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/debug.h>
  14#include <asm/mipsregs.h>
  15
  16static 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
  49static 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
  84static int segments_open(struct inode *inode, struct file *file)
  85{
  86        return single_open(file, show_segments, NULL);
  87}
  88
  89static const struct file_operations segments_fops = {
  90        .open           = segments_open,
  91        .read           = seq_read,
  92        .llseek         = seq_lseek,
  93        .release        = single_release,
  94};
  95
  96static int __init segments_info(void)
  97{
  98        struct dentry *segments;
  99
 100        if (cpu_has_segments) {
 101                if (!mips_debugfs_dir)
 102                        return -ENODEV;
 103
 104                segments = debugfs_create_file("segments", S_IRUGO,
 105                                               mips_debugfs_dir, NULL,
 106                                               &segments_fops);
 107                if (!segments)
 108                        return -ENOMEM;
 109        }
 110        return 0;
 111}
 112
 113device_initcall(segments_info);
 114