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
build_segment_config(char * str,unsigned int cfg)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.
30 */
31 if ((am == 0) || (am > 3)) {
32 str += sprintf(str, " %03lx",
33 ((cfg & MIPS_SEGCFG_PA) >> MIPS_SEGCFG_PA_SHIFT));
34 str += sprintf(str, " %01ld",
35 ((cfg & MIPS_SEGCFG_C) >> MIPS_SEGCFG_C_SHIFT));
36 } else {
37 str += sprintf(str, " UND");
38 str += sprintf(str, " U");
39 }
40
41 /* Exception configuration. */
42 str += sprintf(str, " %01ld\n",
43 ((cfg & MIPS_SEGCFG_EU) >> MIPS_SEGCFG_EU_SHIFT));
44 }
45
show_segments(struct seq_file * m,void * v)46 static int show_segments(struct seq_file *m, void *v)
47 {
48 unsigned int segcfg;
49 char str[42];
50
51 seq_puts(m, "Segment Virtual Size Access Mode Physical Caching EU\n");
52 seq_puts(m, "------- ------- ---- ----------- -------- ------- --\n");
53
54 segcfg = read_c0_segctl0();
55 build_segment_config(str, segcfg);
56 seq_printf(m, " 0 e0000000 512M %s", str);
57
58 segcfg >>= 16;
59 build_segment_config(str, segcfg);
60 seq_printf(m, " 1 c0000000 512M %s", str);
61
62 segcfg = read_c0_segctl1();
63 build_segment_config(str, segcfg);
64 seq_printf(m, " 2 a0000000 512M %s", str);
65
66 segcfg >>= 16;
67 build_segment_config(str, segcfg);
68 seq_printf(m, " 3 80000000 512M %s", str);
69
70 segcfg = read_c0_segctl2();
71 build_segment_config(str, segcfg);
72 seq_printf(m, " 4 40000000 1G %s", str);
73
74 segcfg >>= 16;
75 build_segment_config(str, segcfg);
76 seq_printf(m, " 5 00000000 1G %s\n", str);
77
78 return 0;
79 }
80
segments_open(struct inode * inode,struct file * file)81 static int segments_open(struct inode *inode, struct file *file)
82 {
83 return single_open(file, show_segments, NULL);
84 }
85
86 static const struct file_operations segments_fops = {
87 .open = segments_open,
88 .read = seq_read,
89 .llseek = seq_lseek,
90 .release = single_release,
91 };
92
segments_info(void)93 static int __init segments_info(void)
94 {
95 struct dentry *segments;
96
97 if (cpu_has_segments) {
98 if (!mips_debugfs_dir)
99 return -ENODEV;
100
101 segments = debugfs_create_file("segments", S_IRUGO,
102 mips_debugfs_dir, NULL,
103 &segments_fops);
104 if (!segments)
105 return -ENOMEM;
106 }
107 return 0;
108 }
109
110 device_initcall(segments_info);
111