Commit Graph

16 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
Jeff Dike b68e31d0eb [PATCH] const struct tty_operations
As part of an SMP cleanliness pass over UML, I consted a bunch of
structures in order to not have to document their locking.  One of these
structures was a struct tty_operations.  In order to const it in UML
without introducing compiler complaints, the declaration of
tty_set_operations needs to be changed, and then all of its callers need to
be fixed.

This patch declares all struct tty_operations in the tree as const.  In all
cases, they are static and used only as input to tty_set_operations.  As an
extra check, I ran an i386 allyesconfig build which produced no extra
warnings.

53 drivers are affected.  I checked the history of a bunch of them, and in
most cases, there have been only a handful of maintenance changes in the
last six months.  serial_core.c was the busiest one that I looked at.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:14 -07:00
Thomas Gleixner dace145374 [PATCH] irq-flags: misc drivers: 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>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:50 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Greg Kroah-Hartman 331b831983 [PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEV
I've always found this flag confusing.  Now that devfs is no longer around, it
has been renamed, and the documentation for when this flag should be used has
been updated.

Also fixes all drivers that use this flag.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:09 -07:00
Greg Kroah-Hartman f4eaa37017 [PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer needed
Also fixes all drivers that set this field.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:09 -07:00
Adrian Bunk 41c28ff163 [PATCH] kill _INLINE_
This patch removes all occurances of _INLINE_ in the kernel.

With the exception of tty_flip.h, I've simply removed the inline's since
gcc should know best which functions to be inlined.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 07:38:16 -08:00
Al Viro 1b8623545b [PATCH] remove bogus asm/bug.h includes.
A bunch of asm/bug.h includes are both not needed (since it will get
pulled anyway) and bogus (since they are done too early).  Removed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-07 20:56:35 -05:00
Maciej W. Rozycki 0905780aae [MIPS] zs.c: Resurrect the deceased zs.c for now.
Not that it's meant to be sustained for long, but from time to time it's
useful to have some console...

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-11-17 16:23:39 +00:00
Ralf Baechle 2862279597 Add .gitignore files for Turbochannel 2005-11-07 18:05:37 +00:00
Maciej W. Rozycki a5fc9c0bbe Use physical addresses at the interface level, letting drivers remap
them as appropriate.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:35 +01:00
Maciej W. Rozycki 2e2849670a Remove left-over unused bits.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:27 +01:00
Maciej W. Rozycki 778220f7c4 Fix function types to ones appropriate for initcalls.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:24 +01:00
Maciej W. Rozycki 3bd4c902da Deal with the bloody KSEG vs CKSEG horror...
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:31:23 +01:00
Peter Osterlund fb911ee849 [PATCH] Remove unnecessary check_region references in comments
Remove check_region references from comments and printk statements so that
searching for real users of this deprecated function gets easier.

Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-13 08:22:29 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
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!
2005-04-16 15:20:36 -07:00