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Date:   Fri, 30 Oct 2020 18:04:42 +1100
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Subject: [PATCH 1/1] debugfs: Add a helper to export atomic64_t values
From:   Anand K Mistry <amistry@google.com>
To:     linux-kernel@vger.kernel.org
Cc:     Anand K Mistry <amistry@google.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>
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Precedence: bulk

This mirrors support for exporting atomic_t values.

Signed-off-by: Anand K Mistry <amistry@google.com>

---

 fs/debugfs/file.c       | 37 +++++++++++++++++++++++++++++++++++++
 include/linux/debugfs.h |  6 ++++++
 2 files changed, 43 insertions(+)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index a768a09430c3..798bd3bdedec 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -770,6 +770,43 @@ 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(fops_atomic64_t, debugfs_atomic64_t_get,
+			debugfs_atomic64_t_set, "%lld\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic64_t_ro, debugfs_atomic64_t_get, NULL,
+			"%lld\n");
+DEFINE_DEBUGFS_ATTRIBUTE(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 851dd1f9a8a5..0fac84c53eab 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -126,6 +126,8 @@ 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);
 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 				  struct dentry *parent, bool *value);
 
@@ -291,6 +293,10 @@ static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
 					   atomic_t *value)
 { }
 
+static inline void debugfs_create_atomic64_t(const char *name, umode_t mode,
+					     struct dentry *parent, atomic64_t *value)
+{ }
+
 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode,
 						 struct dentry *parent,
 						 bool *value)
-- 
2.29.1.341.ge80a0c044ae-goog