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. 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 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 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 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