diff options
Diffstat (limited to 'sys/compat/linuxkpi/common/include/linux/kref.h')
-rw-r--r-- | sys/compat/linuxkpi/common/include/linux/kref.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/sys/compat/linuxkpi/common/include/linux/kref.h b/sys/compat/linuxkpi/common/include/linux/kref.h new file mode 100644 index 000000000000..d5b45ba59313 --- /dev/null +++ b/sys/compat/linuxkpi/common/include/linux/kref.h @@ -0,0 +1,131 @@ +/*- + * Copyright (c) 2010 Isilon Systems, Inc. + * Copyright (c) 2010 iX Systems, Inc. + * Copyright (c) 2010 Panasas, Inc. + * 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 + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice unmodified, this list of conditions, and the following + * disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * $FreeBSD$ + */ +#ifndef _LINUX_KREF_H_ +#define _LINUX_KREF_H_ + +#include <sys/types.h> +#include <sys/refcount.h> + +#include <linux/compiler.h> +#include <linux/kernel.h> +#include <linux/mutex.h> +#include <linux/refcount.h> + +#include <asm/atomic.h> + +struct kref { + atomic_t refcount; +}; + +static inline void +kref_init(struct kref *kref) +{ + + refcount_init(&kref->refcount.counter, 1); +} + +static inline unsigned int +kref_read(const struct kref *kref) +{ + + return (atomic_read(&kref->refcount)); +} + +static inline void +kref_get(struct kref *kref) +{ + + refcount_acquire(&kref->refcount.counter); +} + +static inline int +kref_put(struct kref *kref, void (*rel)(struct kref *kref)) +{ + + if (refcount_release(&kref->refcount.counter)) { + rel(kref); + return 1; + } + return 0; +} + +static inline int +kref_put_lock(struct kref *kref, void (*rel)(struct kref *kref), + spinlock_t *lock) +{ + + if (refcount_release(&kref->refcount.counter)) { + spin_lock(lock); + 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); +} + +static inline int kref_put_mutex(struct kref *kref, + void (*release)(struct kref *kref), struct mutex *lock) +{ + WARN_ON(release == NULL); + if (unlikely(!atomic_add_unless(&kref->refcount, -1, 1))) { + mutex_lock(lock); + if (unlikely(!atomic_dec_and_test(&kref->refcount))) { + mutex_unlock(lock); + return 0; + } + release(kref); + return 1; + } + return 0; +} + +#endif /* _LINUX_KREF_H_ */ |