1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2013 Imagination Technologies Ltd.
7 */
8
9#include <linux/kernel.h>
10#include <linux/debugfs.h>
11#include <linux/seq_file.h>
12#include <asm/cpu.h>
13#include <asm/debug.h>
14#include <asm/mipsregs.h>
15
16static void build_segment_config(char *str, unsigned int cfg)
17{
18	unsigned int am;
19	static const char * const am_str[] = {
20		"UK", "MK", "MSK", "MUSK", "MUSUK", "USK",
21		"RSRVD", "UUSK"};
22
23	/* Segment access mode. */
24	am = (cfg & MIPS_SEGCFG_AM) >> MIPS_SEGCFG_AM_SHIFT;
25	str += sprintf(str, "%-5s", am_str[am]);
26
27	/*
28	 * Access modes MK, MSK and MUSK are mapped segments. Therefore
29	 * there is no direct physical address mapping unless it becomes
30	 * unmapped uncached at error level due to EU.
31	 */
32	if ((am == 0) || (am > 3) || (cfg & MIPS_SEGCFG_EU))
33		str += sprintf(str, "         %03lx",
34			((cfg & MIPS_SEGCFG_PA) >> MIPS_SEGCFG_PA_SHIFT));
35	else
36		str += sprintf(str, "         UND");
37
38	if ((am == 0) || (am > 3))
39		str += sprintf(str, "         %01ld",
40			((cfg & MIPS_SEGCFG_C) >> MIPS_SEGCFG_C_SHIFT));
41	else
42		str += sprintf(str, "         U");
43
44	/* Exception configuration. */
45	str += sprintf(str, "       %01ld\n",
46		((cfg & MIPS_SEGCFG_EU) >> MIPS_SEGCFG_EU_SHIFT));
47}
48
49static int segments_show(struct seq_file *m, void *v)
50{
51	unsigned int segcfg;
52	char str[42];
53
54	seq_puts(m, "Segment   Virtual    Size   Access Mode   Physical   Caching   EU\n");
55	seq_puts(m, "-------   -------    ----   -----------   --------   -------   --\n");
56
57	segcfg = read_c0_segctl0();
58	build_segment_config(str, segcfg);
59	seq_printf(m, "   0      e0000000   512M      %s", str);
60
61	segcfg >>= 16;
62	build_segment_config(str, segcfg);
63	seq_printf(m, "   1      c0000000   512M      %s", str);
64
65	segcfg = read_c0_segctl1();
66	build_segment_config(str, segcfg);
67	seq_printf(m, "   2      a0000000   512M      %s", str);
68
69	segcfg >>= 16;
70	build_segment_config(str, segcfg);
71	seq_printf(m, "   3      80000000   512M      %s", str);
72
73	segcfg = read_c0_segctl2();
74	build_segment_config(str, segcfg);
75	seq_printf(m, "   4      40000000    1G       %s", str);
76
77	segcfg >>= 16;
78	build_segment_config(str, segcfg);
79	seq_printf(m, "   5      00000000    1G       %s\n", str);
80
81	return 0;
82}
83DEFINE_SHOW_ATTRIBUTE(segments);
84
85static int __init segments_info(void)
86{
87	if (cpu_has_segments)
88		debugfs_create_file("segments", S_IRUGO, mips_debugfs_dir, NULL,
89				    &segments_fops);
90	return 0;
91}
92
93device_initcall(segments_info);
94