1 files changed, 98 insertions, 0 deletions
diff --git a/backport-include/linux/wait.h b/backport-include/linux/wait.h
new file mode 100644
index 0000000..15a674c
--- /dev/null
+++ b/backport-include/linux/wait.h
@@ -0,0 +1,98 @@
+#ifndef __BACKPORT_LINUX_WAIT_H
+#define __BACKPORT_LINUX_WAIT_H
+#include_next <linux/wait.h>
+
+#if LINUX_VERSION_IS_LESS(3,17,0)
+extern int bit_wait(void *);
+extern int bit_wait_io(void *);
+
+static inline int
+backport_wait_on_bit(void *word, int bit, unsigned mode)
+{
+	return wait_on_bit(word, bit, bit_wait, mode);
+}
+
+static inline int
+backport_wait_on_bit_io(void *word, int bit, unsigned mode)
+{
+	return wait_on_bit(word, bit, bit_wait_io, mode);
+}
+
+#define wait_on_bit LINUX_BACKPORT(wait_on_bit)
+#define wait_on_bit_io LINUX_BACKPORT(wait_on_bit_io)
+
+#endif
+
+#if LINUX_VERSION_IS_LESS(3,18,12)
+#define WQ_FLAG_WOKEN		0x02
+
+#define wait_woken LINUX_BACKPORT(wait_woken)
+long wait_woken(wait_queue_t *wait, unsigned mode, long timeout);
+#define wait_woken LINUX_BACKPORT(wait_woken)
+int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
+#endif
+
+/**
+ * For wait_on_bit_timeout() an extra member in struct wait_bit_key is needed.
+ * This was introuced in kernel 3.17 and we are only able to backport this
+ * function on these kernel versions.
+ */
+#if LINUX_VERSION_IS_GEQ(3,17,0)
+#if LINUX_VERSION_IS_LESS(3,18,0)
+#define out_of_line_wait_on_bit_timeout LINUX_BACKPORT(out_of_line_wait_on_bit_timeout)
+int out_of_line_wait_on_bit_timeout(void *, int, wait_bit_action_f *, unsigned, unsigned long);
+
+#define bit_wait_timeout LINUX_BACKPORT(bit_wait_timeout)
+extern int bit_wait_timeout(struct wait_bit_key *);
+#endif
+
+#if LINUX_VERSION_IS_LESS(3,20,0)
+#define wait_on_bit_timeout LINUX_BACKPORT(wait_on_bit_timeout)
+/**
+ * wait_on_bit_timeout - wait for a bit to be cleared or a timeout elapses
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ * @timeout: timeout, in jiffies
+ *
+ * Use the standard hashed waitqueue table to wait for a bit
+ * to be cleared. This is similar to wait_on_bit(), except also takes a
+ * timeout parameter.
+ *
+ * Returned value will be zero if the bit was cleared before the
+ * @timeout elapsed, or non-zero if the @timeout elapsed or process
+ * received a signal and the mode permitted wakeup on that signal.
+ */
+static inline int
+wait_on_bit_timeout(void *word, int bit, unsigned mode, unsigned long timeout)
+{
+	might_sleep();
+	if (!test_bit(bit, word))
+		return 0;
+	return out_of_line_wait_on_bit_timeout(word, bit,
+					       bit_wait_timeout,
+					       mode, timeout);
+}
+#endif
+#endif
+
+#if LINUX_VERSION_IS_LESS(4,13,0)
+#define wait_queue_entry_t wait_queue_t
+
+#define wait_event_killable_timeout(wq_head, condition, timeout)	\
+({									\
+	long __ret = timeout;						\
+	might_sleep();							\
+	if (!___wait_cond_timeout(condition))				\
+		__ret = __wait_event_killable_timeout(wq_head,		\
+						condition, timeout);	\
+	__ret;								\
+})
+
+#define __wait_event_killable_timeout(wq_head, condition, timeout)	\
+	___wait_event(wq_head, ___wait_cond_timeout(condition),		\
+		      TASK_KILLABLE, 0, timeout,			\
+		      __ret = schedule_timeout(__ret))
+#endif
+
+#endif /* __BACKPORT_LINUX_WAIT_H */