1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015 Imagination Technologies
4 * Author: Paul Burton <paul.burton@mips.com>
5 */
6
7#include <asm/bcache.h>
8#include <asm/debug.h>
9#include <linux/uaccess.h>
10#include <linux/debugfs.h>
11#include <linux/init.h>
12
13static ssize_t sc_prefetch_read(struct file *file, char __user *user_buf,
14 size_t count, loff_t *ppos)
15{
16 bool enabled = bc_prefetch_is_enabled();
17 char buf[3];
18
19 buf[0] = enabled ? 'Y' : 'N';
20 buf[1] = '\n';
21 buf[2] = 0;
22
23 return simple_read_from_buffer(to: user_buf, count, ppos, from: buf, available: 2);
24}
25
26static ssize_t sc_prefetch_write(struct file *file,
27 const char __user *user_buf,
28 size_t count, loff_t *ppos)
29{
30 bool enabled;
31 int err;
32
33 err = kstrtobool_from_user(s: user_buf, count, res: &enabled);
34 if (err)
35 return err;
36
37 if (enabled)
38 bc_prefetch_enable();
39 else
40 bc_prefetch_disable();
41
42 return count;
43}
44
45static const struct file_operations sc_prefetch_fops = {
46 .open = simple_open,
47 .llseek = default_llseek,
48 .read = sc_prefetch_read,
49 .write = sc_prefetch_write,
50};
51
52static int __init sc_debugfs_init(void)
53{
54 struct dentry *dir;
55
56 dir = debugfs_create_dir(name: "l2cache", parent: mips_debugfs_dir);
57 debugfs_create_file(name: "prefetch", S_IRUGO | S_IWUSR, parent: dir, NULL,
58 fops: &sc_prefetch_fops);
59 return 0;
60}
61late_initcall(sc_debugfs_init);
62

source code of linux/arch/mips/mm/sc-debugfs.c