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
sc_prefetch_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)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
sc_prefetch_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)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
sc_debugfs_init(void)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);
75