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
16#ifndef __ASSEMBLY__
17extern unsigned long tb_ticks_per_usec;
18
19/* define these here to prevent circular dependencies */
20#define __HMT_low()	asm volatile("or 1,1,1")
21#define __HMT_medium()	asm volatile("or 2,2,2")
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}
38
39static inline void udelay(unsigned long usecs)
40{
41	unsigned long loops = tb_ticks_per_usec * usecs;
42
43	__delay(loops);
44	__HMT_medium();
45}
46#endif /* !__ASSEMBLY__ */
47
48#endif /* _PPC64_DELAY_H */
49