Commit Graph

12 Commits

Author SHA1 Message Date
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
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 <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Ingo Molnar 12aa757905 [ALSA] semaphore -> mutex (Archs, misc buses)
Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-03-22 10:25:43 +01:00
Nicolas Pitre ea265c0a43 [ALSA] make the pxa2xx-ac97 module more robust against PXA27x bugs
Modules: ARM PXA2XX driver

The SDONE and CDONE interrupt on the PXA27x might become unusable in
some conditions.  Let's use an hybrid approach (interrupt with timeout)
to have the best possible behavior in all conditions.

Also let's not care about CAR_CAIP anymore.  This is useless.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-01-03 12:30:51 +01:00
Takashi Iwai 792a6c5187 [ALSA] Fix PM support
Modules: ARM AACI PL041 driver,ARM PXA2XX driver

Fix PM support of aaci and pxa2xx drivers.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-01-03 12:28:46 +01:00
Takashi Iwai d18f83764e [ALSA] Remove xxx_t typedefs: ARM PXA2xx
Modules: ARM PXA2XX driver

Remove xxx_t typedefs from the ARM PXA2xx driver.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-01-03 12:20:03 +01:00
Russell King 3ae5eaec1d [DRIVER MODEL] Convert platform drivers to use struct platform_driver
This allows us to eliminate the casts in the drivers, and eventually
remove the use of the device_driver function pointer methods for
platform device drivers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-09 22:32:44 +00:00
Russell King d052d1beff Create platform_device.h to contain all the platform device details.
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-29 19:07:23 +01:00
Russell King 9480e307cd [PATCH] DRIVER MODEL: Get rid of the obsolete tri-level suspend/resume callbacks
In PM v1, all devices were called at SUSPEND_DISABLE level.  Then
all devices were called at SUSPEND_SAVE_STATE level, and finally
SUSPEND_POWER_DOWN level.  However, with PM v2, to maintain
compatibility for platform devices, I arranged for the PM v2
suspend/resume callbacks to call the old PM v1 suspend/resume
callbacks three times with each level in order so that existing
drivers continued to work.

Since this is obsolete infrastructure which is no longer necessary,
we can remove it.  Here's an (untested) patch to do exactly that.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28 09:52:56 -07:00
Dirk Opfer 1dcee12591 [ALSA] Fix pm_message_t in PXA2XX-AC97 driver
ARM PXA2XX driver
Fix pm_message_t in PXA2XX-AC97 driver.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-10-07 14:45:32 +02:00
Dirk Opfer a55bfdc582 [ALSA] Fix compiler warnings in PXA2XX-AC97
ARM PXA2XX driver
-  change pxa2xx_ac97_do_suspend and pxa2xx_ac97_do_resume to use
   the expected arguments

Signed-off-by: Dirk Opfer <dirk@do13.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-08-30 08:44:29 +02:00
Liam Girdwood 4a677ac5d0 [ALSA] PXA27x AC97 warm reset
ARM PXA2XX driver
This patch extends the period of an AC97 warm reset on the PXA27x from
50uS to 500uS. The shorter reset didn't always guarantee that the codec
would wake up.

Changes:-

  o Change pxa27x warm reset period to 500uS
  o Removed double semi-colon.

Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-08-30 08:44:10 +02:00
Takashi Iwai 2c484df0d2 [ALSA] Add ARM PXA2xx AC97 driver
Documentation,ARM,/arm/Makefile,ARM PXA2XX driver
Added ARM PXA2xx AC97 driver by Nicolas Pitre
(moved from alsa-driver tree).

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-07-28 12:21:20 +02:00