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)
appletouch uses urb->transfer_dma after having freed the urb, this shows
up only if the system is compiled with slab debugging. This patch fixes
it by reordering the free calls.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move <linux/usb_input.h> to <linux/usb/input.h> and remove some
redundant includes.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for MacBook touchpad in appletouch driver.
Thanks to Alex Harper for the informations.
Use u16 instead of int16_t in atp_is_geyser* functions.
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Nicolas Boichat <nicolas@boichat.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds support for the Geyser 2 touchpads used on post Oct 2005
Apple PowerBooks to the appletouch driver.
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Rene Nussbaumer <linux-kernel@killerfox.forkbomb.ch>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This is a driver for the USB touchpad which can be found on post-February 2005
Apple PowerBooks.
This driver is derived from Johannes Berg's appletrackpad driver [1],
but it has been improved in some areas:
* appletouch is a full kernel driver, no userspace program is necessary
* appletouch can be interfaced with the synaptics X11 driver[2], in order
to have touchpad acceleration, scrolling, two/three finger tap, etc.
This driver has been tested by the readers of the 'debian-powerpc' mailing
list for a few weeks now and I believe it is now ready for inclusion into the
mainline kernel.
Credits go to Johannes Berg for reverse-engineering the touchpad protocol,
Frank Arnold for further improvements, and Alex Harper for some additional
information about the inner workings of the touchpad sensors.
Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
David Howells