// SPDX-License-Identifier: GPL-2.0#include <linux/cpumask.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/kernel_stat.h>#include <linux/proc_fs.h>#include <linux/sched.h>#include <linux/sched/stat.h>#include <linux/seq_file.h>#include <linux/slab.h>#include <linux/time.h>#include <linux/irqnr.h>#include <linux/sched/cputime.h>#include <linux/tick.h> #ifndef arch_irq_stat_cpu#define arch_irq_stat_cpu(cpu) 0#endif#ifndef arch_irq_stat#define arch_irq_stat() 0#endif #ifdef arch_idle_time static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu){	u64 idle; 	idle = kcs->cpustat[CPUTIME_IDLE];	if (cpu_online(cpu) && !nr_iowait_cpu(cpu))		idle += arch_idle_time(cpu);	return idle;} static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu){	u64 iowait; 	iowait = kcs->cpustat[CPUTIME_IOWAIT];	if (cpu_online(cpu) && nr_iowait_cpu(cpu))		iowait += arch_idle_time(cpu);	return iowait;} #else static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu){	u64 idle, idle_usecs = -1ULL; 	if (cpu_online(cpu))		idle_usecs = get_cpu_idle_time_us(cpu, NULL); 	if (idle_usecs == -1ULL)		/* !NO_HZ or cpu offline so we can rely on cpustat.idle */		idle = kcs->cpustat[CPUTIME_IDLE];	else		idle = idle_usecs * NSEC_PER_USEC; 	return idle;} static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu){	u64 iowait, iowait_usecs = -1ULL; 	if (cpu_online(cpu))		iowait_usecs = get_cpu_iowait_time_us(cpu, NULL); 	if (iowait_usecs == -1ULL)		/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */		iowait = kcs->cpustat[CPUTIME_IOWAIT];	else		iowait = iowait_usecs * NSEC_PER_USEC; 	return iowait;} #endif static void show_irq_gap(struct seq_file *p, unsigned int gap){	static const char zeros[] = " 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0"; 	while (gap > 0) {		unsigned int inc; 		inc = min_t(unsigned int, gap, ARRAY_SIZE(zeros) / 2);		seq_write(p, zeros, 2 * inc);		gap -= inc;	}} static void show_all_irqs(struct seq_file *p){	unsigned int i, next = 0; 	for_each_active_irq(i) {		show_irq_gap(p, i - next);		seq_put_decimal_ull(p, " ", kstat_irqs_usr(i));		next = i + 1;	}	show_irq_gap(p, nr_irqs - next);} static int show_stat(struct seq_file *p, void *v){	int i, j;	u64 user, nice, system, idle, iowait, irq, softirq, steal;	u64 guest, guest_nice;	u64 sum = 0;	u64 sum_softirq = 0;	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};	struct timespec64 boottime; 	user = nice = system = idle = iowait =		irq = softirq = steal = 0;	guest = guest_nice = 0;	getboottime64(&boottime); 	for_each_possible_cpu(i) {		struct kernel_cpustat *kcs = &kcpustat_cpu(i); 		user += kcs->cpustat[CPUTIME_USER];		nice += kcs->cpustat[CPUTIME_NICE];		system += kcs->cpustat[CPUTIME_SYSTEM];		idle += get_idle_time(kcs, i);		iowait += get_iowait_time(kcs, i);		irq += kcs->cpustat[CPUTIME_IRQ];		softirq += kcs->cpustat[CPUTIME_SOFTIRQ];		steal += kcs->cpustat[CPUTIME_STEAL];		guest += kcs->cpustat[CPUTIME_GUEST];		guest_nice += kcs->cpustat[CPUTIME_GUEST_NICE];		sum += kstat_cpu_irqs_sum(i);		sum += arch_irq_stat_cpu(i); 		for (j = 0; j < NR_SOFTIRQS; j++) {			unsigned int softirq_stat = kstat_softirqs_cpu(j, i); 			per_softirq_sums[j] += softirq_stat;			sum_softirq += softirq_stat;		}	}	sum += arch_irq_stat(); 	seq_put_decimal_ull(p, "cpu  ", nsec_to_clock_t(user));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));	seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));	seq_putc(p, '\n'); 	for_each_online_cpu(i) {		struct kernel_cpustat *kcs = &kcpustat_cpu(i); 		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */		user = kcs->cpustat[CPUTIME_USER];		nice = kcs->cpustat[CPUTIME_NICE];		system = kcs->cpustat[CPUTIME_SYSTEM];		idle = get_idle_time(kcs, i);		iowait = get_iowait_time(kcs, i);		irq = kcs->cpustat[CPUTIME_IRQ];		softirq = kcs->cpustat[CPUTIME_SOFTIRQ];		steal = kcs->cpustat[CPUTIME_STEAL];		guest = kcs->cpustat[CPUTIME_GUEST];		guest_nice = kcs->cpustat[CPUTIME_GUEST_NICE];		seq_printf(p, "cpu%d", i);		seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));		seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));		seq_putc(p, '\n');	}	seq_put_decimal_ull(p, "intr ", (unsigned long long)sum); 	show_all_irqs(p); 	seq_printf(p,		"\nctxt %llu\n"		"btime %llu\n"		"processes %lu\n"		"procs_running %lu\n"		"procs_blocked %lu\n",		nr_context_switches(),		(unsigned long long)boottime.tv_sec,		total_forks,		nr_running(),		nr_iowait()); 	seq_put_decimal_ull(p, "softirq ", (unsigned long long)sum_softirq); 	for (i = 0; i < NR_SOFTIRQS; i++)		seq_put_decimal_ull(p, " ", per_softirq_sums[i]);	seq_putc(p, '\n'); 	return 0;} static int stat_open(struct inode *inode, struct file *file){	unsigned int size = 1024 + 128 * num_online_cpus(); 	/* minimum size to display an interrupt count : 2 bytes */	size += 2 * nr_irqs;	return single_open_size(file, show_stat, NULL, size);} static const struct file_operations proc_stat_operations = {	.open		= stat_open,	.read		= seq_read,	.llseek		= seq_lseek,	.release	= single_release,}; static int __init proc_stat_init(void){	proc_create("stat", 0, NULL, &proc_stat_operations);	return 0;}fs_initcall(proc_stat_init);