LXR linux/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
  20void __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}
  28EXPORT_SYMBOL(__udelay);
  29
  30void __ndelay(unsigned long nsecs)
  31{
  32        cycles_t target = get_cycles();
  33        target += ns2cycles(nsecs);
  34        while (get_cycles() < target)
  35                cpu_relax();
  36}
  37EXPORT_SYMBOL(__ndelay);
  38
  39void __delay(unsigned long cycles)
  40{
  41        cycles_t target = get_cycles() + cycles;
  42        while (get_cycles() < target)
  43                cpu_relax();
  44}
  45EXPORT_SYMBOL(__delay);
  46