Merge LinuxKPI changes from DragonflyBSD:

- Define the kref structure identical to the one found in Linux.
- Update clients referring inside the kref structure.
- Implement kref_sub() for FreeBSD.

Reviewed by:	np @
Sponsored by:	Mellanox Technologies

2 files changed, 30 insertions, 6 deletions

diff --git a/sys/ofed/drivers/infiniband/core/uverbs_main.c b/sys/ofed/drivers/infiniband/core/uverbs_main.c
index 12bc0d3..5a6b605 100644
--- a/sys/ofed/drivers/infiniband/core/uverbs_main.c
+++ b/sys/ofed/drivers/infiniband/core/uverbs_main.c
@@ -1168,7 +1168,7 @@ static ssize_t show_dev_ref_cnt(struct device *device,
 	if (!dev)
 		return -ENODEV;
 
-	return sprintf(buf, "%d\n",  dev->ref.count);
+	return sprintf(buf, "%d\n",  atomic_read(&dev->ref.refcount));
 }
 static DEVICE_ATTR(ref_cnt, S_IRUGO, show_dev_ref_cnt, NULL);
 
diff --git a/sys/ofed/include/linux/kref.h b/sys/ofed/include/linux/kref.h
index 883e1a1..ecf3c8a 100644
--- a/sys/ofed/include/linux/kref.h
+++ b/sys/ofed/include/linux/kref.h
@@ -2,7 +2,8 @@
  * Copyright (c) 2010 Isilon Systems, Inc.
  * Copyright (c) 2010 iX Systems, Inc.
  * Copyright (c) 2010 Panasas, Inc.
- * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
+ * Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
+ * Copyright (c) 2013 François Tigeot
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -32,33 +33,56 @@
 #include <sys/types.h>
 #include <sys/refcount.h>
 
+#include <asm/atomic.h>
+
 struct kref {
-        volatile u_int count;
+	atomic_t refcount;
 };
 
 static inline void
 kref_init(struct kref *kref)
 {
 
-	refcount_init(&kref->count, 1);
+	refcount_init(&kref->refcount.counter, 1);
 }
 
 static inline void
 kref_get(struct kref *kref)
 {
 
-	refcount_acquire(&kref->count);
+	refcount_acquire(&kref->refcount.counter);
 }
 
 static inline int
 kref_put(struct kref *kref, void (*rel)(struct kref *kref))
 {
 
-	if (refcount_release(&kref->count)) {
+	if (refcount_release(&kref->refcount.counter)) {
 		rel(kref);
 		return 1;
 	}
 	return 0;
 }
 
+static inline int
+kref_sub(struct kref *kref, unsigned int count,
+    void (*rel)(struct kref *kref))
+{
+
+	while (count--) {
+		if (refcount_release(&kref->refcount.counter)) {
+			rel(kref);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static inline int __must_check
+kref_get_unless_zero(struct kref *kref)
+{
+
+	return atomic_add_unless(&kref->refcount, 1, 0);
+}
+
 #endif /* _LINUX_KREF_H_ */