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 char buf[32]; 35 ssize_t buf_size; 36 bool enabled; 37 int err; 38 39 buf_size = min(count, sizeof(buf) - 1); 40 if (copy_from_user(buf, user_buf, buf_size)) 41 return -EFAULT; 42 43 buf[buf_size] = '\0'; 44 err = strtobool(buf, &enabled); 45 if (err) 46 return err; 47 48 if (enabled) 49 bc_prefetch_enable(); 50 else 51 bc_prefetch_disable(); 52 53 return count; 54 } 55 56 static const struct file_operations sc_prefetch_fops = { 57 .open = simple_open, 58 .llseek = default_llseek, 59 .read = sc_prefetch_read, 60 .write = sc_prefetch_write, 61 }; 62 63 static int __init sc_debugfs_init(void) 64 { 65 struct dentry *dir, *file; 66 67 if (!mips_debugfs_dir) 68 return -ENODEV; 69 70 dir = debugfs_create_dir("l2cache", mips_debugfs_dir); 71 if (IS_ERR(dir)) 72 return PTR_ERR(dir); 73 74 file = debugfs_create_file("prefetch", S_IRUGO | S_IWUSR, dir, 75 NULL, &sc_prefetch_fops); 76 if (!file) 77 return -ENOMEM; 78 79 return 0; 80 } 81 late_initcall(sc_debugfs_init); 82