454 lines
10 KiB
C
454 lines
10 KiB
C
#ifndef __ARCH_X86_64_ATOMIC__
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#define __ARCH_X86_64_ATOMIC__
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#include <asm/alternative.h>
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#include <asm/cmpxchg.h>
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/* atomic_t should be 32 bit signed type */
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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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#ifdef CONFIG_SMP
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#define LOCK "lock ; "
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#else
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#define LOCK ""
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#endif
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/*
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* Make sure gcc doesn't try to be clever and move things around
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* on us. We need to use _exactly_ the address the user gave us,
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* not some alias that contains the same information.
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*/
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typedef struct {
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int counter;
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} atomic_t;
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#define ATOMIC_INIT(i) { (i) }
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/**
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* atomic_read - read atomic variable
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* @v: pointer of type atomic_t
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*
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* Atomically reads the value of @v.
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*/
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#define atomic_read(v) ((v)->counter)
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/**
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* atomic_set - set atomic variable
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* @v: pointer of type atomic_t
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* @i: required value
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*
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* Atomically sets the value of @v to @i.
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*/
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#define atomic_set(v, i) (((v)->counter) = (i))
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/**
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* atomic_add - add integer to atomic variable
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* @i: integer value to add
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* @v: pointer of type atomic_t
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*
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* Atomically adds @i to @v.
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*/
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static inline void atomic_add(int i, atomic_t *v)
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{
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asm volatile(LOCK_PREFIX "addl %1,%0"
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: "=m" (v->counter)
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: "ir" (i), "m" (v->counter));
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}
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/**
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* atomic_sub - subtract the atomic variable
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* @i: integer value to subtract
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* @v: pointer of type atomic_t
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*
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* Atomically subtracts @i from @v.
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*/
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static inline void atomic_sub(int i, atomic_t *v)
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{
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asm volatile(LOCK_PREFIX "subl %1,%0"
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: "=m" (v->counter)
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: "ir" (i), "m" (v->counter));
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}
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/**
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* atomic_sub_and_test - subtract value from variable and test result
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* @i: integer value to subtract
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* @v: pointer of type atomic_t
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*
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* Atomically subtracts @i from @v and returns
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* true if the result is zero, or false for all
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* other cases.
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*/
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static inline int atomic_sub_and_test(int i, atomic_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "subl %2,%0; sete %1"
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: "=m" (v->counter), "=qm" (c)
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: "ir" (i), "m" (v->counter) : "memory");
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return c;
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}
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/**
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* atomic_inc - increment atomic variable
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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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*/
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static inline void atomic_inc(atomic_t *v)
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{
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asm volatile(LOCK_PREFIX "incl %0"
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: "=m" (v->counter)
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: "m" (v->counter));
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}
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/**
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* atomic_dec - decrement atomic variable
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* @v: pointer of type atomic_t
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*
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* Atomically decrements @v by 1.
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*/
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static inline void atomic_dec(atomic_t *v)
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{
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asm volatile(LOCK_PREFIX "decl %0"
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: "=m" (v->counter)
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: "m" (v->counter));
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}
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/**
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* atomic_dec_and_test - decrement and test
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* @v: pointer of type atomic_t
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*
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* Atomically decrements @v by 1 and
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* returns true if the result is 0, or false for all other
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* cases.
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*/
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static inline int atomic_dec_and_test(atomic_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "decl %0; sete %1"
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: "=m" (v->counter), "=qm" (c)
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: "m" (v->counter) : "memory");
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return c != 0;
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}
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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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static inline int atomic_inc_and_test(atomic_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "incl %0; sete %1"
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: "=m" (v->counter), "=qm" (c)
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: "m" (v->counter) : "memory");
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return c != 0;
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}
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/**
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* atomic_add_negative - add and test if negative
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* @i: integer value to add
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* @v: pointer of type atomic_t
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*
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* Atomically adds @i to @v and returns true
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* if the result is negative, or false when
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* result is greater than or equal to zero.
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*/
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static inline int atomic_add_negative(int i, atomic_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "addl %2,%0; sets %1"
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: "=m" (v->counter), "=qm" (c)
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: "ir" (i), "m" (v->counter) : "memory");
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return c;
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}
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/**
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* atomic_add_return - add and return
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* @i: integer value to add
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* @v: pointer of type atomic_t
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*
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* Atomically adds @i to @v and returns @i + @v
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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 __i = i;
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asm volatile(LOCK_PREFIX "xaddl %0, %1"
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: "+r" (i), "+m" (v->counter)
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: : "memory");
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return i + __i;
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}
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static inline int atomic_sub_return(int i, atomic_t *v)
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{
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return atomic_add_return(-i, v);
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}
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#define atomic_inc_return(v) (atomic_add_return(1, v))
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#define atomic_dec_return(v) (atomic_sub_return(1, v))
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/* An 64bit atomic type */
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typedef struct {
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long counter;
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} atomic64_t;
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#define ATOMIC64_INIT(i) { (i) }
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/**
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* atomic64_read - read atomic64 variable
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* @v: pointer of type atomic64_t
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*
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* Atomically reads the value of @v.
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* Doesn't imply a read memory barrier.
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*/
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#define atomic64_read(v) ((v)->counter)
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/**
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* atomic64_set - set atomic64 variable
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* @v: pointer to type atomic64_t
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* @i: required value
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*
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* Atomically sets the value of @v to @i.
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*/
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#define atomic64_set(v, i) (((v)->counter) = (i))
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/**
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* atomic64_add - add integer to atomic64 variable
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* @i: integer value to add
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* @v: pointer to type atomic64_t
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*
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* Atomically adds @i to @v.
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*/
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static inline void atomic64_add(long i, atomic64_t *v)
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{
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asm volatile(LOCK_PREFIX "addq %1,%0"
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: "=m" (v->counter)
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: "ir" (i), "m" (v->counter));
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}
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/**
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* atomic64_sub - subtract the atomic64 variable
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* @i: integer value to subtract
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* @v: pointer to type atomic64_t
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*
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* Atomically subtracts @i from @v.
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*/
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static inline void atomic64_sub(long i, atomic64_t *v)
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{
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asm volatile(LOCK_PREFIX "subq %1,%0"
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: "=m" (v->counter)
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: "ir" (i), "m" (v->counter));
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}
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/**
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* atomic64_sub_and_test - subtract value from variable and test result
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* @i: integer value to subtract
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* @v: pointer to type atomic64_t
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*
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* Atomically subtracts @i from @v and returns
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* true if the result is zero, or false for all
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* other cases.
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*/
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static inline int atomic64_sub_and_test(long i, atomic64_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "subq %2,%0; sete %1"
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: "=m" (v->counter), "=qm" (c)
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: "ir" (i), "m" (v->counter) : "memory");
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return c;
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}
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/**
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* atomic64_inc - increment atomic64 variable
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* @v: pointer to type atomic64_t
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*
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* Atomically increments @v by 1.
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*/
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static inline void atomic64_inc(atomic64_t *v)
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{
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asm volatile(LOCK_PREFIX "incq %0"
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: "=m" (v->counter)
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: "m" (v->counter));
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}
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/**
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* atomic64_dec - decrement atomic64 variable
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* @v: pointer to type atomic64_t
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*
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* Atomically decrements @v by 1.
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*/
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static inline void atomic64_dec(atomic64_t *v)
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{
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asm volatile(LOCK_PREFIX "decq %0"
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: "=m" (v->counter)
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: "m" (v->counter));
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}
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/**
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* atomic64_dec_and_test - decrement and test
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* @v: pointer to type atomic64_t
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*
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* Atomically decrements @v by 1 and
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* returns true if the result is 0, or false for all other
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* cases.
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*/
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static inline int atomic64_dec_and_test(atomic64_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "decq %0; sete %1"
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: "=m" (v->counter), "=qm" (c)
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: "m" (v->counter) : "memory");
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return c != 0;
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}
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/**
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* atomic64_inc_and_test - increment and test
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* @v: pointer to type atomic64_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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static inline int atomic64_inc_and_test(atomic64_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "incq %0; sete %1"
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: "=m" (v->counter), "=qm" (c)
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: "m" (v->counter) : "memory");
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return c != 0;
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}
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/**
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* atomic64_add_negative - add and test if negative
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* @i: integer value to add
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* @v: pointer to type atomic64_t
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*
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* Atomically adds @i to @v and returns true
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* if the result is negative, or false when
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* result is greater than or equal to zero.
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*/
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static inline int atomic64_add_negative(long i, atomic64_t *v)
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{
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unsigned char c;
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asm volatile(LOCK_PREFIX "addq %2,%0; sets %1"
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: "=m" (v->counter), "=qm" (c)
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: "ir" (i), "m" (v->counter) : "memory");
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return c;
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}
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/**
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* atomic64_add_return - add and return
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* @i: integer value to add
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* @v: pointer to type atomic64_t
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*
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* Atomically adds @i to @v and returns @i + @v
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*/
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static inline long atomic64_add_return(long i, atomic64_t *v)
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{
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long __i = i;
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asm volatile(LOCK_PREFIX "xaddq %0, %1;"
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: "+r" (i), "+m" (v->counter)
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: : "memory");
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return i + __i;
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}
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static inline long atomic64_sub_return(long i, atomic64_t *v)
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{
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return atomic64_add_return(-i, v);
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}
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#define atomic64_inc_return(v) (atomic64_add_return(1, (v)))
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#define atomic64_dec_return(v) (atomic64_sub_return(1, (v)))
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#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
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#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
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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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/**
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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 non-zero if @v was not @u, and zero otherwise.
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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 != (u);
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}
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#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
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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 non-zero if @v was not @u, and zero otherwise.
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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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/* These are x86-specific, used by some header files */
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#define atomic_clear_mask(mask, addr) \
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asm volatile(LOCK_PREFIX "andl %0,%1" \
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: : "r" (~(mask)), "m" (*(addr)) : "memory")
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#define atomic_set_mask(mask, addr) \
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asm volatile(LOCK_PREFIX "orl %0,%1" \
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: : "r" ((unsigned)(mask)), "m" (*(addr)) \
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: "memory")
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/* Atomic operations are already serializing on x86 */
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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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#include <asm-generic/atomic.h>
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#endif
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