[PATCH v3 9/9] docs: document WID DT properties

[Radim Krcmar]

2026-10-27T16:35:09+08:00, Yu-Chien Peter Lin <peter.lin at sifive.com>:
> Add "wid" and "widdeleg" properties to domain instance node
> documentation and example DT. Add a "Root Domain Node" section
> describing the "root" subnode under the domain configuration
> node for root domain WID configuration
>
> Signed-off-by: Yu-Chien Peter Lin <peter.lin at sifive.com>
> ---
> Change v2->v3:
> - Mark 'wid' property as mandatory when Smlwid is present for both root
>   and domain instance nodes.
> - Remove mention of M-mode WID fallback when 'wid' is absent.
> ---
> diff --git a/docs/domain_support.md b/docs/domain_support.md
> @@ -205,6 +225,13 @@ The DT properties of a domain instance DT node are as follows:
> +* **wid** (Mandatory if Smlwid is present) - The 32-bit World ID for
> +  lower-privilege modes (S/U-mode) for the domain instance. If the hart
> +  supports the Smlwid extension, this property must be provided.

WID CSR field with Smlwid is log_2(MXLEN)-bit.

> +* **widdeleg** (Optional) - The 64 bit World ID delegation bitmask for

mwiddeleg CSR with Smwiddeleg is MXLEN-bit.

BIT_ULL(dom->wid) in [6/9] is UB because DT parser allows WID above
MXLEN, but it's easy to blame the platform for that...
How much do we want to sanitize the DT?

Thanks.