Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...

[linux-2.6.git] / include / asm-arm / spinlock.h

diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h
index 406ca97..01b7c26 100644 (file)
--- a/include/asm-arm/spinlock.h
+++ b/include/asm-arm/spinlock.h
@@ -199,7 +199,21 @@ static inline void __raw_read_unlock(raw_rwlock_t *rw)
        : "cc");
 }
 
-#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
+static inline int __raw_read_trylock(raw_rwlock_t *rw)
+{
+       unsigned long tmp, tmp2 = 1;
+
+       __asm__ __volatile__(
+"1:    ldrex   %0, [%2]\n"
+"      adds    %0, %0, #1\n"
+"      strexpl %1, %0, [%2]\n"
+       : "=&r" (tmp), "+r" (tmp2)
+       : "r" (&rw->lock)
+       : "cc");
+
+       smp_mb();
+       return tmp2 == 0;
+}
 
 /* read_can_lock - would read_trylock() succeed? */
 #define __raw_read_can_lock(x)         ((x)->lock < 0x80000000)