arch/tile/lib/delay.c

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/delay.h>
  17 #include <linux/thread_info.h>
  18 #include <asm/timex.h>
  19
  20 void __udelay(unsigned long usecs)
  21 {
  22         if (usecs > ULONG_MAX / 1000) {
  23                 WARN_ON_ONCE(usecs > ULONG_MAX / 1000);
  24                 usecs = ULONG_MAX / 1000;
  25         }
  26         __ndelay(usecs * 1000);
  27 }
  28 EXPORT_SYMBOL(__udelay);
  29
  30 void __ndelay(unsigned long nsecs)
  31 {
  32         cycles_t target = get_cycles();
  33         target += ns2cycles(nsecs);
  34         while (get_cycles() < target)
  35                 cpu_relax();
  36 }
  37 EXPORT_SYMBOL(__ndelay);
  38
  39 void __delay(unsigned long cycles)
  40 {
  41         cycles_t target = get_cycles() + cycles;
  42         while (get_cycles() < target)
  43                 cpu_relax();
  44 }
  45 EXPORT_SYMBOL(__delay);