mirror of https://gitee.com/openkylin/linux.git
156 lines
3.7 KiB
C
156 lines
3.7 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*
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* Atomic primitives.
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*/
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#ifndef _ASM_TILE_ATOMIC_H
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#define _ASM_TILE_ATOMIC_H
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#include <asm/cmpxchg.h>
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#ifndef __ASSEMBLY__
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#include <linux/compiler.h>
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#include <linux/types.h>
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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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static inline int atomic_read(const atomic_t *v)
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{
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return ACCESS_ONCE(v->counter);
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}
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/**
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* atomic_sub_return - subtract integer and return
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* @v: pointer of type atomic_t
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* @i: integer value to subtract
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*
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* Atomically subtracts @i from @v and returns @v - @i
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*/
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#define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v))
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/**
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* atomic_sub - subtract integer from 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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#define atomic_sub(i, v) atomic_add((int)(-(i)), (v))
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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 true if the result is
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* zero, or false for all other cases.
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*/
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#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
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/**
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* atomic_inc_return - increment memory and return
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* @v: pointer of type atomic_t
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*
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* Atomically increments @v by 1 and returns the new value.
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*/
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#define atomic_inc_return(v) atomic_add_return(1, (v))
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/**
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* atomic_dec_return - decrement memory and return
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* @v: pointer of type atomic_t
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*
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* Atomically decrements @v by 1 and returns the new value.
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*/
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#define atomic_dec_return(v) atomic_sub_return(1, (v))
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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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#define atomic_inc(v) atomic_add(1, (v))
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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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#define atomic_dec(v) atomic_sub(1, (v))
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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 returns true if the result is 0.
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*/
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#define atomic_dec_and_test(v) (atomic_dec_return(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 and returns true if the result is 0.
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*/
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#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
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/**
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* atomic_add_negative - add and test if negative
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* @v: pointer of type atomic_t
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* @i: integer value to add
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*
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* Atomically adds @i to @v and returns true if the result is
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* negative, or false when result is greater than or equal to zero.
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*/
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#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
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#endif /* __ASSEMBLY__ */
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#ifndef __tilegx__
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#include <asm/atomic_32.h>
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#else
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#include <asm/atomic_64.h>
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#endif
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#ifndef __ASSEMBLY__
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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 c, old, dec;
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c = atomic64_read(v);
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for (;;) {
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dec = c - 1;
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if (unlikely(dec < 0))
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break;
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old = atomic64_cmpxchg((v), c, dec);
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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 dec;
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}
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_TILE_ATOMIC_H */
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