linux-toradex.git/drivers/acorn, branch v2.6.19.2

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

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 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

fix file specification in comments

2006-10-03T21:01:26+00:00

Many files include the filename at the beginning, serveral used a wrong one.

Signed-off-by: Uwe Zeisberger 
Signed-off-by: Adrian Bunk

i2c-algo-bit: Discard the mdelay data struct member

2006-09-26T22:38:51+00:00

i2c-algo-bit: Discard the mdelay data struct member

The i2c_algo_bit_data structure has an mdelay member, which is not
used by the algorithm code (the code has always been ifdef'd out.)
Let's discard it to save some code and memory.

Signed-off-by: Jean Delvare 
Acked-by: Mauro Carvalho Chehab 
Cc: Adrian Bunk 
Signed-off-by: Greg Kroah-Hartman

[PATCH] irq-flags: misc drivers: Use the new IRQF_ constants

2006-07-02T20:58:50+00:00

Signed-off-by: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial

2006-06-30T22:39:30+00:00

* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
  Remove obsolete #include 
  remove obsolete swsusp_encrypt
  arch/arm26/Kconfig typos
  Documentation/IPMI typos
  Kconfig: Typos in net/sched/Kconfig
  v9fs: do not include linux/version.h
  Documentation/DocBook/mtdnand.tmpl: typo fixes
  typo fixes: specfic -> specific
  typo fixes in Documentation/networking/pktgen.txt
  typo fixes: occuring -> occurring
  typo fixes: infomation -> information
  typo fixes: disadvantadge -> disadvantage
  typo fixes: aquire -> acquire
  typo fixes: mecanism -> mechanism
  typo fixes: bandwith -> bandwidth
  fix a typo in the RTC_CLASS help text
  smb is no longer maintained

Manually merged trivial conflict in arch/um/kernel/vmlinux.lds.S

[PATCH] show Acorn-specific block devices menu only when required

2006-06-30T18:25:38+00:00

Don't show a menu that can't be entered due to lack of contents on arm (the
options are only available on arm26).

Signed-off-by: Adrian Bunk 
Acked-by: Ian Molton 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk

[PATCH] move capable() to capability.h

2006-01-12T02:42:13+00:00

- Move capable() from sched.h to capability.h;

- Use  where capable() is used
	(in include/, block/, ipc/, kernel/, a few drivers/,
	mm/, security/, & sound/;
	many more drivers/ to go)

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Add block_device_operations.getgeo block device method

2006-01-09T04:13:54+00:00

HDIO_GETGEO is implemented in most block drivers, and all of them have to
duplicate the code to copy the structure to userspace, as well as getting
the start sector.  This patch moves that to common code [1] and adds a
->getgeo method to fill out the raw kernel hd_geometry structure.  For many
drivers this means ->ioctl can go away now.

[1] the s390 block drivers are odd in this respect.  xpram sets ->start
    to 4 always which seems more than odd, and the dasd driver shifts
    the start offset around, probably because of it's non-standard
    sector size.

Signed-off-by: Christoph Hellwig 
Cc: Jens Axboe 
Cc: 
Cc: Jeff Dike 
Cc: Paolo Giarrusso 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Neil Brown 
Cc: Markus Lidel 
Cc: Russell King 
Cc: David Woodhouse 
Cc: Martin Schwidefsky 
Cc: James Bottomley 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] I2C: Remove .owner setting from i2c_driver as it's no longer needed

2006-01-06T06:16:25+00:00

Now that i2c_add_driver() doesn't need the module owner to be set by
hand, we can delete it from the drivers.  This patch catches all of the
drivers that I found in the current tree (if a driver sets the .owner by
hand, it's not a problem, just not needed.)

Signed-off-by: Greg Kroah-Hartman 
Cc: Jean Delvare