[PATCH 4.18 307/350] arm64: lse: remove -fcall-used-x0 flag

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tri Vo <trong@xxxxxxxxxxx>

commit 2a6c7c367de82951c98a290a21156770f6f82c84 upstream.

x0 is not callee-saved in the PCS. So there is no need to specify
-fcall-used-x0.

Clang doesn't currently support -fcall-used flags. This patch will help
building the kernel with clang.

Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Tri Vo <trong@xxxxxxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/arm64/lib/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -12,7 +12,7 @@ lib-y		:= bitops.o clear_user.o delay.o
 # when supported by the CPU. Result and argument registers are handled
 # correctly, based on the function prototype.
 lib-$(CONFIG_ARM64_LSE_ATOMICS) += atomic_ll_sc.o
-CFLAGS_atomic_ll_sc.o	:= -fcall-used-x0 -ffixed-x1 -ffixed-x2		\
+CFLAGS_atomic_ll_sc.o	:= -ffixed-x1 -ffixed-x2        		\
 		   -ffixed-x3 -ffixed-x4 -ffixed-x5 -ffixed-x6		\
 		   -ffixed-x7 -fcall-saved-x8 -fcall-saved-x9		\
 		   -fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12	\