arch/sparc64/lib/delay.c

   1 /* delay.c: Delay loops for sparc64
   2  *
   3  * Copyright (C) 2004 David S. Miller <davem@redhat.com>
   4  *
   5  * Based heavily upon x86 variant which is:
   6  *      Copyright (C) 1993 Linus Torvalds
   7  *      Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   8  */
   9
  10 #include <linux/delay.h>
  11
  12 void __delay(unsigned long loops)
  13 {
  14         __asm__ __volatile__(
  15 "       b,pt    %%xcc, 1f\n"
  16 "        cmp    %0, 0\n"
  17 "       .align  32\n"
  18 "1:\n"
  19 "       bne,pt  %%xcc, 1b\n"
  20 "        subcc  %0, 1, %0\n"
  21         : "=&r" (loops)
  22         : "0" (loops)
  23         : "cc");
  24 }
  25
  26 /* We used to multiply by HZ after shifting down by 32 bits
  27  * but that runs into problems for higher values of HZ and
  28  * slow cpus.
  29  */
  30 void __const_udelay(unsigned long n)
  31 {
  32         n *= 4;
  33
  34         n *= (cpu_data(_smp_processor_id()).udelay_val * (HZ/4));
  35         n >>= 32;
  36
  37         __delay(n + 1);
  38 }
  39
  40 void __udelay(unsigned long n)
  41 {
  42         __const_udelay(n * 0x10c7UL);
  43 }
  44
  45
  46 void __ndelay(unsigned long n)
  47 {
  48         __const_udelay(n * 0x5UL);
  49 }