Consolidation: remove the irq_affinity[NR_IRQS] array and move it into the
irq_desc[NR_IRQS].affinity field.

[akpm@osdl.org: sparc64 build fix]
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>

This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.

While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.

The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.

This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.

As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.

The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.

We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.

This patch:

rename desc->handler to desc->chip.

Originally i did not want to do this, because it's a big patch.  But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.

I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.

So lets get over with this quickly.  The conversion was done automatically
via scripts and converts all the code in the kernel.

This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.

[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
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>

On i386, kernel irq balance doesn't work.

1) In function do_irq_balance, after kernel finds the min_loaded cpu but
   before calling set_pending_irq to really pin the selected_irq to the
   target cpu, kernel does a cpus_and with irq_affinity[selected_irq].
   Later on, when the irq is acked, kernel would calls
   move_native_irq=>desc->handler->set_affinity to change the irq affinity.
    However, every function pointed by
   hw_interrupt_type->set_affinity(unsigned int irq, cpumask_t cpumask)
   always changes irq_affinity[irq] to cpumask.  Next time when recalling
   do_irq_balance, it has to do cpu_ands again with
   irq_affinity[selected_irq], but irq_affinity[selected_irq] already
   becomes one cpu selected by the first irq balance.

2) Function balance_irq in file arch/i386/kernel/io_apic.c has the same
   issue.

[akpm@osdl.org: cleanups]
Signed-off-by: NZhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch contains the following cleanups:
- make needlessly global functions static
- every file should include the headers containing the prototypes for
  it's global functions
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: N"Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Thanks to Christoph for doing most of the work.

This allows automatic SMP IRQ affinity assignment other than default "all
interrupts on all CPUs" which is rather expensive.  This might be useful if
the hardware can be programmed to distribute interrupts among different
CPUs, like Alpha does.
Signed-off-by: NIvan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When handling writes to /proc/irq, current code is re-programming rte
entries directly. This is not recommended and could potentially cause
chipset's to lockup, or cause missing interrupts.

CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the
interrupt is pending. The same needs to be done for /proc/irq handling as well.
Otherwise user space irq balancers are really not doing the right thing.

- Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for
  lack of a generic name.
- added move_irq out of IRQ_BALANCE, and added this same to X86_64
- Added new proc handler for write, so we can do deferred write at irq
  handling time.
- Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead
  it now shows only active cpu masks, or exactly what was set.
- Provided a common move_irq implementation, instead of duplicating
  when using generic irq framework.

Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off.
Tested UP builds as well.

MSI testing: tbd: I have cards, need to look for a x-over cable, although I
did test an earlier version of this patch.  Will test in a couple days.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Acked-by: NZwane Mwaikambo <zwane@holomorphy.com>
Grudgingly-acked-by: NAndi Kleen <ak@muc.de>
Signed-off-by: NCoywolf Qi Hunt <coywolf@lovecn.org>
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!