[S390] Inline assembly cleanup.

Major cleanup of all s390 inline assemblies. They now have a common
coding style. Quite a few have been shortened, mainly by using register
asm variables. Use of the EX_TABLE macro helps  as well. The atomic ops,
bit ops and locking inlines new use the Q-constraint if a newer gcc
is used.  That results in slightly better code.

Thanks to Christian Borntraeger for proof reading the changes.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 23 insertions, 4 deletions

diff --git a/include/asm-s390/spinlock.h b/include/asm-s390/spinlock.h
index 273dbecf8ace..ce3edf6d63b3 100644
--- a/include/asm-s390/spinlock.h
+++ b/include/asm-s390/spinlock.h
@@ -11,17 +11,36 @@
 #ifndef __ASM_SPINLOCK_H
 #define __ASM_SPINLOCK_H
 
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
+
+static inline int
+_raw_compare_and_swap(volatile unsigned int *lock,
+                      unsigned int old, unsigned int new)
+{
+        asm volatile(
+                "       cs      %0,%3,%1"
+                : "=d" (old), "=Q" (*lock)
+                : "0" (old), "d" (new), "Q" (*lock)
+                : "cc", "memory" );
+        return old;
+}
+
+#else /* __GNUC__ */
+
 static inline int
 _raw_compare_and_swap(volatile unsigned int *lock,
                       unsigned int old, unsigned int new)
 {
-        asm volatile ("cs %0,%3,0(%4)"
-                      : "=d" (old), "=m" (*lock)
-                      : "0" (old), "d" (new), "a" (lock), "m" (*lock)
-                      : "cc", "memory" );
+        asm volatile(
+                "       cs      %0,%3,0(%4)"
+                : "=d" (old), "=m" (*lock)
+                : "0" (old), "d" (new), "a" (lock), "m" (*lock)
+                : "cc", "memory" );
         return old;
 }
 
+#endif /* __GNUC__ */
+
 /*
  * Simple spin lock operations.  There are two variants, one clears IRQ's
  * on the local processor, one does not.