arch/parisc/include/asm/delay.h

   1 #ifndef _PARISC_DELAY_H
   2 #define _PARISC_DELAY_H
   3
   4 #include <asm/special_insns.h>    /* for mfctl() */
   5 #include <asm/processor.h> /* for boot_cpu_data */
   6
   7
   8 /*
   9  * Copyright (C) 1993 Linus Torvalds
  10  *
  11  * Delay routines
  12  */
  13
  14 static __inline__ void __delay(unsigned long loops) {
  15         asm volatile(
  16         "       .balignl        64,0x34000034\n"
  17         "       addib,UV -1,%0,.\n"
  18         "       nop\n"
  19                 : "=r" (loops) : "0" (loops));
  20 }
  21
  22 static __inline__ void __cr16_delay(unsigned long clocks) {
  23         unsigned long start;
  24
  25         /*
  26          * Note: Due to unsigned math, cr16 rollovers shouldn't be
  27          * a problem here. However, on 32 bit, we need to make sure
  28          * we don't pass in too big a value. The current default
  29          * value of MAX_UDELAY_MS should help prevent this.
  30          */
  31
  32         start = mfctl(16);
  33         while ((mfctl(16) - start) < clocks)
  34             ;
  35 }
  36
  37 static __inline__ void __udelay(unsigned long usecs) {
  38         __cr16_delay(usecs * ((unsigned long)boot_cpu_data.cpu_hz / 1000000UL));
  39 }
  40
  41 #define udelay(n) __udelay(n)
  42
  43 #endif /* defined(_PARISC_DELAY_H) */