linux.git/drivers/char/mbcs.c, branch v2.6.30

mbcs: cdev lock_kernel() pushdown

2008-06-20T20:05:48+00:00

This driver would appear to have no internal locking at all.

Signed-off-by: Jonathan Corbet

MBCS: convert dmareadlock to mutex

2008-02-07T16:42:25+00:00

MBCS: Convert the semaphore dmareadlock to the mutex API

Signed-off-by: Matthias Kaehlcke 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MBCS: convert dmawritelock to mutex

2008-02-07T16:42:25+00:00

MBCS: Convert the semaphore dmawritelock to the mutex API

Signed-off-by: Matthias Kaehlcke 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MBCS: convert algolock to mutex

2008-02-07T16:42:25+00:00

MBCS: Convert the semaphore algolock to the mutex API

Signed-off-by: Matthias Kaehlcke 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Clean up duplicate includes in drivers/char/

2007-10-17T15:42:48+00:00

This patch cleans up duplicate includes in
	drivers/char/

Signed-off-by: Jesper Juhl 
Cc: Richard Purdie 
Cc: Ralf Baechle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mbcs: Remove lots of global symbols

2007-07-19T17:04:43+00:00

MBCS has a collection of things that searches say are not used elsewhere
and could be static.  If this is the case they should be static, if not
then someone at SGI should rename things like "soft_list" so they don't
pollute the global namespace with generic names...

Signed-off-by: Alan Cox 
Acked-by: Bruce Losure 
Cc: Jes Sorensen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

unregister_chrdev(): ignore the return value

2007-07-19T17:04:43+00:00

unregister_chrdev() always returns 0.  There is no need to check the return
value.

Signed-off-by: Akinobu Mita 
Cc: "David S. Miller" 
Cc: Takashi Iwai 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] mark struct file_operations const 3

2007-02-12T17:48:45+00:00

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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)

[PATCH] MBCS: Use SEEK_{SET, CUR, END} instead of hardcoded values

2006-10-01T07:39:21+00:00

MBCS: Use SEEK_{SET,CUR,END} instead of hardcoded values

Signed-off-by: Josef 'Jeff' Sipek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds