Message-ID: <0253c25d-f5fd-46f1-b4d3-ec56909d5eac@riscstar.com>
Date: Fri, 26 Dec 2025 15:28:43 -0600
From: Alex Elder <elder@...cstar.com>
To: Guodong Xu <guodong@...cstar.com>, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Paul Walmsley <pjw@...nel.org>,
 Palmer Dabbelt <palmer@...belt.com>, Albert Ou <aou@...s.berkeley.edu>,
 Alexandre Ghiti <alex@...ti.fr>, Yixun Lan <dlan@...too.org>,
 Daniel Lezcano <daniel.lezcano@...aro.org>,
 Thomas Gleixner <tglx@...utronix.de>,
 Samuel Holland <samuel.holland@...ive.com>, Anup Patel
 <anup@...infault.org>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Jiri Slaby <jirislaby@...nel.org>, Lubomir Rintel <lkundrak@...sk>,
 Yangyu Chen <cyy@...self.name>
Cc: Paul Walmsley <paul.walmsley@...ive.com>, Conor Dooley
 <conor@...nel.org>, Heinrich Schuchardt <xypron.glpk@....de>,
 Kevin Meng Zhang <zhangmeng.kevin@...ux.spacemit.com>,
 Andrew Jones <ajones@...tanamicro.com>, devicetree@...r.kernel.org,
 linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
 spacemit@...ts.linux.dev, linux-serial@...r.kernel.org
Subject: Re: [PATCH v2 10/13] dt-bindings: riscv: Add Sha and its comprised
 extensions

On 12/22/25 7:04 AM, Guodong Xu wrote:
> Add descriptions for the Sha extension and the seven extensions it
> comprises: Shcounterenw, Shgatpa, Shtvala, Shvsatpa, Shvstvala, Shvstvecd,
> and Ssstateen.
> 
> Sha is ratified in the RVA23 Profiles Version 1.0 (commit 0273f3c921b6
> "rva23/rvb23 ratified") as a new profile-defined extension that captures
> the full set of features that are mandated to be supported along with
> the H extension.
> 
> Extensions Shcounterenw, Shgatpa, Shtvala, Shvsatpa, Shvstvala, Shvstvecd,
> and Ssstateen are ratified in the RISC-V Profiles Version 1.0 (commit
> b1d806605f87 "Updated to ratified state").
> 
> The requirement status for Sha and its comprised extension in RISC-V
> Profiles are:
>   - Sha: Mandatory in RVA23S64
>   - H: Optional in RVA22S64; Mandatory in RVA23S64
>   - Shcounterenw: Optional in RVA22S64; Mandatory in RVA23S64
>   - Shgatpa: Optional in RVA22S64; Mandatory in RVA23S64
>   - Shtvala: Optional in RVA22S64; Mandatory in RVA23S64
>   - Shvsatpa: Optional in RVA22S64; Mandatory in RVA23S64
>   - Shvstvala: Optional in RVA22S64; Mandatory in RVA23S64
>   - Shvstvecd: Optional in RVA22S64; Mandatory in RVA23S64
>   - Ssstateen: Optional in RVA22S64; Mandatory in RVA23S64
> 
> Add schema checks to enforce that Sha implies the presence of all its
> comprised extensions.

Like patch 7 in your series, I *think* what you're doing
in trying to imply the presence of these other extensions
is actually requiring all those extensions to be present
*in addition* to just "Sha".  I don't think that's what
we want.

					-Alex

> Signed-off-by: Guodong Xu <guodong@...cstar.com>
> ---
> v2: New patch.
> ---
>   .../devicetree/bindings/riscv/extensions.yaml      | 79 ++++++++++++++++++++++
>   1 file changed, 79 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
> index ed7a88c0ab3b7dc7ad4a4d2fd300d6fb33ef050c..1066b7e65dab89704dbac449db4aa5605c95b9d3 100644
> --- a/Documentation/devicetree/bindings/riscv/extensions.yaml
> +++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
> @@ -128,6 +128,57 @@ properties:
>               version of the privileged ISA specification.
>   
>           # multi-letter extensions, sorted alphanumerically
> +        - const: sha
> +          description: |
> +            The standard Sha extension for augmented hypervisor extension as
> +            ratified in RVA23 Profiles Version 1.0, with commit 0273f3c921b6
> +            ("rva23/rvb23 ratified").
> +
> +            Sha captures the full set of features that are mandated to be
> +            supported along with the H extension. Sha comprises the following
> +            extensions: H, Shcounterenw, Shgatpa, Shtvala, Shvsatpa, Shvstvala,
> +            Shvstvecd, and Ssstateen.
> +
> +        - const: shcounterenw
> +          description: |
> +            The standard Shcounterenw extension for support writable enables
> +            in hcounteren for any supported counter, as ratified in RISC-V
> +            Profiles Version 1.0, with commit b1d806605f87 ("Updated to
> +            ratified state.")
> +
> +        - const: shgatpa
> +          description: |
> +            The standard Shgatpa extension indicates that for each supported
> +            virtual memory scheme SvNN supported in satp, the corresponding
> +            hgatp SvNNx4 mode must be supported. The hgatp mode Bare must
> +            also be supported. It is ratified in RISC-V Profiles Version 1.0,
> +            with commit b1d806605f87 ("Updated to ratified state.")
> +
> +        - const: shtvala
> +          description: |
> +            The standard Shtvala extension for htval be written with the
> +            faulting guest physical address in all circumstances permitted by
> +            the ISA. It is ratified in RISC-V Profiles Version 1.0, with
> +            commit b1d806605f87 ("Updated to ratified state.")
> +
> +        - const: shvsatpa
> +          description: |
> +            The standard Shvsatpa extension for vsatp supporting all translation
> +            modes supported in satp, as ratified in RISC-V Profiles Version 1.0,
> +            with commit b1d806605f87 ("Updated to ratified state.")
> +
> +        - const: shvstvala
> +          description: |
> +            The standard Shvstvala extension for vstval provides all needed
> +            values as ratified in RISC-V Profiles Version 1.0, with commit
> +            b1d806605f87 ("Updated to ratified state.")
> +
> +        - const: shvstvecd
> +          description: |
> +            The standard Shvstvecd extension for vstvec supporting Direct mode,
> +            as ratified in RISC-V Profiles Version 1.0, with commit b1d806605f87
> +            ("Updated to ratified state.")
> +
>           - const: smaia
>             description: |
>               The standard Smaia supervisor-level extension for the advanced
> @@ -186,6 +237,12 @@ properties:
>               ratified at commit d70011dde6c2 ("Update to ratified state")
>               of riscv-j-extension.
>   
> +        - const: ssstateen
> +          description: |
> +            The standard Ssstateen extension for supervisor-mode view of the
> +            state-enable extension, as ratified in RISC-V Profiles Version 1.0,
> +            with commit b1d806605f87 ("Updated to ratified state.")
> +
>           - const: sstc
>             description: |
>               The standard Sstc supervisor-level extension for time compare as
> @@ -813,6 +870,28 @@ properties:
>                   const: zbb
>               - contains:
>                   const: zbs
> +      # sha comprises the following extensions
> +      - if:
> +          contains:
> +            const: sha
> +        then:
> +          allOf:
> +            - contains:
> +                const: h
> +            - contains:
> +                const: shcounterenw
> +            - contains:
> +                const: shgatpa
> +            - contains:
> +                const: shtvala
> +            - contains:
> +                const: shvsatpa
> +            - contains:
> +                const: shvstvala
> +            - contains:
> +                const: shvstvecd
> +            - contains:
> +                const: ssstateen
>         # Zcb depends on Zca
>         - if:
>             contains:
> 

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