en Copyright 2015 Java http://kernelsources.org:8080/source/history/linux/arch/x86/kernel/cpu/cpuid_parser.h#fa6dcbc69ad495eeea315870278100a554a4ca18 x86/cpuid: Introduce a centralized CPUID parserIntroduce a CPUID parser for populating the system's CPUID tables.Since accessing a leaf within the CPUID table requires compile timetokenization, split the parser into two stages: (a) Compile-time macros for tokenizing the leaf/subleaf offsets within the CPUID table. (b) Generic runtime code to fill the CPUID data, using a parsing table which collects these compile-time offsets.For actual CPUID output parsing, support both generic and leaf-specificread functions.To ensure CPUID data early availability, invoke the parser during earlyboot, early Xen boot, and at early secondary CPUs bring up.Provide call site APIs to refresh a single leaf, or a leaf range, withinthe CPUID tables. This is for sites issuing MSR writes that partiallychange the CPU's CPUID layout. Doing full CPUID table rescans in suchcases will be destructive since the CPUID tables will host all of thekernel's X86_FEATURE flags at a later stage.Suggested-by: Thomas Gleixner <tglx@kernel.org>Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>Link: https://lore.kernel.org/all/20260327021645.555257-1-darwi@linutronix.de List of files: /linux/arch/x86/kernel/cpu/cpuid_parser.h Fri, 27 Mar 2026 03:15:23 +0100 Ahmed S. Darwish <darwi@linutronix.de>