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-rw-r--r--arch/arm/include/asm/spinlock.h13
-rw-r--r--arch/arm/include/asm/spinlock_types.h2
2 files changed, 11 insertions, 4 deletions
diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h
index e1ce45230913..499900781d59 100644
--- a/arch/arm/include/asm/spinlock.h
+++ b/arch/arm/include/asm/spinlock.h
@@ -5,7 +5,7 @@
#error SMP not supported on pre-ARMv6 CPUs
#endif
-#include <asm/processor.h>
+#include <linux/prefetch.h>
/*
* sev and wfe are ARMv6K extensions. Uniprocessor ARMv6 may not have the K
@@ -70,6 +70,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
u32 newval;
arch_spinlock_t lockval;
+ prefetchw(&lock->slock);
__asm__ __volatile__(
"1: ldrex %0, [%3]\n"
" add %1, %0, %4\n"
@@ -93,6 +94,7 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock)
unsigned long contended, res;
u32 slock;
+ prefetchw(&lock->slock);
do {
__asm__ __volatile__(
" ldrex %0, [%3]\n"
@@ -145,6 +147,7 @@ static inline void arch_write_lock(arch_rwlock_t *rw)
{
unsigned long tmp;
+ prefetchw(&rw->lock);
__asm__ __volatile__(
"1: ldrex %0, [%1]\n"
" teq %0, #0\n"
@@ -163,6 +166,7 @@ static inline int arch_write_trylock(arch_rwlock_t *rw)
{
unsigned long contended, res;
+ prefetchw(&rw->lock);
do {
__asm__ __volatile__(
" ldrex %0, [%2]\n"
@@ -196,7 +200,7 @@ static inline void arch_write_unlock(arch_rwlock_t *rw)
}
/* write_can_lock - would write_trylock() succeed? */
-#define arch_write_can_lock(x) ((x)->lock == 0)
+#define arch_write_can_lock(x) (ACCESS_ONCE((x)->lock) == 0)
/*
* Read locks are a bit more hairy:
@@ -214,6 +218,7 @@ static inline void arch_read_lock(arch_rwlock_t *rw)
{
unsigned long tmp, tmp2;
+ prefetchw(&rw->lock);
__asm__ __volatile__(
"1: ldrex %0, [%2]\n"
" adds %0, %0, #1\n"
@@ -234,6 +239,7 @@ static inline void arch_read_unlock(arch_rwlock_t *rw)
smp_mb();
+ prefetchw(&rw->lock);
__asm__ __volatile__(
"1: ldrex %0, [%2]\n"
" sub %0, %0, #1\n"
@@ -252,6 +258,7 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
{
unsigned long contended, res;
+ prefetchw(&rw->lock);
do {
__asm__ __volatile__(
" ldrex %0, [%2]\n"
@@ -273,7 +280,7 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
}
/* read_can_lock - would read_trylock() succeed? */
-#define arch_read_can_lock(x) ((x)->lock < 0x80000000)
+#define arch_read_can_lock(x) (ACCESS_ONCE((x)->lock) < 0x80000000)
#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
diff --git a/arch/arm/include/asm/spinlock_types.h b/arch/arm/include/asm/spinlock_types.h
index b262d2f8b478..47663fcb10ad 100644
--- a/arch/arm/include/asm/spinlock_types.h
+++ b/arch/arm/include/asm/spinlock_types.h
@@ -25,7 +25,7 @@ typedef struct {
#define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } }
typedef struct {
- volatile unsigned int lock;
+ u32 lock;
} arch_rwlock_t;
#define __ARCH_RW_LOCK_UNLOCKED { 0 }