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
16 static 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
49 static 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 }
83 DEFINE_SHOW_ATTRIBUTE(segments);
84
85 static 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
93 device_initcall(segments_info);
94
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