GNU Linux-libre 4.19.286-gnu1
[releases.git] / arch / mips / mm / sc-debugfs.c
1 /*
2  * Copyright (C) 2015 Imagination Technologies
3  * Author: Paul Burton <paul.burton@mips.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License as published by the
7  * Free Software Foundation; either version 2 of the License, or (at your
8  * option) any later version.
9  */
10
11 #include <asm/bcache.h>
12 #include <asm/debug.h>
13 #include <linux/uaccess.h>
14 #include <linux/debugfs.h>
15 #include <linux/init.h>
16
17 static ssize_t sc_prefetch_read(struct file *file, char __user *user_buf,
18                                 size_t count, loff_t *ppos)
19 {
20         bool enabled = bc_prefetch_is_enabled();
21         char buf[3];
22
23         buf[0] = enabled ? 'Y' : 'N';
24         buf[1] = '\n';
25         buf[2] = 0;
26
27         return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
28 }
29
30 static ssize_t sc_prefetch_write(struct file *file,
31                                  const char __user *user_buf,
32                                  size_t count, loff_t *ppos)
33 {
34         bool enabled;
35         int err;
36
37         err = kstrtobool_from_user(user_buf, count, &enabled);
38         if (err)
39                 return err;
40
41         if (enabled)
42                 bc_prefetch_enable();
43         else
44                 bc_prefetch_disable();
45
46         return count;
47 }
48
49 static const struct file_operations sc_prefetch_fops = {
50         .open = simple_open,
51         .llseek = default_llseek,
52         .read = sc_prefetch_read,
53         .write = sc_prefetch_write,
54 };
55
56 static int __init sc_debugfs_init(void)
57 {
58         struct dentry *dir, *file;
59
60         if (!mips_debugfs_dir)
61                 return -ENODEV;
62
63         dir = debugfs_create_dir("l2cache", mips_debugfs_dir);
64         if (IS_ERR(dir))
65                 return PTR_ERR(dir);
66
67         file = debugfs_create_file("prefetch", S_IRUGO | S_IWUSR, dir,
68                                    NULL, &sc_prefetch_fops);
69         if (!file)
70                 return -ENOMEM;
71
72         return 0;
73 }
74 late_initcall(sc_debugfs_init);