Commit Graph

10 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
Rolf Eike Beer
d6bd3a39f7 [PATCH] Move valid_dma_direction() from x86_64 to generic code
As suggested by Muli Ben-Yehuda this function is moved to generic code as
may be useful for all archs.

[akpm@osdl.org: fix]
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:10 -07:00
Jeff Garzik
7282d491ec drivers/net: const-ify ethtool_ops declarations
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-13 14:30:00 -04:00
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
Rusty Russell
8d3b33f67f [PATCH] Remove MODULE_PARM
MODULE_PARM was actually breaking: recent gcc version optimize them out as
unused.  It's time to replace the last users, which are generally in the
most unloved drivers anyway.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:52 -08:00
John W. Linville
a7a461b32f [PATCH] fec_8xx: make CONFIG_FEC_8XX depend on CONFIG_8xx
Change CONFIG_FEC_8XX to depend on CONFIG_8xx instead of CONFIG_FEC.
CONFIG_FEC depends on ColdFire CPUs, which does not apply for the
PPC 8xx processors.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
2005-11-18 13:51:34 -05:00
Jeff Garzik
ecf8b596cf [netdrvr] fac_8xx build fix 2005-11-05 23:40:16 -05:00
Pantelis Antoniou
23da0c20ef [PATCH] fec_8xx: Add support for Intel PHY LX971
The following patch add support for the Intel LX971 PHY.

Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
2005-10-29 18:20:30 -04:00
Pantelis Antoniou
b90bd04d41 [PATCH] fec_8xx: Remove dependency on NETTA & NETPHONE
The following patch removes the dependency of the fec_8xx driver on
the NETTA & NETPHONE boards. Other people use the driver too, and
we await their board support patches.

Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
2005-10-29 18:20:30 -04:00
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