linux/arch/m32r/lib/delay.c
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   1/*
   2 * linux/arch/m32r/lib/delay.c
   3 *
   4 * Copyright (c) 2002  Hitoshi Yamamoto, Hirokazu Takata
   5 * Copyright (c) 2004  Hirokazu Takata
   6 */
   7
   8#include <linux/param.h>
   9#include <linux/module.h>
  10#ifdef CONFIG_SMP
  11#include <linux/sched.h>
  12#include <asm/current.h>
  13#include <asm/smp.h>
  14#endif  /* CONFIG_SMP */
  15#include <asm/processor.h>
  16
  17void __delay(unsigned long loops)
  18{
  19#ifdef CONFIG_ISA_DUAL_ISSUE
  20        __asm__ __volatile__ (
  21                "beqz   %0, 2f                  \n\t"
  22                "addi   %0, #-1                 \n\t"
  23
  24                " .fillinsn                     \n\t"
  25                "1:                             \n\t"
  26                "cmpz   %0  ||  addi  %0, #-1   \n\t"
  27                "bc     2f  ||  cmpz  %0        \n\t"
  28                "bc     2f  ||  addi  %0, #-1   \n\t"
  29                "cmpz   %0  ||  addi  %0, #-1   \n\t"
  30                "bc     2f  ||  cmpz  %0        \n\t"
  31                "bnc    1b  ||  addi  %0, #-1   \n\t"
  32                " .fillinsn                     \n\t"
  33                "2:                             \n\t"
  34                : "+r" (loops)
  35                : "r" (0)
  36                : "cbit"
  37        );
  38#else
  39        __asm__ __volatile__ (
  40                "beqz   %0, 2f                  \n\t"
  41                " .fillinsn                     \n\t"
  42                "1:                             \n\t"
  43                "addi   %0, #-1                 \n\t"
  44                "blez   %0, 2f                  \n\t"
  45                "addi   %0, #-1                 \n\t"
  46                "blez   %0, 2f                  \n\t"
  47                "addi   %0, #-1                 \n\t"
  48                "blez   %0, 2f                  \n\t"
  49                "addi   %0, #-1                 \n\t"
  50                "bgtz   %0, 1b                  \n\t"
  51                " .fillinsn                     \n\t"
  52                "2:                             \n\t"
  53                : "+r" (loops)
  54                : "r" (0)
  55        );
  56#endif
  57}
  58
  59void __const_udelay(unsigned long xloops)
  60{
  61#if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
  62        /*
  63         * loops [1] = (xloops >> 32) [sec] * loops_per_jiffy [1/jiffy]
  64         *            * HZ [jiffy/sec]
  65         *          = (xloops >> 32) [sec] * (loops_per_jiffy * HZ) [1/sec]
  66         *          = (((xloops * loops_per_jiffy) >> 32) * HZ) [1]
  67         *
  68         * NOTE:
  69         *   - '[]' depicts variable's dimension in the above equation.
  70         *   - "rac" instruction rounds the accumulator in word size.
  71         */
  72        __asm__ __volatile__ (
  73                "srli   %0, #1                          \n\t"
  74                "mulwhi %0, %1  ; a0                    \n\t"
  75                "mulwu1 %0, %1  ; a1                    \n\t"
  76                "sadd           ; a0 += (a1 >> 16)      \n\t"
  77                "rac    a0, a0, #1                      \n\t"
  78                "mvfacmi %0, a0                         \n\t"
  79                : "+r" (xloops)
  80                : "r" (current_cpu_data.loops_per_jiffy)
  81                : "a0", "a1"
  82        );
  83#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
  84        /*
  85         * u64 ull;
  86         * ull = (u64)xloops * (u64)current_cpu_data.loops_per_jiffy;
  87         * xloops = (ull >> 32);
  88         */
  89        __asm__ __volatile__ (
  90                "and3   r4, %0, #0xffff         \n\t"
  91                "and3   r5, %1, #0xffff         \n\t"
  92                "mul    r4, r5                  \n\t"
  93                "srl3   r6, %0, #16             \n\t"
  94                "srli   r4, #16                 \n\t"
  95                "mul    r5, r6                  \n\t"
  96                "add    r4, r5                  \n\t"
  97                "and3   r5, %0, #0xffff         \n\t"
  98                "srl3   r6, %1, #16             \n\t"
  99                "mul    r5, r6                  \n\t"
 100                "add    r4, r5                  \n\t"
 101                "srl3   r5, %0, #16             \n\t"
 102                "srli   r4, #16                 \n\t"
 103                "mul    r5, r6                  \n\t"
 104                "add    r4, r5                  \n\t"
 105                "mv     %0, r4                  \n\t"
 106                : "+r" (xloops)
 107                : "r" (current_cpu_data.loops_per_jiffy)
 108                : "r4", "r5", "r6"
 109        );
 110#else
 111#error unknown isa configuration
 112#endif
 113        __delay(xloops * HZ);
 114}
 115
 116void __udelay(unsigned long usecs)
 117{
 118        __const_udelay(usecs * 0x000010c7);  /* 2**32 / 1000000 (rounded up) */
 119}
 120
 121void __ndelay(unsigned long nsecs)
 122{
 123        __const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */
 124}
 125EXPORT_SYMBOL(__ndelay);
 126