mirror of https://gitee.com/openkylin/linux.git
49 lines
1.1 KiB
C
49 lines
1.1 KiB
C
#ifndef _PPC64_DELAY_H
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#define _PPC64_DELAY_H
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/*
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* Copyright 1996, Paul Mackerras.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
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* Anton Blanchard.
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*/
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extern unsigned long tb_ticks_per_usec;
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/* define these here to prevent circular dependencies */
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#define __HMT_low() asm volatile("or 1,1,1")
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#define __HMT_medium() asm volatile("or 2,2,2")
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#define __barrier() asm volatile("":::"memory")
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static inline unsigned long __get_tb(void)
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{
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unsigned long rval;
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asm volatile("mftb %0" : "=r" (rval));
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return rval;
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}
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static inline void __delay(unsigned long loops)
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{
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unsigned long start = __get_tb();
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while((__get_tb()-start) < loops)
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__HMT_low();
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__HMT_medium();
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__barrier();
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}
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static inline void udelay(unsigned long usecs)
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{
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unsigned long loops = tb_ticks_per_usec * usecs;
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__delay(loops);
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}
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#endif /* _PPC64_DELAY_H */
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