drivers/ras/debugfs.c

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