236 lines
6.3 KiB
C
236 lines
6.3 KiB
C
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/* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
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* Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
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*/
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#ifndef _ASM_PARISC_ATOMIC_H_
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#define _ASM_PARISC_ATOMIC_H_
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#include <linux/types.h>
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#include <asm/cmpxchg.h>
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/*
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* Atomic operations that C can't guarantee us. Useful for
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* resource counting etc..
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*
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* And probably incredibly slow on parisc. OTOH, we don't
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* have to write any serious assembly. prumpf
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*/
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#ifdef CONFIG_SMP
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#include <asm/spinlock.h>
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#include <asm/cache.h> /* we use L1_CACHE_BYTES */
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/* Use an array of spinlocks for our atomic_ts.
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* Hash function to index into a different SPINLOCK.
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* Since "a" is usually an address, use one spinlock per cacheline.
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*/
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# define ATOMIC_HASH_SIZE 4
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# define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) (a))/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ]))
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extern arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned;
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/* Can't use raw_spin_lock_irq because of #include problems, so
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* this is the substitute */
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#define _atomic_spin_lock_irqsave(l,f) do { \
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arch_spinlock_t *s = ATOMIC_HASH(l); \
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local_irq_save(f); \
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arch_spin_lock(s); \
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} while(0)
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#define _atomic_spin_unlock_irqrestore(l,f) do { \
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arch_spinlock_t *s = ATOMIC_HASH(l); \
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arch_spin_unlock(s); \
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local_irq_restore(f); \
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} while(0)
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#else
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# define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0)
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# define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0)
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#endif
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/*
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* Note that we need not lock read accesses - aligned word writes/reads
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* are atomic, so a reader never sees inconsistent values.
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*/
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/* It's possible to reduce all atomic operations to either
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* __atomic_add_return, atomic_set and atomic_read (the latter
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* is there only for consistency).
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*/
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static __inline__ int __atomic_add_return(int i, atomic_t *v)
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{
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int ret;
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unsigned long flags;
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_atomic_spin_lock_irqsave(v, flags);
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ret = (v->counter += i);
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_atomic_spin_unlock_irqrestore(v, flags);
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return ret;
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}
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static __inline__ void atomic_set(atomic_t *v, int i)
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{
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unsigned long flags;
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_atomic_spin_lock_irqsave(v, flags);
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v->counter = i;
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_atomic_spin_unlock_irqrestore(v, flags);
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}
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static __inline__ int atomic_read(const atomic_t *v)
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{
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return (*(volatile int *)&(v)->counter);
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}
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/* exported interface */
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#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
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#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
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/**
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* __atomic_add_unless - add unless the number is a given value
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* @v: pointer of type atomic_t
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* @a: the amount to add to v...
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* @u: ...unless v is equal to u.
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*
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* Atomically adds @a to @v, so long as it was not @u.
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* Returns the old value of @v.
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*/
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static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
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{
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int c, old;
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c = atomic_read(v);
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for (;;) {
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if (unlikely(c == (u)))
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break;
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old = atomic_cmpxchg((v), c, c + (a));
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if (likely(old == c))
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break;
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c = old;
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}
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return c;
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}
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#define atomic_add(i,v) ((void)(__atomic_add_return( (i),(v))))
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#define atomic_sub(i,v) ((void)(__atomic_add_return(-(i),(v))))
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#define atomic_inc(v) ((void)(__atomic_add_return( 1,(v))))
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#define atomic_dec(v) ((void)(__atomic_add_return( -1,(v))))
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#define atomic_add_return(i,v) (__atomic_add_return( (i),(v)))
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#define atomic_sub_return(i,v) (__atomic_add_return(-(i),(v)))
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#define atomic_inc_return(v) (__atomic_add_return( 1,(v)))
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#define atomic_dec_return(v) (__atomic_add_return( -1,(v)))
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#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
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/*
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* atomic_inc_and_test - increment and test
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* @v: pointer of type atomic_t
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*
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* Atomically increments @v by 1
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* and returns true if the result is zero, or false for all
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* other cases.
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*/
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#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
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#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
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#define atomic_sub_and_test(i,v) (atomic_sub_return((i),(v)) == 0)
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#define ATOMIC_INIT(i) ((atomic_t) { (i) })
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#define smp_mb__before_atomic_dec() smp_mb()
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#define smp_mb__after_atomic_dec() smp_mb()
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#define smp_mb__before_atomic_inc() smp_mb()
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#define smp_mb__after_atomic_inc() smp_mb()
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#ifdef CONFIG_64BIT
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#define ATOMIC64_INIT(i) ((atomic64_t) { (i) })
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static __inline__ s64
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__atomic64_add_return(s64 i, atomic64_t *v)
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{
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s64 ret;
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unsigned long flags;
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_atomic_spin_lock_irqsave(v, flags);
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ret = (v->counter += i);
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_atomic_spin_unlock_irqrestore(v, flags);
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return ret;
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}
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static __inline__ void
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atomic64_set(atomic64_t *v, s64 i)
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{
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unsigned long flags;
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_atomic_spin_lock_irqsave(v, flags);
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v->counter = i;
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_atomic_spin_unlock_irqrestore(v, flags);
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}
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static __inline__ s64
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atomic64_read(const atomic64_t *v)
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{
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return (*(volatile long *)&(v)->counter);
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}
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#define atomic64_add(i,v) ((void)(__atomic64_add_return( ((s64)(i)),(v))))
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#define atomic64_sub(i,v) ((void)(__atomic64_add_return(-((s64)(i)),(v))))
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#define atomic64_inc(v) ((void)(__atomic64_add_return( 1,(v))))
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#define atomic64_dec(v) ((void)(__atomic64_add_return( -1,(v))))
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#define atomic64_add_return(i,v) (__atomic64_add_return( ((s64)(i)),(v)))
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#define atomic64_sub_return(i,v) (__atomic64_add_return(-((s64)(i)),(v)))
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#define atomic64_inc_return(v) (__atomic64_add_return( 1,(v)))
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#define atomic64_dec_return(v) (__atomic64_add_return( -1,(v)))
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#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
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#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
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#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
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#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i),(v)) == 0)
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/* exported interface */
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#define atomic64_cmpxchg(v, o, n) \
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((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
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#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
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/**
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* atomic64_add_unless - add unless the number is a given value
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* @v: pointer of type atomic64_t
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* @a: the amount to add to v...
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* @u: ...unless v is equal to u.
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*
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* Atomically adds @a to @v, so long as it was not @u.
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* Returns the old value of @v.
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*/
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static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
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{
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long c, old;
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c = atomic64_read(v);
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for (;;) {
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if (unlikely(c == (u)))
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break;
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old = atomic64_cmpxchg((v), c, c + (a));
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if (likely(old == c))
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break;
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c = old;
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}
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return c != (u);
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}
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#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
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#endif /* !CONFIG_64BIT */
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#endif /* _ASM_PARISC_ATOMIC_H_ */
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