From: Andrey Konovalov <andreyknvl@google.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, "David S. Miller" <davem@davemloft.net>,
Peter Zijlstra <peterz@infradead.org>,
Alexander Duyck <alexander.h.duyck@redhat.com>,
Borislav Petkov <bp@suse.de>,
linux-kernel@vger.kernel.org
Cc: Andrey Konovalov <andreyknvl@google.com>,
Dmitry Vyukov <dvyukov@google.com>
Subject: [PATCH] x86: use WRITE_ONCE/READ_ONCE in smp_store_release/smp_load_acquire
Date: Sat, 1 Aug 2015 18:45:34 +0200 [thread overview]
Message-ID: <1438447534-14517-1-git-send-email-andreyknvl@google.com> (raw)
Replace ACCESS_ONCE() macro in smp_store_release() and smp_load_acquire()
from arch/x86/include/asm/barrier.h with WRITE_ONCE() and READ_ONCE() since
ACCESS_ONCE does not work reliably on non-scalar types.
WRITE_ONCE() and READ_ONCE() were introduced in the commits 230fa253df63
("kernel: Provide READ_ONCE and ASSIGN_ONCE") and 43239cbe79fc ("kernel:
Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)").
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
arch/x86/include/asm/barrier.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index e51a8f8..d2bcfbe 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -57,12 +57,12 @@
do { \
compiletime_assert_atomic_type(*p); \
smp_mb(); \
- ACCESS_ONCE(*p) = (v); \
+ WRITE_ONCE(*p, v); \
} while (0)
#define smp_load_acquire(p) \
({ \
- typeof(*p) ___p1 = ACCESS_ONCE(*p); \
+ typeof(*p) ___p1 = READ_ONCE(*p); \
compiletime_assert_atomic_type(*p); \
smp_mb(); \
___p1; \
@@ -74,12 +74,12 @@ do { \
do { \
compiletime_assert_atomic_type(*p); \
barrier(); \
- ACCESS_ONCE(*p) = (v); \
+ WRITE_ONCE(*p, v); \
} while (0)
#define smp_load_acquire(p) \
({ \
- typeof(*p) ___p1 = ACCESS_ONCE(*p); \
+ typeof(*p) ___p1 = READ_ONCE(*p); \
compiletime_assert_atomic_type(*p); \
barrier(); \
___p1; \
--
2.5.0.rc2.392.g76e840b
next reply other threads:[~2015-08-01 16:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-01 16:45 Andrey Konovalov [this message]
2015-08-01 16:55 ` Borislav Petkov
2015-08-01 17:18 ` Peter Zijlstra
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