57 lines
1.8 KiB
C
57 lines
1.8 KiB
C
/* Low-level functions for atomic operations. ix86 version, x >= 4.
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Copyright (C) 1997, 2000, 2001 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 Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the 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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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _ATOMICITY_H
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#define _ATOMICITY_H 1
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static inline uint32_t
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__attribute__ ((unused))
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exchange_and_add (volatile uint32_t *mem, uint32_t val)
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{
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register uint32_t result;
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__asm__ __volatile__ ("lock; xaddl %0,%1"
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: "=r" (result), "=m" (*mem) : "m" (val), "1" (*mem));
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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 %1,%0"
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: "=m" (*mem) : "ir" (val), "m" (*mem));
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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), "1" (*p), "a" (oldval));
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return ret;
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}
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#endif /* atomicity.h */
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