linux.git/kernel/irq/handle.c, branch v2.6.19

Don't call "note_interrupt()" with irq descriptor lock held

2006-11-22T17:32:06+00:00

This reverts commit f72fa707604c015a6625e80f269506032d5430dc, and solves
the problem that it tried to fix by simply making "__do_IRQ()" call the
note_interrupt() function without the lock held, the way everybody else
does.

It should be noted that all interrupt handling code must never allow the
descriptor actors to be entered "recursively" (that's why we do all the
magic IRQ_PENDING stuff in the first place), so there actually is
exclusion at that much higher level, even in the absense of locking.

Acked-by: Vivek Goyal 
Acked-by:Pavel Emelianov 
Cc: Andrew Morton 
Cc: Ingo Molnar 
Cc: Adrian Bunk 
Signed-off-by: Linus Torvalds

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

[PATCH] FRV: permit __do_IRQ() to be dispensed with

2006-09-26T15:48:53+00:00

Permit __do_IRQ() to be dispensed with based on a configuration option.

Signed-off-by: David Howells 
Cc: Benjamin Herrenschmidt 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kerneldoc for handle_bad_irq()

2006-09-01T18:39:09+00:00

Adds the description of the parameters from handle_bad_irq().

Signed-off-by: Henrik Kretzschmar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] lockdep: annotate enable_in_hardirq()

2006-07-03T22:27:09+00:00

Make use of local_irq_enable_in_hardirq() API to annotate places that enable
hardirqs in hardirq context.

Has no effect on non-lockdep kernels.

Signed-off-by: Ingo Molnar 
Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] lockdep: annotate genirq

2006-07-03T22:27:06+00:00

Teach special (recursive) locking code to the lock validator.  Has no effect
on non-lockdep kernels.

Signed-off-by: Ingo Molnar 
Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: ARM dyntick cleanup

2006-07-03T00:29:21+00:00

Linus: "The hacks in kernel/irq/handle.c are really horrid. REALLY
horrid."

They are indeed. Move the dyntick quirks to ARM where they belong.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Linus Torvalds

Merge branch 'genirq' of master.kernel.org:/home/rmk/linux-2.6-arm

2006-07-02T22:07:45+00:00

* 'genirq' of master.kernel.org:/home/rmk/linux-2.6-arm: (24 commits)
  [ARM] 3683/2:  ARM: Convert at91rm9200 to generic irq handling
  [ARM] 3682/2:  ARM: Convert ixp4xx to generic irq handling
  [ARM] 3702/1: ARM: Convert ixp23xx to generic irq handling
  [ARM] 3701/1: ARM: Convert plat-omap to generic irq handling
  [ARM] 3700/1: ARM: Convert lh7a40x to generic irq handling
  [ARM] 3699/1: ARM: Convert s3c2410 to generic irq handling
  [ARM] 3698/1: ARM: Convert sa1100 to generic irq handling
  [ARM] 3697/1: ARM: Convert shark to generic irq handling
  [ARM] 3696/1: ARM: Convert clps711x to generic irq handling
  [ARM] 3694/1: ARM: Convert ecard driver to generic irq handling
  [ARM] 3693/1: ARM: Convert omap1 to generic irq handling
  [ARM] 3691/1: ARM: Convert imx to generic irq handling
  [ARM] 3688/1: ARM: Convert clps7500 to generic irq handling
  [ARM] 3687/1: ARM: Convert integrator to generic irq handling
  [ARM] 3685/1: ARM: Convert pxa to generic irq handling
  [ARM] 3684/1: ARM: Convert l7200 to generic irq handling
  [ARM] 3681/1: ARM: Convert ixp2000 to generic irq handling
  [ARM] 3680/1: ARM: Convert footbridge to generic irq handling
  [ARM] 3695/1: ARM drivers/pcmcia: Fixup includes
  [ARM] 3689/1: ARM drivers/input/touchscreen: Fixup includes
  ...

Manual conflict resolved in kernel/irq/handle.c (butt-ugly ARM tickless
code).

[PATCH] irq-flags: generic irq: Use the new IRQF_ constants

2006-07-02T20:58:49+00:00

Signed-off-by: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[ARM] 3690/1: genirq: Introduce and make use of dummy irq chip

2006-07-01T21:30:08+00:00

Patch from Thomas Gleixner

From: Thomas Gleixner 

ARM has a couple of really dumb interrupt controllers.
Implement a generic one and fixup the ARM migration. ARM reused
the no_irq_chip for this purpose, but this does not work out
for platforms which are not converted to the new interrupt
type handling model.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Signed-off-by: Russell King