File: spinlock.h

package info (click to toggle)
kernel-source-2.1.125 2.1.125-1
  • links: PTS
  • area: main
  • in suites: slink
  • size: 61,100 kB
  • ctags: 177,944
  • sloc: ansic: 1,045,652; asm: 47,658; makefile: 7,656; sh: 1,038; perl: 836; cpp: 521; tcl: 427; lisp: 218; awk: 133; sed: 72
file content (64 lines) | stat: -rw-r--r-- 1,874 bytes parent folder | download
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
#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H

#ifndef __SMP__

/*
 * Your basic spinlocks, allowing only a single CPU anywhere
 */
#if (__GNUC__ > 2) || (__GNUC_MINOR__ >= 8)
  typedef struct { } spinlock_t;
# define SPIN_LOCK_UNLOCKED { }
#else
  typedef unsigned char spinlock_t;
# define SPIN_LOCK_UNLOCKED 0
#endif

#define spin_lock_init(lock)	do { } while(0)
#define spin_lock(lock)		do { } while(0)
#define spin_trylock(lock)	do { } while(0)
#define spin_unlock_wait(lock)	do { } while(0)
#define spin_unlock(lock)	do { } while(0)
#define spin_lock_irq(lock)	cli()
#define spin_unlock_irq(lock)	sti()

#define spin_lock_irqsave(lock, flags) \
	do { __save_flags_cli(flags); } while (0)
#define spin_unlock_irqrestore(lock, flags) \
	restore_flags(flags)

/*
 * Read-write spinlocks, allowing multiple readers
 * but only one writer.
 *
 * NOTE! it is quite common to have readers in interrupts
 * but no interrupt writers. For those circumstances we
 * can "mix" irq-safe locks - any writer needs to get a
 * irq-safe write-lock, but readers can get non-irqsafe
 * read-locks.
 */
typedef struct { } rwlock_t;
#define RW_LOCK_UNLOCKED { }

#define read_lock(lock)		do { } while(0)
#define read_unlock(lock)	do { } while(0)
#define write_lock(lock)	do { } while(0)
#define write_unlock(lock)	do { } while(0)
#define read_lock_irq(lock)	cli()
#define read_unlock_irq(lock)	sti()
#define write_lock_irq(lock)	cli()
#define write_unlock_irq(lock)	sti()

#define read_lock_irqsave(lock, flags)	\
	do { __save_flags_cli(flags); } while (0)
#define read_unlock_irqrestore(lock, flags) \
	restore_flags(flags)
#define write_lock_irqsave(lock, flags)	\
	do { __save_flags_cli(flags); } while (0)
#define write_unlock_irqrestore(lock, flags) \
	restore_flags(flags)

#else
#error ARM architecture does not support spin locks
#endif /* SMP */
#endif /* __ASM_SPINLOCK_H */