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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | /* $Id$ * * Atomic operations that C can't guarantee us. Useful for * resource counting etc.. * * But use these as seldom as possible since they are much more slower * than regular operations. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1996, 1997, 1999 by Ralf Baechle */ #ifndef _ASM_ATOMIC_H #define _ASM_ATOMIC_H #include <linux/config.h> #include <asm/sgidefs.h> #ifdef CONFIG_SMP typedef struct { volatile int counter; } atomic_t; #else typedef struct { int counter; } atomic_t; #endif #ifdef __KERNEL__ #define ATOMIC_INIT(i) { (i) } #define atomic_read(v) ((v)->counter) #define atomic_set(v,i) ((v)->counter = (i)) /* * Make sure gcc doesn't try to be clever and move things around * on us. We need to use _exactly_ the address the user gave us, * not some alias that contains the same information. */ #define __atomic_fool_gcc(x) (*(volatile struct { int a[100]; } *)x) extern __inline__ void atomic_add(int i, volatile atomic_t * v) { unsigned long temp; __asm__ __volatile__( "1:\tll\t%0,%1\n\t" "addu\t%0,%2\n\t" "sc\t%0,%1\n\t" "beqz\t%0,1b" :"=&r" (temp), "=m" (__atomic_fool_gcc(v)) :"Ir" (i), "m" (__atomic_fool_gcc(v))); } extern __inline__ void atomic_sub(int i, volatile atomic_t * v) { unsigned long temp; __asm__ __volatile__( "1:\tll\t%0,%1\n\t" "subu\t%0,%2\n\t" "sc\t%0,%1\n\t" "beqz\t%0,1b" :"=&r" (temp), "=m" (__atomic_fool_gcc(v)) :"Ir" (i), "m" (__atomic_fool_gcc(v))); } /* * Same as above, but return the result value */ extern __inline__ int atomic_add_return(int i, atomic_t * v) { unsigned long temp, result; __asm__ __volatile__( ".set\tnoreorder\n" "1:\tll\t%1,%2\n\t" "addu\t%0,%1,%3\n\t" "sc\t%0,%2\n\t" "beqz\t%0,1b\n\t" "addu\t%0,%1,%3\n\t" ".set\treorder" :"=&r" (result), "=&r" (temp), "=m" (__atomic_fool_gcc(v)) :"Ir" (i), "m" (__atomic_fool_gcc(v))); return result; } extern __inline__ int atomic_sub_return(int i, atomic_t * v) { unsigned long temp, result; __asm__ __volatile__( ".set\tnoreorder\n" "1:\tll\t%1,%2\n\t" "subu\t%0,%1,%3\n\t" "sc\t%0,%2\n\t" "beqz\t%0,1b\n\t" "subu\t%0,%1,%3\n\t" ".set\treorder" :"=&r" (result), "=&r" (temp), "=m" (__atomic_fool_gcc(v)) :"Ir" (i), "m" (__atomic_fool_gcc(v))); return result; } #define atomic_dec_return(v) atomic_sub_return(1,(v)) #define atomic_inc_return(v) atomic_add_return(1,(v)) #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) #define atomic_inc(v) atomic_add(1,(v)) #define atomic_dec(v) atomic_sub(1,(v)) #endif /* defined(__KERNEL__) */ #endif /* _ASM_ATOMIC_H */ |