Re: [PATCH v3 01/14] RISC-V: fix funct4 definition for c.jalr in parse_asm.h

Andrew Jones
2022-12-01T17:00:39Z

On Wed, Nov 30, 2022 at 11:56:01PM +0100, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner@vrull.eu>
>
> The opcode definition for c.jalr is
> c.jalr c_rs1_n0 1..0=2 15..13=4 12=1 6..2=0
>
> This means funct4 consisting of bit [15:12] is 1001b, so the value is 0x9.

I presume kgdb c.jalr stepping was broken before this patch and, if so,
then we should add a comment stating that and also

Fixes: edde5584c7ab ("riscv: Add SW single-step support for KDB")

and maybe to help keep me motivated :-)

Reported-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew

>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
> ---
> arch/riscv/include/asm/parse_asm.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/parse_asm.h b/arch/riscv/include/asm/parse_asm.h
> index f36368de839f..7fee806805c1 100644
> --- a/arch/riscv/include/asm/parse_asm.h
> +++ b/arch/riscv/include/asm/parse_asm.h
> @@ -125,7 +125,7 @@
> #define FUNCT3_C_J 0xa000
> #define FUNCT3_C_JAL 0x2000
> #define FUNCT4_C_JR 0x8000
> -#define FUNCT4_C_JALR 0xf000
> +#define FUNCT4_C_JALR 0x9000
>
> #define FUNCT12_SRET 0x10200000
>
> --
> 2.35.1