From ef50770eb84845636bbfd949e0d08430ca88d85d Mon Sep 17 00:00:00 2001
From: =?utf8?q?Fran=C3=A7ois=20Tigeot?= <ftigeot@wolfpond.org>
Date: Mon, 8 Jun 2020 07:42:20 +0200
Subject: [PATCH] drm/linux: Add mutex_lock_nested() and
 mutex_trylock_recursive()

---
 sys/dev/drm/include/linux/mutex.h | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/sys/dev/drm/include/linux/mutex.h b/sys/dev/drm/include/linux/mutex.h
index 69c8f1ed39..c10c76b8f9 100644
--- a/sys/dev/drm/include/linux/mutex.h
+++ b/sys/dev/drm/include/linux/mutex.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2019 François Tigeot <ftigeot@wolfpond.org>
+ * Copyright (c) 2014-2020 François Tigeot <ftigeot@wolfpond.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -59,4 +59,24 @@ mutex_destroy(struct lock *mutex)
 	lockuninit(mutex);
 }
 
+#define mutex_lock_nested(lock, unused)	mutex_lock(lock)
+
+enum mutex_trylock_recursive_enum {
+	MUTEX_TRYLOCK_FAILED    = 0,
+	MUTEX_TRYLOCK_SUCCESS   = 1,
+	MUTEX_TRYLOCK_RECURSIVE,
+};
+
+static inline enum mutex_trylock_recursive_enum
+mutex_trylock_recursive(struct lock *lock)
+{
+	if (lockowned(lock))
+		return MUTEX_TRYLOCK_RECURSIVE;
+
+	if (mutex_trylock(lock))
+		return MUTEX_TRYLOCK_SUCCESS;
+
+	return MUTEX_TRYLOCK_FAILED;
+}
+
 #endif	/* _LINUX_MUTEX_H_ */
-- 
2.41.0