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

[Borislav Petkov]

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@xxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> ---
>  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.

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