Commit graph

17 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
Jens Axboe
cdd6026217 [PATCH] Remove ->rq_status from struct request
After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.

So kill/clean the remaining users, straight forward.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:23 +02:00
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
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
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
Alexey Dobriyan
ec33b5fe1a [PATCH] drivers/fc4/fc.c: memset correct length
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:11 -08:00
Adrian Bunk
0b57ee9e55 [SPARC]: introduce a SPARC Kconfig symbol
Introduce a Kconfig symbol SPARC that is defined on both the sparc and
sparc64 architectures.

This symbol makes some dependencies more readable.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-22 23:09:54 -08:00
Jesper Juhl
6044ec8882 [PATCH] kfree cleanup: misc remaining drivers
This is the remaining misc drivers/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in misc files in
drivers/.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
Acked-by: Roland Dreier <rolandd@cisco.com>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Acked-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Len Brown <len.brown@intel.com>
Acked-by: "Antonino A. Daplas" <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:54:05 -08:00
Deepak Saxena
49d0c6039d [PATCH] drivers/fc4: kmalloc + memset -> kzalloc conversion
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:59 -08:00
Andrew Morton
e572f7cc28 [SCSI] fc4 warning fix
drivers/fc4/fc.c: In function `fcp_scsi_dev_reset':
drivers/fc4/fc.c:933: warning: control reaches end of non-void function

Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-07-30 09:47:53 -05:00
Christoph Hellwig
fc2b035d38 [SCSI] ifdef out broken fc4 EH code
This code pokes deep into EH internals and duplicates scsi_error.c code
wrongly.  It doesn't compile anymore in scsi-misc, so let's #if 0 out
the code - the driver hasn't worked for more than five years anyway.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-07-02 19:12:10 -05:00
Jeff Garzik
98f72a1c51 fc4/fc: fix warnings and errors related to recent SCSI EH updates 2005-06-19 21:47:56 -04:00
Jeff Garzik
df0ae2497d [SCSI] allow sleeping in ->eh_host_reset_handler()
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-06-17 12:05:18 -05:00
Jeff Garzik
68b3aa7c98 [SCSI] allow sleeping in ->eh_bus_reset_handler()
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-06-17 12:05:10 -05:00
Jeff Garzik
e3df715501 [SCSI] Remove unnecessary locking around completion function calls
The SCSI ->done() hook should not be called from inside a spinlock.

Drivers that do this are mostly cut-n-paste from 2.2.x-era.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-06-17 12:04:37 -05:00
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