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jiffies.h revision 1.5 
      1 /*	$NetBSD: jiffies.h,v 1.5 2014/07/26 06:20:25 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _LINUX_JIFFIES_H_
     33 #define _LINUX_JIFFIES_H_
     34 
     35 #include <sys/param.h>
     36 #include <sys/kernel.h>
     37 
     38 #define	jiffies		hardclock_ticks
     39 #define	jiffies_64	hardclock_ticks /* XXX */
     40 
     41 /* XXX Er, what?  */
     42 #define	MAX_JIFFY_OFFSET	((INT_MAX >> 1) - 1)
     43 
     44 static inline unsigned int
     45 msecs_to_jiffies(unsigned int msec)
     46 {
     47 	return mstohz(msec);
     48 }
     49 
     50 static inline unsigned int
     51 jiffies_to_msecs(unsigned int j)
     52 {
     53 	return hztoms(j);
     54 }
     55 
     56 static inline unsigned int
     57 usecs_to_jiffies(unsigned int usec)
     58 {
     59 	if (hz <= 100)
     60 		return mstohz(roundup(usec, (1000 / hz)));
     61 
     62 	/*
     63 	 * Avoid integer overflow on 32-bit platforms.  The cutoff is
     64 	 * kinda arbitrary; for hz <= 2000, 0x200000 is safe, but both
     65 	 * values could wiggle around a little.
     66 	 */
     67 	KASSERT(hz <= 2000);
     68 	if (usec <= 0x200000)
     69 		return ((usec * hz) / 1000000);
     70 	else
     71 		return ((usec / 1000000) * hz);
     72 }
     73 
     74 static inline unsigned int
     75 timespec_to_jiffies(const struct timespec *ts)
     76 {
     77 	return tstohz(ts);
     78 }
     79 
     80 /* XXX long is the wrong type here times...  */
     81 
     82 #define	__linux_time_compare(A, OP, B)	(((long)(A) - (long)(B)) OP 0)
     83 
     84 static inline bool
     85 time_after(unsigned long a, unsigned long b)
     86 {
     87 	return __linux_time_compare(a, >, b);
     88 }
     89 
     90 static inline bool
     91 time_after_eq(unsigned long a, unsigned long b)
     92 {
     93 	return __linux_time_compare(a, >=, b);
     94 }
     95 
     96 static inline bool
     97 time_before(unsigned long a, unsigned long b)
     98 {
     99 	return __linux_time_compare(a, <, b);
    100 }
    101 
    102 static inline bool
    103 time_before_eq(unsigned long a, unsigned long b)
    104 {
    105 	return __linux_time_compare(a, <=, b);
    106 }
    107 
    108 #endif  /* _LINUX_JIFFIES_H_ */
    109