riscv: Use -mno-relax when using lld linker

lld does not implement the RISCV relaxation optimizations like GNU ld
therefore disable it when building with lld, 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@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 3eb9590a077591af541e79eebe83785e170955bc..4be02069542894aa3d299bb374b66531338ecaed 100644 (file)
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -38,6 +38,15 @@ else
        KBUILD_LDFLAGS += -melf32lriscv
 endif
 
+ifeq ($(CONFIG_LD_IS_LLD),y)
+       KBUILD_CFLAGS += -mno-relax
+       KBUILD_AFLAGS += -mno-relax
+ifneq ($(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