Commit Graph

15 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
Jon Smirl a8f340e394 [PATCH] vt: Remove VT-specific declarations and definitions from tty.h
MAX_NR_CONSOLES, fg_console, want_console and last_console are more of a
function of the VT layer than the TTY one.  Moving these to vt.h and vt_kern.h
allows all of the framebuffer and VT console drivers to remove their
dependency on tty.h.

[akpm@osdl.org: fix alpha build]
Signed-off-by: Jon Smirl <jonsmir@gmail.com>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:16 -07:00
Thomas Gleixner 63a43399db [PATCH] irq-flags: video: Use the new IRQF_ constants
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:53 -07:00
Arnaud Patard 6931a764e1 [PATCH] s3c2410fb: Fix resume
regs.lcdcon1 was not updated on suspend.  The result was a garbaged display on
resume.  This bug was first noticed by Christer Weinigel.  This patch is a
modified version of the one he sent to me.

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:31 -07:00
Herbert Poetzl ba09cf2bcf [ARM] remove duplicate #includes
Signed-off-by: Herbert P?tzl <herbert@13thfloor.at>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-15 10:13:02 +00:00
Arnaud Patard 740f14ba53 [PATCH] s3c2410fb: cleanup and fix
Here are some cleanups for the s3c2410fb drivers. It :
* Removes a buggy call to s3c2410fb_init_registers. There was two calls
  to this function but the first was done without all initialisations
  done. No oops but it may confuse some LCDs.
* Makes two functions static.

Signed-Off-By: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-Off-By: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:51 -08:00
Russell King f8ce25476d [ARM] Move asm/hardware/clock.h to linux/clk.h
This is needs to be visible to other architectures using the AMBA
bus and peripherals.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-07 16:15:52 +00:00
Russell King a8d3584a2d [ARM] Remove clk_use()/clk_unuse()
It seems that clk_use() and clk_unuse() are additional complexity
which isn't required anymore.  Remove them from the clock framework
to avoid the additional confusion which they cause, and update all
ARM machine types except for OMAP.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-03 18:41:37 +00:00
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
Ben Dooks 2726bff344 [PATCH] s3c2410fb: initialise device_driver .owner
Initialise the .owner field, so that if the driver is built as a module, the
system has a link to the owner

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:52 -08:00
Antonino A. Daplas c465e05a03 [PATCH] fbcon/fbdev: Move softcursor out of fbdev to fbcon
According to Jon Smirl, filling in the field fb_cursor with soft_cursor for
drivers that do not support hardware cursors is redundant.  The soft_cursor
function is usable by all drivers because it is just a wrapper around
fb_imageblit.  And because soft_cursor is an fbcon-specific hook, the file is
moved to the console directory.

Thus, drivers that do not support hardware cursors can leave the fb_cursor
field blank.  For drivers that do, they can fill up this field with their own
version.

The end result is a smaller code size.  And if the framebuffer console is not
loaded, module/kernel size is also reduced because the soft_cursor module will
also not be loaded.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:50 -08:00
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
Ben Dooks fe984bba30 [PATCH] s3c2410fb: Minor warning fix
The function s3c2410fb_activate_var does not return
a value, therefore it should be declared void.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-29 08:54:20 -07:00
Arnaud Patard 20fd576768 [PATCH] s3c2410fb: ARM S3C2410 framebuffer driver
This set of two patches add support for the framebuffer of the Samsung S3C2410
ARM SoC.  This driver was started about one year ago and is now used on iPAQ
h1930/h1940, Acer n30 and probably other s3c2410-based machines I'm not aware
of.  I've also heard yesterday that it's working also on iPAQ rx3715/rx3115
(s3c2440-based machines).

Signed-Off-By: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Ben Dooks <ben@trinity.fluff.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09 14:03:42 -07:00