[PATCH 4/4] arm64: drop binutils version checks

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

Now that gcc-8 and binutils-2.30 are the minimum versions, a lot of
the individual feature checks can go away for simplification.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm64/Kconfig              | 37 ++-------------------------------
 arch/arm64/Makefile             | 21 ++-----------------
 arch/arm64/include/asm/rwonce.h |  4 ----
 arch/arm64/kvm/Kconfig          |  1 -
 arch/arm64/lib/xor-neon.c       |  2 +-
 5 files changed, 5 insertions(+), 60 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a182295e6f08..d33e3955566d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -642,9 +642,6 @@ config ARM64_ERRATUM_843419
 
 	  If unsure, say Y.
 
-config ARM64_LD_HAS_FIX_ERRATUM_843419
-	def_bool $(ld-option,--fix-cortex-a53-843419)
-
 config ARM64_ERRATUM_1024718
 	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
 	default y
@@ -1890,13 +1887,9 @@ config ARM64_PAN
 	  The feature is detected at runtime, and will remain as a 'nop'
 	  instruction if the cpu does not implement the feature.
 
-config AS_HAS_LSE_ATOMICS
-	def_bool $(as-instr,.arch_extension lse)
-
 config ARM64_LSE_ATOMICS
 	bool
 	default ARM64_USE_LSE_ATOMICS
-	depends on AS_HAS_LSE_ATOMICS
 
 config ARM64_USE_LSE_ATOMICS
 	bool "Atomic instructions"
@@ -1908,20 +1901,12 @@ config ARM64_USE_LSE_ATOMICS
 
 	  Say Y here to make use of these instructions for the in-kernel
 	  atomic routines. This incurs a small overhead on CPUs that do
-	  not support these instructions and requires the kernel to be
-	  built with binutils >= 2.25 in order for the new instructions
-	  to be used.
+	  not support these instructions.
 
 endmenu # "ARMv8.1 architectural features"
 
 menu "ARMv8.2 architectural features"
 
-config AS_HAS_ARMV8_2
-	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
-
-config AS_HAS_SHA3
-	def_bool $(as-instr,.arch armv8.2-a+sha3)
-
 config ARM64_PMEM
 	bool "Enable support for persistent memory"
 	select ARCH_HAS_PMEM_API
@@ -1995,7 +1980,6 @@ config ARM64_PTR_AUTH_KERNEL
 	bool "Use pointer authentication for kernel"
 	default y
 	depends on ARM64_PTR_AUTH
-	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
 	# Modern compilers insert a .note.gnu.property section note for PAC
 	# which is only understood by binutils starting with version 2.33.1.
 	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
@@ -2016,19 +2000,10 @@ config CC_HAS_BRANCH_PROT_PAC_RET
 	# GCC 9 or later, clang 8 or later
 	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
 
-config CC_HAS_SIGN_RETURN_ADDRESS
-	# GCC 7, 8
-	def_bool $(cc-option,-msign-return-address=all)
-
-config AS_HAS_ARMV8_3
-	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
-
 config AS_HAS_CFI_NEGATE_RA_STATE
+	# binutils 2.34+
 	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
 
-config AS_HAS_LDAPR
-	def_bool $(as-instr,.arch_extension rcpc)
-
 endmenu # "ARMv8.3 architectural features"
 
 menu "ARMv8.4 architectural features"
@@ -2056,20 +2031,13 @@ config ARM64_AMU_EXTN
 	  correctly reflect reality. Most commonly, the value read will be 0,
 	  indicating that the counter is not enabled.
 
-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 # "ARMv8.4 architectural features"
 
 menu "ARMv8.5 architectural features"
@@ -2145,7 +2113,6 @@ config ARM64_MTE
 	default y
 	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
 	depends on AS_HAS_ARMV8_5
-	depends on AS_HAS_LSE_ATOMICS
 	# Required for tag checking in the uaccess routines
 	select ARM64_PAN
 	select ARCH_HAS_SUBPAGE_FAULTS
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 1d5dfcd1c13e..73a10f65ce8b 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -16,14 +16,11 @@ ifeq ($(CONFIG_RELOCATABLE), y)
 # Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
 # for relative relocs, since this leads to better Image compression
 # with the relocation offsets always being zero.
-LDFLAGS_vmlinux		+= -shared -Bsymbolic -z notext \
-			$(call ld-option, --no-apply-dynamic-relocs)
+LDFLAGS_vmlinux	+= -shared -Bsymbolic -z notext --no-apply-dynamic-relocs
 endif
 
 ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
-  ifeq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
 LDFLAGS_vmlinux	+= --fix-cortex-a53-843419
-  endif
 endif
 
 cc_has_k_constraint := $(call try-run,echo				\
@@ -105,12 +102,8 @@ endif
 # hardware.
 ifeq ($(CONFIG_AS_HAS_ARMV8_5), y)
   asm-arch := armv8.5-a
-else ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)
+else
   asm-arch := armv8.4-a
-else ifeq ($(CONFIG_AS_HAS_ARMV8_3), y)
-  asm-arch := armv8.3-a
-else ifeq ($(CONFIG_AS_HAS_ARMV8_2), y)
-  asm-arch := armv8.2-a
 endif
 
 ifdef asm-arch
@@ -201,16 +194,6 @@ install zinstall:
 
 archprepare:
 	$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
-ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
-  ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
-	@echo "warning: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum" >&2
-  endif
-endif
-ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
-  ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
-	@echo "warning: LSE atomics not supported by binutils" >&2
-  endif
-endif
 
 ifeq ($(KBUILD_EXTMOD),)
 # We need to generate vdso-offsets.h before compiling certain files in kernel/.
diff --git a/arch/arm64/include/asm/rwonce.h b/arch/arm64/include/asm/rwonce.h
index 56f7b1d4d54b..97d9256d33c9 100644
--- a/arch/arm64/include/asm/rwonce.h
+++ b/arch/arm64/include/asm/rwonce.h
@@ -12,16 +12,12 @@
 
 #ifndef BUILD_VDSO
 
-#ifdef CONFIG_AS_HAS_LDAPR
 #define __LOAD_RCPC(sfx, regs...)					\
 	ALTERNATIVE(							\
 		"ldar"	#sfx "\t" #regs,				\
 		".arch_extension rcpc\n"				\
 		"ldapr"	#sfx "\t" #regs,				\
 	ARM64_HAS_LDAPR)
-#else
-#define __LOAD_RCPC(sfx, regs...)	"ldar" #sfx "\t" #regs
-#endif /* CONFIG_AS_HAS_LDAPR */
 
 /*
  * When building with LTO, there is an increased risk of the compiler
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 096e45acadb2..713248f240e0 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -19,7 +19,6 @@ if VIRTUALIZATION
 
 menuconfig KVM
 	bool "Kernel-based Virtual Machine (KVM) support"
-	depends on AS_HAS_ARMV8_4
 	select KVM_COMMON
 	select KVM_GENERIC_HARDWARE_ENABLING
 	select KVM_GENERIC_MMU_NOTIFIER
diff --git a/arch/arm64/lib/xor-neon.c b/arch/arm64/lib/xor-neon.c
index f9a53b7f9842..8fffebfa17b2 100644
--- a/arch/arm64/lib/xor-neon.c
+++ b/arch/arm64/lib/xor-neon.c
@@ -319,7 +319,7 @@ static void xor_arm64_eor3_5(unsigned long bytes,
 
 static int __init xor_neon_init(void)
 {
-	if (IS_ENABLED(CONFIG_AS_HAS_SHA3) && cpu_have_named_feature(SHA3)) {
+	if (cpu_have_named_feature(SHA3)) {
 		xor_block_inner_neon.do_3 = xor_arm64_eor3_3;
 		xor_block_inner_neon.do_4 = xor_arm64_eor3_4;
 		xor_block_inner_neon.do_5 = xor_arm64_eor3_5;
-- 
2.39.5