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)
By using milliseconds instead of jiffies to calculate acceleration
factor we make the code immune to changes in HZ.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
When emulating button toggle drivers need to send input_sync()
between 'down' and 'up' events, otherwise some users might miss
keypress because device's state is only considered finalized
after EV_SYN/SYN_REPORT is received.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
When HZ is set to 250 (new default) or 100, the time span during which
repeated events from the device are ignored could be too small due to
ms->jiffies rounding. This causes the auto repeat to kick in early making
it impossible for the user to generate individual press/release events.
Increate the timeout to compensate.
Signed-off-by: Marko Macek <Marko.Macek@gmx.net>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
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>
the patch below converts a bunch of semaphores-used-as-mutex in the USB
code to mutexes
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
They deal with wrapping correctly and are nicer to read.
Signed-off-by: Marcelo Feitoza Parisi <marcelo@feitoza.com.br>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
patch below marks various USB tables and variables as const so that they
end up in .rodata section and don't cacheline share with things that get
written to. For the non-array variables it also allows gcc to optimize
more.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
> On Sun, Apr 10, 2005 at 07:21:28PM +0600, Viktor A. Danilov wrote:
> >
> > PROBLEM: aiptek input doesn`t register `device` & `driver` section in sysfs (/sys/class/input/event#)
> > REASON: `dev` - field not filled...
> > SOLUTION: in linux/drivers/usb/input/aiptek.c write
> > aiptek->inputdev.dev = &intf->dev;
> > before calling
> > input_register_device(&aiptek->inputdev);
The following (tested) patch fixes the exact same issue with the ATI
Remote input driver.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
when stealing code from ati_remote for a GPL-driver of my usbradio (because of
its neat usb int transfers) I found out, that the inbuf is freed twice.
I don't have the ati-remote, so I don't know it is a problem at all, but it
looks strange to me anyway. Also I don't know if it has been fixed already in
newer kernel versions.
From: Patrick Boettcher <patrick.boettcher@desy.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
David Howells