From: Aurelien Jarno Date: Wed, 26 Jan 2022 17:14:42 +0000 (+0100) Subject: riscv: fix build with binutils 2.38 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=6df2a016c0c8a3d0933ef33dd192ea6606b115e3;p=kernel.git riscv: fix build with binutils 2.38 From version 2.38, binutils default to ISA spec version 20191213. This means that the csr read/write (csrr*/csrw*) instructions and fence.i instruction has separated from the `I` extension, become two standalone extensions: Zicsr and Zifencei. As the kernel uses those instruction, this causes the following build failure: CC arch/riscv/kernel/vdso/vgettimeofday.o <>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages: <>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' <>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' <>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' <>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' The fix is to specify those extensions explicitely in -march. However as older binutils version do not support this, we first need to detect that. Signed-off-by: Aurelien Jarno Tested-by: Alexandre Ghiti Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 8a107ed18b0dc..7d81102cffd48 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I) := rv32ima riscv-march-$(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) := $(riscv-march-y)_zicsr_zifencei + KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y)) KBUILD_AFLAGS += -march=$(riscv-march-y)