sparc32: make __cmpxchg_u32() return u32

Conversion between u32 and unsigned long is tautological there,
and the only use of return value is to return it from
__cmpxchg() (which return unsigned long).

Get rid of explicit casts in __cmpxchg_u32() call, while we are
at it - normal conversions for arguments will do just fine.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

arch/sparc/include/asm/cmpxchg_32.h

@@ -39,7 +39,7 @@ static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ v
 /* bug catcher for when unsupported size is used - won't link */
 void __cmpxchg_called_with_bad_pointer(void);
 /* we only need to support cmpxchg of a u32 on sparc */
-unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
+u32 __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
 
 /* don't worry...optimizer will get rid of most of this */
 static inline unsigned long
@@ -47,7 +47,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
 {
 	switch (size) {
 	case 4:
-		return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
+		return __cmpxchg_u32(ptr, old, new_);
 	default:
 		__cmpxchg_called_with_bad_pointer();
 		break;

arch/sparc/lib/atomic32.c

@@ -159,7 +159,7 @@ unsigned long sp32___change_bit(unsigned long *addr, unsigned long mask)
 }
 EXPORT_SYMBOL(sp32___change_bit);
 
-unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
+u32 __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
 {
 	unsigned long flags;
 	u32 prev;
@@ -169,7 +169,7 @@ unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
 		*ptr = new;
 	spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
 
-	return (unsigned long)prev;
+	return prev;
 }
 EXPORT_SYMBOL(__cmpxchg_u32);