Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/kernel/drivers/tty/tty_mutex.c b/kernel/drivers/tty/tty_mutex.c
new file mode 100644
index 000000000..0efcf713b
--- /dev/null
+++ b/kernel/drivers/tty/tty_mutex.c
@@ -0,0 +1,52 @@
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/semaphore.h>
+#include <linux/sched.h>
+
+/* Legacy tty mutex glue */
+
+/*
+ * Getting the big tty mutex.
+ */
+
+void __lockfunc tty_lock(struct tty_struct *tty)
+{
+	if (tty->magic != TTY_MAGIC) {
+		pr_err("L Bad %p\n", tty);
+		WARN_ON(1);
+		return;
+	}
+	tty_kref_get(tty);
+	mutex_lock(&tty->legacy_mutex);
+}
+EXPORT_SYMBOL(tty_lock);
+
+void __lockfunc tty_unlock(struct tty_struct *tty)
+{
+	if (tty->magic != TTY_MAGIC) {
+		pr_err("U Bad %p\n", tty);
+		WARN_ON(1);
+		return;
+	}
+	mutex_unlock(&tty->legacy_mutex);
+	tty_kref_put(tty);
+}
+EXPORT_SYMBOL(tty_unlock);
+
+void __lockfunc tty_lock_slave(struct tty_struct *tty)
+{
+	if (tty && tty != tty->link)
+		tty_lock(tty);
+}
+
+void __lockfunc tty_unlock_slave(struct tty_struct *tty)
+{
+	if (tty && tty != tty->link)
+		tty_unlock(tty);
+}
+
+void tty_set_lock_subclass(struct tty_struct *tty)
+{
+	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
+}