[PATCH] ARM SMP: Fix ARMv6 spinlock and semaphore implementations

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 21 insertions, 18 deletions

diff --git a/include/asm-arm/locks.h b/include/asm-arm/locks.h
index c26298f3891f..9cb33fcc06c1 100644
--- a/include/asm-arm/locks.h
+++ b/include/asm-arm/locks.h
@@ -61,7 +61,7 @@
 "       strex   ip, lr, [%0]\n"                 \
 "       teq     ip, #0\n"                       \
 "       bne     1b\n"                           \
-"       teq     lr, #0\n"                       \
+"       cmp     lr, #0\n"                       \
 "       movle   ip, %0\n"                       \
 "       blle    " #wake                         \
         :                                       \
@@ -100,7 +100,7 @@
         __asm__ __volatile__(                   \
         "@ up_op_read\n"                        \
 "1:     ldrex   lr, [%0]\n"                     \
-"       add     lr, lr, %1\n"                   \
+"       adds    lr, lr, %1\n"                   \
 "       strex   ip, lr, [%0]\n"                 \
 "       teq     ip, #0\n"                       \
 "       bne     1b\n"                           \
diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h
index 182323619caa..9705d5eec94c 100644
--- a/include/asm-arm/spinlock.h
+++ b/include/asm-arm/spinlock.h
@@ -79,7 +79,8 @@ typedef struct {
 } rwlock_t;
 
 #define RW_LOCK_UNLOCKED        (rwlock_t) { 0 }
-#define rwlock_init(x)          do { *(x) + RW_LOCK_UNLOCKED; } while (0)
+#define rwlock_init(x)          do { *(x) = RW_LOCK_UNLOCKED; } while (0)
+#define rwlock_is_locked(x)     (*((volatile unsigned int *)(x)) != 0)
 
 /*
  * Write locks are easy - we just set bit 31.  When unlocking, we can
@@ -100,6 +101,21 @@ static inline void _raw_write_lock(rwlock_t *rw)
         : "cc", "memory");
 }
 
+static inline int _raw_write_trylock(rwlock_t *rw)
+{
+        unsigned long tmp;
+
+        __asm__ __volatile__(
+"1:     ldrex   %0, [%1]\n"
+"       teq     %0, #0\n"
+"       strexeq %0, %2, [%1]"
+        : "=&r" (tmp)
+        : "r" (&rw->lock), "r" (0x80000000)
+        : "cc", "memory");
+
+        return tmp == 0;
+}
+
 static inline void _raw_write_unlock(rwlock_t *rw)
 {
         __asm__ __volatile__(
@@ -138,6 +154,8 @@ static inline void _raw_read_lock(rwlock_t *rw)
 
 static inline void _raw_read_unlock(rwlock_t *rw)
 {
+        unsigned long tmp, tmp2;
+
         __asm__ __volatile__(
 "1:     ldrex   %0, [%2]\n"
 "       sub     %0, %0, #1\n"
@@ -151,19 +169,4 @@ static inline void _raw_read_unlock(rwlock_t *rw)
 
 #define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
 
-static inline int _raw_write_trylock(rwlock_t *rw)
-{
-        unsigned long tmp;
-
-        __asm__ __volatile__(
-"1:     ldrex   %0, [%1]\n"
-"       teq     %0, #0\n"
-"       strexeq %0, %2, [%1]"
-        : "=&r" (tmp)
-        : "r" (&rw->lock), "r" (0x80000000)
-        : "cc", "memory");
-
-        return tmp == 0;
-}
-
 #endif /* __ASM_SPINLOCK_H */