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)
ucb1x00-ts: handle errors from input_register_device()
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Pavel Machek
From: Dirk Opfer <Dirk@Opfer-Online.de>
Fix ucb initialization on collie. Wrong frequency was used and that
led to things not working quite correctly. (I had to actually disable
checks in my tree to get it to boot). It now includes all the
neccessary parts to get it to compile :-).
Signed-off-by: Pavel Machek <pavel@suse.cz>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
While reviewing the IRQ autoprobing code i found the attached buglet.
probe_irq_on()/off() calls must always be in pairs, because the generic IRQ
code uses a global semaphore to serialize all autoprobing activites.
(which does make sense) The ARM code's probe_irq_*() implementation does
not do this, but if this driver is ever used on another platform, this bug
might bite.
(It probably does not trigger in practice, because a zero probing mask
returned should be rare - but still.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On architectures like i386, the "Multimedia Capabilities Port drivers" menu is
visible, but it can't be visited since it contains nothing usable for
!ARCH_SA1100.
This patch therefore shows this menu only on ARCH_SA1100.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
linux/delay.h included twice
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some ARM platforms have the ability to program the interrupt controller to
detect various interrupt edges and/or levels. For some platforms, this is
critical to setup correctly, particularly those which the setting is dependent
on the device.
Currently, ARM drivers do (eg) the following:
err = request_irq(irq, ...);
set_irq_type(irq, IRQT_RISING);
However, if the interrupt has previously been programmed to be level sensitive
(for whatever reason) then this will cause an interrupt storm.
Hence, if we combine set_irq_type() with request_irq(), we can then safely set
the type prior to unmasking the interrupt. The unfortunate problem is that in
order to support this, these flags need to be visible outside of the ARM
architecture - drivers such as smc91x need these flags and they're
cross-architecture.
Finally, the SA_TRIGGER_* flag passed to request_irq() should reflect the
property that the device would like. The IRQ controller code should do its
best to select the most appropriate supported mode.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The bd62266319 commit broke the UCB1x00
touchscreen driver since the idev structure was assumed to be into the ts
structure, simply casting the former to the later in a couple places.
This patch fixes those, and also cache the idev pointer between multiple
calls to input_report_abs() to avoid growing the compiled code needlessly.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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>
Fix more include file problems that surfaced since I submitted the previous
fix-missing-includes.patch. This should now allow not to include sched.h
from module.h, which is done by a followup patch.
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds support for sharp zaurus sl-5500 touchscreen. It introduces
some not-too-nice ifs, but I guess copying whole ucb1x00-ts.c would be
bad idea...
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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>
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>
Patch from Nicolas Pitre
drivers/mfd/ucb1x00-core.c: In function 'ucb1x00_probe':
drivers/mfd/ucb1x00-core.c:482: error: 'ucb1x00_class' undeclared (first use in this function)
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
drivers/mfd/ucb1x00-core.c:555: error: static declaration of 'ucb1x00_class' follows non-static declaration
drivers/mfd/ucb1x00.h:109: error: previous declaration of 'ucb1x00_class' was here
Since ucb1x00_class isn't used by anything, remove the extern
declaration and the symbol export.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
These are small ucb1x00-ts cleanups, as suggested by Vojtech, Dmitri
and the lists.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add the core device support code for the Philips UCB1200 and
UCB1300 devices. Also includes the following from Pavel:
This fixes u32 vs. pm_message_t confusion and uses cleaner
try_to_freeze() [fixing compilation as a side-effect on newer
kernels.]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add platform device data for the SA11x0 MCP device. This allows
platforms to customise the configuration of the SA11x0 MCP device
according to their needs.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add support for the core of the multimedia communication port
framework. This is a port used to communicate with devices
with two DMA paths and a control path.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
