1 /*- 2 * Copyright (c) 2020 The FreeBSD Foundation 3 * 4 * This software was developed by Emmanuel Vadot under sponsorship 5 * from the FreeBSD Foundation. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #ifndef _LINUXKPI_LINUX_REFCOUNT_H 32 #define _LINUXKPI_LINUX_REFCOUNT_H 33 34 #include <linux/atomic.h> 35 36 struct refcount_linux { 37 atomic_t value; 38 }; 39 typedef struct refcount_linux refcount_t; 40 41 static inline void 42 refcount_set(refcount_t *ref, unsigned int i) 43 { 44 atomic_set(&ref->value, i); 45 } 46 47 static inline void 48 refcount_inc(refcount_t *ref) 49 { 50 atomic_inc(&ref->value); 51 } 52 53 static inline bool 54 refcount_inc_not_zero(refcount_t *ref) 55 { 56 return (atomic_inc_not_zero(&ref->value)); 57 } 58 59 static inline void 60 refcount_dec(refcount_t *ref) 61 { 62 atomic_dec(&ref->value); 63 } 64 65 static inline unsigned int 66 refcount_read(refcount_t *ref) 67 { 68 return atomic_read(&ref->value); 69 } 70 71 static inline bool 72 refcount_dec_and_lock_irqsave(refcount_t *ref, spinlock_t *lock, 73 unsigned long *flags) 74 { 75 if (atomic_dec_and_test(&ref->value) == true) { 76 spin_lock_irqsave(lock, flags); 77 return (true); 78 } 79 return (false); 80 } 81 82 /* 83 * struct kref uses atomic_t and not refcount_t so 84 * we differ from Linux here. 85 */ 86 static inline bool 87 refcount_dec_and_test(atomic_t *r) 88 { 89 90 return (atomic_dec_and_test(r)); 91 } 92 93 #endif /* __LINUXKPI_LINUX_REFCOUNT_H__ */ 94