linux-kernel - Re: [RFC PATCH 4/4] cpufreq: acpi-cpufreq: Use identifiers for AMD processor family

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 30 Nov 2020 15:02:24 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Punit Agrawal <punitagrawal@...il.com>
Cc:     rjw@...ysocki.net, wei.huang2@....com,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        x86@...nel.org, Tom Lendacky <thomas.lendacky@....com>,
        Yazen Ghannam <yazen.ghannam@....com>
Subject: Re: [RFC PATCH 4/4] cpufreq: acpi-cpufreq: Use identifiers for AMD
 processor family

On Wed, Nov 25, 2020 at 11:48:47PM +0900, Punit Agrawal wrote:
> Replace the raw values for AMD processor family with recently
> introduced identifier macros to improve code readability and
> maintainability.
> 
> Signed-off-by: Punit Agrawal <punitagrawal@...il.com>
> ---
>  drivers/cpufreq/acpi-cpufreq.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> index 29f1cd93541e..d8b8300ae9e0 100644
> --- a/drivers/cpufreq/acpi-cpufreq.c
> +++ b/drivers/cpufreq/acpi-cpufreq.c
> @@ -202,8 +202,8 @@ static int override_acpi_psd(unsigned int cpu_id)
>  		 * CPU's before Zen3 (except some Zen2) need the
>  		 * override.
>  		 */
> -		return (c->x86 < 0x19) &&
> -			!(c->x86 == 0x17 && c->x86_model == 0x60 &&
> +		return (c->x86 < AMD_FAM_ZEN3) &&
> +			!(c->x86 == AMD_FAM_ZEN && c->x86_model == 0x60 &&

This is what I mean - that's Zen2 as the comment above says so having

		c->x86 == AMD_FAM_ZEN

is not enough. And you have a comment above it stating which CPUs are
matched here so I'm not sure those family defines make it any better...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette