Commit graph

13 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
David S. Miller
25848c4e50 [SCSI] esp: Fix build on SUN4.
Noted by Alexey Dobriyan.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-08-23 15:33:07 -07:00
David S. Miller
6bc063d414 [SCSI] esp: Fix build.
The data_cmd[] member got deleted, so do not use it any more.  Scsi
commands do not have their ->cmd[] overwritten temporary to probe for
status after an error before retrying.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-24 22:47:14 -07:00
Christoph Hellwig
79bd3f8563 [SCSI] More buffer->request_buffer changes
Seem like quite a few splipped through the cracks.  Here's a patch to
update all references I could find:

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-07-14 09:41:13 -05:00
Thomas Gleixner
1d6f359a2e [PATCH] irq-flags: scsi: 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: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:53 -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
David S. Miller
7bd5ed5dd4 [SCSI] esp: Fix bug in esp_remove_common.
Do not try to kfree(esp), scsi_host_put() takes care of that.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 23:16:13 -07:00
David S. Miller
411aa55405 [SCSI] sparc: Port esp to new SBUS driver layer.
This also turns the driver into a new-style scsi driver.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 23:15:54 -07:00
David S. Miller
c6387a48cf [SPARC]: Kill __irq_itoa().
This ugly hack was long overdue to die.

It was a way to print out Sparc interrupts in a more freindly format,
since IRQ numbers were arbitrary opaque 32-bit integers which vectored
into PIL levels.  These 32-bit integers were not necessarily in the
0-->NR_IRQS range, but the PILs they vectored to were.

The idea now is that we will increase NR_IRQS a little bit and use a
virtual<-->real IRQ number mapping scheme similar to PowerPC.

That makes this IRQ printing hack irrelevant, and furthermore only a
handful of drivers actually used __irq_itoa() making it even less
useful.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-20 01:21:29 -07:00
Christoph Hellwig
a6ceda7457 [SCSI] esp: fix eh locking
esp_reset didn't get fixed when the EH locking changed.
->eh_bus_reset_handler is now called without the host lock held.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-22 14:35:52 -08:00
Al Viro
0f73832fd8 [PATCH] drivers/scsi NULL noise removal
NULL noise in sbus scsi drivers got missed

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-26 07:43:42 -07:00
Tom 'spot' Callaway
10158286e7 [SPARC]: module version cleanups
Minor cleanups for sparc specific drivers (sunbmac, sunqe, sunlance,
sunhme, esp) so that they have a full module version definition that is
consistent with other upstream drivers.

Signed-off-by: Tom 'spot' Callaway <tcallawa@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-24 20:35:20 -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