linux/include/asm-generic/local.h
Russell King ba84be2338 remove linux/hardirq.h from asm-generic/local.h
While looking at reducing the amount of architecture namespace pollution
in the generic kernel, I found that asm/irq.h is included in the vast
majority of compilations on ARM (around 650 files.)

Since asm/irq.h includes a sub-architecture include file on ARM, this
causes a negative impact on the ccache's ability to re-use the build
results from other sub-architectures, so we have a desire to reduce the
dependencies on asm/irq.h.

It turns out that a major cause of this is the needless include of
linux/hardirq.h into asm-generic/local.h.  The patch below removes this
include, resulting in some 250 to 300 files (around half) of the kernel
then omitting asm/irq.h.

My test builds still succeed, provided two ARM files are fixed
(arch/arm/kernel/traps.c and arch/arm/mm/fault.c) - so there may be
negative impacts for this on other architectures.

Note that x86 does not include asm/irq.h nor linux/hardirq.h in its
asm/local.h, so this patch can be viewed as bringing the generic version
into line with the x86 version.

[kosaki.motohiro@jp.fujitsu.com: add #include <linux/irqflags.h> to acpi/processor_idle.c]
[adobriyan@gmail.com: fix sparc64]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:13 -08:00

75 lines
3.1 KiB
C

#ifndef _ASM_GENERIC_LOCAL_H
#define _ASM_GENERIC_LOCAL_H
#include <linux/percpu.h>
#include <asm/atomic.h>
#include <asm/types.h>
/*
* A signed long type for operations which are atomic for a single CPU.
* Usually used in combination with per-cpu variables.
*
* This is the default implementation, which uses atomic_long_t. Which is
* rather pointless. The whole point behind local_t is that some processors
* can perform atomic adds and subtracts in a manner which is atomic wrt IRQs
* running on this CPU. local_t allows exploitation of such capabilities.
*/
/* Implement in terms of atomics. */
/* Don't use typedef: don't want them to be mixed with atomic_t's. */
typedef struct
{
atomic_long_t a;
} local_t;
#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }
#define local_read(l) atomic_long_read(&(l)->a)
#define local_set(l,i) atomic_long_set((&(l)->a),(i))
#define local_inc(l) atomic_long_inc(&(l)->a)
#define local_dec(l) atomic_long_dec(&(l)->a)
#define local_add(i,l) atomic_long_add((i),(&(l)->a))
#define local_sub(i,l) atomic_long_sub((i),(&(l)->a))
#define local_sub_and_test(i, l) atomic_long_sub_and_test((i), (&(l)->a))
#define local_dec_and_test(l) atomic_long_dec_and_test(&(l)->a)
#define local_inc_and_test(l) atomic_long_inc_and_test(&(l)->a)
#define local_add_negative(i, l) atomic_long_add_negative((i), (&(l)->a))
#define local_add_return(i, l) atomic_long_add_return((i), (&(l)->a))
#define local_sub_return(i, l) atomic_long_sub_return((i), (&(l)->a))
#define local_inc_return(l) atomic_long_inc_return(&(l)->a)
#define local_cmpxchg(l, o, n) atomic_long_cmpxchg((&(l)->a), (o), (n))
#define local_xchg(l, n) atomic_long_xchg((&(l)->a), (n))
#define local_add_unless(l, a, u) atomic_long_add_unless((&(l)->a), (a), (u))
#define local_inc_not_zero(l) atomic_long_inc_not_zero(&(l)->a)
/* Non-atomic variants, ie. preemption disabled and won't be touched
* in interrupt, etc. Some archs can optimize this case well. */
#define __local_inc(l) local_set((l), local_read(l) + 1)
#define __local_dec(l) local_set((l), local_read(l) - 1)
#define __local_add(i,l) local_set((l), local_read(l) + (i))
#define __local_sub(i,l) local_set((l), local_read(l) - (i))
/* Use these for per-cpu local_t variables: on some archs they are
* much more efficient than these naive implementations. Note they take
* a variable (eg. mystruct.foo), not an address.
*/
#define cpu_local_read(l) local_read(&__get_cpu_var(l))
#define cpu_local_set(l, i) local_set(&__get_cpu_var(l), (i))
#define cpu_local_inc(l) local_inc(&__get_cpu_var(l))
#define cpu_local_dec(l) local_dec(&__get_cpu_var(l))
#define cpu_local_add(i, l) local_add((i), &__get_cpu_var(l))
#define cpu_local_sub(i, l) local_sub((i), &__get_cpu_var(l))
/* Non-atomic increments, ie. preemption disabled and won't be touched
* in interrupt, etc. Some archs can optimize this case well.
*/
#define __cpu_local_inc(l) __local_inc(&__get_cpu_var(l))
#define __cpu_local_dec(l) __local_dec(&__get_cpu_var(l))
#define __cpu_local_add(i, l) __local_add((i), &__get_cpu_var(l))
#define __cpu_local_sub(i, l) __local_sub((i), &__get_cpu_var(l))
#endif /* _ASM_GENERIC_LOCAL_H */