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87 lines
2.3 KiB
C
87 lines
2.3 KiB
C
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/* Low-level functions for atomic operations. ARM version.
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Copyright (C) 1997, 1998, 1999, 2000 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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int tmp1;
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int tmp2;
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int result;
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__asm__ ("\n"
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"0:\tldr\t%0,[%3]\n\t"
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"add\t%1,%0,%4\n\t"
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"swp\t%2,%1,[%3]\n\t"
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"cmp\t%0,%2\n\t"
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"swpne\t%1,%2,[%3]\n\t"
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"bne\t0b"
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: "=&r" (result), "=&r" (tmp1), "=&r" (tmp2)
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: "r" (mem), "r"(val)
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: "cc", "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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int tmp1;
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int tmp2;
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int tmp3;
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__asm__ ("\n"
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"0:\tldr\t%0,[%3]\n\t"
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"add\t%1,%0,%4\n\t"
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"swp\t%2,%1,[%3]\n\t"
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"cmp\t%0,%2\n\t"
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"swpne\t%1,%2,[%3]\n\t"
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"bne\t0b"
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: "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
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: "r" (mem), "r"(val)
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: "cc", "memory");
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}
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static inline int
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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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int result, tmp;
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__asm__ ("\n"
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"0:\tldr\t%1,[%2]\n\t"
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"mov\t%0,#0\n\t"
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"cmp\t%1,%4\n\t"
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"bne\t1f\n\t"
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"swp\t%0,%3,[%2]\n\t"
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"cmp\t%1,%0\n\t"
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"swpne\t%1,%0,[%2]\n\t"
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"bne\t0b\n\t"
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"mov\t%0,#1\n"
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"1:"
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: "=&r" (result), "=&r" (tmp)
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: "r" (p), "r" (newval), "r" (oldval)
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: "cc", "memory");
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}
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#endif /* atomicity.h */
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