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#ifdef __KERNEL__

#ifndef _PPC_DELAY_H

#define _PPC_DELAY_H

#include <asm/param.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.

 */

extern unsigned long loops_per_jiffy;

extern void __delay(unsigned int loops);

/*

 * Note that 19 * 226 == 4294 ==~ 2^32 / 10^6, so

 * loops = (4294 * usecs * loops_per_jiffy * HZ) / 2^32.

 *

 * The mulhwu instruction gives us loops = (a * b) / 2^32.

 * We choose a = usecs * 19 * HZ and b = loops_per_jiffy * 226

 * because this lets us support a wide range of HZ and

 * loops_per_jiffy values without either a or b overflowing 2^32.

 * Thus we need usecs * HZ <= (2^32 - 1) / 19 = 226050910 and

 * loops_per_jiffy <= (2^32 - 1) / 226 = 19004280

 * (which corresponds to ~3800 bogomips at HZ = 100).

 *  -- paulus

 */

#define __MAX_UDELAY    (226050910UL/HZ)        /* maximum udelay argument */

#define __MAX_NDELAY    (4294967295UL/HZ)       /* maximum ndelay argument */

extern __inline__ void __udelay(unsigned int x)

{

        unsigned int loops;

        __asm__("mulhwu %0,%1,%2" : "=r" (loops) :

                "r" (x), "r" (loops_per_jiffy * 226));

        __delay(loops);

}

extern __inline__ void __ndelay(unsigned int x)

{

        unsigned int loops;

        __asm__("mulhwu %0,%1,%2" : "=r" (loops) :

                "r" (x), "r" (loops_per_jiffy * 5));

        __delay(loops);

}

extern void __bad_udelay(void);         /* deliberately undefined */

extern void __bad_ndelay(void);         /* deliberately undefined */

#define udelay(n) (__builtin_constant_p(n)? \

        ((n) > __MAX_UDELAY? __bad_udelay(): __udelay((n) * (19 * HZ))) : \

        __udelay((n) * (19 * HZ)))

#define ndelay(n) (__builtin_constant_p(n)? \

        ((n) > __MAX_NDELAY? __bad_ndelay(): __ndelay((n) * HZ)) : \

        __ndelay((n) * HZ))

#endif /* defined(_PPC_DELAY_H) */

#endif /* __KERNEL__ */