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-rw-r--r--include/asm-arm/bitops.h4
-rw-r--r--include/asm-arm/locks.h36
-rw-r--r--include/asm-arm/spinlock.h53
-rw-r--r--include/asm-arm/system.h5
4 files changed, 69 insertions, 29 deletions
diff --git a/include/asm-arm/bitops.h b/include/asm-arm/bitops.h
index 4edd4dc40c5b..c1adc6b3e86d 100644
--- a/include/asm-arm/bitops.h
+++ b/include/asm-arm/bitops.h
@@ -21,8 +21,8 @@
#include <asm/system.h>
-#define smp_mb__before_clear_bit() do { } while (0)
-#define smp_mb__after_clear_bit() do { } while (0)
+#define smp_mb__before_clear_bit() mb()
+#define smp_mb__after_clear_bit() mb()
/*
* These functions are the basis of our bit ops.
diff --git a/include/asm-arm/locks.h b/include/asm-arm/locks.h
index 9cb33fcc06c1..f08dc8447913 100644
--- a/include/asm-arm/locks.h
+++ b/include/asm-arm/locks.h
@@ -28,7 +28,8 @@
" blmi " #fail \
: \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
})
#define __down_op_ret(ptr,fail) \
@@ -48,12 +49,14 @@
" mov %0, ip" \
: "=&r" (ret) \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
ret; \
})
#define __up_op(ptr,wake) \
({ \
+ smp_mb(); \
__asm__ __volatile__( \
"@ up_op\n" \
"1: ldrex lr, [%0]\n" \
@@ -66,7 +69,7 @@
" blle " #wake \
: \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
})
/*
@@ -92,11 +95,13 @@
" blne " #fail \
: \
: "r" (ptr), "I" (RW_LOCK_BIAS) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
})
#define __up_op_write(ptr,wake) \
({ \
+ smp_mb(); \
__asm__ __volatile__( \
"@ up_op_read\n" \
"1: ldrex lr, [%0]\n" \
@@ -108,7 +113,7 @@
" blcs " #wake \
: \
: "r" (ptr), "I" (RW_LOCK_BIAS) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
})
#define __down_op_read(ptr,fail) \
@@ -116,6 +121,7 @@
#define __up_op_read(ptr,wake) \
({ \
+ smp_mb(); \
__asm__ __volatile__( \
"@ up_op_read\n" \
"1: ldrex lr, [%0]\n" \
@@ -128,7 +134,7 @@
" bleq " #wake \
: \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
})
#else
@@ -148,7 +154,8 @@
" blmi " #fail \
: \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
})
#define __down_op_ret(ptr,fail) \
@@ -169,12 +176,14 @@
" mov %0, ip" \
: "=&r" (ret) \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
ret; \
})
#define __up_op(ptr,wake) \
({ \
+ smp_mb(); \
__asm__ __volatile__( \
"@ up_op\n" \
" mrs ip, cpsr\n" \
@@ -188,7 +197,7 @@
" blle " #wake \
: \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
})
/*
@@ -215,7 +224,8 @@
" blne " #fail \
: \
: "r" (ptr), "I" (RW_LOCK_BIAS) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
})
#define __up_op_write(ptr,wake) \
@@ -233,7 +243,8 @@
" blcs " #wake \
: \
: "r" (ptr), "I" (RW_LOCK_BIAS) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
})
#define __down_op_read(ptr,fail) \
@@ -241,6 +252,7 @@
#define __up_op_read(ptr,wake) \
({ \
+ smp_mb(); \
__asm__ __volatile__( \
"@ up_op_read\n" \
" mrs ip, cpsr\n" \
@@ -254,7 +266,7 @@
" bleq " #wake \
: \
: "r" (ptr), "I" (1) \
- : "ip", "lr", "cc", "memory"); \
+ : "ip", "lr", "cc"); \
})
#endif
diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h
index 9705d5eec94c..1f906d09b688 100644
--- a/include/asm-arm/spinlock.h
+++ b/include/asm-arm/spinlock.h
@@ -8,9 +8,10 @@
/*
* ARMv6 Spin-locking.
*
- * We (exclusively) read the old value, and decrement it. If it
- * hits zero, we may have won the lock, so we try (exclusively)
- * storing it.
+ * We exclusively read the old value. If it is zero, we may have
+ * won the lock, so we try exclusively storing it. A memory barrier
+ * is required after we get a lock, and before we release it, because
+ * V6 CPUs are assumed to have weakly ordered memory.
*
* Unlocked value: 0
* Locked value: 1
@@ -41,7 +42,9 @@ static inline void _raw_spin_lock(spinlock_t *lock)
" bne 1b"
: "=&r" (tmp)
: "r" (&lock->lock), "r" (1)
- : "cc", "memory");
+ : "cc");
+
+ smp_mb();
}
static inline int _raw_spin_trylock(spinlock_t *lock)
@@ -54,18 +57,25 @@ static inline int _raw_spin_trylock(spinlock_t *lock)
" strexeq %0, %2, [%1]"
: "=&r" (tmp)
: "r" (&lock->lock), "r" (1)
- : "cc", "memory");
-
- return tmp == 0;
+ : "cc");
+
+ if (tmp == 0) {
+ smp_mb();
+ return 1;
+ } else {
+ return 0;
+ }
}
static inline void _raw_spin_unlock(spinlock_t *lock)
{
+ smp_mb();
+
__asm__ __volatile__(
" str %1, [%0]"
:
: "r" (&lock->lock), "r" (0)
- : "cc", "memory");
+ : "cc");
}
/*
@@ -98,7 +108,9 @@ static inline void _raw_write_lock(rwlock_t *rw)
" bne 1b"
: "=&r" (tmp)
: "r" (&rw->lock), "r" (0x80000000)
- : "cc", "memory");
+ : "cc");
+
+ smp_mb();
}
static inline int _raw_write_trylock(rwlock_t *rw)
@@ -111,18 +123,25 @@ static inline int _raw_write_trylock(rwlock_t *rw)
" strexeq %0, %2, [%1]"
: "=&r" (tmp)
: "r" (&rw->lock), "r" (0x80000000)
- : "cc", "memory");
-
- return tmp == 0;
+ : "cc");
+
+ if (tmp == 0) {
+ smp_mb();
+ return 1;
+ } else {
+ return 0;
+ }
}
static inline void _raw_write_unlock(rwlock_t *rw)
{
+ smp_mb();
+
__asm__ __volatile__(
"str %1, [%0]"
:
: "r" (&rw->lock), "r" (0)
- : "cc", "memory");
+ : "cc");
}
/*
@@ -149,13 +168,17 @@ static inline void _raw_read_lock(rwlock_t *rw)
" bmi 1b"
: "=&r" (tmp), "=&r" (tmp2)
: "r" (&rw->lock)
- : "cc", "memory");
+ : "cc");
+
+ smp_mb();
}
static inline void _raw_read_unlock(rwlock_t *rw)
{
unsigned long tmp, tmp2;
+ smp_mb();
+
__asm__ __volatile__(
"1: ldrex %0, [%2]\n"
" sub %0, %0, #1\n"
@@ -164,7 +187,7 @@ static inline void _raw_read_unlock(rwlock_t *rw)
" bne 1b"
: "=&r" (tmp), "=&r" (tmp2)
: "r" (&rw->lock)
- : "cc", "memory");
+ : "cc");
}
#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h
index 3f9c3626a73c..8efa4ebdcacb 100644
--- a/include/asm-arm/system.h
+++ b/include/asm-arm/system.h
@@ -139,7 +139,12 @@ extern unsigned int user_debug;
#define vectors_high() (0)
#endif
+#if __LINUX_ARM_ARCH__ >= 6
+#define mb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \
+ : : "r" (0) : "memory")
+#else
#define mb() __asm__ __volatile__ ("" : : : "memory")
+#endif
#define rmb() mb()
#define wmb() mb()
#define read_barrier_depends() do { } while(0)
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