Use CC_SET(z)/CC_OUT(z) instead of explicit setz instruction.
Using these two defines, the compiler that supports generation of
condition code outputs from inline assembly flags generates e.g.:
cmpxchg8b %fs:(%esi)
jne 172255 <__kmalloc+0x65>
instead of
cmpxchg8b %fs:(%esi)
sete %al
test %al,%al
je 172255 <__kmalloc+0x65>
Note that older compilers now generate
cmpxchg8b %fs:(%esi)
sete %cl
test %cl,%cl
je 173a85 <__kmalloc+0x65>
since we have to mark that cmpxchg8b instruction outputs to %eax
register and this way clobbers the value in the register.
Signed-off-by: Uros Bizjak <ubiz...@gmail.com>
Cc: x...@kernel.org
---
arch/x86/include/asm/percpu.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index a06b07399d17..e9202a0de8f0 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -450,9 +450,10 @@ do {
\
bool __ret; \
typeof(pcp1) __o1 = (o1), __n1 = (n1); \
typeof(pcp2) __o2 = (o2), __n2 = (n2); \
- asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t" \
- : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
- : "b" (__n1), "c" (__n2), "a" (__o1)); \
+ asm volatile("cmpxchg8b "__percpu_arg(1) \
+ CC_SET(z) \
+ : CC_OUT(z) (__ret), "+m" (pcp1), "+m" (pcp2), "+a"
(__o1), "+d" (__o2) \
+ : "b" (__n1), "c" (__n2)); \
__ret; \
})
--
2.17.1
