xref: /dragonfly/sys/dev/drm/include/linux/spinlock.h (revision 631c21f2)
1 /*
2  * Copyright (c) 2015-2020 François Tigeot <ftigeot@wolfpond.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef _LINUX_SPINLOCK_H_
28 #define _LINUX_SPINLOCK_H_
29 
30 #include <linux/typecheck.h>
31 #include <linux/preempt.h>
32 #include <linux/linkage.h>
33 #include <linux/compiler.h>
34 #include <linux/irqflags.h>
35 #include <linux/thread_info.h>
36 #include <linux/kernel.h>
37 #include <linux/stringify.h>
38 #include <linux/bottom_half.h>
39 #include <asm/barrier.h>
40 
41 #include <linux/spinlock_types.h>
42 
43 #include <linux/rwlock.h>
44 
45 #include <sys/spinlock2.h>
46 #include <sys/lock.h>
47 
48 #define spin_is_locked(x)	spin_held(x)
49 
50 #define assert_spin_locked(x)	KKASSERT(lockinuse(x))
51 
52 /*
53  * The spin_lock_irq() family of functions stop hardware interrupts
54  * from being delivered to the local CPU.
55  */
56 static inline void spin_lock_irq(spinlock_t *lock)
57 {
58 	local_irq_disable();
59 	preempt_disable();
60 	lockmgr(lock, LK_EXCLUSIVE);
61 }
62 
63 static inline void spin_unlock_irq(spinlock_t *lock)
64 {
65 	lockmgr(lock, LK_RELEASE);
66 	local_irq_enable();
67 	preempt_enable();
68 }
69 
70 #define spin_lock_irqsave(lock, flags)	\
71 ({					\
72 	local_irq_save(flags);		\
73 	preempt_disable();		\
74 	lockmgr(lock, LK_EXCLUSIVE);	\
75 })
76 
77 static inline void
78 spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
79 {
80 	lockmgr(lock, LK_RELEASE);
81 	local_irq_restore(flags);
82 	preempt_enable();
83 }
84 
85 /*
86   XXX: the spin_lock_bh() and spin_unlock_bh() functions are possibly incorrect
87   XXX: see also in_interrupt()
88 */
89 static inline void
90 spin_lock_bh(struct lock *lock)
91 {
92 	crit_enter();
93 	lockmgr(lock, LK_EXCLUSIVE);
94 }
95 
96 static inline void
97 spin_unlock_bh(struct lock *lock)
98 {
99 	lockmgr(lock, LK_RELEASE);
100 	crit_exit();
101 }
102 
103 #define DEFINE_SPINLOCK(x)	struct lock x = LOCK_INITIALIZER("ds##x", 0, 0)
104 
105 #define spin_lock_irqsave_nested(lock, flags, subclass)	\
106 	    spin_lock_irqsave(lock, flags)
107 
108 #endif	/* _LINUX_SPINLOCK_H_ */
109