File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c
new file mode 100644
index 0000000..0322acf
--- /dev/null
+++ b/drivers/ras/debugfs.c
@@ -0,0 +1,56 @@
+#include <linux/debugfs.h>
+
+static struct dentry *ras_debugfs_dir;
+
+static atomic_t trace_count = ATOMIC_INIT(0);
+
+int ras_userspace_consumers(void)
+{
+ return atomic_read(&trace_count);
+}
+EXPORT_SYMBOL_GPL(ras_userspace_consumers);
+
+static int trace_show(struct seq_file *m, void *v)
+{
+ return atomic_read(&trace_count);
+}
+
+static int trace_open(struct inode *inode, struct file *file)
+{
+ atomic_inc(&trace_count);
+ return single_open(file, trace_show, NULL);
+}
+
+static int trace_release(struct inode *inode, struct file *file)
+{
+ atomic_dec(&trace_count);
+ return single_release(inode, file);
+}
+
+static const struct file_operations trace_fops = {
+ .open = trace_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = trace_release,
+};
+
+int __init ras_add_daemon_trace(void)
+{
+ struct dentry *fentry;
+
+ if (!ras_debugfs_dir)
+ return -ENOENT;
+
+ fentry = debugfs_create_file("daemon_active", S_IRUSR, ras_debugfs_dir,
+ NULL, &trace_fops);
+ if (!fentry)
+ return -ENODEV;
+
+ return 0;
+
+}
+
+void __init ras_debugfs_init(void)
+{
+ ras_debugfs_dir = debugfs_create_dir("ras", NULL);
+}