root/arch/x86/kernel/cpu/proc.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/smp.h>
#include <linux/timex.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/cpufreq.h>
#include <asm/prctl.h>
#include <linux/proc_fs.h>

#include "cpu.h"

#ifdef CONFIG_X86_VMX_FEATURE_NAMES
extern const char * const x86_vmx_flags[NVMXINTS*32];
#endif

/*
 *      Get CPU information for use by the procfs.
 */
static void show_cpuinfo_core(struct seq_file *m, struct cpuinfo_x86 *c,
                              unsigned int cpu)
{
#ifdef CONFIG_SMP
        seq_printf(m, "physical id\t: %d\n", c->topo.pkg_id);
        seq_printf(m, "siblings\t: %d\n",
                   cpumask_weight(topology_core_cpumask(cpu)));
        seq_printf(m, "core id\t\t: %d\n", c->topo.core_id);
        seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
        seq_printf(m, "apicid\t\t: %d\n", c->topo.apicid);
        seq_printf(m, "initial apicid\t: %d\n", c->topo.initial_apicid);
#endif
}

#ifdef CONFIG_X86_32
static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
{
        seq_printf(m,
                   "fdiv_bug\t: %s\n"
                   "f00f_bug\t: %s\n"
                   "coma_bug\t: %s\n"
                   "fpu\t\t: %s\n"
                   "fpu_exception\t: %s\n"
                   "cpuid level\t: %d\n"
                   "wp\t\t: yes\n",
                   str_yes_no(boot_cpu_has_bug(X86_BUG_FDIV)),
                   str_yes_no(boot_cpu_has_bug(X86_BUG_F00F)),
                   str_yes_no(boot_cpu_has_bug(X86_BUG_COMA)),
                   str_yes_no(boot_cpu_has(X86_FEATURE_FPU)),
                   str_yes_no(boot_cpu_has(X86_FEATURE_FPU)),
                   c->cpuid_level);
}
#else
static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
{
        seq_printf(m,
                   "fpu\t\t: yes\n"
                   "fpu_exception\t: yes\n"
                   "cpuid level\t: %d\n"
                   "wp\t\t: yes\n",
                   c->cpuid_level);
}
#endif

static int show_cpuinfo(struct seq_file *m, void *v)
{
        struct cpuinfo_x86 *c = v;
        unsigned int cpu;
        int i;

        cpu = c->cpu_index;
        seq_printf(m, "processor\t: %u\n"
                   "vendor_id\t: %s\n"
                   "cpu family\t: %d\n"
                   "model\t\t: %u\n"
                   "model name\t: %s\n",
                   cpu,
                   c->x86_vendor_id[0] ? c->x86_vendor_id : "unknown",
                   c->x86,
                   c->x86_model,
                   c->x86_model_id[0] ? c->x86_model_id : "unknown");

        if (c->x86_stepping || c->cpuid_level >= 0)
                seq_printf(m, "stepping\t: %d\n", c->x86_stepping);
        else
                seq_puts(m, "stepping\t: unknown\n");
        if (c->microcode)
                seq_printf(m, "microcode\t: 0x%x\n", c->microcode);

        if (cpu_has(c, X86_FEATURE_TSC)) {
                int freq = arch_freq_get_on_cpu(cpu);

                if (freq < 0)
                        seq_puts(m, "cpu MHz\t\t: Unknown\n");
                else
                        seq_printf(m, "cpu MHz\t\t: %u.%03u\n", freq / 1000, (freq % 1000));
        }

        /* Cache size */
        if (c->x86_cache_size)
                seq_printf(m, "cache size\t: %u KB\n", c->x86_cache_size);

        show_cpuinfo_core(m, c, cpu);
        show_cpuinfo_misc(m, c);

        seq_puts(m, "flags\t\t:");
        for (i = 0; i < 32*NCAPINTS; i++)
                if (cpu_has(c, i) && x86_cap_flags[i] != NULL)
                        seq_printf(m, " %s", x86_cap_flags[i]);

#ifdef CONFIG_X86_VMX_FEATURE_NAMES
        if (cpu_has(c, X86_FEATURE_VMX) && c->vmx_capability[0]) {
                seq_puts(m, "\nvmx flags\t:");
                for (i = 0; i < 32*NVMXINTS; i++) {
                        if (test_bit(i, (unsigned long *)c->vmx_capability) &&
                            x86_vmx_flags[i] != NULL)
                                seq_printf(m, " %s", x86_vmx_flags[i]);
                }
        }
#endif

        seq_puts(m, "\nbugs\t\t:");
        for (i = 0; i < 32*NBUGINTS; i++) {
                unsigned int bug_bit = 32*NCAPINTS + i;

                if (cpu_has_bug(c, bug_bit) && x86_bug_flags[i])
                        seq_printf(m, " %s", x86_bug_flags[i]);
        }

        seq_printf(m, "\nbogomips\t: %lu.%02lu\n",
                   c->loops_per_jiffy/(500000/HZ),
                   (c->loops_per_jiffy/(5000/HZ)) % 100);

#ifdef CONFIG_X86_64
        if (c->x86_tlbsize > 0)
                seq_printf(m, "TLB size\t: %d 4K pages\n", c->x86_tlbsize);
#endif
        seq_printf(m, "clflush size\t: %u\n", c->x86_clflush_size);
        seq_printf(m, "cache_alignment\t: %d\n", c->x86_cache_alignment);
        seq_printf(m, "address sizes\t: %u bits physical, %u bits virtual\n",
                   c->x86_phys_bits, c->x86_virt_bits);

        seq_puts(m, "power management:");
        for (i = 0; i < 32; i++) {
                if (c->x86_power & (1 << i)) {
                        if (i < ARRAY_SIZE(x86_power_flags) &&
                            x86_power_flags[i])
                                seq_printf(m, "%s%s",
                                           x86_power_flags[i][0] ? " " : "",
                                           x86_power_flags[i]);
                        else
                                seq_printf(m, " [%d]", i);
                }
        }

        seq_puts(m, "\n\n");

        return 0;
}

static void *c_start(struct seq_file *m, loff_t *pos)
{
        *pos = cpumask_next(*pos - 1, cpu_online_mask);
        if ((*pos) < nr_cpu_ids)
                return &cpu_data(*pos);
        return NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
        (*pos)++;
        return c_start(m, pos);
}

static void c_stop(struct seq_file *m, void *v)
{
}

const struct seq_operations cpuinfo_op = {
        .start  = c_start,
        .next   = c_next,
        .stop   = c_stop,
        .show   = show_cpuinfo,
};

#ifdef CONFIG_X86_USER_SHADOW_STACK
static void dump_x86_features(struct seq_file *m, unsigned long features)
{
        if (features & ARCH_SHSTK_SHSTK)
                seq_puts(m, "shstk ");
        if (features & ARCH_SHSTK_WRSS)
                seq_puts(m, "wrss ");
}

void arch_proc_pid_thread_features(struct seq_file *m, struct task_struct *task)
{
        seq_puts(m, "x86_Thread_features:\t");
        dump_x86_features(m, task->thread.features);
        seq_putc(m, '\n');

        seq_puts(m, "x86_Thread_features_locked:\t");
        dump_x86_features(m, task->thread.features_locked);
        seq_putc(m, '\n');
}
#endif /* CONFIG_X86_USER_SHADOW_STACK */