[src/trunk]: src/sys/external/bsd/drm2/include/linux Add down_read_trylock an...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1f0d518febdf
branches:  trunk
changeset: 992782:1f0d518febdf
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 27 07:47:01 2018 +0000

description:
Add down_read_trylock and downgrade_write.

diffstat:

 sys/external/bsd/drm2/include/linux/rwsem.h |  16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)

diffs (35 lines):

diff -r 57cb6a2f011a -r 1f0d518febdf sys/external/bsd/drm2/include/linux/rwsem.h
--- a/sys/external/bsd/drm2/include/linux/rwsem.h       Mon Aug 27 07:46:48 2018 +0000
+++ b/sys/external/bsd/drm2/include/linux/rwsem.h       Mon Aug 27 07:47:01 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rwsem.h,v 1.1 2014/07/16 20:59:58 riastradh Exp $      */
+/*     $NetBSD: rwsem.h,v 1.2 2018/08/27 07:47:01 riastradh Exp $      */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -70,6 +70,13 @@
        rw_enter(&rwsem->rws_lock, RW_READER);
 }
 
+static inline bool
+down_read_trylock(struct rw_semaphore *rwsem)
+{
+
+       return rw_tryenter(&rwsem->rws_lock, RW_READER);
+}
+
 static inline void
 down_write(struct rw_semaphore *rwsem)
 {
@@ -91,4 +98,11 @@
        rw_exit(&rwsem->rws_lock);
 }
 
+static inline void
+downgrade_write(struct rw_semaphore *rwsem)
+{
+
+       rw_downgrade(&rwsem->rws_lock);
+}
+
 #endif  /* _LINUX_RWSEM_H_ */