Re: [PATCH v2 01/13] RISC-V: add helper function to read the vector VLEN

Eric Biggers
2023-11-28T03:46:03Z

On Mon, Nov 27, 2023 at 03:06:51PM +0800, Jerry Shih wrote:
> From: Heiko Stuebner <heiko.stuebner@vrull.eu>
>
> VLEN describes the length of each vector register and some instructions
> need specific minimal VLENs to work correctly.
>
> The vector code already includes a variable riscv_v_vsize that contains
> the value of "32 vector registers with vlenb length" that gets filled
> during boot. vlenb is the value contained in the CSR_VLENB register and
> the value represents "VLEN / 8".
>
> So add riscv_vector_vlen() to return the actual VLEN value for in-kernel
> users when they need to check the available VLEN.
>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
> Signed-off-by: Jerry Shih <jerry.shih@sifive.com>
> ---
> arch/riscv/include/asm/vector.h | 11 +++++++++++
> 1 file changed, 11 insertions(+)

Reviewed-by: Eric Biggers <ebiggers@google.com>

- Eric