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 typedef atomic_t refcount_t; 35 36 static inline void 37 refcount_set(refcount_t *ref, unsigned int i) 38 { 39 atomic_set(ref, i); 40 } 41 42 static inline void 43 refcount_inc(refcount_t *ref) 44 { 45 atomic_inc(ref); 46 } 47 48 static inline bool 49 refcount_inc_not_zero(refcount_t *ref) 50 { 51 return (atomic_inc_not_zero(ref)); 52 } 53 54 static inline void 55 refcount_dec(refcount_t *ref) 56 { 57 atomic_dec(ref); 58 } 59 60 static inline unsigned int 61 refcount_read(refcount_t *ref) 62 { 63 return atomic_read(ref); 64 } 65 66 static inline bool 67 refcount_dec_and_lock_irqsave(refcount_t *ref, spinlock_t *lock, 68 unsigned long *flags) 69 { 70 if (atomic_dec_and_test(ref) == true) { 71 spin_lock_irqsave(lock, flags); 72 return (true); 73 } 74 return (false); 75 } 76 77 static inline bool 78 refcount_dec_and_test(refcount_t *r) 79 { 80 81 return (atomic_dec_and_test(r)); 82 } 83 84 #endif /* __LINUXKPI_LINUX_REFCOUNT_H__ */ 85