Re: [PATCH v2 1/3] crypto: padlock-sha: Matches CPU with Family with 6 explicitly

[Dave Hansen]

On 1/22/24 18:28, Tony W Wang-oc wrote:
> Updates the supporting qualification for packlock-sha driver, making
> it support CPUs whose vendor ID is Centaur and Famliy is 6.

This changelog isn't telling us very much.  *Why* is this a good change?

> diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c
> index 6865c7f1fc1a..2e82c5e77f7a 100644
> --- a/drivers/crypto/padlock-sha.c
> +++ b/drivers/crypto/padlock-sha.c
> @@ -491,7 +491,7 @@ static struct shash_alg sha256_alg_nano = {
>  };
>  
>  static const struct x86_cpu_id padlock_sha_ids[] = {
> -	X86_MATCH_FEATURE(X86_FEATURE_PHE, NULL),
> +	X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 6, X86_FEATURE_PHE, NULL),
>  	{}
>  };

Logically, this is saying that there are non-CENTAUR or non-family-6
CPUs that set X86_FEATURE_PHE, but don't support X86_FEATURE_PHE.  Is
that the case?

The one Intel use of X86_MATCH_VENDOR_FAM_FEATURE() also looks a bit
suspect, btw.