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/seq_file.h>
6 #include <linux/blkdev.h>
7 #include "internal.h"
8
9 static int devinfo_show(struct seq_file *f, void *v)
10 {
11 int i = *(loff_t *) v;
12
13 if (i < CHRDEV_MAJOR_MAX) {
14 if (i == 0)
15 seq_puts(f, "Character devices:\n");
16 chrdev_show(f, i);
17 }
18 #ifdef CONFIG_BLOCK
19 else {
20 i -= CHRDEV_MAJOR_MAX;
21 if (i == 0)
22 seq_puts(f, "\nBlock devices:\n");
23 blkdev_show(f, i);
24 }
25 #endif
26 return 0;
27 }
28
29 static void *devinfo_start(struct seq_file *f, loff_t *pos)
30 {
31 if (*pos < (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
32 return pos;
33 return NULL;
34 }
35
36 static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
37 {
38 (*pos)++;
39 if (*pos >= (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
40 return NULL;
41 return pos;
42 }
43
44 static void devinfo_stop(struct seq_file *f, void *v)
45 {
46 /* Nothing to do */
47 }
48
49 static const struct seq_operations devinfo_ops = {
50 .start = devinfo_start,
51 .next = devinfo_next,
52 .stop = devinfo_stop,
53 .show = devinfo_show
54 };
55
56 static int __init proc_devices_init(void)
57 {
58 struct proc_dir_entry *pde;
59
60 pde = proc_create_seq("devices", 0, NULL, &devinfo_ops);
61 pde_make_permanent(pde);
62 return 0;
63 }
64 fs_initcall(proc_devices_init);
65
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