58 lines
1.8 KiB
C
58 lines
1.8 KiB
C
/* Low-level functions for atomic operations. ix86 version, x >= 4.
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Copyright (C) 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#ifndef _ATOMICITY_H
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#define _ATOMICITY_H 1
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#include <inttypes.h>
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static inline int
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__attribute__ ((unused))
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exchange_and_add (volatile uint32_t *mem, int val)
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{
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register int result;
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__asm__ __volatile__ ("lock; xaddl %0,%1"
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: "=r" (result) : "0" (val), "m" (*mem) : "memory");
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return result;
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}
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static inline void
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__attribute__ ((unused))
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atomic_add (volatile uint32_t *mem, int val)
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{
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__asm__ __volatile__ ("lock; addl %0,%1"
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: : "ir" (val), "m" (*mem) : "memory");
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}
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static inline char
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__attribute__ ((unused))
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compare_and_swap (volatile long int *p, long int oldval, long int newval)
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{
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char ret;
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long int readval;
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__asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
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: "=q" (ret), "=m" (*p), "=a" (readval)
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: "r" (newval), "m" (*p), "a" (oldval));
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return ret;
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}
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#endif /* atomicity.h */
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