[PATCH 05/18] riscv: asm: use .insn for making custom instructioons

[Andrew Jones]

On Fri, Aug 22, 2025 at 05:52:35PM +0100, Ben Dooks wrote:
> Using .word breaks with big endian builds, making something which
> is not a valid or worse an instruction or pair that does something
> which is not intended.
> 
> Signed-off-by: Ben Dooks <ben.dooks at codethink.co.uk>
> ---
>  arch/riscv/include/asm/insn-def.h | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/insn-def.h b/arch/riscv/include/asm/insn-def.h
> index d5adbaec1d01..2a3019bc1a3b 100644
> --- a/arch/riscv/include/asm/insn-def.h
> +++ b/arch/riscv/include/asm/insn-def.h
> @@ -256,10 +256,17 @@
>  	INSN_S(OPCODE_OP_IMM, FUNC3(6), __RS2(3),		\
>  	       SIMM12((offset) & 0xfe0), RS1(base))
>  
> +#ifndef CONFIG_AS_HAS_INSN
>  #define RISCV_PAUSE	".4byte 0x100000f"
>  #define ZAWRS_WRS_NTO	".4byte 0x00d00073"
>  #define ZAWRS_WRS_STO	".4byte 0x01d00073"
>  #define RISCV_NOP4	".4byte 0x00000013"
> +#else
> +#define RISCV_PAUSE	".insn 0x100000f"
> +#define ZAWRS_WRS_NTO	".insn 0x00d00073"
> +#define ZAWRS_WRS_STO	".insn 0x01d00073"
> +#define RISCV_NOP4	".insn 0x00000013"
> +#endif

I agree we should use .insn when possible because it provides validation
and allows mapping symbols to identify the words as instructions. So ack
to the change, but without adding a depends on AS_HAS_INSN to the riscv
CPU_BIG_ENDIAN config, then the commit message should drop the reference
to big endian for its motivation.

Thanks,
drew