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/*
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 * Copyright (C) 2005 Ondrej Palkovsky
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#ifndef __mips32_ATOMIC_H__
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#define __mips32_ATOMIC_H__
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#include <arch/types.h>
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#define atomic_inc(x)   ((void) atomic_add(x, 1))
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#define atomic_dec(x)   ((void) atomic_add(x, -1))
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#define atomic_inc_pre(x) (atomic_add(x, 1) - 1)
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#define atomic_dec_pre(x) (atomic_add(x, -1) + 1)
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#define atomic_inc_post(x) atomic_add(x, 1)
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#define atomic_dec_post(x) atomic_add(x, -1)
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typedef struct { volatile __u32 count; } atomic_t;
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/* Atomic addition of immediate value.
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 *
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 * @param val Memory location to which will be the immediate value added.
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 * @param i Signed immediate that will be added to *val.
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 *
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 * @return Value after addition.
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 */
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static inline atomic_t atomic_add(atomic_t *val, int i)
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{
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    atomic_t tmp, v;
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    __asm__ volatile (
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        "1:\n"
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        "   ll %0, %1\n"
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        "   addiu %0, %0, %3\n" /* same as addi, but never traps on overflow */
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        "       move %2, %0\n"
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        "   sc %0, %1\n"
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        "   beq %0, %4, 1b\n"   /* if the atomic operation failed, try again */
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        /*  nop */      /* nop is inserted automatically by compiler */
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        : "=r" (tmp), "=m" (val->count), "=r" (v)
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        : "i" (i), "i" (0)
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        );
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    return v;
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}
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/* Reads/writes are atomic on mips for 4-bytes */
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static inline void atomic_set(atomic_t *val, __u32 i)
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{
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    val->count = i;
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}
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static inline __u32 atomic_get(atomic_t *val)
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{
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    return val->count;
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}
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#endif