linux/arch/x86/boot/cpuflags.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/types.h>
#include "bitops.h"

#include <asm/processor-flags.h>
#include <asm/required-features.h>
#include <asm/msr-index.h>
#include "cpuflags.h"

struct cpu_features cpu;
u32 cpu_vendor[3];

static bool loaded_flags;

static int has_fpu(void)
{ … }

/*
 * For building the 16-bit code we want to explicitly specify 32-bit
 * push/pop operations, rather than just saying 'pushf' or 'popf' and
 * letting the compiler choose. But this is also included from the
 * compressed/ directory where it may be 64-bit code, and thus needs
 * to be 'pushfq' or 'popfq' in that case.
 */
#ifdef __x86_64__
#define PUSHF …
#define POPF …
#else
#define PUSHF …
#define POPF …
#endif

int has_eflag(unsigned long mask)
{ … }

void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d)
{ … }

#define cpuid(id, a, b, c, d) …

void get_cpuflags(void)
{ … }