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/*

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 1994 by Waldorf Electronics

 * Copyright (C) 1995 - 2000 by Ralf Baechle

 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.

 */

#ifndef _ASM_DELAY_H

#define _ASM_DELAY_H

#include <linux/config.h>

#include <linux/param.h>

extern unsigned long loops_per_jiffy;

static __inline__ void

__delay(unsigned long loops)

{

        __asm__ __volatile__ (

                ".set\tnoreorder\n"

                "1:\tbnez\t%0,1b\n\t"

                "dsubu\t%0,1\n\t"

                ".set\treorder"

                :"=r" (loops)

                :"0" (loops));

}

/*

 * Division by multiplication: you don't have to worry about

 * loss of precision.

 *

 * Use only for very small delays ( < 1 msec).  Should probably use a

 * lookup table, really, as the multiplications take much too long with

 * short delays.  This is a "reasonable" implementation, though (and the

 * first constant multiplications gets optimized away if the delay is

 * a constant)

 */

static inline void __udelay(unsigned long usecs, unsigned long lpj)

{

        unsigned long lo;

        /*

         * The common rates of 1000 and 128 are rounded wrongly by the

         * catchall case.  Excessive precission?  Probably ...

         */

#if (HZ == 128)

        usecs *= 0x0008637bd05af6c7UL;          /* 2**64 / (1000000 / HZ) */

#elif (HZ == 1000)

        usecs *= 0x004189374BC6A7f0UL;          /* 2**64 / (1000000 / HZ) */

#else

        usecs *= (0x8000000000000000UL / (500000 / HZ));

#endif

        __asm__("dmultu\t%2,%3"

                :"=h" (usecs), "=l" (lo)

                :"r" (usecs),"r" (lpj));

        __delay(usecs);

}

static inline void __ndelay(unsigned long nsecs, unsigned long lpj)

{

        unsigned long lo;

        /*

         * The common rates of 1000 and 128 are rounded wrongly by the

         * catchall case.  Excessive precission?  Probably ...

         */

#if (HZ == 128)

        nsecs *= 0x000001ad7f29abcbUL;          /* 2**64 / (1000000000 / HZ) */

#elif (HZ == 1000)

        nsecs *= 0x0010c6f7a0b5eeUL;            /* 2**64 / (1000000000 / HZ) */

#else

        nsecs *= (0x8000000000000000UL / (500000000 / HZ));

#endif

        __asm__("dmultu\t%2,%3"

                :"=h" (nsecs), "=l" (lo)

                :"r" (nsecs),"r" (lpj));

        __delay(nsecs);

}

#ifdef CONFIG_SMP

#define __udelay_val cpu_data[smp_processor_id()].udelay_val

#else

#define __udelay_val loops_per_jiffy

#endif

#define udelay(usecs) __udelay((usecs),__udelay_val)

#define ndelay(nsecs) __ndelay((nsecs),__udelay_val)

#endif /* _ASM_DELAY_H */