There is no need to keep NMI_DISABLED definition and use it
for nmi_watchdog by default. Here is the point why:

- IO-APIC and APIC chips are programmed for nmi_watchdog support at very
  early stage of kernel booting and not having nmi_watchdog specified as
  boot option lead only to nmi_watchdog becomes to NMI_NONE anyway
- enable nmi_watchdog thru /proc/sys/kernel/nmi if it was not specified at
  boot is not possible too (even having this sysfs entry)
Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Cc: macro@linux-mips.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We create a version of it for i386, and then take the CONFIG_X86_64
ifdef out of the game. We could create a __setup_vector_irq for i386,
but it would incur in an unnecessary lock taking. Moreover, it is better
practice to only export setup_vector_irq anyway.
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

> That helped a lot, the system seems to work normally now.
>
> Here's the relevant snippet from dmesg:
>
> [    0.108006] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
> [    0.108006] ..MP-BIOS bug: 8254 timer not connected to IO-APIC
> [    0.108006] ...trying to set up timer (IRQ0) through the 8259A ... <3>
> [    0.108006] ..... (found apic 0 pin 2) ...<3> failed.
> [    0.108006] ...trying to set up timer as Virtual Wire IRQ...<3> works.
>
> and the whole thing is at: http://www.sisk.pl/kernel/debug/20080618/dmesg-2.log

 Hmm, that only proved the 8259A is indeed wired to the pin #2 of the I/O
APIC.

> I, personally, don't have any and AMD only has SB600 documentation on its
> web page (it's still marked as "AMD confidential" ;-)).

 Well, the IC block is most likely the same as that's not rocket science
and once done there is no need to fiddle with that.  That written, I am
afraid there is nothing useful about the IC in the document, except that
it's there and consists of an I/O APIC providing 24 inputs and the usual
pair of 8259A cores.  Thanks for the reference anyway.

> There is an interrupt controller in there, but I'm not sure if there's any
> 8259A.  The northbridge is on the CPU, actually.

 I will praise the day someone ships an x86 machine without an 8259A core!

 As expressed in another mail I suspect there may actually be a direct
route from the 8254 to INTIN0 in the southbridge -- this is what other
bootstrap logs seen in the Internet suggest.  This would mean this
particular BIOS is buggy (is it the latest version?) and provides an
incorrect IRQ override in its ACPI tables, for example because the
responsible block has been blindly copied from a machine using a commoner
wiring.  This could be moderately easily fixed up with a quirk based on
the PCI ID (after checking it again, we actually used to have a quirk for
ATI in this area, but the way it was done suggests the issue was not
understood well enough).

 Could you please remove the hack sent yesterday and test the patch
provided below?  I do hope it builds, but I have no immediate means to
check it.  Please report the output.  The intent is to test INTIN0
directly before testing INTIN2 through the 8259A.  Thanks.

 Aside of that, what I have gathered from your reports (please correct me
if I have got it wrong) is that when the through-8259A mode is used, then
after a while 8254 timer interrupts stop arriving.  What's interesting,
the "Virtual Wire IRQ" seems to work for you correctly (that's quite an
odd setup where a local APIC input is used in the native mode -- please
post /proc/interrupts for confirmation), which in turn implies the master
8259A drives its INT output as we expect.  Why would the I/O APIC input
have problems then?  Hmm...

[ mingo@elte.hu: revert the "x86: fix IO APIC breakage on HP nx6325"
  version. ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

On Thu, 19 Jun 2008, Rafael J. Wysocki wrote:

> >  With such a configuration the "x86: I/O APIC: timer through 8259A
> > second-chance" patch should not matter, because the only change it
> > introduces is an attempt to try the same I/O APIC pin again, but with the
> > IRQ0 line of the master 8259A enabled.  That's not a terribly unusual
> > configuration and nothing should get confused in the system.
>
> But it _does_ get confused, really.

 Something certainly gets confused, but so far I am not sure which bit
exactly it is, are you?

> >  Barring the unlikely possibility of the 8259A actually being wired to
> > INTIN2 of the I/O APIC I can see two possible explanations:
> >
> > 1. The 8259A interrupt actually escapes to the CPU somehow and is handled
> >    as an ExtINTA interrupt.  This would make the code in check_timer()
> >    decide it has found a working configuration, while actually it has been
> >    fooled.
[...]
> Here you go:
>
> [    0.108006] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
> [    0.108006] ..MP-BIOS bug: 8254 timer not connected to IO-APIC
> [    0.108006] ...trying to set up timer (IRQ0) through the 8259A ... <3>
> [    0.108006] ..... (found apic 0 pin 2) ...<3> works.
>
> The full dmesg is at: http://www.sisk.pl/kernel/debug/20080618/dmesg-1.log

Thanks.  In this case I suspect the case #1 quoted above happens, that is
the 8259A manages to deliver its interrupt somehow.  Note at this stage it
is meant to be in the AEOI mode, so it can happily resubmit the interrupt
indefinitely with no additional handling as long as it receives INTA
cycles.

Can you please try the patch below on top of "x86: I/O APIC: timer
through 8259A second-chance" to see whether my hypothesis is true?  It
modifies the through-8259A setup path so that the APIC input gets masked,
but the 8259A has the timer interrupt still enabled.  Let me know how the
timer interrupt is routed in this case.
Bisected-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Tested-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch replaces some hard-coded numbers with predefined names.
Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Not sure but maybe it is better to use NMI_DISABLED,
will take a look. But for now this patch is not change
anything in logic so it will not hurt/broke the kernel.
For most cases nmi_watchdog assignment is by one of NMI_*
macro so I think there it make sense too.
Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

  arch/x86/kernel/io_apic_64.c: In function 'check_timer':
  arch/x86/kernel/io_apic_64.c:1688: error: 'vector' undeclared (first use in this function)
  arch/x86/kernel/io_apic_64.c:1688: error: (Each undeclared identifier is reported only once
  arch/x86/kernel/io_apic_64.c:1688: error: for each function it appears in.)

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

Some systems incorrectly report the ExtINTA pin of the I/O APIC as the
genuine target of the timer interrupt.  Here is a change that copies timer
pin information found to the other pin if one has been found only.  This
way both a direct and a through-8259A route is tested with the pin letting
these problematic systems work well enough.  If no timer pin information
has been found for the I/O APIC, then local APIC variations are tried
only, similarly to what is done without the change (except without the
misleading messages).

Obviously if we try the first-chance path without being told by the BIOS
to do so, we should not complain either, so do not print the message in
this case.

The 64-bit variation should be updated with a call to
replace_pin_at_irq() which can be done with the upcoming merge.  Since
add_pin_to_irq() is now always called in the first-chance path, the
condition to require it in the second-chance path no longer happens.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Keep the timer interrupt line masked when reconfiguring its interrupt
redirection entry in the I/O APIC.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Unmask the timer interrupt line set up in the through-8259A mode
explicitly after setup_timer_IRQ0_pin() has set up the I/O APIC interrupt
redirection entry to let the two operations be unbound from each other.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Rename setup_ExtINT_IRQ0_pin() to setup_timer_IRQ0_pin() to better
reflect the upcoming role of a function setting up a (semi-)arbitrary I/O
APIC pin appropriately for the 8254 timer.  By "appropriate" the following
settings are meant: edge-triggered, active-high, all the other settings
per-architecture.  Adjust comments to reflect code appropriately.  No
functional changes.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The LINT0 line of the local APIC is masked in the LVT0 entry in
check_timer() before this function is ever called.  Removed the
redundant unmasking for better control.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For a better control the masking and unmasking of the timer interrupt
line in the 8259A operating in the 'Virtual Wire' mode has been moved out
of setup_ExtINT_IRQ0_pin() now, so remove the redundant calls from the
function.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There is no point in keeping the 8259A enabled if the I/O APIC NMI
watchdog has failed and the 8259A is not used to pass through regular
timer interrupts.  This fixes problems with some systems where some logic
gets confused.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Disable the 8259A acting in the "virtual wire" mode to keep the interrupt
line inactive while fiddling with local APIC interrupt vector registers
associated with its destination inputs.  To be on the safe side,
especially concerning flipping the trigger mode.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Disable the 8259A when routing of the timer interrupt through the chip to
the local APIC of the primary processor has failed.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove the "disable_8254_timer" and "enable_8254_timer" kernel
parameters.  Now that AEOI acknowledgements are no longer needed for
correct timer operation, the 8259A can be kept disabled unconditionally
unless interrupts, either timer or watchdog ones, are actually passed
through it.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The code that used to be in do_slow_gettimeoffset() that relied on the
IRR bit of the master 8259A PIC for IRQ0 to check the state of the output
timer 0 of the PIT is no longer there.  As a result, there is no need to
use the POLL command to acknowledge the timer interrupt in the "8259A
Virtual Wire", except for the NMI watchdog when the i82489DX APIC is used
(this is because this particular APIC treats NMIs as level-triggered and
keeping the input asserted would keep motherboard NMI sources held off for
too long).  Remove the unneeded bits and adjust comments accordingly.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The SGI UV system needs several more system vectors than a vanilla
x86_64 system.  Rather than burden the other archs with extra system
vectors that they don't use, change FIRST_SYSTEM_VECTOR to a variable,
so that it can be dynamic.
Signed-off-by: NAlan Mayer <ajm@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch fixes section mismatch warnings in unlock_ExtINT_logic().

WARNING: arch/x86/kernel/built-in.o(.text+0x14a92): Section mismatch in reference from the function unlock_ExtINT_logic()
to the function .init.text:find_isa_irq_pin()
The function unlock_ExtINT_logic() references
the function __init find_isa_irq_pin().
This is often because unlock_ExtINT_logic lacks a __init
annotation or the annotation of find_isa_irq_pin is wrong.
Signed-off-by: NJacek Luczak <luczak.jacek@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

 *  Replace usages of CPU_MASK_NONE, CPU_MASK_ALL, NODE_MASK_NONE,
    NODE_MASK_ALL to reduce stack requirements for large NR_CPUS
    and MAXNODES counts.

 *  In some cases, the cpumask variable was initialized but then overwritten
    with another value.  This is the case for changes like this:

    -       cpumask_t oldmask = CPU_MASK_ALL;
    +       cpumask_t oldmask;
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use cpumask_of_cpu() rather than the pair of cpus_clear() and cpu_set().
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There is no reason to use obscurer name.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

No need to clear the memory allocated by alloc_bootmem().
It is already filled with zero.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove duplicate code by using ioapic_read_entry() and ioapic_write_entry()
in io_apic_{32,64}.c
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

If one can find an ack pending pin, there is no need to check
the rest of them.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Introduce a function to read the local APIC_ID.

This change is in preparation for additional changes to
the APICID functions that will come in a later patch.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

take them out of the x86_64-specific asm/mach_apic.h
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

take them out of the x86_64-only asm/mach_apic.h
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.

A simplified version of the semantic patch making this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@ change_compare_np @
expression E;
@@

(
- jiffies <= E
+ time_before_eq(jiffies,E)
|
- jiffies >= E
+ time_after_eq(jiffies,E)
|
- jiffies < E
+ time_before(jiffies,E)
|
- jiffies > E
+ time_after(jiffies,E)
)

@ include depends on change_compare_np @
@@

#include <linux/jiffies.h>

@ no_include depends on !include && change_compare_np @
@@

  #include <linux/...>
+ #include <linux/jiffies.h>
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Its previous use in a call to on_each_cpu() was pointless, as at the
time that code gets executed only one CPU is online. Further, the
function can be __cpuinit, and for this to work without
CONFIG_HOTPLUG_CPU setup_nmi() must also get an attribute (this one
can even be __init; on 64-bits check_timer() also was lacking that
attribute).
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We have a lot of code which differs only by the naming of specific
members of structures that contain registers.  In order to enable
additional unifications, this patch drops the e- or r- size prefix
from the register names in struct pt_regs, and drops the x- prefixes
for segment registers on the 32-bit side.

This patch also performs the equivalent renames in some additional
places that might be candidates for unification in the future.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>