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linux/arch/powerpc/include/asm/local.h
Uros Bizjak 5e0eb67974 locking/local, arch: Rewrite local_add_unless() as a static inline function
Rewrite local_add_unless() as a static inline function with boolean
return value, similar to the arch_atomic_add_unless() arch fallbacks.

The function is currently unused.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230731084458.28096-1-ubizjak@gmail.com
2023-10-04 11:38:11 +02:00

160 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ARCH_POWERPC_LOCAL_H
#define _ARCH_POWERPC_LOCAL_H
#ifdef CONFIG_PPC_BOOK3S_64
#include <linux/percpu.h>
#include <linux/atomic.h>
#include <linux/irqflags.h>
#include <asm/hw_irq.h>
typedef struct
{
long v;
} local_t;
#define LOCAL_INIT(i) { (i) }
static __inline__ long local_read(const local_t *l)
{
return READ_ONCE(l->v);
}
static __inline__ void local_set(local_t *l, long i)
{
WRITE_ONCE(l->v, i);
}
#define LOCAL_OP(op, c_op) \
static __inline__ void local_##op(long i, local_t *l) \
{ \
unsigned long flags; \
\
powerpc_local_irq_pmu_save(flags); \
l->v c_op i; \
powerpc_local_irq_pmu_restore(flags); \
}
#define LOCAL_OP_RETURN(op, c_op) \
static __inline__ long local_##op##_return(long a, local_t *l) \
{ \
long t; \
unsigned long flags; \
\
powerpc_local_irq_pmu_save(flags); \
t = (l->v c_op a); \
powerpc_local_irq_pmu_restore(flags); \
\
return t; \
}
#define LOCAL_OPS(op, c_op) \
LOCAL_OP(op, c_op) \
LOCAL_OP_RETURN(op, c_op)
LOCAL_OPS(add, +=)
LOCAL_OPS(sub, -=)
#define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
#define local_inc_return(l) local_add_return(1LL, l)
#define local_inc(l) local_inc_return(l)
/*
* local_inc_and_test - increment and test
* @l: pointer of type local_t
*
* Atomically increments @l by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define local_inc_and_test(l) (local_inc_return(l) == 0)
#define local_dec_return(l) local_sub_return(1LL, l)
#define local_dec(l) local_dec_return(l)
#define local_sub_and_test(a, l) (local_sub_return((a), (l)) == 0)
#define local_dec_and_test(l) (local_dec_return((l)) == 0)
static __inline__ long local_cmpxchg(local_t *l, long o, long n)
{
long t;
unsigned long flags;
powerpc_local_irq_pmu_save(flags);
t = l->v;
if (t == o)
l->v = n;
powerpc_local_irq_pmu_restore(flags);
return t;
}
static __inline__ bool local_try_cmpxchg(local_t *l, long *po, long n)
{
long o = *po, r;
r = local_cmpxchg(l, o, n);
if (unlikely(r != o))
*po = r;
return likely(r == o);
}
static __inline__ long local_xchg(local_t *l, long n)
{
long t;
unsigned long flags;
powerpc_local_irq_pmu_save(flags);
t = l->v;
l->v = n;
powerpc_local_irq_pmu_restore(flags);
return t;
}
/**
* local_add_unless - add unless the number is already a given value
* @l: pointer of type local_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @l, if @v was not already @u.
* Returns true if the addition was done.
*/
static __inline__ bool local_add_unless(local_t *l, long a, long u)
{
unsigned long flags;
bool ret = false;
powerpc_local_irq_pmu_save(flags);
if (l->v != u) {
l->v += a;
ret = true;
}
powerpc_local_irq_pmu_restore(flags);
return ret;
}
#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
/* Use these for per-cpu local_t variables: on some archs they are
* much more efficient than these naive implementations. Note they take
* a variable, not an address.
*/
#define __local_inc(l) ((l)->v++)
#define __local_dec(l) ((l)->v++)
#define __local_add(i,l) ((l)->v+=(i))
#define __local_sub(i,l) ((l)->v-=(i))
#else /* CONFIG_PPC64 */
#include <asm-generic/local.h>
#endif /* CONFIG_PPC64 */
#endif /* _ARCH_POWERPC_LOCAL_H */