Commit a9d0adce authored by Tony Luck's avatar Tony Luck Committed by Borislav Petkov (AMD)
Browse files

x86/cpu/vfm: Add/initialize x86_vfm field to struct cpuinfo_x86 

Refactor struct cpuinfo_x86 so that the vendor, family, and model
fields are overlaid in a union with a 32-bit field that combines
all three (together with a one byte reserved field in the upper
byte).

This will make it easy, cheap, and reliable to check all three
values at once.

See

  https://lore.kernel.org/r/Zgr6kT8oULbnmEXx@agluck-desk3



for why the ordering is (low-to-high bits):

  (vendor, family, model)

  [ bp: Move comments over the line, add the backstory about the
    particular order of the fields. ]

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240416211941.9369-2-tony.luck@intel.com
parent 90167e96

arch/x86/include/asm/processor.h

+17 −3
Original line number Diff line number Diff line
@@ -108,9 +108,23 @@ struct cpuinfo_topology { 
};



struct cpuinfo_x86 {

	__u8			x86;		/* CPU family */

	__u8			x86_vendor;	/* CPU vendor */

	union {

		/*

		 * The particular ordering (low-to-high) of (vendor,

		 * family, model) is done in case range of models, like

		 * it is usually done on AMD, need to be compared.

		 */

		struct {

			__u8	x86_model;

			/* CPU family */

			__u8	x86;

			/* CPU vendor */

			__u8	x86_vendor;

			__u8	x86_reserved;

		};

		/* combined vendor, family, model */

		__u32		x86_vfm;

	};

	__u8			x86_stepping;

#ifdef CONFIG_X86_64

	/* Number of 4K pages in DTLB/ITLB combined(in pages): */