[PATCH] ARM: do not assemble iwmmxt.S with LLVM toolchain

[Jian Cai]

iwmmxt.S contains XScale instructions LLVM ARM backend does not support.
Skip this file if LLVM integrated assemmbler or LLD is used to build ARM
kernel.

Signed-off-by: Jian Cai <caij2003@xxxxxxxxx>
---
 arch/arm/Kconfig | 2 +-
 init/Kconfig     | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 66a04f6f4775..39de8fc64a73 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -804,7 +804,7 @@ source "arch/arm/mm/Kconfig"
 
 config IWMMXT
 	bool "Enable iWMMXt support"
-	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
+	depends on !AS_IS_CLANG && !LD_IS_LLD && (CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B)
 	default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
 	help
 	  Enable support for iWMMXt context switching at run time if
diff --git a/init/Kconfig b/init/Kconfig
index 1c12059e0f7e..b0ab3271e900 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -19,6 +19,12 @@ config GCC_VERSION
 config CC_IS_CLANG
 	def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
 
+config AS_IS_CLANG
+	def_bool $(success,$(AS) --version | head -n 1 | grep -q clang)
+
+config LD_IS_LLD
+	def_bool $(success,$(LD) --version | head -n 1 | grep -q LLD)
+
 config CLANG_VERSION
 	int
 	default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
-- 
2.26.0.110.g2183baf09c-goog