1/*
2 * debugfs ops for process ASIDs
3 *
4 *  Copyright (C) 2000, 2001  Paolo Alberelli
5 *  Copyright (C) 2003 - 2008  Paul Mundt
6 *  Copyright (C) 2003, 2004  Richard Curnow
7 *
8 * Provides a debugfs file that lists out the ASIDs currently associated
9 * with the processes.
10 *
11 * In the SH-5 case, if the DM.PC register is examined through the debug
12 * link, this shows ASID + PC. To make use of this, the PID->ASID
13 * relationship needs to be known. This is primarily for debugging.
14 *
15 * This file is subject to the terms and conditions of the GNU General Public
16 * License.  See the file "COPYING" in the main directory of this archive
17 * for more details.
18 */
19#include <linux/init.h>
20#include <linux/module.h>
21#include <linux/debugfs.h>
22#include <linux/seq_file.h>
23#include <linux/spinlock.h>
24#include <asm/processor.h>
25#include <asm/mmu_context.h>
26
27static int asids_seq_show(struct seq_file *file, void *iter)
28{
29	struct task_struct *p;
30
31	read_lock(&tasklist_lock);
32
33	for_each_process(p) {
34		int pid = p->pid;
35
36		if (unlikely(!pid))
37			continue;
38
39		if (p->mm)
40			seq_printf(file, "%5d : %04lx\n", pid,
41				   cpu_asid(smp_processor_id(), p->mm));
42	}
43
44	read_unlock(&tasklist_lock);
45
46	return 0;
47}
48
49static int asids_debugfs_open(struct inode *inode, struct file *file)
50{
51	return single_open(file, asids_seq_show, inode->i_private);
52}
53
54static const struct file_operations asids_debugfs_fops = {
55	.owner		= THIS_MODULE,
56	.open		= asids_debugfs_open,
57	.read		= seq_read,
58	.llseek		= seq_lseek,
59	.release	= single_release,
60};
61
62static int __init asids_debugfs_init(void)
63{
64	struct dentry *asids_dentry;
65
66	asids_dentry = debugfs_create_file("asids", S_IRUSR, arch_debugfs_dir,
67					   NULL, &asids_debugfs_fops);
68	if (!asids_dentry)
69		return -ENOMEM;
70
71	return PTR_ERR_OR_ZERO(asids_dentry);
72}
73module_init(asids_debugfs_init);
74
75MODULE_LICENSE("GPL v2");
76