arch/powerpc/mm/ptdump/segment_regs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2018, Christophe Leroy CS S.I.
   4  * <christophe.leroy@c-s.fr>
   5  *
   6  * This dumps the content of Segment Registers
   7  */
   8
   9 #include <asm/debugfs.h>
  10
  11 static void seg_show(struct seq_file *m, int i)
  12 {
  13         u32 val = mfsrin(i << 28);
  14
  15         seq_printf(m, "0x%01x0000000-0x%01xfffffff ", i, i);
  16         seq_printf(m, "Kern key %d ", (val >> 30) & 1);
  17         seq_printf(m, "User key %d ", (val >> 29) & 1);
  18         if (val & 0x80000000) {
  19                 seq_printf(m, "Device 0x%03x", (val >> 20) & 0x1ff);
  20                 seq_printf(m, "-0x%05x", val & 0xfffff);
  21         } else {
  22                 if (val & 0x10000000)
  23                         seq_puts(m, "No Exec ");
  24                 seq_printf(m, "VSID 0x%06x", val & 0xffffff);
  25         }
  26         seq_puts(m, "\n");
  27 }
  28
  29 static int sr_show(struct seq_file *m, void *v)
  30 {
  31         int i;
  32
  33         seq_puts(m, "---[ User Segments ]---\n");
  34         for (i = 0; i < TASK_SIZE >> 28; i++)
  35                 seg_show(m, i);
  36
  37         seq_puts(m, "\n---[ Kernel Segments ]---\n");
  38         for (; i < 16; i++)
  39                 seg_show(m, i);
  40
  41         return 0;
  42 }
  43
  44 static int sr_open(struct inode *inode, struct file *file)
  45 {
  46         return single_open(file, sr_show, NULL);
  47 }
  48
  49 static const struct file_operations sr_fops = {
  50         .open           = sr_open,
  51         .read           = seq_read,
  52         .llseek         = seq_lseek,
  53         .release        = single_release,
  54 };
  55
  56 static int __init sr_init(void)
  57 {
  58         debugfs_create_file("segment_registers", 0400, powerpc_debugfs_root,
  59                             NULL, &sr_fops);
  60         return 0;
  61 }
  62 device_initcall(sr_init);