drivers/ras/debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/debugfs.h>
   3 #include <linux/ras.h>
   4 #include "debugfs.h"
   5
   6 static struct dentry *ras_debugfs_dir;
   7
   8 static atomic_t trace_count = ATOMIC_INIT(0);
   9
  10 struct dentry *ras_get_debugfs_root(void)
  11 {
  12         return ras_debugfs_dir;
  13 }
  14 EXPORT_SYMBOL_GPL(ras_get_debugfs_root);
  15
  16 int ras_userspace_consumers(void)
  17 {
  18         return atomic_read(&trace_count);
  19 }
  20 EXPORT_SYMBOL_GPL(ras_userspace_consumers);
  21
  22 static int trace_show(struct seq_file *m, void *v)
  23 {
  24         return 0;
  25 }
  26
  27 static int trace_open(struct inode *inode, struct file *file)
  28 {
  29         atomic_inc(&trace_count);
  30         return single_open(file, trace_show, NULL);
  31 }
  32
  33 static int trace_release(struct inode *inode, struct file *file)
  34 {
  35         atomic_dec(&trace_count);
  36         return single_release(inode, file);
  37 }
  38
  39 static const struct file_operations trace_fops = {
  40         .open    = trace_open,
  41         .read    = seq_read,
  42         .llseek  = seq_lseek,
  43         .release = trace_release,
  44 };
  45
  46 int __init ras_add_daemon_trace(void)
  47 {
  48         struct dentry *fentry;
  49
  50         if (!ras_debugfs_dir)
  51                 return -ENOENT;
  52
  53         fentry = debugfs_create_file("daemon_active", S_IRUSR, ras_debugfs_dir,
  54                                      NULL, &trace_fops);
  55         if (IS_ERR(fentry))
  56                 return -ENODEV;
  57
  58         return 0;
  59
  60 }
  61
  62 void __init ras_debugfs_init(void)
  63 {
  64         ras_debugfs_dir = debugfs_create_dir("ras", NULL);
  65 }