[PATCH] riscv: Use -mno-relax when using lld linker

[Palmer Dabbelt]

On Sat, 29 May 2021 11:40:39 PDT (-0700), Palmer Dabbelt wrote:
> On Fri, 14 May 2021 13:56:43 PDT (-0700), Khem Raj wrote:
>> lld does not implement the RISCV relaxation optimizations like GNU ld
>> therefore disable it when building with LLVM=1, Also pass it to
>> assembler when using external GNU assembler ( LLVM_IAS != 1 ), this
>> ensures that relevant assembler option is also enabled along. if these
>> options are not used then we see following relocations in objects
>>
>> 0000000000000000 R_RISCV_ALIGN     *ABS*+0x0000000000000002
>>
>> These are then rejected by lld
>> ld.lld: error: capability.c:(.fixup+0x0): relocation R_RISCV_ALIGN requires unimplemented linker relaxation; recompile with -mno-relax but the .o is already compiled with -mno-relax
>>
>> Signed-off-by: Khem Raj <raj.khem at gmail.com>
>> Cc: Paul Walmsley <paul.walmsley at sifive.com>
>> Cc: Palmer Dabbelt <palmer at dabbelt.com>
>> Cc: Albert Ou <aou at eecs.berkeley.edu>
>> Cc: Nathan Chancellor <nathan at kernel.org>
>> Cc: Nick Desaulniers <ndesaulniers at google.com>
>> ---
>>  arch/riscv/Makefile | 9 +++++++++
>>  1 file changed, 9 insertions(+)
>>
>> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
>> index 3eb9590a0775..519f133e0d53 100644
>> --- a/arch/riscv/Makefile
>> +++ b/arch/riscv/Makefile
>> @@ -38,6 +38,15 @@ else
>>  	KBUILD_LDFLAGS += -melf32lriscv
>>  endif
>>
>> +ifeq ($(LLVM),1)
>> +	KBUILD_CFLAGS += -mno-relax
>> +	KBUILD_AFLAGS += -mno-relax
>> +ifneq ($(LLVM_IAS),1)
>> +	KBUILD_CFLAGS += -Wa,-mno-relax
>> +	KBUILD_AFLAGS += -Wa,-mno-relax
>> +endif
>> +endif
>> +
>>  # ISA string setting
>>  riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
>>  riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
>
> Thanks, this is on fixes.

Sorry, replied to the v1 but I merged the v2.