LXR linux/arch/mips/kernel/segment.c

   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
  15static 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
  45static 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
  80static int segments_open(struct inode *inode, struct file *file)
  81{
  82        return single_open(file, show_segments, NULL);
  83}
  84
  85static const struct file_operations segments_fops = {
  86        .open           = segments_open,
  87        .read           = seq_read,
  88        .llseek         = seq_lseek,
  89        .release        = single_release,
  90};
  91
  92static 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
 110device_initcall(segments_info);
 111