LXR linux/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
  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(user_buf, count, ppos, buf, 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(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
  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("l2cache", mips_debugfs_dir);
  57        debugfs_create_file("prefetch", S_IRUGO | S_IWUSR, dir, NULL,
  58                            &sc_prefetch_fops);
  59        return 0;
  60}
  61late_initcall(sc_debugfs_init);
  62