From 8790ccf8daf1a8c53b6cb8ce0c9a109274bd3fa8 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Thu, 14 Jan 2021 10:34:16 -0700 Subject: MIPS: Compare __SYNC_loongson3_war against 0 When building with clang when CONFIG_CPU_LOONGSON3_WORKAROUNDS is enabled: In file included from lib/errseq.c:4: In file included from ./include/linux/atomic.h:7: ./arch/mips/include/asm/atomic.h:52:1: warning: converting the result of '<<' to a boolean always evaluates to true [-Wtautological-constant-compare] ATOMIC_OPS(atomic64, s64) ^ ./arch/mips/include/asm/atomic.h:40:9: note: expanded from macro 'ATOMIC_OPS' return cmpxchg(&v->counter, o, n); ^ ./arch/mips/include/asm/cmpxchg.h:194:7: note: expanded from macro 'cmpxchg' if (!__SYNC_loongson3_war) ^ ./arch/mips/include/asm/sync.h:147:34: note: expanded from macro '__SYNC_loongson3_war' # define __SYNC_loongson3_war (1 << 31) ^ While it is not wrong that the result of this shift is always true in a boolean context, it is not a problem here. Regardless, the warning is really noisy so rather than making the shift a boolean implicitly, use it in an equality comparison so the shift is used as an integer value. Fixes: 4d1dbfe6cbec ("MIPS: atomic: Emit Loongson3 sync workarounds within asm") Fixes: a91f2a1dba44 ("MIPS: cmpxchg: Omit redundant barriers for Loongson3") Reported-by: kernel test robot Signed-off-by: Nathan Chancellor Acked-by: Nick Desaulniers Signed-off-by: Thomas Bogendoerfer --- arch/mips/include/asm/atomic.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/mips/include/asm/atomic.h') diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index f904084fcb1f..27ad76791539 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -248,7 +248,7 @@ static __inline__ int pfx##_sub_if_positive(type i, pfx##_t * v) \ * bltz that can branch to code outside of the LL/SC loop. As \ * such, we don't need to emit another barrier here. \ */ \ - if (!__SYNC_loongson3_war) \ + if (__SYNC_loongson3_war == 0) \ smp_mb__after_atomic(); \ \ return result; \ -- cgit v1.2.3