linux/include/asm-ppc64/delay.h

49 lines
1.1 KiB
C

#ifndef _PPC64_DELAY_H
#define _PPC64_DELAY_H
/*
* Copyright 1996, Paul Mackerras.
*
* 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
* 2 of the License, or (at your option) any later version.
*
* PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
* Anton Blanchard.
*/
extern unsigned long tb_ticks_per_usec;
/* define these here to prevent circular dependencies */
#define __HMT_low() asm volatile("or 1,1,1")
#define __HMT_medium() asm volatile("or 2,2,2")
#define __barrier() asm volatile("":::"memory")
static inline unsigned long __get_tb(void)
{
unsigned long rval;
asm volatile("mftb %0" : "=r" (rval));
return rval;
}
static inline void __delay(unsigned long loops)
{
unsigned long start = __get_tb();
while((__get_tb()-start) < loops)
__HMT_low();
__HMT_medium();
__barrier();
}
static inline void udelay(unsigned long usecs)
{
unsigned long loops = tb_ticks_per_usec * usecs;
__delay(loops);
}
#endif /* _PPC64_DELAY_H */