linux/arch/arm64/include/asm/atomic.h
Will Deacon 305d454aaa arm64: atomics: implement native {relaxed, acquire, release} atomics
Commit 654672d4ba ("locking/atomics: Add _{acquire|release|relaxed}()
variants of some atomic operation") introduced a relaxed atomic API to
Linux that maps nicely onto the arm64 memory model, including the new
ARMv8.1 atomic instructions.

This patch hooks up the API to our relaxed atomic instructions, rather
than have them all expand to the full-barrier variants as they do
currently.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-12 17:36:58 +01:00

151 lines
5.7 KiB
C

/*
* Based on arch/arm/include/asm/atomic.h
*
* Copyright (C) 1996 Russell King.
* Copyright (C) 2002 Deep Blue Solutions Ltd.
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_ATOMIC_H
#define __ASM_ATOMIC_H
#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/barrier.h>
#include <asm/lse.h>
#ifdef __KERNEL__
#define __ARM64_IN_ATOMIC_IMPL
#if defined(CONFIG_ARM64_LSE_ATOMICS) && defined(CONFIG_AS_LSE)
#include <asm/atomic_lse.h>
#else
#include <asm/atomic_ll_sc.h>
#endif
#undef __ARM64_IN_ATOMIC_IMPL
#include <asm/cmpxchg.h>
#define ___atomic_add_unless(v, a, u, sfx) \
({ \
typeof((v)->counter) c, old; \
\
c = atomic##sfx##_read(v); \
while (c != (u) && \
(old = atomic##sfx##_cmpxchg((v), c, c + (a))) != c) \
c = old; \
c; \
})
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) READ_ONCE((v)->counter)
#define atomic_set(v, i) (((v)->counter) = (i))
#define atomic_add_return_relaxed atomic_add_return_relaxed
#define atomic_add_return_acquire atomic_add_return_acquire
#define atomic_add_return_release atomic_add_return_release
#define atomic_add_return atomic_add_return
#define atomic_inc_return_relaxed(v) atomic_add_return_relaxed(1, (v))
#define atomic_inc_return_acquire(v) atomic_add_return_acquire(1, (v))
#define atomic_inc_return_release(v) atomic_add_return_release(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic_sub_return_relaxed atomic_sub_return_relaxed
#define atomic_sub_return_acquire atomic_sub_return_acquire
#define atomic_sub_return_release atomic_sub_return_release
#define atomic_sub_return atomic_sub_return
#define atomic_dec_return_relaxed(v) atomic_sub_return_relaxed(1, (v))
#define atomic_dec_return_acquire(v) atomic_sub_return_acquire(1, (v))
#define atomic_dec_return_release(v) atomic_sub_return_release(1, (v))
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_xchg_relaxed(v, new) xchg_relaxed(&((v)->counter), (new))
#define atomic_xchg_acquire(v, new) xchg_acquire(&((v)->counter), (new))
#define atomic_xchg_release(v, new) xchg_release(&((v)->counter), (new))
#define atomic_xchg(v, new) xchg(&((v)->counter), (new))
#define atomic_cmpxchg_relaxed(v, old, new) \
cmpxchg_relaxed(&((v)->counter), (old), (new))
#define atomic_cmpxchg_acquire(v, old, new) \
cmpxchg_acquire(&((v)->counter), (old), (new))
#define atomic_cmpxchg_release(v, old, new) \
cmpxchg_release(&((v)->counter), (old), (new))
#define atomic_cmpxchg(v, old, new) cmpxchg(&((v)->counter), (old), (new))
#define atomic_inc(v) atomic_add(1, (v))
#define atomic_dec(v) atomic_sub(1, (v))
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
#define __atomic_add_unless(v, a, u) ___atomic_add_unless(v, a, u,)
#define atomic_andnot atomic_andnot
/*
* 64-bit atomic operations.
*/
#define ATOMIC64_INIT ATOMIC_INIT
#define atomic64_read atomic_read
#define atomic64_set atomic_set
#define atomic64_add_return_relaxed atomic64_add_return_relaxed
#define atomic64_add_return_acquire atomic64_add_return_acquire
#define atomic64_add_return_release atomic64_add_return_release
#define atomic64_add_return atomic64_add_return
#define atomic64_inc_return_relaxed(v) atomic64_add_return_relaxed(1, (v))
#define atomic64_inc_return_acquire(v) atomic64_add_return_acquire(1, (v))
#define atomic64_inc_return_release(v) atomic64_add_return_release(1, (v))
#define atomic64_inc_return(v) atomic64_add_return(1, (v))
#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
#define atomic64_sub_return_acquire atomic64_sub_return_acquire
#define atomic64_sub_return_release atomic64_sub_return_release
#define atomic64_sub_return atomic64_sub_return
#define atomic64_dec_return_relaxed(v) atomic64_sub_return_relaxed(1, (v))
#define atomic64_dec_return_acquire(v) atomic64_sub_return_acquire(1, (v))
#define atomic64_dec_return_release(v) atomic64_sub_return_release(1, (v))
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
#define atomic64_xchg_relaxed atomic_xchg_relaxed
#define atomic64_xchg_acquire atomic_xchg_acquire
#define atomic64_xchg_release atomic_xchg_release
#define atomic64_xchg atomic_xchg
#define atomic64_cmpxchg_relaxed atomic_cmpxchg_relaxed
#define atomic64_cmpxchg_acquire atomic_cmpxchg_acquire
#define atomic64_cmpxchg_release atomic_cmpxchg_release
#define atomic64_cmpxchg atomic_cmpxchg
#define atomic64_inc(v) atomic64_add(1, (v))
#define atomic64_dec(v) atomic64_sub(1, (v))
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
#define atomic64_add_negative(i, v) (atomic64_add_return((i), (v)) < 0)
#define atomic64_add_unless(v, a, u) (___atomic_add_unless(v, a, u, 64) != u)
#define atomic64_andnot atomic64_andnot
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
#endif
#endif