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authorAurelien Jarno <aurelien@aurel32.net>2022-01-26 18:14:42 +0100
committerPalmer Dabbelt <palmer@rivosinc.com>2022-02-10 09:17:01 -0800
commit6df2a016c0c8a3d0933ef33dd192ea6606b115e3 (patch)
tree0075ef1458bcd226b42197c6a483bfc5a1fa82cd /arch
parentf40fe31c01445f31253b15bef2412b33ae31093b (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/riscv/Makefile6
1 files changed, 6 insertions, 0 deletions
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)