xref: /freebsd/sys/contrib/openzfs/include/os/linux/spl/sys/atomic.h (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
4  *  Copyright (C) 2007 The Regents of the University of California.
5  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
6  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
7  *  UCRL-CODE-235197
8  *
9  *  This file is part of the SPL, Solaris Porting Layer.
10  *
11  *  The SPL is free software; you can redistribute it and/or modify it
12  *  under the terms of the GNU General Public License as published by the
13  *  Free Software Foundation; either version 2 of the License, or (at your
14  *  option) any later version.
15  *
16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
19  *  for more details.
20  *
21  *  You should have received a copy of the GNU General Public License along
22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
23  */
24 
25 #ifndef _SPL_ATOMIC_H
26 #define	_SPL_ATOMIC_H
27 
28 #include <linux/module.h>
29 #include <linux/spinlock.h>
30 #include <sys/types.h>
31 
32 /*
33  * Map the atomic_* functions to the Linux counterparts.  This relies on the
34  * fact that the atomic types are internally really a uint32 or uint64.  If
35  * this were to change an alternate approach would be needed.
36  *
37  * N.B. Due to the limitations of the original API atomicity is not strictly
38  * preserved when using the 64-bit functions on a 32-bit system.  In order
39  * to support this all consumers would need to be updated to use the Linux
40  * provided atomic_t and atomic64_t types.
41  */
42 #define	atomic_inc_32(v)	atomic_inc((atomic_t *)(v))
43 #define	atomic_dec_32(v)	atomic_dec((atomic_t *)(v))
44 #define	atomic_add_32(v, i)	atomic_add((i), (atomic_t *)(v))
45 #define	atomic_sub_32(v, i)	atomic_sub((i), (atomic_t *)(v))
46 #define	atomic_inc_32_nv(v)	atomic_inc_return((atomic_t *)(v))
47 #define	atomic_dec_32_nv(v)	atomic_dec_return((atomic_t *)(v))
48 #define	atomic_add_32_nv(v, i)	atomic_add_return((i), (atomic_t *)(v))
49 #define	atomic_sub_32_nv(v, i)	atomic_sub_return((i), (atomic_t *)(v))
50 #define	atomic_cas_32(v, x, y)	atomic_cmpxchg((atomic_t *)(v), x, y)
51 #define	atomic_swap_32(v, x)	atomic_xchg((atomic_t *)(v), x)
52 #define	atomic_load_32(v)	atomic_read((atomic_t *)(v))
53 #define	atomic_store_32(v, x)	atomic_set((atomic_t *)(v), x)
54 #define	atomic_inc_64(v)	atomic64_inc((atomic64_t *)(v))
55 #define	atomic_dec_64(v)	atomic64_dec((atomic64_t *)(v))
56 #define	atomic_add_64(v, i)	atomic64_add((i), (atomic64_t *)(v))
57 #define	atomic_sub_64(v, i)	atomic64_sub((i), (atomic64_t *)(v))
58 #define	atomic_inc_64_nv(v)	atomic64_inc_return((atomic64_t *)(v))
59 #define	atomic_dec_64_nv(v)	atomic64_dec_return((atomic64_t *)(v))
60 #define	atomic_add_64_nv(v, i)	atomic64_add_return((i), (atomic64_t *)(v))
61 #define	atomic_sub_64_nv(v, i)	atomic64_sub_return((i), (atomic64_t *)(v))
62 #define	atomic_cas_64(v, x, y)	atomic64_cmpxchg((atomic64_t *)(v), x, y)
63 #define	atomic_swap_64(v, x)	atomic64_xchg((atomic64_t *)(v), x)
64 #define	atomic_load_64(v)	atomic64_read((atomic64_t *)(v))
65 #define	atomic_store_64(v, x)	atomic64_set((atomic64_t *)(v), x)
66 
67 #ifdef _LP64
68 static __inline__ void *
atomic_cas_ptr(volatile void * target,void * cmp,void * newval)69 atomic_cas_ptr(volatile void *target,  void *cmp, void *newval)
70 {
71 	return ((void *)atomic_cas_64((volatile uint64_t *)target,
72 	    (uint64_t)cmp, (uint64_t)newval));
73 }
74 #else /* _LP64 */
75 static __inline__ void *
atomic_cas_ptr(volatile void * target,void * cmp,void * newval)76 atomic_cas_ptr(volatile void *target,  void *cmp, void *newval)
77 {
78 	return ((void *)atomic_cas_32((volatile uint32_t *)target,
79 	    (uint32_t)cmp, (uint32_t)newval));
80 }
81 #endif /* _LP64 */
82 
83 #endif  /* _SPL_ATOMIC_H */
84