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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
  17 void __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
  59 void __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
 116 void __udelay(unsigned long usecs)
 117 {
 118         __const_udelay(usecs * 0x000010c7);  /* 2**32 / 1000000 (rounded up) */
 119 }
 120
 121 void __ndelay(unsigned long nsecs)
 122 {
 123         __const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */
 124 }
 125 EXPORT_SYMBOL(__ndelay);