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
Andrew de Quincey
6ba475042f V4L/DVB (4296): Remove stradis MODULE_DEVICE_INFO definition
To prevent autoloading of the driver, as it then conflicts with every other
saa7146 device in existence.

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-07-29 17:22:14 -03:00
Thomas Gleixner
8076fe32a7 [PATCH] irq-flags: media: 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: Mauro Carvalho Chehab <mchehab@infradead.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
Adrian Bunk
b9553d7b0c V4L/DVB (4260): Stradis.c: make 2 functions static
This patch makes two needlessly global functions static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-06-27 00:17:41 -03:00
Mauro Carvalho Chehab
5e87efa3b2 V4L/DVB (4068): Removed all references to kernel stuff from videodev.h and videodev2.h
The videodev.h and videodev2.h describe the public API for V4L and V4L2.
It shouldn't have there any kernel-specific stuff. Those were moved to
v4l2-dev.h.
This patch removes some uneeded headers and include v4l2-common.h on all
V4L driver. This header includes device implementation of V4L2 API provided
on v4l2-dev.h as well as V4L2 internal ioctls that provides connections
between master driver and its i2c devices.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-06-25 02:05:05 -03:00
Mauro Carvalho Chehab
d56410e0a5 V4L/DVB (3599b): Whitespace cleanups under drivers/media
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-03-25 09:29:23 -03:00
Jiri Slaby
805f123d50 V4L/DVB (3439a): media video stradis memory fix
memset clears once set structure, there is actually no need for memset,
because configure function do it for us.  Next, vfree(NULL) is legal, so
avoid useless labels.

Thanks Dave Jones for reporting this.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-01-26 04:41:32 -02:00
Jiri Slaby
f823f67936 V4L/DVB (3344e): Stradis Lindent
Stradis Lindent + some handwork

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-01-11 19:41:32 -02:00
Jiri Slaby
91fb8357c3 V4L/DVB (3344d): Stradis video little cleanup
Unused function removed.
Used container_of instead of for loop.  
Some small changes

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-01-11 19:41:21 -02:00
Jiri Slaby
9ae82293ff V4L/DVB (3344c): Pci probing for stradis driver
- Pci probing functions added, some functions were rewritten.

- Use PCI_DEVICE macro.

- dev_ used for printing when pci_dev available.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-01-11 19:41:13 -02:00
Arnd Bergmann
0d0fbf8152 V4L (926_2): Moves compat32 functions from fs to v4l subsystem
This moves the 32 bit ioctl compatibility handlers for
Video4Linux into a new file and adds explicit calls to them
to each v4l device driver.

Unfortunately, there does not seem to be any code handling
the v4l2 ioctls, so quite often the code goes through two
separate conversions, first from 32 bit v4l to 64 bit v4l,
and from there to 64 bit v4l2. My patch does not change
that, so there is still much room for improvement.

Also, some drivers have additional ioctl numbers, for
which the conversion should be handled internally to
that driver.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
2006-01-09 15:24:57 -02:00
Jesper Juhl
f9101210e7 [PATCH] vfree and kfree cleanup in drivers/
This patch does a full cleanup of 'NULL checks before vfree', and a partial
cleanup of calls to kfree for all of drivers/ - the kfree bit is partial in
that I only did the files that also had vfree calls in them.  The patch
also gets rid of some redundant (void *) casts of pointers being passed to
[vk]free, and a some tiny whitespace corrections also crept in.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 10:06:30 -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