Re: [RFC PATCH 3/4] x86/cpu: amd: Define processor families

Borislav Petkov
2020-11-30T14:01:07Z

On Wed, Nov 25, 2020 at 11:48:46PM +0900, Punit Agrawal wrote:
> So far, the AMD processor identifier (family, models, stepping) are
> referred to by raw values making it easy to make mistakes. It is also
> harder to read and maintain. Additionally, these values are also being
> used in subsystems outside the arch code where not everybody maybe be
> as familiar with the processor identifiers.
>
> As a first step towards improving the status quo, add macros for the
> AMD processor families and propagate them through the existing
> cpu_device_id.h header used for this purpose.
>
> Signed-off-by: Punit Agrawal <punitagrawal@gmail.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: x86@kernel.org
> ---
> arch/x86/include/asm/amd-family.h | 18 ++++++++++++++++++
> arch/x86/include/asm/cpu_device_id.h | 2 ++
> 2 files changed, 20 insertions(+)
> create mode 100644 arch/x86/include/asm/amd-family.h
>
> diff --git a/arch/x86/include/asm/amd-family.h b/arch/x86/include/asm/amd-family.h
> new file mode 100644
> index 000000000000..dff4d13b8e74
> --- /dev/null
> +++ b/arch/x86/include/asm/amd-family.h
> @@ -0,0 +1,18 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_X86_AMD_FAMILY_H
> +#define _ASM_X86_AMD_FAMILY_H
> +
> +#define AMD_FAM_K5 0x04
> +#define AMD_FAM_K6 0x05
> +#define AMD_FAM_K7 0x06
> +#define AMD_FAM_K8 0x0F
> +#define AMD_FAM_K10 0x10

Fam 0x10 is Greyhound and a lot more core names. I'd let the AMD folks
on Cc say what they wanna call it but I don't think K10 was used
anywhere except outside of AMD. :)

> +#define AMD_FAM_K8_K10_HYBRID 0x11

That was called Griffin so AMD_FAM_GRIFFIN I guess. If not used anywhere
in the tree, no need to add the define. Same holds true for the rest of
the defines - add them only when they're used.

> +#define AMD_FAM_LLANO 0x12
> +#define AMD_FAM_BOBCAT 0x14
> +#define AMD_FAM_BULLDOZER 0x15
> +#define AMD_FAM_JAGUAR 0x16
> +#define AMD_FAM_ZEN 0x17

ZEN2 is also 0x17 but different models so this is where the family
matching scheme doesn't work - you'd need the models too.

0x18 is HYGON

> +#define AMD_FAM_ZEN3 0x19
> +
> +#endif /* _ASM_X86_AMD_FAMILY_H */
> diff --git a/arch/x86/include/asm/cpu_device_id.h b/arch/x86/include/asm/cpu_device_id.h
> index eb8fcede9e3b..bbb48ba4c7ff 100644
> --- a/arch/x86/include/asm/cpu_device_id.h
> +++ b/arch/x86/include/asm/cpu_device_id.h
> @@ -12,6 +12,8 @@
> #include <linux/mod_devicetable.h>
> /* Get the INTEL_FAM* model defines */
> #include <asm/intel-family.h>
> +/* Get the AMD model defines */
> +#include <asm/amd-family.h>
> /* And the X86_VENDOR_* ones */
> #include <asm/processor.h>
>
> --
> 2.29.2
>

--
Regards/Gruss,
Boris.