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/mipsregs.h> 14 15 static void build_segment_config(char *str, unsigned int cfg) 16 { 17 unsigned int am; 18 static const char * const am_str[] = { 19 "UK", "MK", "MSK", "MUSK", "MUSUK", "USK", 20 "RSRVD", "UUSK"}; 21 22 /* Segment access mode. */ 23 am = (cfg & MIPS_SEGCFG_AM) >> MIPS_SEGCFG_AM_SHIFT; 24 str += sprintf(str, "%-5s", am_str[am]); 25 26 /* 27 * Access modes MK, MSK and MUSK are mapped segments. Therefore 28 * there is no direct physical address mapping. 29 */ 30 if ((am == 0) || (am > 3)) { 31 str += sprintf(str, " %03lx", 32 ((cfg & MIPS_SEGCFG_PA) >> MIPS_SEGCFG_PA_SHIFT)); 33 str += sprintf(str, " %01ld", 34 ((cfg & MIPS_SEGCFG_C) >> MIPS_SEGCFG_C_SHIFT)); 35 } else { 36 str += sprintf(str, " UND"); 37 str += sprintf(str, " U"); 38 } 39 40 /* Exception configuration. */ 41 str += sprintf(str, " %01ld\n", 42 ((cfg & MIPS_SEGCFG_EU) >> MIPS_SEGCFG_EU_SHIFT)); 43 } 44 45 static int show_segments(struct seq_file *m, void *v) 46 { 47 unsigned int segcfg; 48 char str[42]; 49 50 seq_puts(m, "Segment Virtual Size Access Mode Physical Caching EU\n"); 51 seq_puts(m, "------- ------- ---- ----------- -------- ------- --\n"); 52 53 segcfg = read_c0_segctl0(); 54 build_segment_config(str, segcfg); 55 seq_printf(m, " 0 e0000000 512M %s", str); 56 57 segcfg >>= 16; 58 build_segment_config(str, segcfg); 59 seq_printf(m, " 1 c0000000 512M %s", str); 60 61 segcfg = read_c0_segctl1(); 62 build_segment_config(str, segcfg); 63 seq_printf(m, " 2 a0000000 512M %s", str); 64 65 segcfg >>= 16; 66 build_segment_config(str, segcfg); 67 seq_printf(m, " 3 80000000 512M %s", str); 68 69 segcfg = read_c0_segctl2(); 70 build_segment_config(str, segcfg); 71 seq_printf(m, " 4 40000000 1G %s", str); 72 73 segcfg >>= 16; 74 build_segment_config(str, segcfg); 75 seq_printf(m, " 5 00000000 1G %s\n", str); 76 77 return 0; 78 } 79 80 static int segments_open(struct inode *inode, struct file *file) 81 { 82 return single_open(file, show_segments, NULL); 83 } 84 85 static const struct file_operations segments_fops = { 86 .open = segments_open, 87 .read = seq_read, 88 .llseek = seq_lseek, 89 .release = single_release, 90 }; 91 92 static int __init segments_info(void) 93 { 94 extern struct dentry *mips_debugfs_dir; 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