8426e1f6af
Introduce an atomic_inc_not_zero operation. Make this a special case of atomic_add_unless because lockless pagecache actually wants atomic_inc_not_negativeone due to its offset refcount. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
160 lines
3.5 KiB
C
160 lines
3.5 KiB
C
#ifndef __ARCH_M68K_ATOMIC__
|
|
#define __ARCH_M68K_ATOMIC__
|
|
|
|
#include <linux/config.h>
|
|
|
|
#include <asm/system.h> /* local_irq_XXX() */
|
|
|
|
/*
|
|
* Atomic operations that C can't guarantee us. Useful for
|
|
* resource counting etc..
|
|
*/
|
|
|
|
/*
|
|
* We do not have SMP m68k systems, so we don't have to deal with that.
|
|
*/
|
|
|
|
typedef struct { int counter; } atomic_t;
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
#define atomic_read(v) ((v)->counter)
|
|
#define atomic_set(v, i) (((v)->counter) = i)
|
|
|
|
static inline void atomic_add(int i, atomic_t *v)
|
|
{
|
|
__asm__ __volatile__("addl %1,%0" : "+m" (*v) : "id" (i));
|
|
}
|
|
|
|
static inline void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
__asm__ __volatile__("subl %1,%0" : "+m" (*v) : "id" (i));
|
|
}
|
|
|
|
static inline void atomic_inc(atomic_t *v)
|
|
{
|
|
__asm__ __volatile__("addql #1,%0" : "+m" (*v));
|
|
}
|
|
|
|
static inline void atomic_dec(atomic_t *v)
|
|
{
|
|
__asm__ __volatile__("subql #1,%0" : "+m" (*v));
|
|
}
|
|
|
|
static inline int atomic_dec_and_test(atomic_t *v)
|
|
{
|
|
char c;
|
|
__asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
|
|
return c != 0;
|
|
}
|
|
|
|
static inline int atomic_inc_and_test(atomic_t *v)
|
|
{
|
|
char c;
|
|
__asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
|
|
return c != 0;
|
|
}
|
|
|
|
#ifdef CONFIG_RMW_INSNS
|
|
static inline int atomic_add_return(int i, atomic_t *v)
|
|
{
|
|
int t, tmp;
|
|
|
|
__asm__ __volatile__(
|
|
"1: movel %2,%1\n"
|
|
" addl %3,%1\n"
|
|
" casl %2,%1,%0\n"
|
|
" jne 1b"
|
|
: "+m" (*v), "=&d" (t), "=&d" (tmp)
|
|
: "g" (i), "2" (atomic_read(v)));
|
|
return t;
|
|
}
|
|
|
|
static inline int atomic_sub_return(int i, atomic_t *v)
|
|
{
|
|
int t, tmp;
|
|
|
|
__asm__ __volatile__(
|
|
"1: movel %2,%1\n"
|
|
" subl %3,%1\n"
|
|
" casl %2,%1,%0\n"
|
|
" jne 1b"
|
|
: "+m" (*v), "=&d" (t), "=&d" (tmp)
|
|
: "g" (i), "2" (atomic_read(v)));
|
|
return t;
|
|
}
|
|
#else /* !CONFIG_RMW_INSNS */
|
|
static inline int atomic_add_return(int i, atomic_t * v)
|
|
{
|
|
unsigned long flags;
|
|
int t;
|
|
|
|
local_irq_save(flags);
|
|
t = atomic_read(v);
|
|
t += i;
|
|
atomic_set(v, t);
|
|
local_irq_restore(flags);
|
|
|
|
return t;
|
|
}
|
|
|
|
static inline int atomic_sub_return(int i, atomic_t * v)
|
|
{
|
|
unsigned long flags;
|
|
int t;
|
|
|
|
local_irq_save(flags);
|
|
t = atomic_read(v);
|
|
t -= i;
|
|
atomic_set(v, t);
|
|
local_irq_restore(flags);
|
|
|
|
return t;
|
|
}
|
|
#endif /* !CONFIG_RMW_INSNS */
|
|
|
|
#define atomic_dec_return(v) atomic_sub_return(1, (v))
|
|
#define atomic_inc_return(v) atomic_add_return(1, (v))
|
|
|
|
static inline int atomic_sub_and_test(int i, atomic_t *v)
|
|
{
|
|
char c;
|
|
__asm__ __volatile__("subl %2,%1; seq %0" : "=d" (c), "+m" (*v): "g" (i));
|
|
return c != 0;
|
|
}
|
|
|
|
static inline int atomic_add_negative(int i, atomic_t *v)
|
|
{
|
|
char c;
|
|
__asm__ __volatile__("addl %2,%1; smi %0" : "=d" (c), "+m" (*v): "g" (i));
|
|
return c != 0;
|
|
}
|
|
|
|
static inline void atomic_clear_mask(unsigned long mask, unsigned long *v)
|
|
{
|
|
__asm__ __volatile__("andl %1,%0" : "+m" (*v) : "id" (~(mask)));
|
|
}
|
|
|
|
static inline void atomic_set_mask(unsigned long mask, unsigned long *v)
|
|
{
|
|
__asm__ __volatile__("orl %1,%0" : "+m" (*v) : "id" (mask));
|
|
}
|
|
|
|
#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
|
|
|
|
#define atomic_add_unless(v, a, u) \
|
|
({ \
|
|
int c, old; \
|
|
c = atomic_read(v); \
|
|
while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
|
|
c = old; \
|
|
c != (u); \
|
|
})
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
/* Atomic operations are already serializing */
|
|
#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()
|
|
|
|
#endif /* __ARCH_M68K_ATOMIC __ */
|