[PATCH AUTOSEL 4.19 127/237] sparc64: Rework xchg() definition to avoid warnings.

Sasha Levin
2019-11-16T15:43:56Z

From: "David S. Miller" <davem@davemloft.net>

[ Upstream commit 6c2fc9cddc1ffdef8ada1dc8404e5affae849953 ]

Such as:

fs/ocfs2/file.c: In function ‘ocfs2_file_write_iter’:
./arch/sparc/include/asm/cmpxchg_64.h:55:22: warning: value computed is not used [-Wunused-value]
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))

and

drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c: In function ‘ixgbevf_xdp_setup’:
./arch/sparc/include/asm/cmpxchg_64.h:55:22: warning: value computed is not used [-Wunused-value]
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/sparc/include/asm/cmpxchg_64.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h
index f71ef3729888f..316faa0130bab 100644
--- a/arch/sparc/include/asm/cmpxchg_64.h
+++ b/arch/sparc/include/asm/cmpxchg_64.h
@@ -52,7 +52,12 @@ static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long
return val;
}

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

void __xchg_called_with_bad_pointer(void);

--
2.20.1