linux/include/asm-powerpc/delay.h
Paul Mackerras c55377ee73 powerpc: Move a bunch of ppc64 headers to include/asm-powerpc
... and also delete some that are no longer used because we already
had an include/asm-powerpc version of the header.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-14 17:22:01 +11:00

56 lines
1.3 KiB
C

#ifndef _ASM_POWERPC_DELAY_H
#define _ASM_POWERPC_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;
#ifdef CONFIG_PPC64
/* define these here to prevent circular dependencies */
/* these instructions control the thread priority on multi-threaded cpus */
#define __HMT_low() asm volatile("or 1,1,1")
#define __HMT_medium() asm volatile("or 2,2,2")
#else
#define __HMT_low()
#define __HMT_medium()
#endif
#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 /* _ASM_POWERPC_DELAY_H */