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3c7654e4ad
(atomic_add): Likewise. (compare_and_swap): Return 0 only when failed to compare. Use branch likely.
138 lines
3.2 KiB
C
138 lines
3.2 KiB
C
/* Low-level functions for atomic operations. Mips version.
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Copyright (C) 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 _MIPS_ATOMICITY_H
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#define _MIPS_ATOMICITY_H 1
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#include <sgidefs.h>
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#include <inttypes.h>
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#if (_MIPS_ISA >= _MIPS_ISA_MIPS2)
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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 result, tmp;
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__asm__ __volatile__
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("/* Inline exchange & add */\n\t"
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"ll %0,%3\n"
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"1:\n\t"
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"addu %1,%4,%0\n\t"
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"sc %1,%2\n\t"
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".set push\n\t"
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".set noreorder\n\t"
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"beqzl %1,1b\n\t"
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" ll %0,%3\n\t"
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".set pop\n\t"
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"/* End exchange & add */"
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: "=&r"(result), "=&r"(tmp), "=m"(*mem)
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: "m" (*mem), "r"(val)
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: "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 result;
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__asm__ __volatile__
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("/* Inline atomic add */\n\t"
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"ll %0,%2\n"
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"1:\n\t"
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"addu %0,%3,%0\n\t"
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"sc %0,%1\n\t"
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".set push\n\t"
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".set noreorder\n\t"
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"beqzl %0,1b\n\t"
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" ll %0,%2\n\t"
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".set pop\n\t"
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"/* End atomic add */"
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: "=&r"(result), "=m"(*mem)
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: "m" (*mem), "r"(val)
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: "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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long int ret, temp;
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__asm__ __volatile__
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("/* Inline compare & swap */\n\t"
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"ll %1,%5\n"
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"1:\n\t"
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".set push\n\t"
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".set noreorder\n\t"
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"bne %1,%3,2f\n\t"
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" move %0,$0\n\t"
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"move %0,%4\n\t"
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"sc %0,%2\n\t"
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"beqzl %0,1b\n\t"
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" ll %1,%5\n\t"
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".set pop\n"
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"2:\n\t"
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"/* End compare & swap */"
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: "=&r" (ret), "=&r" (temp), "=m" (*p)
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: "r" (oldval), "r" (newval), "m" (*p)
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: "memory");
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return ret;
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}
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#else /* (_MIPS_ISA >= _MIPS_ISA_MIPS2) */
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#warning MIPS I atomicity functions are not atomic
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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 result = *mem;
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*mem += val;
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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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*mem += val;
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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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if (*p != oldval)
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return 0;
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*p = newval;
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return 1;
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}
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#endif /* !(_MIPS_ISA >= _MIPS_ISA_MIPS2) */
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#endif /* atomicity.h */
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