[PATCH 12/12] arm64: Kbuild: Remove vestigial big-endian support

[Will Deacon]

Since 1cf89b6bf660 ("arm64: Kconfig: Make CPU_BIG_ENDIAN depend on
BROKEN"), CONFIG_CPU_BIG_ENDIAN has depended on BROKEN for arm64.

Remove the last traces of its existence and unconditionally force a
little-endian kernel build.

Signed-off-by: Will Deacon <will at kernel.org>
---
 arch/arm64/Kconfig  | 35 ++++-------------------------------
 arch/arm64/Makefile | 12 ++----------
 2 files changed, 6 insertions(+), 41 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b3afe0688919..84cf009c0021 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -73,7 +73,7 @@ config ARM64
 	select ARCH_SUPPORTS_HUGETLBFS
 	select ARCH_SUPPORTS_MEMORY_FAILURE
 	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
-	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
+	select ARCH_SUPPORTS_LTO_CLANG
 	select ARCH_SUPPORTS_LTO_CLANG_THIN
 	select ARCH_SUPPORTS_CFI
 	select ARCH_SUPPORTS_ATOMIC_RMW
@@ -223,7 +223,7 @@ config ARM64
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select MMU_GATHER_RCU_TABLE_FREE
 	select HAVE_RSEQ
-	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
+	select HAVE_RUST
 	select HAVE_STACKPROTECTOR
 	select HAVE_STATIC_CALL if CFI
 	select HAVE_SYSCALL_TRACEPOINTS
@@ -262,10 +262,6 @@ config ARM64
 	help
 	  ARM 64-bit (AArch64) Linux support.
 
-config RUSTC_SUPPORTS_ARM64
-	def_bool y
-	depends on CPU_LITTLE_ENDIAN
-
 config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
 	def_bool CC_IS_CLANG
 	# https://github.com/ClangBuiltLinux/linux/issues/1507
@@ -1542,28 +1538,6 @@ config ARM64_LPA2
 	def_bool y
 	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
 
-choice
-	prompt "Endianness"
-	default CPU_LITTLE_ENDIAN
-	help
-	  Select the endianness of data accesses performed by the CPU. Userspace
-	  applications will need to be compiled and linked for the endianness
-	  that is selected here.
-
-config CPU_BIG_ENDIAN
-	bool "Build big-endian kernel"
-	depends on BROKEN
-	help
-	  Say Y if you plan on running a kernel with a big-endian userspace.
-
-config CPU_LITTLE_ENDIAN
-	bool "Build little-endian kernel"
-	help
-	  Say Y if you plan on running a kernel with a little-endian userspace.
-	  This is usually the case for distributions targeting arm64.
-
-endchoice
-
 config NR_CPUS
 	int "Maximum number of CPUs (2-4096)"
 	range 2 4096
@@ -1801,7 +1775,6 @@ config KUSER_HELPERS
 
 config COMPAT_VDSO
 	bool "Enable vDSO for 32-bit applications"
-	depends on !CPU_BIG_ENDIAN
 	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
 	default y
 	help
@@ -2263,7 +2236,7 @@ menu "ARMv9.6 architectural features"
 config ARM64_LSUI
 	bool "Support Unprivileged Load Store Instructions (LSUI)"
 	default y
-	depends on AS_HAS_LSUI && !CPU_BIG_ENDIAN
+	depends on AS_HAS_LSUI
 	help
 	  The Unprivileged Load Store Instructions (LSUI) provides
 	  variants load/store instructions that access user-space memory
@@ -2468,7 +2441,7 @@ config EFI_STUB
 
 config EFI
 	bool "UEFI runtime support"
-	depends on OF && !CPU_BIG_ENDIAN
+	depends on OF
 	depends on KERNEL_MODE_NEON
 	select ARCH_SUPPORTS_ACPI
 	select LIBFDT
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 6b005c8fef70..04e1a0d12f8f 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -119,20 +119,12 @@ KBUILD_CFLAGS	+= -ffixed-x18
 KBUILD_RUSTFLAGS += -Zfixed-x18
 endif
 
-ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
-KBUILD_CPPFLAGS	+= -mbig-endian
-CHECKFLAGS	+= -D__AARCH64EB__
-# Prefer the baremetal ELF build target, but not all toolchains include
-# it so fall back to the standard linux version if needed.
-KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
-UTS_MACHINE	:= aarch64_be
-else
 KBUILD_CPPFLAGS	+= -mlittle-endian
 CHECKFLAGS	+= -D__AARCH64EL__
-# Same as above, prefer ELF but fall back to linux target if needed.
+# Prefer the baremetal ELF build target, but not all toolchains include
+# it so fall back to the standard linux version if needed.
 KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
 UTS_MACHINE	:= aarch64
-endif
 
 ifeq ($(CONFIG_LD_IS_LLD), y)
 KBUILD_LDFLAGS	+= -z norelro
-- 
2.55.0.679.g6767b8d81c-goog