Index: include/asm-i386/rwsem.h
===================================================================
RCS file: /src/nsc_linux/src/kernel/include/asm-i386/rwsem.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 rwsem.h
--- include/asm-i386/rwsem.h	2001/04/27 22:48:24	1.1.1.1
+++ include/asm-i386/rwsem.h	2001/07/06 20:54:13
@@ -222,5 +222,34 @@
 	return tmp+delta;
 }
 
+#if __HAVE_ARCH_CMPXCHG
+/* returns 1 if it successfully obtained the semaphore for write */
+static inline int down_write_trylock(struct rw_semaphore *sem)
+{
+	signed long ret = cmpxchg(&sem->count,
+				  RWSEM_UNLOCKED_VALUE, 
+				  RWSEM_ACTIVE_WRITE_BIAS);
+	if (ret == RWSEM_UNLOCKED_VALUE)
+		return 1;
+	return 0;
+}
+
+/* returns 1 if it successfully obtained the semaphore for read */
+static inline int down_read_trylock(struct rw_semaphore *sem)
+{
+	signed long old, new;
+
+repeat:
+	old = (volatile signed long)sem->count;
+	if (old < RWSEM_UNLOCKED_VALUE)
+		return 0;
+	new = old + RWSEM_ACTIVE_READ_BIAS;
+	if (cmpxchg(&sem->count, old, new) == old)
+		return 1;
+	else
+		goto repeat;
+}
+#endif /* __HAVE_ARCH_CMPXCHG */
+
 #endif /* __KERNEL__ */
 #endif /* _I386_RWSEM_H */