[PATCH] ia64: fix xchg() warning

From: Arnd Bergmann
Date: Mon Jan 04 2021 - 03:59:09 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

The definition if xchg() causes a harmless warning in some files, like:

In file included from ../arch/ia64/include/uapi/asm/intrinsics.h:22,
from ../arch/ia64/include/asm/intrinsics.h:11,
from ../arch/ia64/include/asm/bitops.h:19,
from ../include/linux/bitops.h:32,
from ../include/linux/kernel.h:11,
from ../fs/nfs/read.c:12:
../fs/nfs/read.c: In function 'nfs_read_completion':
../arch/ia64/include/uapi/asm/cmpxchg.h:57:2: warning: value computed is not used [-Wunused-value]
57 | ((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr))))
| ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../fs/nfs/read.c:196:5: note: in expansion of macro 'xchg'
196 | xchg(&nfs_req_openctx(req)->error, error);
| ^~~~

Change it to a compound expression like the other architectures have
to get a clean defconfig build.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/ia64/include/uapi/asm/cmpxchg.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/ia64/include/uapi/asm/cmpxchg.h b/arch/ia64/include/uapi/asm/cmpxchg.h
index d69c979936d4..5d90307fd6e0 100644
--- a/arch/ia64/include/uapi/asm/cmpxchg.h
+++ b/arch/ia64/include/uapi/asm/cmpxchg.h
@@ -54,7 +54,7 @@ extern void ia64_xchg_called_with_bad_pointer(void);
})

#define xchg(ptr, x) \
-((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr))))
+({(__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));})

/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
--
2.29.2