[PATCH 06/13] ARM: atomic: fix gcc-4.4 build

[Arnd Bergmann]

gcc-4.4 fails to build some files with this constraint, which was
added to help out with gcc-4.6 and higher:

fs/btrfs/delayed-ref.c: In function 'add_delayed_tree_ref':
arch/arm/include/asm/atomic.h:280: error: 'asm' operand requires impossible reload

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44492
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 arch/arm/include/asm/atomic.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index 66d0e215a773..65d5b843831a 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h
@@ -280,7 +280,10 @@ static inline long long atomic64_read(const atomic64_t *v)
 	__asm__ __volatile__("@ atomic64_read\n"
 "	ldrd	%0, %H0, [%1]"
 	: "=&r" (result)
-	: "r" (&v->counter), "Qo" (v->counter)
+	: "r" (&v->counter)
+#if GCC_VERSION >= 40600
+	, "Qo" (v->counter)
+#endif
 	);
 
 	return result;
@@ -302,7 +305,10 @@ static inline long long atomic64_read(const atomic64_t *v)
 	__asm__ __volatile__("@ atomic64_read\n"
 "	ldrexd	%0, %H0, [%1]"
 	: "=&r" (result)
-	: "r" (&v->counter), "Qo" (v->counter)
+	: "r" (&v->counter)
+#if GCC_VERSION >= 40600
+	, "Qo" (v->counter)
+#endif
 	);
 
 	return result;
-- 
2.9.0