From 43d86e3cd9a77912772cf7ad37ad94211bf7351d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 14 Feb 2024 21:29:39 +0100 Subject: [PATCH] x86/cpu: Provide cpuid_read() et al. Provide a few helper functions to read CPUID leafs or individual registers into a data structure without requiring unions. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Sohil Mehta Tested-by: Michael Kelley Tested-by: Peter Zijlstra (Intel) Tested-by: Zhang Rui Tested-by: Wang Wendy Tested-by: K Prateek Nayak Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/878r3mg570.ffs@tglx --- arch/x86/include/asm/cpuid.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h index 9bee3e7bf9736..6b122a31da065 100644 --- a/arch/x86/include/asm/cpuid.h +++ b/arch/x86/include/asm/cpuid.h @@ -127,6 +127,42 @@ static inline unsigned int cpuid_edx(unsigned int op) return edx; } +static inline void __cpuid_read(unsigned int leaf, unsigned int subleaf, u32 *regs) +{ + regs[CPUID_EAX] = leaf; + regs[CPUID_ECX] = subleaf; + __cpuid(regs + CPUID_EAX, regs + CPUID_EBX, regs + CPUID_ECX, regs + CPUID_EDX); +} + +#define cpuid_subleaf(leaf, subleaf, regs) { \ + static_assert(sizeof(*(regs)) == 16); \ + __cpuid_read(leaf, subleaf, (u32 *)(regs)); \ +} + +#define cpuid_leaf(leaf, regs) { \ + static_assert(sizeof(*(regs)) == 16); \ + __cpuid_read(leaf, 0, (u32 *)(regs)); \ +} + +static inline void __cpuid_read_reg(unsigned int leaf, unsigned int subleaf, + enum cpuid_regs_idx regidx, u32 *reg) +{ + u32 regs[4]; + + __cpuid_read(leaf, subleaf, regs); + *reg = regs[regidx]; +} + +#define cpuid_subleaf_reg(leaf, subleaf, regidx, reg) { \ + static_assert(sizeof(*(reg)) == 4); \ + __cpuid_read_reg(leaf, subleaf, regidx, (u32 *)(reg)); \ +} + +#define cpuid_leaf_reg(leaf, regidx, reg) { \ + static_assert(sizeof(*(reg)) == 4); \ + __cpuid_read_reg(leaf, 0, regidx, (u32 *)(reg)); \ +} + static __always_inline bool cpuid_function_is_indexed(u32 function) { switch (function) { -- 2.30.2