summaryrefslogtreecommitdiffstats
path: root/drivers/tty/tty_mutex.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/tty/tty_mutex.c')
-rw-r--r--drivers/tty/tty_mutex.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
new file mode 100644
index 000000000..784e46a0a
--- /dev/null
+++ b/drivers/tty/tty_mutex.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/semaphore.h>
+#include <linux/sched.h>
+#include "tty.h"
+
+/* Legacy tty mutex glue */
+
+/*
+ * Getting the big tty mutex.
+ */
+
+void tty_lock(struct tty_struct *tty)
+{
+ tty_kref_get(tty);
+ mutex_lock(&tty->legacy_mutex);
+}
+EXPORT_SYMBOL(tty_lock);
+
+int tty_lock_interruptible(struct tty_struct *tty)
+{
+ int ret;
+
+ tty_kref_get(tty);
+ ret = mutex_lock_interruptible(&tty->legacy_mutex);
+ if (ret)
+ tty_kref_put(tty);
+ return ret;
+}
+
+void tty_unlock(struct tty_struct *tty)
+{
+ mutex_unlock(&tty->legacy_mutex);
+ tty_kref_put(tty);
+}
+EXPORT_SYMBOL(tty_unlock);
+
+void tty_lock_slave(struct tty_struct *tty)
+{
+ if (tty && tty != tty->link)
+ tty_lock(tty);
+}
+
+void 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);
+}