linux/include/asm-generic/atomic64.h
Mark Rutland 1bdadf46ef locking/atomic: atomic64: support ARCH_ATOMIC
We'd like all architectures to convert to ARCH_ATOMIC, as this will
enable functionality, and once all architectures are converted it will
be possible to make significant cleanups to the atomic headers.

A number of architectures use asm-generic/atomic64.h, and it's
impractical to convert the header and all these architectures in one go.
To make it possible to convert them one-by-one, let's make the
asm-generic implementation function as either atomic64_*() or
arch_atomic64_*() depending on whether ARCH_ATOMIC is selected. To do
this, the generic implementations are prefixed as generic_atomic64_*(),
and preprocessor definitions map atomic64_*()/arch_atomic64_*() onto
these as appropriate.

Once all users are moved over to ARCH_ATOMIC the ifdeffery in the header
can be simplified and/or removed entirely.

For existing users (none of which select ARCH_ATOMIC), there should be
no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-11-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00

105 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Generic implementation of 64-bit atomics using spinlocks,
* useful on processors that don't have 64-bit atomic instructions.
*
* Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*/
#ifndef _ASM_GENERIC_ATOMIC64_H
#define _ASM_GENERIC_ATOMIC64_H
#include <linux/types.h>
typedef struct {
s64 counter;
} atomic64_t;
#define ATOMIC64_INIT(i) { (i) }
extern s64 generic_atomic64_read(const atomic64_t *v);
extern void generic_atomic64_set(atomic64_t *v, s64 i);
#define ATOMIC64_OP(op) \
extern void generic_atomic64_##op(s64 a, atomic64_t *v);
#define ATOMIC64_OP_RETURN(op) \
extern s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v);
#define ATOMIC64_FETCH_OP(op) \
extern s64 generic_atomic64_fetch_##op(s64 a, atomic64_t *v);
#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op)
ATOMIC64_OPS(add)
ATOMIC64_OPS(sub)
#undef ATOMIC64_OPS
#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op)
ATOMIC64_OPS(and)
ATOMIC64_OPS(or)
ATOMIC64_OPS(xor)
#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
extern s64 generic_atomic64_dec_if_positive(atomic64_t *v);
extern s64 generic_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n);
extern s64 generic_atomic64_xchg(atomic64_t *v, s64 new);
extern s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u);
#ifdef CONFIG_ARCH_ATOMIC
#define arch_atomic64_read generic_atomic64_read
#define arch_atomic64_set generic_atomic64_set
#define arch_atomic64_set_release generic_atomic64_set
#define arch_atomic64_add generic_atomic64_add
#define arch_atomic64_add_return generic_atomic64_add_return
#define arch_atomic64_fetch_add generic_atomic64_fetch_add
#define arch_atomic64_sub generic_atomic64_sub
#define arch_atomic64_sub_return generic_atomic64_sub_return
#define arch_atomic64_fetch_sub generic_atomic64_fetch_sub
#define arch_atomic64_and generic_atomic64_and
#define arch_atomic64_fetch_and generic_atomic64_fetch_and
#define arch_atomic64_or generic_atomic64_or
#define arch_atomic64_fetch_or generic_atomic64_fetch_or
#define arch_atomic64_xor generic_atomic64_xor
#define arch_atomic64_fetch_xor generic_atomic64_fetch_xor
#define arch_atomic64_dec_if_positive generic_atomic64_dec_if_positive
#define arch_atomic64_cmpxchg generic_atomic64_cmpxchg
#define arch_atomic64_xchg generic_atomic64_xchg
#define arch_atomic64_fetch_add_unless generic_atomic64_fetch_add_unless
#else /* CONFIG_ARCH_ATOMIC */
#define atomic64_read generic_atomic64_read
#define atomic64_set generic_atomic64_set
#define atomic64_set_release generic_atomic64_set
#define atomic64_add generic_atomic64_add
#define atomic64_add_return generic_atomic64_add_return
#define atomic64_fetch_add generic_atomic64_fetch_add
#define atomic64_sub generic_atomic64_sub
#define atomic64_sub_return generic_atomic64_sub_return
#define atomic64_fetch_sub generic_atomic64_fetch_sub
#define atomic64_and generic_atomic64_and
#define atomic64_fetch_and generic_atomic64_fetch_and
#define atomic64_or generic_atomic64_or
#define atomic64_fetch_or generic_atomic64_fetch_or
#define atomic64_xor generic_atomic64_xor
#define atomic64_fetch_xor generic_atomic64_fetch_xor
#define atomic64_dec_if_positive generic_atomic64_dec_if_positive
#define atomic64_cmpxchg generic_atomic64_cmpxchg
#define atomic64_xchg generic_atomic64_xchg
#define atomic64_fetch_add_unless generic_atomic64_fetch_add_unless
#endif /* CONFIG_ARCH_ATOMIC */
#endif /* _ASM_GENERIC_ATOMIC64_H */