1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright 2018, Christophe Leroy CS S.I.
4 * <christophe.leroy@c-s.fr>
5 *
6 * This dumps the content of Segment Registers
7 */
8
9#include <asm/debugfs.h>
10
11static void seg_show(struct seq_file *m, int i)
12{
13	u32 val = mfsrin(i << 28);
14
15	seq_printf(m, "0x%01x0000000-0x%01xfffffff ", i, i);
16	seq_printf(m, "Kern key %d ", (val >> 30) & 1);
17	seq_printf(m, "User key %d ", (val >> 29) & 1);
18	if (val & 0x80000000) {
19		seq_printf(m, "Device 0x%03x", (val >> 20) & 0x1ff);
20		seq_printf(m, "-0x%05x", val & 0xfffff);
21	} else {
22		if (val & 0x10000000)
23			seq_puts(m, "No Exec ");
24		seq_printf(m, "VSID 0x%06x", val & 0xffffff);
25	}
26	seq_puts(m, "\n");
27}
28
29static int sr_show(struct seq_file *m, void *v)
30{
31	int i;
32
33	seq_puts(m, "---[ User Segments ]---\n");
34	for (i = 0; i < TASK_SIZE >> 28; i++)
35		seg_show(m, i);
36
37	seq_puts(m, "\n---[ Kernel Segments ]---\n");
38	for (; i < 16; i++)
39		seg_show(m, i);
40
41	return 0;
42}
43
44static int sr_open(struct inode *inode, struct file *file)
45{
46	return single_open(file, sr_show, NULL);
47}
48
49static const struct file_operations sr_fops = {
50	.open		= sr_open,
51	.read		= seq_read,
52	.llseek		= seq_lseek,
53	.release	= single_release,
54};
55
56static int __init sr_init(void)
57{
58	debugfs_create_file("segment_registers", 0400, powerpc_debugfs_root,
59			    NULL, &sr_fops);
60	return 0;
61}
62device_initcall(sr_init);
63