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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /arch/tile/include/asm/spinlock_64.h
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'arch/tile/include/asm/spinlock_64.h')
-rw-r--r--arch/tile/include/asm/spinlock_64.h5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/tile/include/asm/spinlock_64.h b/arch/tile/include/asm/spinlock_64.h
index 9a12b9c7e..b9718fb4e 100644
--- a/arch/tile/include/asm/spinlock_64.h
+++ b/arch/tile/include/asm/spinlock_64.h
@@ -18,6 +18,8 @@
#ifndef _ASM_TILE_SPINLOCK_64_H
#define _ASM_TILE_SPINLOCK_64_H
+#include <linux/compiler.h>
+
/* Shifts and masks for the various fields in "lock". */
#define __ARCH_SPIN_CURRENT_SHIFT 17
#define __ARCH_SPIN_NEXT_MASK 0x7fff
@@ -44,7 +46,8 @@ static inline u32 arch_spin_next(u32 val)
/* The lock is locked if a task would have to wait to get it. */
static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
- u32 val = lock->lock;
+ /* Use READ_ONCE() to ensure that calling this in a loop is OK. */
+ u32 val = READ_ONCE(lock->lock);
return arch_spin_current(val) != arch_spin_next(val);
}