xref: /dragonfly/sys/dev/drm/include/linux/spinlock.h (revision 5ca0a96d)
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 typedef struct lock spinlock_t;
53 
54 /*
55  * The spin_lock_irq() family of functions stop hardware interrupts
56  * from being delivered to the local CPU.
57  */
58 static inline void spin_lock_irq(spinlock_t *lock)
59 {
60 	local_irq_disable();
61 	preempt_disable();
62 	lockmgr(lock, LK_EXCLUSIVE);
63 }
64 
65 static inline void spin_unlock_irq(spinlock_t *lock)
66 {
67 	lockmgr(lock, LK_RELEASE);
68 	local_irq_enable();
69 	preempt_enable();
70 }
71 
72 #define spin_lock_irqsave(lock, flags)	\
73 ({					\
74 	local_irq_save(flags);		\
75 	preempt_disable();		\
76 	lockmgr(lock, LK_EXCLUSIVE);	\
77 })
78 
79 static inline void
80 spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
81 {
82 	lockmgr(lock, LK_RELEASE);
83 	local_irq_restore(flags);
84 	preempt_enable();
85 }
86 
87 /*
88   XXX: the spin_lock_bh() and spin_unlock_bh() functions are possibly incorrect
89   XXX: see also in_interrupt()
90 */
91 static inline void
92 spin_lock_bh(struct lock *lock)
93 {
94 	crit_enter();
95 	lockmgr(lock, LK_EXCLUSIVE);
96 }
97 
98 static inline void
99 spin_unlock_bh(struct lock *lock)
100 {
101 	lockmgr(lock, LK_RELEASE);
102 	crit_exit();
103 }
104 
105 #define DEFINE_SPINLOCK(x)	struct lock x = LOCK_INITIALIZER("ds##x", 0, 0)
106 
107 #define spin_lock_irqsave_nested(lock, flags, subclass)	\
108 	    spin_lock_irqsave(lock, flags)
109 
110 #endif	/* _LINUX_SPINLOCK_H_ */
111