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delay.c

/*
 * linux/arch/m32r/lib/delay.c
 *
 * Copyright (c) 2002  Hitoshi Yamamoto, Hirokazu Takata
 * Copyright (c) 2004  Hirokazu Takata
 */

#include <linux/param.h>
#include <linux/module.h>
#ifdef CONFIG_SMP
#include <linux/sched.h>
#include <asm/current.h>
#include <asm/smp.h>
#endif  /* CONFIG_SMP */
#include <asm/processor.h>

void __delay(unsigned long loops)
{
#ifdef CONFIG_ISA_DUAL_ISSUE
      __asm__ __volatile__ (
            "beqz %0, 2f                  \n\t"
            "addi %0, #-1                 \n\t"

            " .fillinsn             \n\t"
            "1:                     \n\t"
            "cmpz %0  ||  addi  %0, #-1   \n\t"
            "bc   2f  ||  cmpz  %0  \n\t"
            "bc   2f  ||  addi  %0, #-1   \n\t"
            "cmpz %0  ||  addi  %0, #-1   \n\t"
            "bc   2f  ||  cmpz  %0  \n\t"
            "bnc  1b  ||  addi  %0, #-1   \n\t"
            " .fillinsn             \n\t"
            "2:                     \n\t"
            : "+r" (loops)
            : "r" (0)
            : "cbit"
      );
#else
      __asm__ __volatile__ (
            "beqz %0, 2f                  \n\t"
            " .fillinsn             \n\t"
            "1:                     \n\t"
            "addi %0, #-1                 \n\t"
            "blez %0, 2f                  \n\t"
            "addi %0, #-1                 \n\t"
            "blez %0, 2f                  \n\t"
            "addi %0, #-1                 \n\t"
            "blez %0, 2f                  \n\t"
            "addi %0, #-1                 \n\t"
            "bgtz %0, 1b                  \n\t"
            " .fillinsn             \n\t"
            "2:                     \n\t"
            : "+r" (loops)
            : "r" (0)
      );
#endif
}

void __const_udelay(unsigned long xloops)
{
#if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
      /*
       * loops [1] = (xloops >> 32) [sec] * loops_per_jiffy [1/jiffy]
       *            * HZ [jiffy/sec]
       *          = (xloops >> 32) [sec] * (loops_per_jiffy * HZ) [1/sec]
       *          = (((xloops * loops_per_jiffy) >> 32) * HZ) [1]
       *
       * NOTE:
       *   - '[]' depicts variable's dimension in the above equation.
       *   - "rac" instruction rounds the accumulator in word size.
       */
      __asm__ __volatile__ (
            "srli %0, #1                        \n\t"
            "mulwhi     %0, %1      ; a0              \n\t"
            "mulwu1     %0, %1      ; a1              \n\t"
            "sadd       ; a0 += (a1 >> 16)      \n\t"
            "rac  a0, a0, #1              \n\t"
            "mvfacmi %0, a0                     \n\t"
            : "+r" (xloops)
            : "r" (current_cpu_data.loops_per_jiffy)
            : "a0", "a1"
      );
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
      /*
       * u64 ull;
       * ull = (u64)xloops * (u64)current_cpu_data.loops_per_jiffy;
       * xloops = (ull >> 32);
       */
      __asm__ __volatile__ (
            "and3 r4, %0, #0xffff         \n\t"
            "and3 r5, %1, #0xffff         \n\t"
            "mul  r4, r5                  \n\t"
            "srl3 r6, %0, #16       \n\t"
            "srli r4, #16                 \n\t"
            "mul  r5, r6                  \n\t"
            "add  r4, r5                  \n\t"
            "and3 r5, %0, #0xffff         \n\t"
            "srl3 r6, %1, #16       \n\t"
            "mul  r5, r6                  \n\t"
            "add  r4, r5                  \n\t"
            "srl3 r5, %0, #16       \n\t"
            "srli r4, #16                 \n\t"
            "mul  r5, r6                  \n\t"
            "add  r4, r5                  \n\t"
            "mv   %0, r4                  \n\t"
            : "+r" (xloops)
            : "r" (current_cpu_data.loops_per_jiffy)
            : "r4", "r5", "r6"
      );
#else
#error unknown isa configuration
#endif
      __delay(xloops * HZ);
}

void __udelay(unsigned long usecs)
{
      __const_udelay(usecs * 0x000010c7);  /* 2**32 / 1000000 (rounded up) */
}

void __ndelay(unsigned long nsecs)
{
      __const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */
}

EXPORT_SYMBOL(__delay);
EXPORT_SYMBOL(__const_udelay);
EXPORT_SYMBOL(__udelay);
EXPORT_SYMBOL(__ndelay);

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