arm64: enable tlbi range instructions

mainline inclusion
from mainline-v5.8
commit 7c78f67e
category: feature
CVE: NA

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

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: NZhenyu Ye <yezhenyu2@huawei.com>
Link: https://lore.kernel.org/r/20200715071945.897-3-yezhenyu2@huawei.comSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NYuan Can <yuancan@huawei.com>
Reviewed-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/Kconfig

@@ -1304,6 +1304,24 @@ config AS_HAS_CFI_NEGATE_RA_STATE
 
 endmenu
 
+menu "ARMv8.4 architectural features"
+
+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 ARM64_SVE
 	bool "ARM Scalable Vector Extension support"
 	default y

arch/arm64/Makefile

@@ -68,6 +68,11 @@ branch-prot-flags-$(CONFIG_AS_HAS_PAC) += -Wa,-march=armv8.3-a
 KBUILD_CFLAGS += $(branch-prot-flags-y)
 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__