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); 75