a119365586
The following build error occured during a ia64 build with
swap-over-NFS patches applied.
net/core/sock.c:274:36: error: initializer element is not constant
net/core/sock.c:274:36: error: (near initialization for 'memalloc_socks')
net/core/sock.c:274:36: error: initializer element is not constant
This is identical to a parisc build error. Fengguang Wu, Mel Gorman
and James Bottomley did all the legwork to track the root cause of
the problem. This fix and entire commit log is shamelessly copied
from them with one extra detail to change a dubious runtime use of
ATOMIC_INIT() to atomic_set() in drivers/char/mspec.c
Dave Anglin says:
> Here is the line in sock.i:
>
> struct static_key memalloc_socks = ((struct static_key) { .enabled =
> ((atomic_t) { (0) }) });
The above line contains two compound literals. It also uses a designated
initializer to initialize the field enabled. A compound literal is not a
constant expression.
The location of the above statement isn't fully clear, but if a compound
literal occurs outside the body of a function, the initializer list must
consist of constant expressions.
Cc: <stable@vger.kernel.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
217 lines
5.9 KiB
C
217 lines
5.9 KiB
C
#ifndef _ASM_IA64_ATOMIC_H
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#define _ASM_IA64_ATOMIC_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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* NOTE: don't mess with the types below! The "unsigned long" and
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* "int" types were carefully placed so as to ensure proper operation
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* of the macros.
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*
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* Copyright (C) 1998, 1999, 2002-2003 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*/
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#include <linux/types.h>
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#include <asm/intrinsics.h>
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#define ATOMIC_INIT(i) { (i) }
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#define ATOMIC64_INIT(i) { (i) }
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#define atomic_read(v) (*(volatile int *)&(v)->counter)
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#define atomic64_read(v) (*(volatile long *)&(v)->counter)
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#define atomic_set(v,i) (((v)->counter) = (i))
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#define atomic64_set(v,i) (((v)->counter) = (i))
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static __inline__ int
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ia64_atomic_add (int i, atomic_t *v)
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{
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__s32 old, new;
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CMPXCHG_BUGCHECK_DECL
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do {
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CMPXCHG_BUGCHECK(v);
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old = atomic_read(v);
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new = old + i;
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} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
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return new;
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}
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static __inline__ long
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ia64_atomic64_add (__s64 i, atomic64_t *v)
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{
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__s64 old, new;
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CMPXCHG_BUGCHECK_DECL
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do {
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CMPXCHG_BUGCHECK(v);
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old = atomic64_read(v);
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new = old + i;
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} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
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return new;
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}
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static __inline__ int
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ia64_atomic_sub (int i, atomic_t *v)
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{
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__s32 old, new;
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CMPXCHG_BUGCHECK_DECL
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do {
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CMPXCHG_BUGCHECK(v);
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old = atomic_read(v);
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new = old - i;
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} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
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return new;
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}
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static __inline__ long
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ia64_atomic64_sub (__s64 i, atomic64_t *v)
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{
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__s64 old, new;
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CMPXCHG_BUGCHECK_DECL
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do {
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CMPXCHG_BUGCHECK(v);
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old = atomic64_read(v);
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new = old - i;
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} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
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return new;
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}
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#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
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#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
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#define atomic64_cmpxchg(v, old, new) \
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(cmpxchg(&((v)->counter), old, new))
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#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
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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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static __inline__ long 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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#define atomic_add_return(i,v) \
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({ \
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int __ia64_aar_i = (i); \
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(__builtin_constant_p(i) \
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&& ( (__ia64_aar_i == 1) || (__ia64_aar_i == 4) \
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|| (__ia64_aar_i == 8) || (__ia64_aar_i == 16) \
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|| (__ia64_aar_i == -1) || (__ia64_aar_i == -4) \
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|| (__ia64_aar_i == -8) || (__ia64_aar_i == -16))) \
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? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \
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: ia64_atomic_add(__ia64_aar_i, v); \
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})
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#define atomic64_add_return(i,v) \
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({ \
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long __ia64_aar_i = (i); \
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(__builtin_constant_p(i) \
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&& ( (__ia64_aar_i == 1) || (__ia64_aar_i == 4) \
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|| (__ia64_aar_i == 8) || (__ia64_aar_i == 16) \
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|| (__ia64_aar_i == -1) || (__ia64_aar_i == -4) \
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|| (__ia64_aar_i == -8) || (__ia64_aar_i == -16))) \
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? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \
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: ia64_atomic64_add(__ia64_aar_i, v); \
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})
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/*
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* Atomically add I to V and return TRUE if the resulting value is
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* negative.
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*/
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static __inline__ int
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atomic_add_negative (int i, atomic_t *v)
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{
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return atomic_add_return(i, v) < 0;
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}
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static __inline__ long
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atomic64_add_negative (__s64 i, atomic64_t *v)
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{
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return atomic64_add_return(i, v) < 0;
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}
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#define atomic_sub_return(i,v) \
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({ \
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int __ia64_asr_i = (i); \
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(__builtin_constant_p(i) \
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&& ( (__ia64_asr_i == 1) || (__ia64_asr_i == 4) \
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|| (__ia64_asr_i == 8) || (__ia64_asr_i == 16) \
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|| (__ia64_asr_i == -1) || (__ia64_asr_i == -4) \
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|| (__ia64_asr_i == -8) || (__ia64_asr_i == -16))) \
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? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter) \
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: ia64_atomic_sub(__ia64_asr_i, v); \
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})
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#define atomic64_sub_return(i,v) \
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({ \
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long __ia64_asr_i = (i); \
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(__builtin_constant_p(i) \
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&& ( (__ia64_asr_i == 1) || (__ia64_asr_i == 4) \
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|| (__ia64_asr_i == 8) || (__ia64_asr_i == 16) \
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|| (__ia64_asr_i == -1) || (__ia64_asr_i == -4) \
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|| (__ia64_asr_i == -8) || (__ia64_asr_i == -16))) \
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? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter) \
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: ia64_atomic64_sub(__ia64_asr_i, v); \
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})
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#define atomic_dec_return(v) atomic_sub_return(1, (v))
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#define atomic_inc_return(v) atomic_add_return(1, (v))
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#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
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#define atomic64_inc_return(v) atomic64_add_return(1, (v))
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#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
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#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
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#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
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#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
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#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
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#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
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#define atomic_add(i,v) atomic_add_return((i), (v))
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#define atomic_sub(i,v) atomic_sub_return((i), (v))
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#define atomic_inc(v) atomic_add(1, (v))
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#define atomic_dec(v) atomic_sub(1, (v))
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#define atomic64_add(i,v) atomic64_add_return((i), (v))
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#define atomic64_sub(i,v) atomic64_sub_return((i), (v))
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#define atomic64_inc(v) atomic64_add(1, (v))
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#define atomic64_dec(v) atomic64_sub(1, (v))
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/* Atomic operations are already serializing */
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#define smp_mb__before_atomic_dec() barrier()
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#define smp_mb__after_atomic_dec() barrier()
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#define smp_mb__before_atomic_inc() barrier()
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#define smp_mb__after_atomic_inc() barrier()
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#endif /* _ASM_IA64_ATOMIC_H */
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