1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/fs.h> 3 #include <linux/init.h> 4 #include <linux/proc_fs.h> 5 #include <linux/sched.h> 6 #include <linux/seq_file.h> 7 #include <linux/time.h> 8 #include <linux/kernel_stat.h> 9 10 static int uptime_proc_show(struct seq_file *m, void *v) 11 { 12 struct timespec uptime; 13 struct timespec idle; 14 u64 nsec; 15 u32 rem; 16 int i; 17 18 nsec = 0; 19 for_each_possible_cpu(i) 20 nsec += (__force u64) kcpustat_cpu(i).cpustat[CPUTIME_IDLE]; 21 22 get_monotonic_boottime(&uptime); 23 idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem); 24 idle.tv_nsec = rem; 25 seq_printf(m, "%lu.%02lu %lu.%02lu\n", 26 (unsigned long) uptime.tv_sec, 27 (uptime.tv_nsec / (NSEC_PER_SEC / 100)), 28 (unsigned long) idle.tv_sec, 29 (idle.tv_nsec / (NSEC_PER_SEC / 100))); 30 return 0; 31 } 32 33 static int uptime_proc_open(struct inode *inode, struct file *file) 34 { 35 return single_open(file, uptime_proc_show, NULL); 36 } 37 38 static const struct file_operations uptime_proc_fops = { 39 .open = uptime_proc_open, 40 .read = seq_read, 41 .llseek = seq_lseek, 42 .release = single_release, 43 }; 44 45 static int __init proc_uptime_init(void) 46 { 47 proc_create("uptime", 0, NULL, &uptime_proc_fops); 48 return 0; 49 } 50 fs_initcall(proc_uptime_init); 51