1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/fs.h>
3*4882a593Smuzhiyun #include <linux/init.h>
4*4882a593Smuzhiyun #include <linux/proc_fs.h>
5*4882a593Smuzhiyun #include <linux/seq_file.h>
6*4882a593Smuzhiyun #include <linux/blkdev.h>
7*4882a593Smuzhiyun
devinfo_show(struct seq_file * f,void * v)8*4882a593Smuzhiyun static int devinfo_show(struct seq_file *f, void *v)
9*4882a593Smuzhiyun {
10*4882a593Smuzhiyun int i = *(loff_t *) v;
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun if (i < CHRDEV_MAJOR_MAX) {
13*4882a593Smuzhiyun if (i == 0)
14*4882a593Smuzhiyun seq_puts(f, "Character devices:\n");
15*4882a593Smuzhiyun chrdev_show(f, i);
16*4882a593Smuzhiyun }
17*4882a593Smuzhiyun #ifdef CONFIG_BLOCK
18*4882a593Smuzhiyun else {
19*4882a593Smuzhiyun i -= CHRDEV_MAJOR_MAX;
20*4882a593Smuzhiyun if (i == 0)
21*4882a593Smuzhiyun seq_puts(f, "\nBlock devices:\n");
22*4882a593Smuzhiyun blkdev_show(f, i);
23*4882a593Smuzhiyun }
24*4882a593Smuzhiyun #endif
25*4882a593Smuzhiyun return 0;
26*4882a593Smuzhiyun }
27*4882a593Smuzhiyun
devinfo_start(struct seq_file * f,loff_t * pos)28*4882a593Smuzhiyun static void *devinfo_start(struct seq_file *f, loff_t *pos)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun if (*pos < (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
31*4882a593Smuzhiyun return pos;
32*4882a593Smuzhiyun return NULL;
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun
devinfo_next(struct seq_file * f,void * v,loff_t * pos)35*4882a593Smuzhiyun static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
36*4882a593Smuzhiyun {
37*4882a593Smuzhiyun (*pos)++;
38*4882a593Smuzhiyun if (*pos >= (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
39*4882a593Smuzhiyun return NULL;
40*4882a593Smuzhiyun return pos;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun
devinfo_stop(struct seq_file * f,void * v)43*4882a593Smuzhiyun static void devinfo_stop(struct seq_file *f, void *v)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun /* Nothing to do */
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun static const struct seq_operations devinfo_ops = {
49*4882a593Smuzhiyun .start = devinfo_start,
50*4882a593Smuzhiyun .next = devinfo_next,
51*4882a593Smuzhiyun .stop = devinfo_stop,
52*4882a593Smuzhiyun .show = devinfo_show
53*4882a593Smuzhiyun };
54*4882a593Smuzhiyun
proc_devices_init(void)55*4882a593Smuzhiyun static int __init proc_devices_init(void)
56*4882a593Smuzhiyun {
57*4882a593Smuzhiyun proc_create_seq("devices", 0, NULL, &devinfo_ops);
58*4882a593Smuzhiyun return 0;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun fs_initcall(proc_devices_init);
61