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 29 #ifndef _LINUXKPI_LINUX_REFCOUNT_H 30 #define _LINUXKPI_LINUX_REFCOUNT_H 31 32 #include <linux/atomic.h> 33 34 struct refcount_linux { 35 atomic_t value; 36 }; 37 typedef struct refcount_linux refcount_t; 38 39 static inline void 40 refcount_set(refcount_t *ref, unsigned int i) 41 { 42 atomic_set(&ref->value, i); 43 } 44 45 static inline void 46 refcount_inc(refcount_t *ref) 47 { 48 atomic_inc(&ref->value); 49 } 50 51 static inline bool 52 refcount_inc_not_zero(refcount_t *ref) 53 { 54 return (atomic_inc_not_zero(&ref->value)); 55 } 56 57 static inline void 58 refcount_dec(refcount_t *ref) 59 { 60 atomic_dec(&ref->value); 61 } 62 63 static inline unsigned int 64 refcount_read(refcount_t *ref) 65 { 66 return atomic_read(&ref->value); 67 } 68 69 static inline bool 70 refcount_dec_and_lock_irqsave(refcount_t *ref, spinlock_t *lock, 71 unsigned long *flags) 72 { 73 if (atomic_dec_and_test(&ref->value) == true) { 74 spin_lock_irqsave(lock, flags); 75 return (true); 76 } 77 return (false); 78 } 79 80 /* 81 * struct kref uses atomic_t and not refcount_t so 82 * we differ from Linux here. 83 */ 84 static inline bool 85 refcount_dec_and_test(atomic_t *r) 86 { 87 88 return (atomic_dec_and_test(r)); 89 } 90 91 #endif /* __LINUXKPI_LINUX_REFCOUNT_H__ */ 92