Re: [PATCH v2 1/3] dt-bindings: riscv: document cbom-block-size

From: Rob Herring
Date: Tue May 17 2022 - 20:25:36 EST


On Wed, May 11, 2022 at 11:41:30PM +0200, Heiko Stuebner wrote:
> The Zicbom operates on a block-size defined for the cpu-core,
> which does not necessarily match other cache-sizes used.
>
> So add the necessary property for the system to know the core's
> block-size.
>
> Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
> ---
> Documentation/devicetree/bindings/riscv/cpus.yaml | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml
> index d632ac76532e..b179bfd155a3 100644
> --- a/Documentation/devicetree/bindings/riscv/cpus.yaml
> +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml
> @@ -63,6 +63,13 @@ properties:
> - riscv,sv48
> - riscv,none
>
> + riscv,cbom-block-size:
> + $ref: /schemas/types.yaml#/definitions/uint32

Any value 0-2^32 is valid?

> + description:
> + Blocksize in bytes for the Zicbom cache operations. The block
> + size is a property of the core itself and does not necessarily
> + match other software defined cache sizes.

What about hardware defined cache sizes? I'm scratching my head as to
what a 'software defined cache size' is.

> +
> riscv,isa:
> description:
> Identifies the specific RISC-V instruction set architecture
> --
> 2.35.1
>
>