arch/mips/include/asm/local.h

   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
  11 typedef 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  */
  29 static __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
  74 static __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 */