include/asm/local.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ARCH_POWERPC_LOCAL_H
0003 #define _ARCH_POWERPC_LOCAL_H
0004
0005 #ifdef CONFIG_PPC_BOOK3S_64
0006
0007 #include <linux/percpu.h>
0008 #include <linux/atomic.h>
0009 #include <linux/irqflags.h>
0010
0011 #include <asm/hw_irq.h>
0012
0013 typedef struct
0014 {
0015     long v;
0016 } local_t;
0017
0018 #define LOCAL_INIT(i)   { (i) }
0019
0020 static __inline__ long local_read(const local_t *l)
0021 {
0022     return READ_ONCE(l->v);
0023 }
0024
0025 static __inline__ void local_set(local_t *l, long i)
0026 {
0027     WRITE_ONCE(l->v, i);
0028 }
0029
0030 #define LOCAL_OP(op, c_op)                      \
0031 static __inline__ void local_##op(long i, local_t *l)           \
0032 {                                   \
0033     unsigned long flags;                        \
0034                                     \
0035     powerpc_local_irq_pmu_save(flags);              \
0036     l->v c_op i;                        \
0037     powerpc_local_irq_pmu_restore(flags);               \
0038 }
0039
0040 #define LOCAL_OP_RETURN(op, c_op)                   \
0041 static __inline__ long local_##op##_return(long a, local_t *l)      \
0042 {                                   \
0043     long t;                             \
0044     unsigned long flags;                        \
0045                                     \
0046     powerpc_local_irq_pmu_save(flags);              \
0047     t = (l->v c_op a);                      \
0048     powerpc_local_irq_pmu_restore(flags);               \
0049                                     \
0050     return t;                           \
0051 }
0052
0053 #define LOCAL_OPS(op, c_op)     \
0054     LOCAL_OP(op, c_op)      \
0055     LOCAL_OP_RETURN(op, c_op)
0056
0057 LOCAL_OPS(add, +=)
0058 LOCAL_OPS(sub, -=)
0059
0060 #define local_add_negative(a, l)    (local_add_return((a), (l)) < 0)
0061 #define local_inc_return(l)     local_add_return(1LL, l)
0062 #define local_inc(l)            local_inc_return(l)
0063
0064 /*
0065  * local_inc_and_test - increment and test
0066  * @l: pointer of type local_t
0067  *
0068  * Atomically increments @l by 1
0069  * and returns true if the result is zero, or false for all
0070  * other cases.
0071  */
0072 #define local_inc_and_test(l)       (local_inc_return(l) == 0)
0073
0074 #define local_dec_return(l)     local_sub_return(1LL, l)
0075 #define local_dec(l)            local_dec_return(l)
0076 #define local_sub_and_test(a, l)    (local_sub_return((a), (l)) == 0)
0077 #define local_dec_and_test(l)       (local_dec_return((l)) == 0)
0078
0079 static __inline__ long local_cmpxchg(local_t *l, long o, long n)
0080 {
0081     long t;
0082     unsigned long flags;
0083
0084     powerpc_local_irq_pmu_save(flags);
0085     t = l->v;
0086     if (t == o)
0087         l->v = n;
0088     powerpc_local_irq_pmu_restore(flags);
0089
0090     return t;
0091 }
0092
0093 static __inline__ long local_xchg(local_t *l, long n)
0094 {
0095     long t;
0096     unsigned long flags;
0097
0098     powerpc_local_irq_pmu_save(flags);
0099     t = l->v;
0100     l->v = n;
0101     powerpc_local_irq_pmu_restore(flags);
0102
0103     return t;
0104 }
0105
0106 /**
0107  * local_add_unless - add unless the number is a given value
0108  * @l: pointer of type local_t
0109  * @a: the amount to add to v...
0110  * @u: ...unless v is equal to u.
0111  *
0112  * Atomically adds @a to @l, so long as it was not @u.
0113  * Returns non-zero if @l was not @u, and zero otherwise.
0114  */
0115 static __inline__ int local_add_unless(local_t *l, long a, long u)
0116 {
0117     unsigned long flags;
0118     int ret = 0;
0119
0120     powerpc_local_irq_pmu_save(flags);
0121     if (l->v != u) {
0122         l->v += a;
0123         ret = 1;
0124     }
0125     powerpc_local_irq_pmu_restore(flags);
0126
0127     return ret;
0128 }
0129
0130 #define local_inc_not_zero(l)       local_add_unless((l), 1, 0)
0131
0132 /* Use these for per-cpu local_t variables: on some archs they are
0133  * much more efficient than these naive implementations.  Note they take
0134  * a variable, not an address.
0135  */
0136
0137 #define __local_inc(l)      ((l)->v++)
0138 #define __local_dec(l)      ((l)->v++)
0139 #define __local_add(i,l)    ((l)->v+=(i))
0140 #define __local_sub(i,l)    ((l)->v-=(i))
0141
0142 #else /* CONFIG_PPC64 */
0143
0144 #include <asm-generic/local.h>
0145
0146 #endif /* CONFIG_PPC64 */
0147
0148 #endif /* _ARCH_POWERPC_LOCAL_H */