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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
struct cpui_info {
uint32_t cpuid_max;
char vendor_string[13];
uint8_t family;
uint8_t model;
uint8_t stepping;
};
static struct cpui_info __cpu;
static uint8_t get_family(uint32_t verinfo)
{
uint8_t display_family;
display_family = (verinfo >> 8) & 0xf;
/* Examine Extended Family ID */
if (display_family == 0x0f)
display_family += (verinfo >> 20) & 0xff;
return display_family;
}
static uint8_t get_model(uint32_t verinfo)
{
uint8_t family, display_model;
family = get_family(verinfo);
display_model = (verinfo >> 4) & 0xf;
/* Examine Extended Model ID */
if (family == 0x06 || family == 0x0f)
display_model += ((verinfo >> 16) & 0xf) << 4;
return display_model;
}
static uint8_t get_stepping(uint32_t verinfo)
{
return verinfo & 0xf;
}
static void detect_cpu(struct cpui_info *cpu)
{
/* Get CPU Vendor ID String */
cpuid(0x00, (unsigned int *)&cpu->cpuid_max,
(unsigned int *)&cpu->vendor_string[0],
(unsigned int *)&cpu->vendor_string[8],
(unsigned int *)&cpu->vendor_string[4]);
cpu->vendor_string[12] = '\0';
if (cpu->cpuid_max >= 0x01) {
uint32_t eax, ebx, ecx, edx;
cpuid(0x01, &eax, &ebx, &ecx, &edx);
cpu->family = get_family(eax);
cpu->model = get_model(eax);
cpu->stepping = get_stepping(eax);
}
}
static int __init cpui_init(void)
{
if (!have_cpuid_p()) {
pr_err("CPUID instruction is NOT supported. Aborting.\n");
return 1;
}
pr_info("CPUID instruction is supported.\n");
memset(&__cpu, 0, sizeof(__cpu));
detect_cpu(&__cpu);
pr_info("Maximum Input Value for Basic CPUID Information = %d\n", __cpu.cpuid_max);
pr_info("Identity string = %s\n", __cpu.vendor_string);
return 0;
}
static void __exit cpui_exit(void)
{
pr_info("Exit complete\n");
}
module_init(cpui_init);
module_exit(cpui_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joursoir");
MODULE_DESCRIPTION("A driver that allows users to interact with various internal components of the CPU");
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