f24219b4e9
This is in preparation for more generic atomic primitives based on __atomic_add_unless. Signed-off-by: Arun Sharma <asharma@fb.com> Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
304 lines
6.7 KiB
C
304 lines
6.7 KiB
C
#ifndef _ASM_X86_ATOMIC64_32_H
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#define _ASM_X86_ATOMIC64_32_H
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#include <linux/compiler.h>
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#include <linux/types.h>
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#include <asm/processor.h>
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//#include <asm/cmpxchg.h>
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/* An 64bit atomic type */
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typedef struct {
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u64 __aligned(8) counter;
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} atomic64_t;
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#define ATOMIC64_INIT(val) { (val) }
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#ifdef CONFIG_X86_CMPXCHG64
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#define ATOMIC64_ALTERNATIVE_(f, g) "call atomic64_" #g "_cx8"
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#else
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#define ATOMIC64_ALTERNATIVE_(f, g) ALTERNATIVE("call atomic64_" #f "_386", "call atomic64_" #g "_cx8", X86_FEATURE_CX8)
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#endif
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#define ATOMIC64_ALTERNATIVE(f) ATOMIC64_ALTERNATIVE_(f, f)
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/**
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* atomic64_cmpxchg - cmpxchg atomic64 variable
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* @p: pointer to type atomic64_t
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* @o: expected value
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* @n: new value
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*
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* Atomically sets @v to @n if it was equal to @o and returns
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* the old value.
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*/
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static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
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{
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return cmpxchg64(&v->counter, o, n);
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}
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/**
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* atomic64_xchg - xchg atomic64 variable
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* @v: pointer to type atomic64_t
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* @n: value to assign
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*
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* Atomically xchgs the value of @v to @n and returns
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* the old value.
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*/
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static inline long long atomic64_xchg(atomic64_t *v, long long n)
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{
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long long o;
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unsigned high = (unsigned)(n >> 32);
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unsigned low = (unsigned)n;
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asm volatile(ATOMIC64_ALTERNATIVE(xchg)
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: "=A" (o), "+b" (low), "+c" (high)
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: "S" (v)
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: "memory"
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);
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return o;
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}
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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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* @n: value to assign
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*
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* Atomically sets the value of @v to @n.
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*/
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static inline void atomic64_set(atomic64_t *v, long long i)
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{
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unsigned high = (unsigned)(i >> 32);
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unsigned low = (unsigned)i;
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asm volatile(ATOMIC64_ALTERNATIVE(set)
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: "+b" (low), "+c" (high)
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: "S" (v)
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: "eax", "edx", "memory"
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);
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}
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/**
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* atomic64_read - read atomic64 variable
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* @v: pointer to type atomic64_t
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*
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* Atomically reads the value of @v and returns it.
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*/
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static inline long long atomic64_read(atomic64_t *v)
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{
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long long r;
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asm volatile(ATOMIC64_ALTERNATIVE(read)
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: "=A" (r), "+c" (v)
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: : "memory"
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);
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return r;
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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 long atomic64_add_return(long long i, atomic64_t *v)
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{
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asm volatile(ATOMIC64_ALTERNATIVE(add_return)
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: "+A" (i), "+c" (v)
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: : "memory"
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);
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return i;
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}
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/*
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* Other variants with different arithmetic operators:
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*/
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static inline long long atomic64_sub_return(long long i, atomic64_t *v)
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{
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asm volatile(ATOMIC64_ALTERNATIVE(sub_return)
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: "+A" (i), "+c" (v)
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: : "memory"
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);
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return i;
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}
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static inline long long atomic64_inc_return(atomic64_t *v)
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{
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long long a;
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asm volatile(ATOMIC64_ALTERNATIVE(inc_return)
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: "=A" (a)
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: "S" (v)
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: "memory", "ecx"
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);
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return a;
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}
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static inline long long atomic64_dec_return(atomic64_t *v)
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{
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long long a;
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asm volatile(ATOMIC64_ALTERNATIVE(dec_return)
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: "=A" (a)
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: "S" (v)
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: "memory", "ecx"
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);
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return a;
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}
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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 long long atomic64_add(long long i, atomic64_t *v)
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{
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asm volatile(ATOMIC64_ALTERNATIVE_(add, add_return)
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: "+A" (i), "+c" (v)
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: : "memory"
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);
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return i;
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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 long long atomic64_sub(long long i, atomic64_t *v)
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{
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asm volatile(ATOMIC64_ALTERNATIVE_(sub, sub_return)
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: "+A" (i), "+c" (v)
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: : "memory"
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);
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return i;
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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 long i, atomic64_t *v)
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{
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return atomic64_sub_return(i, v) == 0;
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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(ATOMIC64_ALTERNATIVE_(inc, inc_return)
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: : "S" (v)
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: "memory", "eax", "ecx", "edx"
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);
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}
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/**
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* atomic64_dec - decrement atomic64 variable
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* @ptr: pointer to type atomic64_t
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*
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* Atomically decrements @ptr 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(ATOMIC64_ALTERNATIVE_(dec, dec_return)
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: : "S" (v)
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: "memory", "eax", "ecx", "edx"
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);
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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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return atomic64_dec_return(v) == 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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return atomic64_inc_return(v) == 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 long 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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/**
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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 long a, long long u)
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{
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unsigned low = (unsigned)u;
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unsigned high = (unsigned)(u >> 32);
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asm volatile(ATOMIC64_ALTERNATIVE(add_unless) "\n\t"
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: "+A" (a), "+c" (v), "+S" (low), "+D" (high)
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: : "memory");
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return (int)a;
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}
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static inline int atomic64_inc_not_zero(atomic64_t *v)
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{
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int r;
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asm volatile(ATOMIC64_ALTERNATIVE(inc_not_zero)
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: "=a" (r)
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: "S" (v)
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: "ecx", "edx", "memory"
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);
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return r;
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}
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static inline long long atomic64_dec_if_positive(atomic64_t *v)
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{
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long long r;
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asm volatile(ATOMIC64_ALTERNATIVE(dec_if_positive)
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: "=A" (r)
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: "S" (v)
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: "ecx", "memory"
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);
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return r;
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}
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#undef ATOMIC64_ALTERNATIVE
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#undef ATOMIC64_ALTERNATIVE_
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#endif /* _ASM_X86_ATOMIC64_32_H */
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