Re: [PATCH v2 11/13] riscv: hwprobe: Document thead vendor extensions and xtheadvector extension

[Evan Green <evan@rivosinc.com>]

On Mon, Jun 10, 2024 at 3:57 PM Charlie Jenkins <charlie@rivosinc.com> wrote:
>
> Document support for thead vendor extensions using the key
> RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 and xtheadvector extension using
> the key RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR.
>
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> Reviewed-by: Evan Green <evan@rivosinc.com>
> ---
>  Documentation/arch/riscv/hwprobe.rst | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
> index 204cd4433af5..9c0ef8c57228 100644
> --- a/Documentation/arch/riscv/hwprobe.rst
> +++ b/Documentation/arch/riscv/hwprobe.rst
> @@ -214,3 +214,13 @@ The following keys are defined:
>
>  * :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which
>    represents the size of the Zicboz block in bytes.
> +
> +* :c:macro:`RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0`: A bitmask containing the

Our recent snafoo with CPUPERF_0 popped into my memory
when reading this. Does this work properly with the WHICH_CPUS flag?
Specifically, we need hwprobe_key_is_bitmask() to return true for this
key since it's a bitmask.