eccc2da8c0
Several architectures these have a near-identical implementation based on atomic_read() and atomic_cmpxchg() which we can instead define in <linux/atomic.h>, so let's do so, using something close to the existing x86 implementation with try_cmpxchg(). Where an architecture provides its own atomic_fetch_add_unless(), it must define a preprocessor symbol for it. The instrumented atomics are updated accordingly. Note that arch/arc's existing atomic_fetch_add_unless() had redundant barriers, as these are already present in its atomic_cmpxchg() implementation. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Link: https://lore.kernel.org/lkml/20180621121321.4761-7-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
112 lines
2.6 KiB
C
112 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __ARCH_H8300_ATOMIC__
|
|
#define __ARCH_H8300_ATOMIC__
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/types.h>
|
|
#include <asm/cmpxchg.h>
|
|
#include <asm/irqflags.h>
|
|
|
|
/*
|
|
* Atomic operations that C can't guarantee us. Useful for
|
|
* resource counting etc..
|
|
*/
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
#define atomic_read(v) READ_ONCE((v)->counter)
|
|
#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
|
|
|
|
#define ATOMIC_OP_RETURN(op, c_op) \
|
|
static inline int atomic_##op##_return(int i, atomic_t *v) \
|
|
{ \
|
|
h8300flags flags; \
|
|
int ret; \
|
|
\
|
|
flags = arch_local_irq_save(); \
|
|
ret = v->counter c_op i; \
|
|
arch_local_irq_restore(flags); \
|
|
return ret; \
|
|
}
|
|
|
|
#define ATOMIC_FETCH_OP(op, c_op) \
|
|
static inline int atomic_fetch_##op(int i, atomic_t *v) \
|
|
{ \
|
|
h8300flags flags; \
|
|
int ret; \
|
|
\
|
|
flags = arch_local_irq_save(); \
|
|
ret = v->counter; \
|
|
v->counter c_op i; \
|
|
arch_local_irq_restore(flags); \
|
|
return ret; \
|
|
}
|
|
|
|
#define ATOMIC_OP(op, c_op) \
|
|
static inline void atomic_##op(int i, atomic_t *v) \
|
|
{ \
|
|
h8300flags flags; \
|
|
\
|
|
flags = arch_local_irq_save(); \
|
|
v->counter c_op i; \
|
|
arch_local_irq_restore(flags); \
|
|
}
|
|
|
|
ATOMIC_OP_RETURN(add, +=)
|
|
ATOMIC_OP_RETURN(sub, -=)
|
|
|
|
#define ATOMIC_OPS(op, c_op) \
|
|
ATOMIC_OP(op, c_op) \
|
|
ATOMIC_FETCH_OP(op, c_op)
|
|
|
|
ATOMIC_OPS(and, &=)
|
|
ATOMIC_OPS(or, |=)
|
|
ATOMIC_OPS(xor, ^=)
|
|
ATOMIC_OPS(add, +=)
|
|
ATOMIC_OPS(sub, -=)
|
|
|
|
#undef ATOMIC_OPS
|
|
#undef ATOMIC_OP_RETURN
|
|
#undef ATOMIC_OP
|
|
|
|
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
|
|
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
|
|
|
|
#define atomic_inc_return(v) atomic_add_return(1, v)
|
|
#define atomic_dec_return(v) atomic_sub_return(1, v)
|
|
|
|
#define atomic_inc(v) (void)atomic_inc_return(v)
|
|
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
|
|
|
|
#define atomic_dec(v) (void)atomic_dec_return(v)
|
|
#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
|
|
|
|
static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
|
|
{
|
|
int ret;
|
|
h8300flags flags;
|
|
|
|
flags = arch_local_irq_save();
|
|
ret = v->counter;
|
|
if (likely(ret == old))
|
|
v->counter = new;
|
|
arch_local_irq_restore(flags);
|
|
return ret;
|
|
}
|
|
|
|
static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
|
|
{
|
|
int ret;
|
|
h8300flags flags;
|
|
|
|
flags = arch_local_irq_save();
|
|
ret = v->counter;
|
|
if (ret != u)
|
|
v->counter += a;
|
|
arch_local_irq_restore(flags);
|
|
return ret;
|
|
}
|
|
#define atomic_fetch_add_unless atomic_fetch_add_unless
|
|
|
|
#endif /* __ARCH_H8300_ATOMIC __ */
|