[PATCH v2 5/9] lib: sbi_hart: add WID protection mechanism

[Yu-Chien Peter Lin]

On Mon, Aug 17, 2026 at 05:04:59PM +0800, Yu-Chien Peter Lin wrote:
> Register a WID-based hart protection mechanism that
> configures mlwid and mwiddeleg CSRs on domain entry.
> This enables the protection framework reconfigure WID
> isolation whenever domains are switched.
> 
> Signed-off-by: Yu-Chien Peter Lin <peter.lin at sifive.com>
> ---
> Changes v1 -> v2:
> - Validate WID against pmlwidlist before writing mlwid CSR (Oza)
> ---
>  include/sbi/sbi_hart_worlds.h | 24 ++++++++++++
>  lib/sbi/objects.mk            |  1 +
>  lib/sbi/sbi_hart.c            |  5 +++
>  lib/sbi/sbi_hart_worlds.c     | 72 +++++++++++++++++++++++++++++++++++
>  4 files changed, 102 insertions(+)
>  create mode 100644 include/sbi/sbi_hart_worlds.h
>  create mode 100644 lib/sbi/sbi_hart_worlds.c
> 
> diff --git a/include/sbi/sbi_hart_worlds.h b/include/sbi/sbi_hart_worlds.h
> new file mode 100644
> index 00000000..2bb35a7e
> --- /dev/null
> +++ b/include/sbi/sbi_hart_worlds.h
> @@ -0,0 +1,24 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2026 SiFive Inc.
> + */
> +
> +#ifndef __SBI_HART_WORLDS_H__
> +#define __SBI_HART_WORLDS_H__
> +
> +struct sbi_scratch;
> +
> +/**
> + * Initialize WID hart protection for current HART
> + *
> + * Registers the WID protection mechanism if Smwid/Smlwid
> + * extensions are present.

Only Smlwid is needed for registration. Will update comment here
in the next version.