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 <linux/debugfs.h>
10 
11 static void seg_show(struct seq_file *m, int i)
12 {
13 	u32 val = mfsr(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 
29 static 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 
44 DEFINE_SHOW_ATTRIBUTE(sr);
45 
46 static int __init sr_init(void)
47 {
48 	debugfs_create_file("segment_registers", 0400, arch_debugfs_dir,
49 			    NULL, &sr_fops);
50 	return 0;
51 }
52 device_initcall(sr_init);
53