arch/powerpc/include/asm/local.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ARCH_POWERPC_LOCAL_H
   3 #define _ARCH_POWERPC_LOCAL_H
   4
   5 #ifdef CONFIG_PPC_BOOK3S_64
   6
   7 #include <linux/percpu.h>
   8 #include <linux/atomic.h>
   9 #include <linux/irqflags.h>
  10
  11 #include <asm/hw_irq.h>
  12
  13 typedef struct
  14 {
  15         long v;
  16 } local_t;
  17
  18 #define LOCAL_INIT(i)   { (i) }
  19
  20 static __inline__ long local_read(const local_t *l)
  21 {
  22         return READ_ONCE(l->v);
  23 }
  24
  25 static __inline__ void local_set(local_t *l, long i)
  26 {
  27         WRITE_ONCE(l->v, i);
  28 }
  29
  30 #define LOCAL_OP(op, c_op)                                              \
  31 static __inline__ void local_##op(long i, local_t *l)                   \
  32 {                                                                       \
  33         unsigned long flags;                                            \
  34                                                                         \
  35         powerpc_local_irq_pmu_save(flags);                              \
  36         l->v c_op i;                                            \
  37         powerpc_local_irq_pmu_restore(flags);                           \
  38 }
  39
  40 #define LOCAL_OP_RETURN(op, c_op)                                       \
  41 static __inline__ long local_##op##_return(long a, local_t *l)          \
  42 {                                                                       \
  43         long t;                                                         \
  44         unsigned long flags;                                            \
  45                                                                         \
  46         powerpc_local_irq_pmu_save(flags);                              \
  47         t = (l->v c_op a);                                              \
  48         powerpc_local_irq_pmu_restore(flags);                           \
  49                                                                         \
  50         return t;                                                       \
  51 }
  52
  53 #define LOCAL_OPS(op, c_op)             \
  54         LOCAL_OP(op, c_op)              \
  55         LOCAL_OP_RETURN(op, c_op)
  56
  57 LOCAL_OPS(add, +=)
  58 LOCAL_OPS(sub, -=)
  59
  60 #define local_add_negative(a, l)        (local_add_return((a), (l)) < 0)
  61 #define local_inc_return(l)             local_add_return(1LL, l)
  62 #define local_inc(l)                    local_inc_return(l)
  63
  64 /*
  65  * local_inc_and_test - increment and test
  66  * @l: pointer of type local_t
  67  *
  68  * Atomically increments @l by 1
  69  * and returns true if the result is zero, or false for all
  70  * other cases.
  71  */
  72 #define local_inc_and_test(l)           (local_inc_return(l) == 0)
  73
  74 #define local_dec_return(l)             local_sub_return(1LL, l)
  75 #define local_dec(l)                    local_dec_return(l)
  76 #define local_sub_and_test(a, l)        (local_sub_return((a), (l)) == 0)
  77 #define local_dec_and_test(l)           (local_dec_return((l)) == 0)
  78
  79 static __inline__ long local_cmpxchg(local_t *l, long o, long n)
  80 {
  81         long t;
  82         unsigned long flags;
  83
  84         powerpc_local_irq_pmu_save(flags);
  85         t = l->v;
  86         if (t == o)
  87                 l->v = n;
  88         powerpc_local_irq_pmu_restore(flags);
  89
  90         return t;
  91 }
  92
  93 static __inline__ long local_xchg(local_t *l, long n)
  94 {
  95         long t;
  96         unsigned long flags;
  97
  98         powerpc_local_irq_pmu_save(flags);
  99         t = l->v;
 100         l->v = n;
 101         powerpc_local_irq_pmu_restore(flags);
 102
 103         return t;
 104 }
 105
 106 /**
 107  * local_add_unless - add unless the number is a given value
 108  * @l: pointer of type local_t
 109  * @a: the amount to add to v...
 110  * @u: ...unless v is equal to u.
 111  *
 112  * Atomically adds @a to @l, so long as it was not @u.
 113  * Returns non-zero if @l was not @u, and zero otherwise.
 114  */
 115 static __inline__ int local_add_unless(local_t *l, long a, long u)
 116 {
 117         unsigned long flags;
 118         int ret = 0;
 119
 120         powerpc_local_irq_pmu_save(flags);
 121         if (l->v != u) {
 122                 l->v += a;
 123                 ret = 1;
 124         }
 125         powerpc_local_irq_pmu_restore(flags);
 126
 127         return ret;
 128 }
 129
 130 #define local_inc_not_zero(l)           local_add_unless((l), 1, 0)
 131
 132 /* Use these for per-cpu local_t variables: on some archs they are
 133  * much more efficient than these naive implementations.  Note they take
 134  * a variable, not an address.
 135  */
 136
 137 #define __local_inc(l)          ((l)->v++)
 138 #define __local_dec(l)          ((l)->v++)
 139 #define __local_add(i,l)        ((l)->v+=(i))
 140 #define __local_sub(i,l)        ((l)->v-=(i))
 141
 142 #else /* CONFIG_PPC64 */
 143
 144 #include <asm-generic/local.h>
 145
 146 #endif /* CONFIG_PPC64 */
 147
 148 #endif /* _ARCH_POWERPC_LOCAL_H */