining.

Usually, pxm_to_nid() mapping is fixed at boot time by SRAT.

But, unfortunately, some system (my system!) do not include
full SRAT table for possible cpus.  (Then, I use
additiona_cpus= option.)

For such possible cpus, pxm<->nid should be fixed at
hot-add.  We now have acpi_map_pxm_to_node() which is also
used at boot.  It's suitable here.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

With CONFIG_PHYSICAL_START set to a non default values the i386
boot_ioremap code calculated its pte index wrong and users of boot_ioremap
have their areas incorrectly mapped (for me SRAT table not mapped during
early boot).  This patch removes the addr < BOOT_PTE_PTRS constraint.

[ Keith says this is applicable to 2.6.16 and 2.6.17 as well ]

Signed-off-by: Keith Mannthey<kmannth@us.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: <stable@kernel.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

init_socksys() was marked __init but invoked from a
non-__init function.

Use the correct module_{init,exit}() faciltiies while we're
here and eliminate some seriously bogus ifdefs.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unfortunately, sparc64 doesn't have an easy way to do a "64 X 64 -->
128" bit multiply like PowerPC and IA64 do.  We were doing a
"64 X 64 --> 64" bit multiple which causes overflow very quickly with
a 30-bit quotient shift.

So use a quotientshift count of 10 instead of 30, just like x86 and
ARM do.

This also fixes the wrapping of printk timestamp values every ~17
seconds.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>