| 1 | /*
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| 2 | * Copyright (C) 2005 Ondrej Palkovsky
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | #ifndef __mips32_ATOMIC_H__
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| 30 | #define __mips32_ATOMIC_H__
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| 31 |
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| 32 | #define atomic_inc(x) ((void) atomic_add(x, 1))
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| 33 | #define atomic_dec(x) ((void) atomic_add(x, -1))
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| 34 |
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| 35 | #define atomic_postinc(x) (atomic_add(x, 1) - 1)
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| 36 | #define atomic_postdec(x) (atomic_add(x, -1) + 1)
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| 37 |
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| 38 | #define atomic_preinc(x) atomic_add(x, 1)
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| 39 | #define atomic_predec(x) atomic_add(x, -1)
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| 40 |
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| 41 | /* Atomic addition of immediate value.
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| 42 | *
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| 43 | * @param val Memory location to which will be the immediate value added.
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| 44 | * @param i Signed immediate that will be added to *val.
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| 45 | *
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| 46 | * @return Value after addition.
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| 47 | */
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| 48 | static inline long atomic_add(atomic_t *val, int i)
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| 49 | {
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| 50 | long tmp, v;
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| 51 |
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| 52 | __asm__ volatile (
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| 53 | "1:\n"
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| 54 | " ll %0, %1\n"
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| 55 | " addiu %0, %0, %3\n" /* same as addi, but never traps on overflow */
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| 56 | " move %2, %0\n"
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| 57 | " sc %0, %1\n"
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| 58 | " beq %0, %4, 1b\n" /* if the atomic operation failed, try again */
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| 59 | /* nop */ /* nop is inserted automatically by compiler */
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| 60 | : "=r" (tmp), "=m" (val->count), "=r" (v)
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| 61 | : "i" (i), "i" (0)
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| 62 | );
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| 63 |
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| 64 | return v;
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| 65 | }
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| 66 |
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| 67 | #endif
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