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1#ifndef _PPC64_DELAY_H
2#define _PPC64_DELAY_H
3
4/*
5 * Copyright 1996, Paul Mackerras.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
13 * Anton Blanchard.
14 */
15
16extern unsigned long tb_ticks_per_usec;
17
18/* define these here to prevent circular dependencies */
19#define __HMT_low() asm volatile("or 1,1,1")
20#define __HMT_medium() asm volatile("or 2,2,2")
21#define __barrier() asm volatile("":::"memory")
22
23static inline unsigned long __get_tb(void)
24{
25 unsigned long rval;
26
27 asm volatile("mftb %0" : "=r" (rval));
28 return rval;
29}
30
31static inline void __delay(unsigned long loops)
32{
33 unsigned long start = __get_tb();
34
35 while((__get_tb()-start) < loops)
36 __HMT_low();
37 __HMT_medium();
38 __barrier();
39}
40
41static inline void udelay(unsigned long usecs)
42{
43 unsigned long loops = tb_ticks_per_usec * usecs;
44
45 __delay(loops);
46}
47
48#endif /* _PPC64_DELAY_H */