diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 557c4a8c4087..c192bd7305dc 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -331,6 +331,28 @@ config RISCV_BASE_PMU endmenu +config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI + def_bool y + # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc + depends on AS_IS_GNU && AS_VERSION >= 23800 + help + Newer binutils versions default to ISA spec version 20191213 which + moves some instructions from the I extension to the Zicsr and Zifencei + extensions. + +config TOOLCHAIN_NEEDS_OLD_ISA_SPEC + def_bool y + depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI + # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 + depends on CC_IS_CLANG && CLANG_VERSION < 170000 + help + Certain versions of clang do not support zicsr and zifencei via -march + but newer versions of binutils require it for the reasons noted in the + help text of CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. This + option causes an older ISA spec compatible with these older versions + of clang to be passed to GAS, which has the same result as passing zicsr + and zifencei to -march. + config FPU bool "FPU support" default y diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 14cdeaa2bb32..daa679440000 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -53,10 +53,12 @@ riscv-march-$(CONFIG_ARCH_RV64I) := rv64ima riscv-march-$(CONFIG_FPU) := $(riscv-march-y)fd riscv-march-$(CONFIG_RISCV_ISA_C) := $(riscv-march-y)c -# Newer binutils versions default to ISA spec version 20191213 which moves some -# instructions from the I extension to the Zicsr and Zifencei extensions. -toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei) -riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei +ifdef CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC +KBUILD_CFLAGS += -Wa,-misa-spec=2.2 +KBUILD_AFLAGS += -Wa,-misa-spec=2.2 +else +riscv-march-$(CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI) := $(riscv-march-y)_zicsr_zifencei +endif KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y)) KBUILD_AFLAGS += -march=$(riscv-march-y)