[PATCH 1/1] ARM : missing corrupted reg in __do_div_asm

[chengang.beijing@gmail.com (Chen Gang)]

__xl(R0 in little endian system, or R1 in big endian system) is corrupted
after calling __do_div64 and compiler is not informed about this in
macro __do_div_asm. If n is used again afterwards, __xl won't be
reloaded and n will contain incorrect value.

Signed-off-by: Chen Gang <gangchen@rdamicro.com>
Signed-off-by: Chen Gang <chengang.beijing@gmail.com>
---
 arch/arm/include/asm/div64.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/div64.h b/arch/arm/include/asm/div64.h
index e1f0776..1a6e91a 100644
--- a/arch/arm/include/asm/div64.h
+++ b/arch/arm/include/asm/div64.h
@@ -35,12 +35,14 @@ static inline uint32_t __div64_32(uint64_t *n, uint32_t base)
 	register unsigned long long __n   asm("r0") = *n;
 	register unsigned long long __res asm("r2");
 	register unsigned int __rem       asm(__xh);
+	register unsigned int __clobber   asm(__xl);
 	asm(	__asmeq("%0", __xh)
 		__asmeq("%1", "r2")
+		__asmeq("%3", "r0")
+		__asmeq("%4", "r4")
 		__asmeq("%2", "r0")
-		__asmeq("%3", "r4")
 		"bl	__do_div64"
-		: "=r" (__rem), "=r" (__res)
+		: "=r" (__rem), "=r" (__res), "=r" (__clobber)
 		: "r" (__n), "r" (__base)
 		: "ip", "lr", "cc");
 	*n = __res;
-- 
2.4.3