[PATCH v2 5/6] debugfs: add debugfs_create_atomic64_t for atomic64_t

[Luis Chamberlain <mcgrof@kernel.org>]

Sometimes you want to add debugfs entries for atomic counters which
can be pretty large using atomic64_t. Add support for these.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/debugfs/file.c       | 36 ++++++++++++++++++++++++++++++++++++
 include/linux/debugfs.h |  2 ++
 2 files changed, 38 insertions(+)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 1f971c880dde..76d923503861 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -780,6 +780,42 @@ void debugfs_create_atomic_t(const char *name, umode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
 
+static int debugfs_atomic64_t_set(void *data, u64 val)
+{
+	atomic64_set((atomic64_t *)data, val);
+	return 0;
+}
+static int debugfs_atomic64_t_get(void *data, u64 *val)
+{
+	*val = atomic64_read((atomic64_t *)data);
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic64_t, debugfs_atomic64_t_get,
+			debugfs_atomic64_t_set, "%lld\n");
+DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic64_t_ro, debugfs_atomic64_t_get, NULL,
+			"%lld\n");
+DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic64_t_wo, NULL, debugfs_atomic64_t_set,
+			"%lld\n");
+
+/**
+ * debugfs_create_atomic64_t - create a debugfs file that is used to read and
+ * write an atomic64_t value
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          file will be created in the root of the debugfs filesystem.
+ * @value: a pointer to the variable that the file should read to and write
+ *         from.
+ */
+void debugfs_create_atomic64_t(const char *name, umode_t mode,
+			     struct dentry *parent, atomic64_t *value)
+{
+	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_atomic64_t,
+				   &fops_atomic64_t_ro, &fops_atomic64_t_wo);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_atomic64_t);
+
 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
 			       size_t count, loff_t *ppos)
 {
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index ea2d919fd9c7..f5cc613a545e 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -136,6 +136,8 @@ void debugfs_create_size_t(const char *name, umode_t mode,
 			   struct dentry *parent, size_t *value);
 void debugfs_create_atomic_t(const char *name, umode_t mode,
 			     struct dentry *parent, atomic_t *value);
+void debugfs_create_atomic64_t(const char *name, umode_t mode,
+			       struct dentry *parent, atomic64_t *value);
 void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
 			 bool *value);
 void debugfs_create_str(const char *name, umode_t mode,
-- 
2.39.2