arch/mips/mm/sc-debugfs.c

   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
  13 static 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(user_buf, count, ppos, buf, 2);
  24 }
  25
  26 static 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(user_buf, count, &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
  45 static 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
  52 static int __init sc_debugfs_init(void)
  53 {
  54         struct dentry *dir;
  55
  56         dir = debugfs_create_dir("l2cache", mips_debugfs_dir);
  57         debugfs_create_file("prefetch", S_IRUGO | S_IWUSR, dir, NULL,
  58                             &sc_prefetch_fops);
  59         return 0;
  60 }
  61 late_initcall(sc_debugfs_init);