kref.h revision 282513
1169689Skan/*- 2169689Skan * Copyright (c) 2010 Isilon Systems, Inc. 3169689Skan * Copyright (c) 2010 iX Systems, Inc. 4169689Skan * Copyright (c) 2010 Panasas, Inc. 5169689Skan * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. 6169689Skan * All rights reserved. 7169689Skan * 8169689Skan * Redistribution and use in source and binary forms, with or without 9169689Skan * modification, are permitted provided that the following conditions 10169689Skan * are met: 11169689Skan * 1. Redistributions of source code must retain the above copyright 12169689Skan * notice unmodified, this list of conditions, and the following 13169689Skan * disclaimer. 14169689Skan * 2. Redistributions in binary form must reproduce the above copyright 15169689Skan * notice, this list of conditions and the following disclaimer in the 16169689Skan * documentation and/or other materials provided with the distribution. 17169689Skan * 18169689Skan * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19169689Skan * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20169689Skan * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21169689Skan * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22169689Skan * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23169689Skan * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24169689Skan * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25169689Skan * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26169689Skan * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27169689Skan * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28169689Skan */ 29169689Skan#ifndef _LINUX_KREF_H_ 30169689Skan#define _LINUX_KREF_H_ 31169689Skan 32169689Skan#include <sys/types.h> 33169689Skan#include <sys/refcount.h> 34169689Skan 35169689Skanstruct kref { 36169689Skan volatile u_int count; 37169689Skan}; 38169689Skan 39169689Skanstatic inline void 40169689Skankref_init(struct kref *kref) 41169689Skan{ 42169689Skan 43169689Skan refcount_init(&kref->count, 1); 44169689Skan} 45169689Skan 46169689Skanstatic inline void 47169689Skankref_get(struct kref *kref) 48169689Skan{ 49169689Skan 50169689Skan refcount_acquire(&kref->count); 51169689Skan} 52169689Skan 53169689Skanstatic inline int 54169689Skankref_put(struct kref *kref, void (*rel)(struct kref *kref)) 55169689Skan{ 56169689Skan 57169689Skan if (refcount_release(&kref->count)) { 58169689Skan rel(kref); 59169689Skan return 1; 60169689Skan } 61169689Skan return 0; 62169689Skan} 63169689Skan 64169689Skan#endif /* _LINUX_KREF_H_ */ 65169689Skan