The patch below does not apply to the 6.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6df2a016c0c8a3d0933ef33dd192ea6606b115e3 Mon Sep 17 00:00:00 2001 From: Aurelien Jarno aurelien@aurel32.net Date: Wed, 26 Jan 2022 18:14:42 +0100 Subject: [PATCH] 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 <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages: <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01' <<BUILDDIR>>/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 aurelien@aurel32.net Tested-by: Alexandre Ghiti alexandre.ghiti@canonical.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt palmer@rivosinc.com
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 8a107ed18b0d..7d81102cffd4 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)