Re: [PATCH 3/4] raid6: riscv: Allow code to be compiled in userspace

[Palmer Dabbelt]

On Tue, 10 Jun 2025 03:12:33 PDT (-0700), zhangchunyan@xxxxxxxxxxx wrote:
> To support userspace raid6test, this patch adds __KERNEL__ ifdef for kernel
> header inclusions also userspace wrapper definitions to allow code to be
> compiled in userspace.
>
> Signed-off-by: Chunyan Zhang <zhangchunyan@xxxxxxxxxxx>
> ---
>  lib/raid6/recov_rvv.c |  7 +------
>  lib/raid6/rvv.c       | 11 ++++-------
>  lib/raid6/rvv.h       | 15 +++++++++++++++
>  3 files changed, 20 insertions(+), 13 deletions(-)
>
> diff --git a/lib/raid6/recov_rvv.c b/lib/raid6/recov_rvv.c
> index 500da521a806..8f2be833c015 100644
> --- a/lib/raid6/recov_rvv.c
> +++ b/lib/raid6/recov_rvv.c
> @@ -4,13 +4,8 @@
>   * Author: Chunyan Zhang <zhangchunyan@xxxxxxxxxxx>
>   */
>
> -#include <asm/vector.h>
>  #include <linux/raid/pq.h>
> -
> -static int rvv_has_vector(void)
> -{
> -	return has_vector();
> -}
> +#include "rvv.h"
>
>  static void __raid6_2data_recov_rvv(int bytes, u8 *p, u8 *q, u8 *dp,
>  				    u8 *dq, const u8 *pbmul,
> diff --git a/lib/raid6/rvv.c b/lib/raid6/rvv.c
> index b193ea176d5d..99dfa16d37c7 100644
> --- a/lib/raid6/rvv.c
> +++ b/lib/raid6/rvv.c
> @@ -9,16 +9,13 @@
>   *	Copyright 2002-2004 H. Peter Anvin
>   */
>
> -#include <asm/vector.h>
> -#include <linux/raid/pq.h>
>  #include "rvv.h"
>
> +#ifdef __KERNEL__
>  #define NSIZE	(riscv_v_vsize / 32) /* NSIZE = vlenb */
> -
> -static int rvv_has_vector(void)
> -{
> -	return has_vector();
> -}
> +#else
> +#define NSIZE  16
> +#endif
>
>  static void raid6_rvv1_gen_syndrome_real(int disks, unsigned long bytes, void **ptrs)
>  {
> diff --git a/lib/raid6/rvv.h b/lib/raid6/rvv.h
> index 94044a1b707b..595dfbf95d4e 100644
> --- a/lib/raid6/rvv.h
> +++ b/lib/raid6/rvv.h
> @@ -7,6 +7,21 @@
>   * Definitions for RISC-V RAID-6 code
>   */
>
> +#ifdef __KERNEL__
> +#include <asm/vector.h>
> +#else
> +#define kernel_vector_begin()
> +#define kernel_vector_end()
> +#define has_vector()		(1)

This should be gated on something, as we don't have vector everywhere in 
userspace.  We could dynamically check via hwprobe(), that's probably 
best?

> +#endif
> +
> +#include <linux/raid/pq.h>
> +
> +static int rvv_has_vector(void)
> +{
> +	return has_vector();
> +}
> +
>  #define RAID6_RVV_WRAPPER(_n)						\
>  	static void raid6_rvv ## _n ## _gen_syndrome(int disks,		\
>  					size_t bytes, void **ptrs)	\