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)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (35 commits)
Input: wistron - add support for Acer TravelMate 2424NWXCi
Input: wistron - fix setting up special buttons
Input: add KEY_BLUETOOTH and KEY_WLAN definitions
Input: add new BUS_VIRTUAL bus type
Input: add driver for stowaway serial keyboards
Input: make input_register_handler() return error codes
Input: remove cruft that was needed for transition to sysfs
Input: fix input module refcounting
Input: constify input core
Input: libps2 - rearrange exports
Input: atkbd - support Microsoft Natural Elite Pro keyboards
Input: i8042 - disable MUX mode on Toshiba Equium A110
Input: i8042 - get rid of polling timer
Input: send key up events at disconnect
Input: constify psmouse driver
Input: i8042 - add Amoi to the MUX blacklist
Input: logips2pp - add sugnature 56 (Cordless MouseMan Wheel), cleanup
Input: add driver for Touchwin serial touchscreens
Input: add driver for Touchright serial touchscreens
Input: add driver for Penmount serial touchscreens
...
Add support for stowaway and stowaway compatible (eg. dicota inutPDA)
serial keyboards. Reported to work on palm zire71 and palm tungsten T3.
Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Microsoft Natural Elite Pro keyboard produces unisual response to
the GET ID command - single byte 0xaa (normally keyboards produce
2-byte response). Fail GET ID command so atkbd gets a change to
do alternate probe.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This was introduced in commit 3d0f0fa0cb:
bounds checking is performed against period[32] while indexing delay[4].
Spotted by Coverity, CID 1376.
Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Make atkbd report HANGEUL/HANJA keys by default and use correct scan
codes for these keys (they were swapped). Also make sure their scancodes
reported as EV_MSC/MSC_SCAN events.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Dump the extra mapping in the amikbd interrupt handler, so old Amiga keymaps
work again. Amigas need a special keymap anyway, standard keymaps are not
usable and recreating all keymaps is simply not worth the trouble.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the numbered SW_* entries from the input system and assign names
to the existing users.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
On Thu, Mar 30, 2006 at 08:31:02AM -0500, Dmitry Torokhov wrote:
> Don't do that, its double free. input_unregister_device() normally
> causes release() to be called and free the device. input_free_device
> is only to be called when input_register_device has not been called or
> failed.
>
> Plus you might want to unregister device after closing serio port,
> otherwise your interrupt routine might be referencing already freed
> memory.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Geert Uytterhoeven
Matthew Wilcox
David Howells
Matt LaPlante
Linus Torvalds
Komal Shah
Marek Vasut
Dmitry Torokhov
Florin Malita
Thomas Gleixner
Jörn Engel
Dmitry Torokhov
Jerome Pinot
Roman Zippel
Richard Purdie
Matthew Wilcox
Kyle McMartin
Helge Deller