On 2024-07-12 3:38 AM, Yong-Xuan Wang wrote:
> Add entries for the Svade and Svadu extensions to the riscv,isa-extensions
> property.
>
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@xxxxxxxxxx>
> ---
> .../devicetree/bindings/riscv/extensions.yaml | 28 +++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
> index 468c646247aa..e91a6f4ede38 100644
> --- a/Documentation/devicetree/bindings/riscv/extensions.yaml
> +++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
> @@ -153,6 +153,34 @@ properties:
> ratified at commit 3f9ed34 ("Add ability to manually trigger
> workflow. (#2)") of riscv-time-compare.
>
> + - const: svade
> + description: |
> + The standard Svade supervisor-level extension for SW-managed PTE A/D
> + bit updates as ratified in the 20240213 version of the privileged
> + ISA specification.
> +
> + Both Svade and Svadu extensions control the hardware behavior when
> + the PTE A/D bits need to be set. The default behavior for the four
> + possible combinations of these extensions in the device tree are:
> + 1) Neither Svade nor Svadu present in DT => It is technically
> + unknown whether the platform uses Svade or Svadu. Supervisor
> + software should be prepared to handle either hardware updating
> + of the PTE A/D bits or page faults when they need updated.
> + 2) Only Svade present in DT => Supervisor must assume Svade to be
> + always enabled.
> + 3) Only Svadu present in DT => Supervisor must assume Svadu to be
> + always enabled.
> + 4) Both Svade and Svadu present in DT => Supervisor must assume
> + Svadu turned-off at boot time. To use Svadu, supervisor must
> + explicitly enable it using the SBI FWFT extension.
> +
> + - const: svadu
> + description: |
> + The standard Svadu supervisor-level extension for hardware updating
> + of PTE A/D bits as ratified at commit c1abccf ("Merge pull request
> + #25 from ved-rivos/ratified") of riscv-svadu. Please refer to Svade
Should we be referencing the archived riscv-svadu repository now that Svadu has
been merged to the main privileged ISA manual? Either way:
Reviewed-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
> + dt-binding description for more details.
> +
> - const: svinval
> description:
> The standard Svinval supervisor-level extension for fine-grained
