arch/mips/include/asm/local.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ARCH_MIPS_LOCAL_H
   3 #define _ARCH_MIPS_LOCAL_H
   4
   5 #include <linux/percpu.h>
   6 #include <linux/bitops.h>
   7 #include <linux/atomic.h>
   8 #include <asm/asm.h>
   9 #include <asm/cmpxchg.h>
  10 #include <asm/compiler.h>
  11
  12 typedef struct
  13 {
  14         atomic_long_t a;
  15 } local_t;
  16
  17 #define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
  18
  19 #define local_read(l)   atomic_long_read(&(l)->a)
  20 #define local_set(l, i) atomic_long_set(&(l)->a, (i))
  21
  22 #define local_add(i, l) atomic_long_add((i), (&(l)->a))
  23 #define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
  24 #define local_inc(l)    atomic_long_inc(&(l)->a)
  25 #define local_dec(l)    atomic_long_dec(&(l)->a)
  26
  27 /*
  28  * Same as above, but return the result value
  29  */
  30 static __inline__ long local_add_return(long i, local_t * l)
  31 {
  32         unsigned long result;
  33
  34         if (kernel_uses_llsc) {
  35                 unsigned long temp;
  36
  37                 __asm__ __volatile__(
  38                 "       .set    push                                    \n"
  39                 "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
  40                         __SYNC(full, loongson3_war) "                   \n"
  41                 "1:"    __stringify(LONG_LL)    "       %1, %2          \n"
  42                         __stringify(LONG_ADDU)  "       %0, %1, %3      \n"
  43                         __stringify(LONG_SC)    "       %0, %2          \n"
  44                         __stringify(SC_BEQZ)    "       %0, 1b          \n"
  45                         __stringify(LONG_ADDU)  "       %0, %1, %3      \n"
  46                 "       .set    pop                                     \n"
  47                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  48                 : "Ir" (i), "m" (l->a.counter)
  49                 : "memory");
  50         } else {
  51                 unsigned long flags;
  52
  53                 local_irq_save(flags);
  54                 result = l->a.counter;
  55                 result += i;
  56                 l->a.counter = result;
  57                 local_irq_restore(flags);
  58         }
  59
  60         return result;
  61 }
  62
  63 static __inline__ long local_sub_return(long i, local_t * l)
  64 {
  65         unsigned long result;
  66
  67         if (kernel_uses_llsc) {
  68                 unsigned long temp;
  69
  70                 __asm__ __volatile__(
  71                 "       .set    push                                    \n"
  72                 "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
  73                         __SYNC(full, loongson3_war) "                   \n"
  74                 "1:"    __stringify(LONG_LL)    "       %1, %2          \n"
  75                         __stringify(LONG_SUBU)  "       %0, %1, %3      \n"
  76                         __stringify(LONG_SUBU)  "       %0, %1, %3      \n"
  77                         __stringify(LONG_SC)    "       %0, %2          \n"
  78                         __stringify(SC_BEQZ)    "       %0, 1b          \n"
  79                         __stringify(LONG_SUBU)  "       %0, %1, %3      \n"
  80                 "       .set    pop                                     \n"
  81                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  82                 : "Ir" (i), "m" (l->a.counter)
  83                 : "memory");
  84         } else {
  85                 unsigned long flags;
  86
  87                 local_irq_save(flags);
  88                 result = l->a.counter;
  89                 result -= i;
  90                 l->a.counter = result;
  91                 local_irq_restore(flags);
  92         }
  93
  94         return result;
  95 }
  96
  97 static __inline__ long local_cmpxchg(local_t *l, long old, long new)
  98 {
  99         return cmpxchg_local(&l->a.counter, old, new);
 100 }
 101
 102 static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
 103 {
 104         return try_cmpxchg_local(&l->a.counter,
 105                                  (typeof(l->a.counter) *) old, new);
 106 }
 107
 108 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
 109
 110 /**
 111  * local_add_unless - add unless the number is already a given value
 112  * @l: pointer of type local_t
 113  * @a: the amount to add to l...
 114  * @u: ...unless l is equal to u.
 115  *
 116  * Atomically adds @a to @l, if @v was not already @u.
 117  * Returns true if the addition was done.
 118  */
 119 static __inline__ bool
 120 local_add_unless(local_t *l, long a, long u)
 121 {
 122         long c = local_read(l);
 123
 124         do {
 125                 if (unlikely(c == u))
 126                         return false;
 127         } while (!local_try_cmpxchg(l, &c, c + a));
 128
 129         return true;
 130 }
 131
 132 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 133
 134 #define local_dec_return(l) local_sub_return(1, (l))
 135 #define local_inc_return(l) local_add_return(1, (l))
 136
 137 /*
 138  * local_sub_and_test - subtract value from variable and test result
 139  * @i: integer value to subtract
 140  * @l: pointer of type local_t
 141  *
 142  * Atomically subtracts @i from @l and returns
 143  * true if the result is zero, or false for all
 144  * other cases.
 145  */
 146 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
 147
 148 /*
 149  * local_inc_and_test - increment and test
 150  * @l: pointer of type local_t
 151  *
 152  * Atomically increments @l by 1
 153  * and returns true if the result is zero, or false for all
 154  * other cases.
 155  */
 156 #define local_inc_and_test(l) (local_inc_return(l) == 0)
 157
 158 /*
 159  * local_dec_and_test - decrement by 1 and test
 160  * @l: pointer of type local_t
 161  *
 162  * Atomically decrements @l by 1 and
 163  * returns true if the result is 0, or false for all other
 164  * cases.
 165  */
 166 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
 167
 168 /*
 169  * local_add_negative - add and test if negative
 170  * @l: pointer of type local_t
 171  * @i: integer value to add
 172  *
 173  * Atomically adds @i to @l and returns true
 174  * if the result is negative, or false when
 175  * result is greater than or equal to zero.
 176  */
 177 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
 178
 179 /* Use these for per-cpu local_t variables: on some archs they are
 180  * much more efficient than these naive implementations.  Note they take
 181  * a variable, not an address.
 182  */
 183
 184 #define __local_inc(l)          ((l)->a.counter++)
 185 #define __local_dec(l)          ((l)->a.counter++)
 186 #define __local_add(i, l)       ((l)->a.counter+=(i))
 187 #define __local_sub(i, l)       ((l)->a.counter-=(i))
 188
 189 #endif /* _ARCH_MIPS_LOCAL_H */