[PATCH] s390: atomic primitives

      Hugh Dickins <hugh@veritas.com>

Fix the broken atomic_cmpxchg primitive.  Add atomic_sub_and_test,
atomic64_sub_return, atomic64_sub_and_test, atomic64_cmpxchg,
atomic64_add_unless and atomic64_inc_not_zero.  Replace old style
atomic_compare_and_swap by atomic_cmpxchg.  Shorten the whole header by
defining most primitives with the two inline functions atomic_add_return and
atomic_sub_return.

In addition this patch contains the s390 related fixes of Hugh's "mm: fill
arch atomic64 gaps" patch.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 7008d32..6278739 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -7,7 +7,7 @@
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
  *
- * $Revision: 1.167 $
+ * $Revision: 1.169 $
  */
 
 #include <linux/config.h>
@@ -1323,7 +1323,7 @@
 dasd_schedule_bh(struct dasd_device * device)
 {
 	/* Protect against rescheduling. */
-	if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled))
+	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
 		return;
 	dasd_get_device(device);
 	tasklet_hi_schedule(&device->tasklet);