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 29 static 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 51 DEFINE_SHOW_ATTRIBUTE(asids_debugfs); 52 53 static 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 } 59 device_initcall(asids_debugfs_init); 60