forked from luck/tmp_suning_uos_patched
2cf8d82d63
local_t's were defined to be unsigned. This increases confusion because atomic_t's are signed. The patch goes through and changes all implementations to use signed longs throughout. Also, x86-64 was using 32-bit quantities for the value passed into local_add() and local_sub(). Fixed. All (actually, both) existing users have been audited. (Also s/__inline__/inline/ in x86_64/local.h) Cc: Andi Kleen <ak@muc.de> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Kyle McMartin <kyle@parisc-linux.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
64 lines
2.4 KiB
C
64 lines
2.4 KiB
C
#ifndef _ASM_GENERIC_LOCAL_H
|
|
#define _ASM_GENERIC_LOCAL_H
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/hardirq.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))
|
|
|
|
/* 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(v) local_read(&__get_cpu_var(v))
|
|
#define cpu_local_set(v, i) local_set(&__get_cpu_var(v), (i))
|
|
#define cpu_local_inc(v) local_inc(&__get_cpu_var(v))
|
|
#define cpu_local_dec(v) local_dec(&__get_cpu_var(v))
|
|
#define cpu_local_add(i, v) local_add((i), &__get_cpu_var(v))
|
|
#define cpu_local_sub(i, v) local_sub((i), &__get_cpu_var(v))
|
|
|
|
/* 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(v) __local_inc(&__get_cpu_var(v))
|
|
#define __cpu_local_dec(v) __local_dec(&__get_cpu_var(v))
|
|
#define __cpu_local_add(i, v) __local_add((i), &__get_cpu_var(v))
|
|
#define __cpu_local_sub(i, v) __local_sub((i), &__get_cpu_var(v))
|
|
|
|
#endif /* _ASM_GENERIC_LOCAL_H */
|