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 show_segments(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 84 static int segments_open(struct inode *inode, struct file *file) 85 { 86 return single_open(file, show_segments, NULL); 87 } 88 89 static const struct file_operations segments_fops = { 90 .open = segments_open, 91 .read = seq_read, 92 .llseek = seq_lseek, 93 .release = single_release, 94 }; 95 96 static int __init segments_info(void) 97 { 98 if (cpu_has_segments) 99 debugfs_create_file("segments", S_IRUGO, mips_debugfs_dir, NULL, 100 &segments_fops); 101 return 0; 102 } 103 104 device_initcall(segments_info); 105