linux-toradex.git/include/linux/irq.h, branch v2.6.27.39

genirq: Expose default irq affinity mask (take 3)

2008-06-05T13:18:30+00:00

Current IRQ affinity interface does not provide a way to set affinity
for the IRQs that will be allocated/activated in the future.
This patch creates /proc/irq/default_smp_affinity that lets users set
default affinity mask for the newly allocated IRQs. Changing the default
does not affect affinity masks for the currently active IRQs, they
have to be changed explicitly.

Updated based on Paul J's comments and added some more documentation.

Signed-off-by: Max Krasnyansky 
Cc: pj@sgi.com
Cc: a.p.zijlstra@chello.nl
Cc: tglx@linutronix.de
Cc: rdunlap@xenotime.net
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner

genirq: reenable a nobody cared disabled irq when a new driver arrives

2008-05-02T11:40:34+00:00

Uwe Kleine-Koenig has some strange hardware where one of the shared
interrupts can be asserted during boot before the appropriate driver
loads. Requesting the shared irq line from another driver result in a
spurious interrupt storm which finally disables the interrupt line.

I have seen similar behaviour on resume before (the hardware does not
work anymore so I can not verify).

Change the spurious disable logic to increment the disable depth and
mark the interrupt with an extra flag which allows us to reenable the
interrupt when a new driver arrives which requests the same irq
line. In the worst case this will disable the irq again via the
spurious trap, but there is a decent chance that the new driver is the
one which can handle the already asserted interrupt and makes the box
usable again.

Eric Biederman said further: This case also happens on a regular basis
in kdump kernels where we deliberately don't shutdown the hardware
before starting the new kernel.  This patch should reduce the need for
using irqpoll in that situation by a small amount.

Signed-off-by: Thomas Gleixner 
Tested-and-Acked-by: Uwe Kleine-König

[S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h

2008-04-17T05:47:05+00:00

> Generic code is not supposed to include irq.h. Replace this include
> by linux/hardirq.h instead and add/replace an include of linux/irq.h
> in asm header files where necessary.
> This change should only matter for architectures that make use of
> GENERIC_CLOCKEVENTS.
> Architectures in question are mips, x86, arm, sh, powerpc, uml and sparc64.
>
> I did some cross compile tests for mips, x86_64, arm, powerpc and sparc64.
> This patch fixes also build breakages caused by the include replacement in
> tick-common.h.

I generally dislike adding optional linux/* includes in asm/* includes -
I'm nervous about this causing include loops.

However, there's a separate point to be discussed here.

That is, what interfaces are expected of every architecture in the kernel.
If generic code wants to be able to set the affinity of interrupts, then
that needs to become part of the interfaces listed in linux/interrupt.h
rather than linux/irq.h.

So what I suggest is this approach instead (against Linus' tree of a
couple of days ago) - we move irq_set_affinity() and irq_can_set_affinity()
to linux/interrupt.h, change the linux/irq.h includes to linux/interrupt.h
and include asm/irq_regs.h where needed (asm/irq_regs.h is supposed to be
rarely used include since not much touches the stacked parent context
registers.)

Build tested on ARM PXA family kernels and ARM's Realview platform
kernels which both use genirq.

[ tglx@linutronix.de: add GENERIC_HARDIRQ dependencies ]

Signed-off-by: Russell King 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Heiko Carstens

Final removal of FASTCALL()/fastcall

2008-02-14T00:21:18+00:00

All users are gone, remove definitions and comments referring
to them.

Signed-off-by: Harvey Harrison 
Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

IRQ_NOPROBE helper functions

2008-02-08T17:22:42+00:00

Probing non-ISA interrupts using the handle_percpu_irq as their handle_irq
method may crash the system because handle_percpu_irq does not check
IRQ_WAITING.  This for example hits the MIPS Qemu configuration.

This patch provides two helper functions set_irq_noprobe and set_irq_probe to
set rsp.  clear the IRQ_NOPROBE flag.  The only current caller is MIPS code
but this really belongs into generic code.

As an aside, interrupt probing these days has become a mostly obsolete if not
dangerous art.  I think Linux interrupts should be changed to default to
non-probing but that's subject of this patch.

Signed-off-by: Ralf Baechle 
Acked-and-tested-by: Rob Landley 
Cc: Alan Cox 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove fastcall from linux/include

2008-02-08T17:22:31+00:00

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

genirq: add unlocked version of set_irq_handler()

2007-12-18T17:05:58+00:00

Add unlocked version for use by irq_chip.set_type handlers which may
wish to change handler to level or edge handler when IRQ type is
changed.

The normal set_irq_handler() call cannot be used because it tries to
take irq_desc.lock which is already held when the irq_chip.set_type
hook is called.

Signed-off-by: Kevin Hilman 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

irq.h fix kernel-doc

2007-07-31T22:39:41+00:00

Add kernel-doc entry in  for:

Warning(linux-2.6.22-git12//include/linux/irq.h:177): No description found for parameter 'last_unhandled'

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Improve behaviour of spurious IRQ detect

2007-07-16T16:05:46+00:00

Currently we handle spurious IRQ activity based upon seeing a lot of
invalid interrupts, and we clear things back on the base of lots of valid
interrupts.

Unfortunately in some cases you get legitimate invalid interrupts caused by
timing asynchronicity between the PCI bus and the APIC bus when disabling
interrupts and pulling other tricks.  In this case although the spurious
IRQs are not a problem our unhandled counters didn't clear and they act as
a slow running timebomb.  (This is effectively what the serial port/tty
problem that was fixed by clearing counters when registering a handler
showed up)

It's easy enough to add a second parameter - time.  This means that if we
see a regular stream of harmless spurious interrupts which are not harming
processing we don't go off and do something stupid like disable the IRQ
after a month of running.  OTOH lockups and performance killers show up a
lot more than 10/second

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Alan Cox 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Pad irq_desc to internode cacheline size

2007-05-08T18:15:09+00:00

We noticed a drop in n/w performance due to the irq_desc being cacheline
aligned rather than internode aligned.  We see 50% of expected performance
when two e1000 nics local to two different nodes have consecutive irq
descriptors allocated, due to false sharing.

Note that this patch does away with cacheline padding for the UP case, as
it does not seem useful for UP configurations.

Signed-off-by: Ravikiran Thirumalai 
Signed-off-by: Shai Fultheim 
Cc: "Siddha, Suresh B" 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds