From: Zhenyu Ye <yezhenyu2@huawei.com>
Date: Wed, 15 Jul 2020 15:19:44 +0800
Subject: arm64: enable tlbi range instructions
Git-commit: 7c78f67e9bd97478d56157c2ad53823668b5b822
Patch-mainline: v5.9-rc1
References: jsc#SLE-13697

TLBI RANGE feature instoduces new assembly instructions and only
support by binutils >= 2.30.  Add necessary Kconfig logic to allow
this to be enabled and pass '-march=armv8.4-a' to KBUILD_CFLAGS.

Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com>
Link: https://lore.kernel.org/r/20200715071945.897-3-yezhenyu2@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 arch/arm64/Kconfig  |   14 ++++++++++++++
 arch/arm64/Makefile |    5 +++++
 2 files changed, 19 insertions(+)

--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1616,6 +1616,20 @@ config DMI
 	  However, even with this option, the resultant kernel should
 	  continue to boot on existing non-UEFI platforms.
 
+config AS_HAS_ARMV8_4
+	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
+
+config ARM64_TLB_RANGE
+	bool "Enable support for tlbi range feature"
+	default y
+	depends on AS_HAS_ARMV8_4
+	help
+	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
+	  range of input addresses.
+
+	  The feature introduces new assembly instructions, and they were
+	  support when binutils >= 2.30.
+
 endmenu
 
 config SYSVIPC_COMPAT
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -77,6 +77,11 @@ stack_protector_prepare: prepare0
 					include/generated/asm-offsets.h))
 endif
 
+ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
+# make sure to pass the newest target architecture to -march.
+KBUILD_CFLAGS	+= -Wa,-march=armv8.4-a
+endif
+
 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
 KBUILD_CPPFLAGS	+= -mbig-endian
 CHECKFLAGS	+= -D__AARCH64EB__