Ingo had

[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at mm/bootmem.c:537 alloc_arch_preferred_bootmem+0x2b/0x71()
[    0.000000] Hardware name: System Product Name
[    0.000000] Modules linked in:
[    0.000000] Pid: 0, comm: swapper Tainted: G        W  2.6.30-tip-03087-g0bb2618-dirty #52506
[    0.000000] Call Trace:
[    0.000000]  [<81032588>] warn_slowpath_common+0x60/0x90
[    0.000000]  [<810325c5>] warn_slowpath_null+0xd/0x10
[    0.000000]  [<819d1bc0>] alloc_arch_preferred_bootmem+0x2b/0x71
[    0.000000]  [<819d1c31>] ___alloc_bootmem_nopanic+0x2b/0x9a
[    0.000000]  [<81050a0a>] ? lock_release+0xac/0xb2
[    0.000000]  [<819d1d4c>] ___alloc_bootmem+0xe/0x2d
[    0.000000]  [<819d1e9f>] __alloc_bootmem+0xa/0xc
[    0.000000]  [<819d7c63>] alloc_bootmem_cpumask_var+0x21/0x26
[    0.000000]  [<819d0cc8>] early_irq_init+0x15/0x10d
[    0.000000]  [<819bb75a>] start_kernel+0x167/0x326
[    0.000000]  [<819bb06b>] __init_begin+0x6b/0x70
[    0.000000] ---[ end trace 4eaa2a86a8e2da23 ]---
[    0.000000] NR_IRQS:2304 nr_irqs:424
[    0.000000] CPU 0 irqstacks, hard=821e6000 soft=821e7000

we need to update init_irq_default_affinity
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Fixes the following problem:

[    0.000000] Experimental hierarchical RCU init done.
[    0.000000] NR_IRQS:4352 nr_irqs:256
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at mm/bootmem.c:537 alloc_arch_preferred_bootmem+0x40/0x7e()
[    0.000000] Hardware name: To Be Filled By O.E.M.
[    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30-tip-02161-g7a74539-dirty #59709
[    0.000000] Call Trace:
[    0.000000]  [<ffffffff823f8c8e>] ? alloc_arch_preferred_bootmem+0x40/0x7e
[    0.000000]  [<ffffffff81067168>] warn_slowpath_common+0x88/0xcb
[    0.000000]  [<ffffffff810671d2>] warn_slowpath_null+0x27/0x3d
[    0.000000]  [<ffffffff823f8c8e>] alloc_arch_preferred_bootmem+0x40/0x7e
[    0.000000]  [<ffffffff823f9307>] ___alloc_bootmem_nopanic+0x4e/0xec
[    0.000000]  [<ffffffff823f93c5>] ___alloc_bootmem+0x20/0x61
[    0.000000]  [<ffffffff823f962e>] __alloc_bootmem+0x1e/0x34
[    0.000000]  [<ffffffff823f757c>] early_irq_init+0x6d/0x118
[    0.000000]  [<ffffffff823e0140>] ? early_idt_handler+0x0/0x71
[    0.000000]  [<ffffffff823e0cf7>] start_kernel+0x192/0x394
[    0.000000]  [<ffffffff823e0140>] ? early_idt_handler+0x0/0x71
[    0.000000]  [<ffffffff823e02ad>] x86_64_start_reservations+0xb4/0xcf
[    0.000000]  [<ffffffff823e0000>] ? __init_begin+0x0/0x140
[    0.000000]  [<ffffffff823e0420>] x86_64_start_kernel+0x158/0x17b
[    0.000000] ---[ end trace a7919e7f17c0a725 ]---
[    0.000000] Fast TSC calibration using PIT
[    0.000000] Detected 2002.510 MHz processor.
[    0.004000] Console: colour VGA+ 80x25
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Don't hardcode to node zero for early boot IRQ setup memory allocations.

[ penberg@cs.helsinki.fi: minor cleanups ]
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Presently non-legacy IRQs have their irq_desc allocated with
kzalloc_node(). This assumes that all callers of irq_to_desc_node_alloc()
will be sufficiently late in the boot process that kmalloc is available.

While porting sparseirq support to sh this blew up immediately, as at the
time that we register the CPU's interrupt vector map only bootmem is
available. Check slab_is_available() to work out which path to use.

[ Impact: fix SH early boot crash with sparseirq enabled ]
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
LKML-Reference: <20090522014008.GA2806@linux-sh.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Trying to implement a driver to use threaded irqs, I was confused when the 
return value to use that was described in the comment above 
request_threaded_irq was not defined.

Turns out that the enum is IRQ_WAKE_THREAD where as the comment said 
IRQ_THREAD_WAKE.

[Impact: do not confuse developers with wrong comments ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
LKML-Reference: <alpine.DEB.2.00.0905121431020.13338@gandalf.stny.rr.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

move_irq_desc() will try to move irq_desc to the home node if
the allocated one is not correct, in create_irq_nr().

( This can happen on devices that are on different nodes that
  are using MSI, when drivers are loaded and unloaded randomly. )

v2: fix non-smp build
v3: add NUMA_IRQ_DESC to eliminate #ifdefs

[ Impact: improve irq descriptor locality on NUMA systems ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49F95EAE.2050903@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This reverts commit 044d4084.

The commit added a warning when handle_IRQ_event() is called outside
of hard interrupt context. This breaks the generic tasklet based
interrupt resend mechanism which is used when the hardware has no way
to retrigger the interrupt. So we get a warning for a use case which
is correct and worked for years. Remove it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

"tracing: create automated trace defines" causes this compile error on s390,
as reported by Sachin Sant against linux-next:

 kernel/built-in.o: In function `__do_softirq':
 (.text+0x1c680): undefined reference to `__tracepoint_softirq_entry'

This happens because the definitions of the softirq tracepoints were moved
from kernel/softirq.c to kernel/irq/handle.c. Since s390 doesn't support
generic hardirqs handle.c doesn't get compiled and the definitions are
missing.

So move the tracepoints to softirq.c again.

[ Impact: fix build failure on s390 ]
Reported-by: NSachin Sant <sachinp@in.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: fweisbec@gmail.com
LKML-Reference: <20090429135139.5fac79b8@osiris.boeblingen.de.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This simplifies the node awareness of the code. All our allocators
only deal with a NUMA node ID locality not with CPU ids anyway - so
there's no need to maintain (and transform) a CPU id all across the
IRq layer.

v2: keep move_irq_desc related

[ Impact: cleanup, prepare IRQ code to be NUMA-aware ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
LKML-Reference: <49F65536.2020300@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

irq_set_affinity() and move_masked_irq() try to assign affinity
before calling chip set_affinity(). Some archs are assigning it
in ->set_affinity() again.

We do something like:

 cpumask_cpy(desc->affinity, mask);
 desc->chip->set_affinity(mask);

But in the failure path, affinity should not be touched - otherwise
we'll end up with a different affinity mask despite the failure to
migrate the IRQ.

So try to update the afffinity only if set_affinity returns with 0.
Also call irq_set_thread_affinity accordingly.

v2: update after "irq, x86: Remove IRQ_DISABLED check in process context IRQ move"
v3: according to Ingo, change set_affinity() in irq_chip should return int.
v4: update comments by removing moving irq_desc code.

[ Impact: fix /proc/irq/*/smp_affinity setting corner case bug ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49F65509.60307@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The original feature of migrating irq_desc dynamic was too fragile
and was causing problems: it caused crashes on systems with lots of
cards with MSI-X when user-space irq-balancer was enabled.

We now have new patches that create irq_desc according to device
numa node. This patch removes the leftover bits of the dynamic balancer.

[ Impact: remove dead code ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49F654AF.8000808@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

CPUMASKS_OFFSTACK is not defined anywhere (it is CPUMASK_OFFSTACK).
It is a typo and init_allocate_desc_masks() is called before it set
affinity to all cpus...

Split init_alloc_desc_masks() into all_desc_masks() and init_desc_masks().

Also use CPUMASK_OFFSTACK in alloc_desc_masks().

[ Impact: fix smp_affinity copying/setup when moving irq_desc between CPUs ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
LKML-Reference: <49F6546E.3040406@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: clean up

Create a sub directory in include/trace called events to keep the
trace point headers in their own separate directory. Only headers that
declare trace points should be defined in this directory.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

This patch lowers the number of places a developer must modify to add
new tracepoints. The current method to add a new tracepoint
into an existing system is to write the trace point macro in the
trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or
DECLARE_TRACE, then they must add the same named item into the C file
with the macro DEFINE_TRACE(name) and then add the trace point.

This change cuts out the needing to add the DEFINE_TRACE(name).
Every file that uses the tracepoint must still include the trace/<type>.h
file, but the one C file must also add a define before the including
of that file.

 #define CREATE_TRACE_POINTS
 #include <trace/mytrace.h>

This will cause the trace/mytrace.h file to also produce the C code
necessary to implement the trace point.

Note, if more than one trace/<type>.h is used to create the C code
it is best to list them all together.

 #define CREATE_TRACE_POINTS
 #include <trace/foo.h>
 #include <trace/bar.h>
 #include <trace/fido.h>

Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with
the cleaner solution of the define above the includes over my first
design to have the C code include a "special" header.

This patch converts sched, irq and lockdep and skb to use this new
method.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As discussed in the thread here:

  http://marc.info/?l=linux-kernel&m=123964468521142&w=2

Eric W. Biederman observed:

> It looks like some additional bugs have slipped in since last I looked.
>
> set_irq_affinity does this:
> ifdef CONFIG_GENERIC_PENDING_IRQ
>        if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
>                cpumask_copy(desc->affinity, cpumask);
>                desc->chip->set_affinity(irq, cpumask);
>        } else {
>                desc->status |= IRQ_MOVE_PENDING;
>                cpumask_copy(desc->pending_mask, cpumask);
>        }
> #else
>
> That IRQ_DISABLED case is a software state and as such it has nothing to
> do with how safe it is to move an irq in process context.

[...]

>
> The only reason we migrate MSIs in interrupt context today is that there
> wasn't infrastructure for support migration both in interrupt context
> and outside of it.

Yes. The idea here was to force the MSI migration to happen in process
context. One of the patches in the series did

        disable_irq(dev->irq);
        irq_set_affinity(dev->irq, cpumask_of(dev->cpu));
        enable_irq(dev->irq);

with the above patch adding irq/manage code check for interrupt disabled
and moving the interrupt in process context.

IIRC, there was no IRQ_MOVE_PCNTXT when we were developing this HPET
code and we ended up having this ugly hack. IRQ_MOVE_PCNTXT was there
when we eventually submitted the patch upstream. But, looks like I did a
blind rebasing instead of using IRQ_MOVE_PCNTXT in hpet MSI code.

Below patch fixes this. i.e., revert commit 932775a4
and add PCNTXT to HPET MSI setup. Also removes copying of desc->affinity
in generic code as set_affinity routines are doing it internally.
Reported-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Li Shaohua" <shaohua.li@intel.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: "lcm@us.ibm.com" <lcm@us.ibm.com>
Cc: suresh.b.siddha@intel.com
LKML-Reference: <20090413222058.GB8211@linux-os.sc.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Need to free the old cpumask for affinity and pending_mask.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49D18FF0.50707@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Introduce helper functions allowing us to prevent device drivers from
getting any interrupts (without disabling interrupts on the CPU)
during suspend (or hibernation) and to make them start to receive
interrupts again during the subsequent resume.  These functions make it
possible to keep timer interrupts enabled while the "late" suspend and
"early" resume callbacks provided by device drivers are being
executed.  In turn, this allows device drivers' "late" suspend and
"early" resume callbacks to sleep, execute ACPI callbacks etc.

The functions introduced here will be used to rework the handling of
interrupts during suspend (hibernation) and resume.  Namely,
interrupts will only be disabled on the CPU right before suspending
sysdevs, while device drivers will be prevented from receiving
interrupts, with the help of the new helper function, before their
"late" suspend callbacks run (and analogously during resume).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NIngo Molnar <mingo@elte.hu>

Delta patch to address the review comments.

      - Implement warning when IRQ_WAKE_THREAD is requested and no
        thread handler installed
      - coding style fixes
Pointed-out-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Some devices use devres_request_irq() for to install their interrupt
handler. Add support for threaded interrupts to devres as well.

[tglx - simplified and adapted to latest threadirq version]
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add support for threaded interrupt handlers:

A device driver can request that its main interrupt handler runs in a
thread. To achive this the device driver requests the interrupt with
request_threaded_irq() and provides additionally to the handler a
thread function. The handler function is called in hard interrupt
context and needs to check whether the interrupt originated from the
device. If the interrupt originated from the device then the handler
can either return IRQ_HANDLED or IRQ_WAKE_THREAD. IRQ_HANDLED is
returned when no further action is required. IRQ_WAKE_THREAD causes
the genirq code to invoke the threaded (main) handler. When
IRQ_WAKE_THREAD is returned handler must have disabled the interrupt
on the device level. This is mandatory for shared interrupt handlers,
but we need to do it as well for obscure x86 hardware where disabling
an interrupt on the IO_APIC level redirects the interrupt to the
legacy PIC interrupt lines.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Two years migration time is enough. Remove the compability cruft.

Add the deprecated warning in kernel/irq/handle.c because marking
__do_IRQ itself is way too noisy.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Impact: simplification
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NPeter Zijlstra <peterz@infradead.org>

Impact: cleanup

The code is only compiled if CONFIG_GENERIC_HARDIRQS=y so another
check for this define in the code is redundant. Remove it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Export the setup_irq() and remove_irq() symbols.

I'd like to export these functions since I have timer
code that needs to use setup_irq() early on (too early
for request_irq()), and the same code can also be
compiled as a module.
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
LKML-Reference: <20090312120559.2926.82371.sendpatchset@rx1.opensource.se>
[ changed to _GPL as these are special APIs deep inside the irq layer. ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Modify remove_irq() to match setup_irq().
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
LKML-Reference: <20090312120551.2926.43942.sendpatchset@rx1.opensource.se>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: add new API

This patch adds a remove_irq() function for releasing
interrupts requested with setup_irq().

Without this patch we have no way of releasing such
interrupts since free_irq() today tries to kfree()
the irqaction passed with setup_irq().
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
LKML-Reference: <20090312120542.2926.56609.sendpatchset@rx1.opensource.se>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Make sure the genirq layer handlers are indeed running handlers
in hardirq context. That is the genirq expectation and doing
anything else is broken.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1236006812.5330.632.camel@laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: add new tracepoints

Add them to the generic IRQ code, that way every architecture
gets these new tracepoints, not just x86.

Using Steve's new 'TRACE_FORMAT', I can get function graph
trace as follows using the original two IRQ tracepoints:

 3)               |    handle_IRQ_event() {
 3)               |    /* (irq_handler_entry) irq=28 handler=eth0 */
 3)               |    e1000_intr_msi() {
 3)   2.460 us    |      __napi_schedule();
 3)   9.416 us    |    }
 3)               |    /* (irq_handler_exit) irq=28 handler=eth0 return=handled */
 3) + 22.935 us   |  }
Signed-off-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

'p' stands for pointer - make it clear in setup_irq() and free_irq()
what kind of pointer it is.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Linus noticed that the 'pp' variable can be eliminated
altogether, and the loop can be cleaned up further.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

- separate out the loop from the actual freeing logic, this wins us
  two indentation levels allowing a number of followup prettifications

- turn the WARN_ON() into a more informative WARN().

- clean up the comments and the code flow some more

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

- make printk message git-greppable
- fix a few style details
Signed-off-by: NIngo Molnar <mingo@elte.hu>

request_irq() calls into proc code via __setup_irq() which is not safe
in an atomic context, so request_irq() can itself use the more
reliable GFP_KERNEL allocation for the action descriptor.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

While being at it make every occurrence of 'do_irq_select_affinity'
have the same signature in terms of signedness of the first argument.

Fix this sparse warning:
  kernel/irq/manage.c:112:5: warning: symbol 'do_irq_select_affinity' was not declared. Should it be static?

Also rename do_irq_select_affinity() to setup_affinity() - shorter name
and clearer naming.
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Acked-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Simplify and make init_kstat_irqs etc more type proof, suggested by
Andrew.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: get correct kstat_irqs [/proc/interrupts] for msi/msi-x etc

need to call clear_kstat_irqs(), so when we reuse that irq_desc,
we get correct kstat in /proc/interrupts.

This makes /proc/interrupts not have <NULL> entries.

Don't need to worry about arch that doesn't support genirq, because they
will not call dynamic_irq_cleanup().

v2: simplify and make clear_kstat_irqs more robust
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Eric Paris reported:

> I have an hp dl785g5 which is unable to successfully run
> 2.6.29-0.66.rc3.fc11.x86_64 or 2.6.29-rc2-next-20090126.  During bootup
> (early in userspace daemons starting) I get the below BUG, which quickly
> renders the machine dead.  I assume it is because sparse_irq_lock never
> gets released when the BUG kills that task.

Adjust lock sequence when migrating a descriptor with
CONFIG_NUMA_MIGRATE_IRQ_DESC enabled.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move the initialization of irq_default_affinity to early_irq_init as
core_initcall is too late.

irq_default_affinity can be used in init_IRQ and potentially timer and
SMP init as well.  All of these happen before core_initcall.  Moving
the initialization to early_irq_init ensures that it is initialized
before it is used.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Acked-by: NMike Travis <travis@sgi.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In interrupt.h these functions are declared only if
CONFIG_GENERIC_HARDIRQS is set.  We should define them under identical
conditions.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide a shared interrupt debug facility under CONFIG_DEBUG_SHIRQ:
it uses the existing irqpoll facilities to iterate through all
registered interrupt handlers and call those which can handle shared
IRQ lines.

This can be handy for suspend/resume debugging: if we call this function
early during resume we can trigger crashes in those drivers which have
incorrect assumptions about when exactly their ISRs will be called
during suspend/resume.
Signed-off-by: NIngo Molnar <mingo@elte.hu>