From a9d0adce69075192961f3be466c4810a21b7bc9e Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Tue, 16 Apr 2024 14:19:03 -0700 Subject: [PATCH] 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: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240416211941.9369-2-tony.luck@intel.com --- arch/x86/include/asm/processor.h | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 811548f131f4..e0f9251e105b 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -108,9 +108,23 @@ struct cpuinfo_topology { }; struct cpuinfo_x86 { - __u8 x86; /* CPU family */ - __u8 x86_vendor; /* CPU vendor */ - __u8 x86_model; + 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): */