From e4a05976e768dd542d3cf5e96b8672bd4a5ea512 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Sat, 13 Apr 2019 22:56:39 +0000
Subject: [PATCH] scst/include/backport.h: Add wait_event_lock_irq_timeout()
 backport

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@8193 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/include/backport.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/scst/include/backport.h b/scst/include/backport.h
index c5e59c07b..f9d9baa8f 100644
--- a/scst/include/backport.h
+++ b/scst/include/backport.h
@@ -1543,6 +1543,30 @@ static inline void *vzalloc(unsigned long size)
 }
 #endif
 
+/* <linux/wait.h> */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 20, 0)
+/*
+ * See also commit 25ab0bc334b4 ("scsi: sched/wait: Add
+ * wait_event_lock_irq_timeout for TASK_UNINTERRUPTIBLE usage") # v4.20.
+ */
+#define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state)\
+	___wait_event(wq_head, ___wait_cond_timeout(condition),		\
+		      state, 0, timeout,				\
+		      spin_unlock_irq(&lock);				\
+		      __ret = schedule_timeout(__ret);			\
+		      spin_lock_irq(&lock));
+
+#define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout)	\
+({									\
+	long __ret = timeout;						\
+	if (!___wait_cond_timeout(condition))				\
+		__ret = __wait_event_lock_irq_timeout(			\
+					wq_head, condition, lock, timeout,\
+					TASK_UNINTERRUPTIBLE);		\
+	__ret;								\
+})
+#endif
+
 /* <linux/workqueue.h> */
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)