linux/arch/ia64/include/asm/atomic.h
Tony Luck 01d69a82e1 [IA64] Fix 64-bit atomic routines to return "long"
These have been broken (returning "int") since the dawn of
time. But there were no users that needed the whole value
until commit
 424acaaeb3
 rwsem: wake queued readers when writer blocks on active read lock

made this change:

-           (rwsem_atomic_update(0, sem) & RWSEM_ACTIVE_MASK))
-               /* Someone grabbed the sem already */
+           rwsem_atomic_update(0, sem) < RWSEM_WAITING_BIAS)
+               /* Someone grabbed the sem for write already */

RWSEM_ACTIVE_MASK is 0xffffffffL, so the old code only looked
at the low order 32-bits. The new code needs to see all 64 bits.

Signed-off-by: Tony Luck <tony.luck@intel.com>
2010-08-13 16:41:07 -07:00

220 lines
6.1 KiB
C

#ifndef _ASM_IA64_ATOMIC_H
#define _ASM_IA64_ATOMIC_H
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* NOTE: don't mess with the types below! The "unsigned long" and
* "int" types were carefully placed so as to ensure proper operation
* of the macros.
*
* Copyright (C) 1998, 1999, 2002-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/types.h>
#include <asm/intrinsics.h>
#include <asm/system.h>
#define ATOMIC_INIT(i) ((atomic_t) { (i) })
#define ATOMIC64_INIT(i) ((atomic64_t) { (i) })
#define atomic_read(v) (*(volatile int *)&(v)->counter)
#define atomic64_read(v) (*(volatile long *)&(v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))
#define atomic64_set(v,i) (((v)->counter) = (i))
static __inline__ int
ia64_atomic_add (int i, atomic_t *v)
{
__s32 old, new;
CMPXCHG_BUGCHECK_DECL
do {
CMPXCHG_BUGCHECK(v);
old = atomic_read(v);
new = old + i;
} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
return new;
}
static __inline__ long
ia64_atomic64_add (__s64 i, atomic64_t *v)
{
__s64 old, new;
CMPXCHG_BUGCHECK_DECL
do {
CMPXCHG_BUGCHECK(v);
old = atomic64_read(v);
new = old + i;
} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
return new;
}
static __inline__ int
ia64_atomic_sub (int i, atomic_t *v)
{
__s32 old, new;
CMPXCHG_BUGCHECK_DECL
do {
CMPXCHG_BUGCHECK(v);
old = atomic_read(v);
new = old - i;
} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
return new;
}
static __inline__ long
ia64_atomic64_sub (__s64 i, atomic64_t *v)
{
__s64 old, new;
CMPXCHG_BUGCHECK_DECL
do {
CMPXCHG_BUGCHECK(v);
old = atomic64_read(v);
new = old - i;
} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
return new;
}
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
#define atomic64_cmpxchg(v, old, new) \
(cmpxchg(&((v)->counter), old, new))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
static __inline__ long atomic64_add_unless(atomic64_t *v, long a, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic64_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
#define atomic_add_return(i,v) \
({ \
int __ia64_aar_i = (i); \
(__builtin_constant_p(i) \
&& ( (__ia64_aar_i == 1) || (__ia64_aar_i == 4) \
|| (__ia64_aar_i == 8) || (__ia64_aar_i == 16) \
|| (__ia64_aar_i == -1) || (__ia64_aar_i == -4) \
|| (__ia64_aar_i == -8) || (__ia64_aar_i == -16))) \
? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \
: ia64_atomic_add(__ia64_aar_i, v); \
})
#define atomic64_add_return(i,v) \
({ \
long __ia64_aar_i = (i); \
(__builtin_constant_p(i) \
&& ( (__ia64_aar_i == 1) || (__ia64_aar_i == 4) \
|| (__ia64_aar_i == 8) || (__ia64_aar_i == 16) \
|| (__ia64_aar_i == -1) || (__ia64_aar_i == -4) \
|| (__ia64_aar_i == -8) || (__ia64_aar_i == -16))) \
? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \
: ia64_atomic64_add(__ia64_aar_i, v); \
})
/*
* Atomically add I to V and return TRUE if the resulting value is
* negative.
*/
static __inline__ int
atomic_add_negative (int i, atomic_t *v)
{
return atomic_add_return(i, v) < 0;
}
static __inline__ long
atomic64_add_negative (__s64 i, atomic64_t *v)
{
return atomic64_add_return(i, v) < 0;
}
#define atomic_sub_return(i,v) \
({ \
int __ia64_asr_i = (i); \
(__builtin_constant_p(i) \
&& ( (__ia64_asr_i == 1) || (__ia64_asr_i == 4) \
|| (__ia64_asr_i == 8) || (__ia64_asr_i == 16) \
|| (__ia64_asr_i == -1) || (__ia64_asr_i == -4) \
|| (__ia64_asr_i == -8) || (__ia64_asr_i == -16))) \
? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter) \
: ia64_atomic_sub(__ia64_asr_i, v); \
})
#define atomic64_sub_return(i,v) \
({ \
long __ia64_asr_i = (i); \
(__builtin_constant_p(i) \
&& ( (__ia64_asr_i == 1) || (__ia64_asr_i == 4) \
|| (__ia64_asr_i == 8) || (__ia64_asr_i == 16) \
|| (__ia64_asr_i == -1) || (__ia64_asr_i == -4) \
|| (__ia64_asr_i == -8) || (__ia64_asr_i == -16))) \
? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter) \
: ia64_atomic64_sub(__ia64_asr_i, v); \
})
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
#define atomic64_inc_return(v) atomic64_add_return(1, (v))
#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_and_test(v) (atomic_add_return(1, (v)) == 0)
#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
#define atomic_add(i,v) atomic_add_return((i), (v))
#define atomic_sub(i,v) atomic_sub_return((i), (v))
#define atomic_inc(v) atomic_add(1, (v))
#define atomic_dec(v) atomic_sub(1, (v))
#define atomic64_add(i,v) atomic64_add_return((i), (v))
#define atomic64_sub(i,v) atomic64_sub_return((i), (v))
#define atomic64_inc(v) atomic64_add(1, (v))
#define atomic64_dec(v) atomic64_sub(1, (v))
/* 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()
#include <asm-generic/atomic-long.h>
#endif /* _ASM_IA64_ATOMIC_H */