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 <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/878r3mg570.ffs@tglx
This commit is contained in:
Thomas Gleixner 2024-02-14 21:29:39 +01:00
parent 841c351693
commit 43d86e3cd9

View File

@ -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) {