blob: a3e2fe1dc57cdf561531786b361afaaddc8d2422 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
|
/*
* Copyright (c) 2012-2018 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef KERN_SPINLOCK_I_H
#define KERN_SPINLOCK_I_H
#include <assert.h>
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <kern/atomic.h>
#include <kern/macros.h>
#include <kern/spinlock_types.h>
#include <kern/thread.h>
#include <machine/cpu.h>
/*
* Uncontended lock values.
*
* Any other value implies a contended lock.
*/
#define SPINLOCK_UNLOCKED 0x0
#define SPINLOCK_LOCKED 0x1
#ifdef SPINLOCK_TRACK_OWNER
static inline void
spinlock_own(struct spinlock *lock)
{
assert(!lock->owner);
lock->owner = thread_self();
}
static inline void
spinlock_disown(struct spinlock *lock)
{
assert(lock->owner == thread_self());
lock->owner = NULL;
}
#else /* SPINLOCK_TRACK_OWNER */
#define spinlock_own(lock)
#define spinlock_disown(lock)
#endif /* SPINLOCK_TRACK_OWNER */
static inline int
spinlock_lock_fast(struct spinlock *lock)
{
uint32_t prev;
prev = atomic_cas(&lock->value, SPINLOCK_UNLOCKED,
SPINLOCK_LOCKED, ATOMIC_ACQUIRE);
if (unlikely(prev != SPINLOCK_UNLOCKED)) {
return EBUSY;
}
spinlock_own(lock);
return 0;
}
void spinlock_lock_slow(struct spinlock *lock);
static inline void
spinlock_lock_common(struct spinlock *lock)
{
int error;
error = spinlock_lock_fast(lock);
if (unlikely(error)) {
spinlock_lock_slow(lock);
}
}
static inline void
spinlock_unlock_common(struct spinlock *lock)
{
spinlock_disown(lock);
atomic_and(&lock->value, ~SPINLOCK_LOCKED, ATOMIC_RELEASE);
}
#endif /* KERN_SPINLOCK_I_H */
|
