linux/arch/mips/include/asm/local.h
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   1#ifndef _ARCH_MIPS_LOCAL_H
   2#define _ARCH_MIPS_LOCAL_H
   3
   4#include <linux/percpu.h>
   5#include <linux/bitops.h>
   6#include <linux/atomic.h>
   7#include <asm/cmpxchg.h>
   8#include <asm/compiler.h>
   9#include <asm/war.h>
  10
  11typedef struct
  12{
  13        atomic_long_t a;
  14} local_t;
  15
  16#define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
  17
  18#define local_read(l)   atomic_long_read(&(l)->a)
  19#define local_set(l, i) atomic_long_set(&(l)->a, (i))
  20
  21#define local_add(i, l) atomic_long_add((i), (&(l)->a))
  22#define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
  23#define local_inc(l)    atomic_long_inc(&(l)->a)
  24#define local_dec(l)    atomic_long_dec(&(l)->a)
  25
  26/*
  27 * Same as above, but return the result value
  28 */
  29static __inline__ long local_add_return(long i, local_t * l)
  30{
  31        unsigned long result;
  32
  33        if (kernel_uses_llsc && R10000_LLSC_WAR) {
  34                unsigned long temp;
  35
  36                __asm__ __volatile__(
  37                "       .set    arch=r4000                              \n"
  38                "1:"    __LL    "%1, %2         # local_add_return      \n"
  39                "       addu    %0, %1, %3                              \n"
  40                        __SC    "%0, %2                                 \n"
  41                "       beqzl   %0, 1b                                  \n"
  42                "       addu    %0, %1, %3                              \n"
  43                "       .set    mips0                                   \n"
  44                : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  45                : "Ir" (i), "m" (l->a.counter)
  46                : "memory");
  47        } else if (kernel_uses_llsc) {
  48                unsigned long temp;
  49
  50                __asm__ __volatile__(
  51                "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
  52                "1:"    __LL    "%1, %2         # local_add_return      \n"
  53                "       addu    %0, %1, %3                              \n"
  54                        __SC    "%0, %2                                 \n"
  55                "       beqz    %0, 1b                                  \n"
  56                "       addu    %0, %1, %3                              \n"
  57                "       .set    mips0                                   \n"
  58                : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  59                : "Ir" (i), "m" (l->a.counter)
  60                : "memory");
  61        } else {
  62                unsigned long flags;
  63
  64                local_irq_save(flags);
  65                result = l->a.counter;
  66                result += i;
  67                l->a.counter = result;
  68                local_irq_restore(flags);
  69        }
  70
  71        return result;
  72}
  73
  74static __inline__ long local_sub_return(long i, local_t * l)
  75{
  76        unsigned long result;
  77
  78        if (kernel_uses_llsc && R10000_LLSC_WAR) {
  79                unsigned long temp;
  80
  81                __asm__ __volatile__(
  82                "       .set    arch=r4000                              \n"
  83                "1:"    __LL    "%1, %2         # local_sub_return      \n"
  84                "       subu    %0, %1, %3                              \n"
  85                        __SC    "%0, %2                                 \n"
  86                "       beqzl   %0, 1b                                  \n"
  87                "       subu    %0, %1, %3                              \n"
  88                "       .set    mips0                                   \n"
  89                : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  90                : "Ir" (i), "m" (l->a.counter)
  91                : "memory");
  92        } else if (kernel_uses_llsc) {
  93                unsigned long temp;
  94
  95                __asm__ __volatile__(
  96                "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
  97                "1:"    __LL    "%1, %2         # local_sub_return      \n"
  98                "       subu    %0, %1, %3                              \n"
  99                        __SC    "%0, %2                                 \n"
 100                "       beqz    %0, 1b                                  \n"
 101                "       subu    %0, %1, %3                              \n"
 102                "       .set    mips0                                   \n"
 103                : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
 104                : "Ir" (i), "m" (l->a.counter)
 105                : "memory");
 106        } else {
 107                unsigned long flags;
 108
 109                local_irq_save(flags);
 110                result = l->a.counter;
 111                result -= i;
 112                l->a.counter = result;
 113                local_irq_restore(flags);
 114        }
 115
 116        return result;
 117}
 118
 119#define local_cmpxchg(l, o, n) \
 120        ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
 121#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
 122
 123/**
 124 * local_add_unless - add unless the number is a given value
 125 * @l: pointer of type local_t
 126 * @a: the amount to add to l...
 127 * @u: ...unless l is equal to u.
 128 *
 129 * Atomically adds @a to @l, so long as it was not @u.
 130 * Returns non-zero if @l was not @u, and zero otherwise.
 131 */
 132#define local_add_unless(l, a, u)                               \
 133({                                                              \
 134        long c, old;                                            \
 135        c = local_read(l);                                      \
 136        while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
 137                c = old;                                        \
 138        c != (u);                                               \
 139})
 140#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 141
 142#define local_dec_return(l) local_sub_return(1, (l))
 143#define local_inc_return(l) local_add_return(1, (l))
 144
 145/*
 146 * local_sub_and_test - subtract value from variable and test result
 147 * @i: integer value to subtract
 148 * @l: pointer of type local_t
 149 *
 150 * Atomically subtracts @i from @l and returns
 151 * true if the result is zero, or false for all
 152 * other cases.
 153 */
 154#define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
 155
 156/*
 157 * local_inc_and_test - increment and test
 158 * @l: pointer of type local_t
 159 *
 160 * Atomically increments @l by 1
 161 * and returns true if the result is zero, or false for all
 162 * other cases.
 163 */
 164#define local_inc_and_test(l) (local_inc_return(l) == 0)
 165
 166/*
 167 * local_dec_and_test - decrement by 1 and test
 168 * @l: pointer of type local_t
 169 *
 170 * Atomically decrements @l by 1 and
 171 * returns true if the result is 0, or false for all other
 172 * cases.
 173 */
 174#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
 175
 176/*
 177 * local_add_negative - add and test if negative
 178 * @l: pointer of type local_t
 179 * @i: integer value to add
 180 *
 181 * Atomically adds @i to @l and returns true
 182 * if the result is negative, or false when
 183 * result is greater than or equal to zero.
 184 */
 185#define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
 186
 187/* Use these for per-cpu local_t variables: on some archs they are
 188 * much more efficient than these naive implementations.  Note they take
 189 * a variable, not an address.
 190 */
 191
 192#define __local_inc(l)          ((l)->a.counter++)
 193#define __local_dec(l)          ((l)->a.counter++)
 194#define __local_add(i, l)       ((l)->a.counter+=(i))
 195#define __local_sub(i, l)       ((l)->a.counter-=(i))
 196
 197#endif /* _ARCH_MIPS_LOCAL_H */
 198