forked from Minki/linux
d3cb487149
Several counters already have the need to use 64 atomic variables on 64 bit platforms (see mm_counter_t in sched.h). We have to do ugly ifdefs to fall back to 32 bit atomic on 32 bit platforms. The VM statistics patch that I am working on will also make more extensive use of atomic64. This patch introduces a new type atomic_long_t by providing definitions in asm-generic/atomic.h that works similar to the c "long" type. Its 32 bits on 32 bit platforms and 64 bits on 64 bit platforms. Also cleans up the determination of the mm_counter_t in sched.h. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
145 lines
3.0 KiB
C
145 lines
3.0 KiB
C
#ifndef __ASM_SH_ATOMIC_H
|
|
#define __ASM_SH_ATOMIC_H
|
|
|
|
/*
|
|
* Atomic operations that C can't guarantee us. Useful for
|
|
* resource counting etc..
|
|
*
|
|
*/
|
|
|
|
typedef struct { volatile int counter; } atomic_t;
|
|
|
|
#define ATOMIC_INIT(i) ( (atomic_t) { (i) } )
|
|
|
|
#define atomic_read(v) ((v)->counter)
|
|
#define atomic_set(v,i) ((v)->counter = (i))
|
|
|
|
#include <asm/system.h>
|
|
|
|
/*
|
|
* To get proper branch prediction for the main line, we must branch
|
|
* forward to code at the end of this object's .text section, then
|
|
* branch back to restart the operation.
|
|
*/
|
|
|
|
static __inline__ void atomic_add(int i, atomic_t * v)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
*(long *)v += i;
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static __inline__ void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
*(long *)v -= i;
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static __inline__ int atomic_add_return(int i, atomic_t * v)
|
|
{
|
|
unsigned long temp, flags;
|
|
|
|
local_irq_save(flags);
|
|
temp = *(long *)v;
|
|
temp += i;
|
|
*(long *)v = temp;
|
|
local_irq_restore(flags);
|
|
|
|
return temp;
|
|
}
|
|
|
|
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
|
|
|
|
static __inline__ int atomic_sub_return(int i, atomic_t * v)
|
|
{
|
|
unsigned long temp, flags;
|
|
|
|
local_irq_save(flags);
|
|
temp = *(long *)v;
|
|
temp -= i;
|
|
*(long *)v = temp;
|
|
local_irq_restore(flags);
|
|
|
|
return temp;
|
|
}
|
|
|
|
#define atomic_dec_return(v) atomic_sub_return(1,(v))
|
|
#define atomic_inc_return(v) atomic_add_return(1,(v))
|
|
|
|
/*
|
|
* atomic_inc_and_test - increment and test
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
|
|
|
|
#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
|
|
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
|
|
|
|
#define atomic_inc(v) atomic_add(1,(v))
|
|
#define atomic_dec(v) atomic_sub(1,(v))
|
|
|
|
static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
|
|
{
|
|
int ret;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
ret = v->counter;
|
|
if (likely(ret == old))
|
|
v->counter = new;
|
|
local_irq_restore(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline int atomic_add_unless(atomic_t *v, int a, int u)
|
|
{
|
|
int ret;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
ret = v->counter;
|
|
if (ret != u)
|
|
v->counter += a;
|
|
local_irq_restore(flags);
|
|
|
|
return ret != u;
|
|
}
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
*(long *)v &= ~mask;
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
*(long *)v |= mask;
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/* Atomic operations are already serializing on SH */
|
|
#define smp_mb__before_atomic_dec() barrier()
|
|
#define smp_mb__after_atomic_dec() barrier()
|
|
#define smp_mb__before_atomic_inc() barrier()
|
|
#define smp_mb__after_atomic_inc() barrier()
|
|
|
|
#include <asm-generic/atomic.h>
|
|
#endif /* __ASM_SH_ATOMIC_H */
|