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 <asm/atomic.h>
   7 #include <asm/cmpxchg.h>
   8 #include <asm/war.h>
   9
  10 typedef struct
  11 {
  12         atomic_long_t a;
  13 } local_t;
  14
  15 #define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
  16
  17 #define local_read(l)   atomic_long_read(&(l)->a)
  18 #define local_set(l, i) atomic_long_set(&(l)->a, (i))
  19
  20 #define local_add(i, l) atomic_long_add((i), (&(l)->a))
  21 #define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
  22 #define local_inc(l)    atomic_long_inc(&(l)->a)
  23 #define local_dec(l)    atomic_long_dec(&(l)->a)
  24
  25 /*
  26  * Same as above, but return the result value
  27  */
  28 static __inline__ long local_add_return(long i, local_t * l)
  29 {
  30         unsigned long result;
  31
  32         if (kernel_uses_llsc && R10000_LLSC_WAR) {
  33                 unsigned long temp;
  34
  35                 __asm__ __volatile__(
  36                 "       .set    mips3                                   \n"
  37                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  38                 "       addu    %0, %1, %3                              \n"
  39                         __SC    "%0, %2                                 \n"
  40                 "       beqzl   %0, 1b                                  \n"
  41                 "       addu    %0, %1, %3                              \n"
  42                 "       .set    mips0                                   \n"
  43                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  44                 : "Ir" (i), "m" (l->a.counter)
  45                 : "memory");
  46         } else if (kernel_uses_llsc) {
  47                 unsigned long temp;
  48
  49                 __asm__ __volatile__(
  50                 "       .set    mips3                                   \n"
  51                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  52                 "       addu    %0, %1, %3                              \n"
  53                         __SC    "%0, %2                                 \n"
  54                 "       beqz    %0, 1b                                  \n"
  55                 "       addu    %0, %1, %3                              \n"
  56                 "       .set    mips0                                   \n"
  57                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  58                 : "Ir" (i), "m" (l->a.counter)
  59                 : "memory");
  60         } else {
  61                 unsigned long flags;
  62
  63                 local_irq_save(flags);
  64                 result = l->a.counter;
  65                 result += i;
  66                 l->a.counter = result;
  67                 local_irq_restore(flags);
  68         }
  69
  70         return result;
  71 }
  72
  73 static __inline__ long local_sub_return(long i, local_t * l)
  74 {
  75         unsigned long result;
  76
  77         if (kernel_uses_llsc && R10000_LLSC_WAR) {
  78                 unsigned long temp;
  79
  80                 __asm__ __volatile__(
  81                 "       .set    mips3                                   \n"
  82                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
  83                 "       subu    %0, %1, %3                              \n"
  84                         __SC    "%0, %2                                 \n"
  85                 "       beqzl   %0, 1b                                  \n"
  86                 "       subu    %0, %1, %3                              \n"
  87                 "       .set    mips0                                   \n"
  88                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  89                 : "Ir" (i), "m" (l->a.counter)
  90                 : "memory");
  91         } else if (kernel_uses_llsc) {
  92                 unsigned long temp;
  93
  94                 __asm__ __volatile__(
  95                 "       .set    mips3                                   \n"
  96                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
  97                 "       subu    %0, %1, %3                              \n"
  98                         __SC    "%0, %2                                 \n"
  99                 "       beqz    %0, 1b                                  \n"
 100                 "       subu    %0, %1, %3                              \n"
 101                 "       .set    mips0                                   \n"
 102                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
 103                 : "Ir" (i), "m" (l->a.counter)
 104                 : "memory");
 105         } else {
 106                 unsigned long flags;
 107
 108                 local_irq_save(flags);
 109                 result = l->a.counter;
 110                 result -= i;
 111                 l->a.counter = result;
 112                 local_irq_restore(flags);
 113         }
 114
 115         return result;
 116 }
 117
 118 #define local_cmpxchg(l, o, n) \
 119         ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
 120 #define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
 121
 122 /**
 123  * local_add_unless - add unless the number is a given value
 124  * @l: pointer of type local_t
 125  * @a: the amount to add to l...
 126  * @u: ...unless l is equal to u.
 127  *
 128  * Atomically adds @a to @l, so long as it was not @u.
 129  * Returns non-zero if @l was not @u, and zero otherwise.
 130  */
 131 #define local_add_unless(l, a, u)                               \
 132 ({                                                              \
 133         long c, old;                                            \
 134         c = local_read(l);                                      \
 135         while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
 136                 c = old;                                        \
 137         c != (u);                                               \
 138 })
 139 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 140
 141 #define local_dec_return(l) local_sub_return(1, (l))
 142 #define local_inc_return(l) local_add_return(1, (l))
 143
 144 /*
 145  * local_sub_and_test - subtract value from variable and test result
 146  * @i: integer value to subtract
 147  * @l: pointer of type local_t
 148  *
 149  * Atomically subtracts @i from @l and returns
 150  * true if the result is zero, or false for all
 151  * other cases.
 152  */
 153 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
 154
 155 /*
 156  * local_inc_and_test - increment and test
 157  * @l: pointer of type local_t
 158  *
 159  * Atomically increments @l by 1
 160  * and returns true if the result is zero, or false for all
 161  * other cases.
 162  */
 163 #define local_inc_and_test(l) (local_inc_return(l) == 0)
 164
 165 /*
 166  * local_dec_and_test - decrement by 1 and test
 167  * @l: pointer of type local_t
 168  *
 169  * Atomically decrements @l by 1 and
 170  * returns true if the result is 0, or false for all other
 171  * cases.
 172  */
 173 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
 174
 175 /*
 176  * local_add_negative - add and test if negative
 177  * @l: pointer of type local_t
 178  * @i: integer value to add
 179  *
 180  * Atomically adds @i to @l and returns true
 181  * if the result is negative, or false when
 182  * result is greater than or equal to zero.
 183  */
 184 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
 185
 186 /* Use these for per-cpu local_t variables: on some archs they are
 187  * much more efficient than these naive implementations.  Note they take
 188  * a variable, not an address.
 189  */
 190
 191 #define __local_inc(l)          ((l)->a.counter++)
 192 #define __local_dec(l)          ((l)->a.counter++)
 193 #define __local_add(i, l)       ((l)->a.counter+=(i))
 194 #define __local_sub(i, l)       ((l)->a.counter-=(i))
 195
 196 /* Need to disable preemption for the cpu local counters otherwise we could
 197    still access a variable of a previous CPU in a non atomic way. */
 198 #define cpu_local_wrap_v(l)             \
 199         ({ local_t res__;               \
 200            preempt_disable();           \
 201            res__ = (l);                 \
 202            preempt_enable();            \
 203            res__; })
 204 #define cpu_local_wrap(l)               \
 205         ({ preempt_disable();           \
 206            l;                           \
 207            preempt_enable(); })         \
 208
 209 #define cpu_local_read(l)    cpu_local_wrap_v(local_read(&__get_cpu_var(l)))
 210 #define cpu_local_set(l, i)  cpu_local_wrap(local_set(&__get_cpu_var(l), (i)))
 211 #define cpu_local_inc(l)     cpu_local_wrap(local_inc(&__get_cpu_var(l)))
 212 #define cpu_local_dec(l)     cpu_local_wrap(local_dec(&__get_cpu_var(l)))
 213 #define cpu_local_add(i, l)  cpu_local_wrap(local_add((i), &__get_cpu_var(l)))
 214 #define cpu_local_sub(i, l)  cpu_local_wrap(local_sub((i), &__get_cpu_var(l)))
 215
 216 #define __cpu_local_inc(l)      cpu_local_inc(l)
 217 #define __cpu_local_dec(l)      cpu_local_dec(l)
 218 #define __cpu_local_add(i, l)   cpu_local_add((i), (l))
 219 #define __cpu_local_sub(i, l)   cpu_local_sub((i), (l))
 220
 221 #endif /* _ARCH_MIPS_LOCAL_H */