| From | Thomas Gleixner <> | Subject | [patch V4 23/41] x86/cpu: Provide cpuid_read() et al. | Date | Mon, 14 Aug 2023 10:54:10 +0200 (CEST) |
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Provide a few helper functions to read CPUID leafs or individual registers into a data structure without requiring unions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mikelley@microsoft.com>
--- arch/x86/include/asm/cpuid.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)
--- a/arch/x86/include/asm/cpuid.h +++ b/arch/x86/include/asm/cpuid.h @@ -127,6 +127,42 @@ static inline unsigned int cpuid_edx(uns 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, regs + 1, regs + 2, regs + 3); +} + +#define cpuid_subleaf(leaf, subleaf, regs) { \ + BUILD_BUG_ON(sizeof(*(regs)) != 16); \ + __cpuid_read(leaf, subleaf, (u32 *)(regs)); \ +} + +#define cpuid_leaf(leaf, regs) { \ + BUILD_BUG_ON(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) { \ + BUILD_BUG_ON(sizeof(*(reg)) != 4); \ + __cpuid_read_reg(leaf, subleaf, regidx, (u32 *)(reg)); \ +} + +#define cpuid_leaf_reg(leaf, regidx, reg) { \ + BUILD_BUG_ON(sizeof(*(reg)) != 4); \ + __cpuid_read_reg(leaf, 0, regidx, (u32 *)(reg)); \ +} + static __always_inline bool cpuid_function_is_indexed(u32 function) { switch (function) {
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