LXR linux/arch/sh/mm/asids-debugfs.c

   1/*
   2 * debugfs ops for process ASIDs
   3 *
   4 *  Copyright (C) 2000, 2001  Paolo Alberelli
   5 *  Copyright (C) 2003 - 2008  Paul Mundt
   6 *  Copyright (C) 2003, 2004  Richard Curnow
   7 *
   8 * Provides a debugfs file that lists out the ASIDs currently associated
   9 * with the processes.
  10 *
  11 * In the SH-5 case, if the DM.PC register is examined through the debug
  12 * link, this shows ASID + PC. To make use of this, the PID->ASID
  13 * relationship needs to be known. This is primarily for debugging.
  14 *
  15 * This file is subject to the terms and conditions of the GNU General Public
  16 * License.  See the file "COPYING" in the main directory of this archive
  17 * for more details.
  18 */
  19#include <linux/init.h>
  20#include <linux/debugfs.h>
  21#include <linux/seq_file.h>
  22#include <linux/spinlock.h>
  23#include <linux/sched/signal.h>
  24#include <linux/sched/task.h>
  25
  26#include <asm/processor.h>
  27#include <asm/mmu_context.h>
  28
  29static int asids_debugfs_show(struct seq_file *file, void *iter)
  30{
  31        struct task_struct *p;
  32
  33        read_lock(&tasklist_lock);
  34
  35        for_each_process(p) {
  36                int pid = p->pid;
  37
  38                if (unlikely(!pid))
  39                        continue;
  40
  41                if (p->mm)
  42                        seq_printf(file, "%5d : %04lx\n", pid,
  43                                   cpu_asid(smp_processor_id(), p->mm));
  44        }
  45
  46        read_unlock(&tasklist_lock);
  47
  48        return 0;
  49}
  50
  51DEFINE_SHOW_ATTRIBUTE(asids_debugfs);
  52
  53static int __init asids_debugfs_init(void)
  54{
  55        debugfs_create_file("asids", S_IRUSR, arch_debugfs_dir, NULL,
  56                            &asids_debugfs_fops);
  57        return 0;
  58}
  59device_initcall(asids_debugfs_init);
  60