include/asm-mips/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/war.h>
   8
   9 typedef struct
  10 {
  11         atomic_long_t a;
  12 } local_t;
  13
  14 #define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
  15
  16 #define local_read(l)   atomic_long_read(&(l)->a)
  17 #define local_set(l,i)  atomic_long_set(&(l)->a, (i))
  18
  19 #define local_add(i,l)  atomic_long_add((i),(&(l)->a))
  20 #define local_sub(i,l)  atomic_long_sub((i),(&(l)->a))
  21 #define local_inc(l)    atomic_long_inc(&(l)->a)
  22 #define local_dec(l)    atomic_long_dec(&(l)->a)
  23
  24 /*
  25  * Same as above, but return the result value
  26  */
  27 static __inline__ long local_add_return(long i, local_t * l)
  28 {
  29         unsigned long result;
  30
  31         if (cpu_has_llsc && R10000_LLSC_WAR) {
  32                 unsigned long temp;
  33
  34                 __asm__ __volatile__(
  35                 "       .set    mips3                                   \n"
  36                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  37                 "       addu    %0, %1, %3                              \n"
  38                         __SC    "%0, %2                                 \n"
  39                 "       beqzl   %0, 1b                                  \n"
  40                 "       addu    %0, %1, %3                              \n"
  41                 "       .set    mips0                                   \n"
  42                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  43                 : "Ir" (i), "m" (l->a.counter)
  44                 : "memory");
  45         } else if (cpu_has_llsc) {
  46                 unsigned long temp;
  47
  48                 __asm__ __volatile__(
  49                 "       .set    mips3                                   \n"
  50                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  51                 "       addu    %0, %1, %3                              \n"
  52                         __SC    "%0, %2                                 \n"
  53                 "       beqz    %0, 1b                                  \n"
  54                 "       addu    %0, %1, %3                              \n"
  55                 "       .set    mips0                                   \n"
  56                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  57                 : "Ir" (i), "m" (l->a.counter)
  58                 : "memory");
  59         } else {
  60                 unsigned long flags;
  61
  62                 local_irq_save(flags);
  63                 result = l->a.counter;
  64                 result += i;
  65                 l->a.counter = result;
  66                 local_irq_restore(flags);
  67         }
  68
  69         return result;
  70 }
  71
  72 static __inline__ long local_sub_return(long i, local_t * l)
  73 {
  74         unsigned long result;
  75
  76         if (cpu_has_llsc && R10000_LLSC_WAR) {
  77                 unsigned long temp;
  78
  79                 __asm__ __volatile__(
  80                 "       .set    mips3                                   \n"
  81                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
  82                 "       subu    %0, %1, %3                              \n"
  83                         __SC    "%0, %2                                 \n"
  84                 "       beqzl   %0, 1b                                  \n"
  85                 "       subu    %0, %1, %3                              \n"
  86                 "       .set    mips0                                   \n"
  87                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  88                 : "Ir" (i), "m" (l->a.counter)
  89                 : "memory");
  90         } else if (cpu_has_llsc) {
  91                 unsigned long temp;
  92
  93                 __asm__ __volatile__(
  94                 "       .set    mips3                                   \n"
  95                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
  96                 "       subu    %0, %1, %3                              \n"
  97                         __SC    "%0, %2                                 \n"
  98                 "       beqz    %0, 1b                                  \n"
  99                 "       subu    %0, %1, %3                              \n"
 100                 "       .set    mips0                                   \n"
 101                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
 102                 : "Ir" (i), "m" (l->a.counter)
 103                 : "memory");
 104         } else {
 105                 unsigned long flags;
 106
 107                 local_irq_save(flags);
 108                 result = l->a.counter;
 109                 result -= i;
 110                 l->a.counter = result;
 111                 local_irq_restore(flags);
 112         }
 113
 114         return result;
 115 }
 116
 117 /*
 118  * local_sub_if_positive - conditionally subtract integer from atomic variable
 119  * @i: integer value to subtract
 120  * @l: pointer of type local_t
 121  *
 122  * Atomically test @l and subtract @i if @l is greater or equal than @i.
 123  * The function returns the old value of @l minus @i.
 124  */
 125 static __inline__ long local_sub_if_positive(long i, local_t * l)
 126 {
 127         unsigned long result;
 128
 129         if (cpu_has_llsc && R10000_LLSC_WAR) {
 130                 unsigned long temp;
 131
 132                 __asm__ __volatile__(
 133                 "       .set    mips3                                   \n"
 134                 "1:"    __LL    "%1, %2         # local_sub_if_positive\n"
 135                 "       dsubu   %0, %1, %3                              \n"
 136                 "       bltz    %0, 1f                                  \n"
 137                         __SC    "%0, %2                                 \n"
 138                 "       .set    noreorder                               \n"
 139                 "       beqzl   %0, 1b                                  \n"
 140                 "        dsubu  %0, %1, %3                              \n"
 141                 "       .set    reorder                                 \n"
 142                 "1:                                                     \n"
 143                 "       .set    mips0                                   \n"
 144                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
 145                 : "Ir" (i), "m" (l->a.counter)
 146                 : "memory");
 147         } else if (cpu_has_llsc) {
 148                 unsigned long temp;
 149
 150                 __asm__ __volatile__(
 151                 "       .set    mips3                                   \n"
 152                 "1:"    __LL    "%1, %2         # local_sub_if_positive\n"
 153                 "       dsubu   %0, %1, %3                              \n"
 154                 "       bltz    %0, 1f                                  \n"
 155                         __SC    "%0, %2                                 \n"
 156                 "       .set    noreorder                               \n"
 157                 "       beqz    %0, 1b                                  \n"
 158                 "        dsubu  %0, %1, %3                              \n"
 159                 "       .set    reorder                                 \n"
 160                 "1:                                                     \n"
 161                 "       .set    mips0                                   \n"
 162                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
 163                 : "Ir" (i), "m" (l->a.counter)
 164                 : "memory");
 165         } else {
 166                 unsigned long flags;
 167
 168                 local_irq_save(flags);
 169                 result = l->a.counter;
 170                 result -= i;
 171                 if (result >= 0)
 172                         l->a.counter = result;
 173                 local_irq_restore(flags);
 174         }
 175
 176         return result;
 177 }
 178
 179 #define local_cmpxchg(l, o, n) \
 180         ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
 181 #define local_xchg(l, n) (xchg_local(&((l)->a.counter),(n)))
 182
 183 /**
 184  * local_add_unless - add unless the number is a given value
 185  * @l: pointer of type local_t
 186  * @a: the amount to add to l...
 187  * @u: ...unless l is equal to u.
 188  *
 189  * Atomically adds @a to @l, so long as it was not @u.
 190  * Returns non-zero if @l was not @u, and zero otherwise.
 191  */
 192 #define local_add_unless(l, a, u)                               \
 193 ({                                                              \
 194         long c, old;                                            \
 195         c = local_read(l);                                      \
 196         while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
 197                 c = old;                                        \
 198         c != (u);                                               \
 199 })
 200 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 201
 202 #define local_dec_return(l) local_sub_return(1,(l))
 203 #define local_inc_return(l) local_add_return(1,(l))
 204
 205 /*
 206  * local_sub_and_test - subtract value from variable and test result
 207  * @i: integer value to subtract
 208  * @l: pointer of type local_t
 209  *
 210  * Atomically subtracts @i from @l and returns
 211  * true if the result is zero, or false for all
 212  * other cases.
 213  */
 214 #define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
 215
 216 /*
 217  * local_inc_and_test - increment and test
 218  * @l: pointer of type local_t
 219  *
 220  * Atomically increments @l by 1
 221  * and returns true if the result is zero, or false for all
 222  * other cases.
 223  */
 224 #define local_inc_and_test(l) (local_inc_return(l) == 0)
 225
 226 /*
 227  * local_dec_and_test - decrement by 1 and test
 228  * @l: pointer of type local_t
 229  *
 230  * Atomically decrements @l by 1 and
 231  * returns true if the result is 0, or false for all other
 232  * cases.
 233  */
 234 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
 235
 236 /*
 237  * local_dec_if_positive - decrement by 1 if old value positive
 238  * @l: pointer of type local_t
 239  */
 240 #define local_dec_if_positive(l)        local_sub_if_positive(1, l)
 241
 242 /*
 243  * local_add_negative - add and test if negative
 244  * @l: pointer of type local_t
 245  * @i: integer value to add
 246  *
 247  * Atomically adds @i to @l and returns true
 248  * if the result is negative, or false when
 249  * result is greater than or equal to zero.
 250  */
 251 #define local_add_negative(i,l) (local_add_return(i, (l)) < 0)
 252
 253 /* Use these for per-cpu local_t variables: on some archs they are
 254  * much more efficient than these naive implementations.  Note they take
 255  * a variable, not an address.
 256  */
 257
 258 #define __local_inc(l)          ((l)->a.counter++)
 259 #define __local_dec(l)          ((l)->a.counter++)
 260 #define __local_add(i,l)        ((l)->a.counter+=(i))
 261 #define __local_sub(i,l)        ((l)->a.counter-=(i))
 262
 263 /* Need to disable preemption for the cpu local counters otherwise we could
 264    still access a variable of a previous CPU in a non atomic way. */
 265 #define cpu_local_wrap_v(l)             \
 266         ({ local_t res__;               \
 267            preempt_disable();           \
 268            res__ = (l);                 \
 269            preempt_enable();            \
 270            res__; })
 271 #define cpu_local_wrap(l)               \
 272         ({ preempt_disable();           \
 273            l;                           \
 274            preempt_enable(); })         \
 275
 276 #define cpu_local_read(l)    cpu_local_wrap_v(local_read(&__get_cpu_var(l)))
 277 #define cpu_local_set(l, i)  cpu_local_wrap(local_set(&__get_cpu_var(l), (i)))
 278 #define cpu_local_inc(l)     cpu_local_wrap(local_inc(&__get_cpu_var(l)))
 279 #define cpu_local_dec(l)     cpu_local_wrap(local_dec(&__get_cpu_var(l)))
 280 #define cpu_local_add(i, l)  cpu_local_wrap(local_add((i), &__get_cpu_var(l)))
 281 #define cpu_local_sub(i, l)  cpu_local_wrap(local_sub((i), &__get_cpu_var(l)))
 282
 283 #define __cpu_local_inc(l)      cpu_local_inc(l)
 284 #define __cpu_local_dec(l)      cpu_local_dec(l)
 285 #define __cpu_local_add(i, l)   cpu_local_add((i), (l))
 286 #define __cpu_local_sub(i, l)   cpu_local_sub((i), (l))
 287
 288 #endif /* _ARCH_MIPS_LOCAL_H */