[src/trunk]: src/sys/external/bsd/drm2/linux Acquire references in add_shared...

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

details:   https://anonhg.NetBSD.org/src/rev/fb75b0684ea7
branches:  trunk
changeset: 835326:fb75b0684ea7
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 27 14:13:00 2018 +0000

description:
Acquire references in add_shared/excl.

diffstat:

 sys/external/bsd/drm2/linux/linux_reservation.c |  27 +++++++++++++++++-------
 1 files changed, 19 insertions(+), 8 deletions(-)

diffs (69 lines):

diff -r dbecdf71efc7 -r fb75b0684ea7 sys/external/bsd/drm2/linux/linux_reservation.c
--- a/sys/external/bsd/drm2/linux/linux_reservation.c   Mon Aug 27 14:12:44 2018 +0000
+++ b/sys/external/bsd/drm2/linux/linux_reservation.c   Mon Aug 27 14:13:00 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux_reservation.c,v 1.4 2018/08/27 14:01:14 riastradh Exp $  */
+/*     $NetBSD: linux_reservation.c,v 1.5 2018/08/27 14:13:00 riastradh Exp $  */
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_reservation.c,v 1.4 2018/08/27 14:01:14 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_reservation.c,v 1.5 2018/08/27 14:13:00 riastradh Exp $");
 
 #include <linux/fence.h>
 #include <linux/reservation.h>
@@ -311,9 +311,9 @@
 /*
  * reservation_object_add_excl_fence(robj, fence)
  *
- *     Replace robj's exclusive fence, if any, by fence, and empty its
- *     list of shared fences.  The old exclusive fence and all old
- *     shared fences are released.
+ *     Empty and release all of robj's shared fences, and clear and
+ *     release its exclusive fence.  If fence is nonnull, acquire a
+ *     reference to it and save it as robj's exclusive fence.
  *
  *     Caller must have robj locked.
  */
@@ -328,6 +328,13 @@
 
        KASSERT(reservation_object_held(robj));
 
+       /*
+        * If we are setting rather than just removing a fence, acquire
+        * a reference for ourselves.
+        */
+       if (fence)
+               (void)fence_get(fence);
+
        /* If there are any shared fences, remember how many.  */
        if (old_list)
                old_shared_count = old_list->shared_count;
@@ -357,9 +364,9 @@
 /*
  * reservation_object_add_shared_fence(robj, fence)
  *
- *     Add a shared fence to robj.  If any fence was already added
- *     with the same context number, release it and replace it by this
- *     one.
+ *     Acquire a reference to fence and add it to robj's shared list.
+ *     If any fence was already added with the same context number,
+ *     release it and replace it by this one.
  *
  *     Caller must have robj locked, and must have preceded with a
  *     call to reservation_object_reserve_shared for each shared fence
@@ -377,6 +384,10 @@
 
        KASSERT(reservation_object_held(robj));
 
+       /* Acquire a reference to the fence.  */
+       KASSERT(fence != NULL);
+       (void)fence_get(fence);
+
        /* Check for a preallocated replacement list.  */
        if (prealloc == NULL) {
                KASSERT(list->shared_count < list->shared_max);