zfs/module/spl/spl-time.c

/*
 *  This file is part of the SPL: Solaris Porting Layer.
 *
 *  Copyright (c) 2008 Lawrence Livermore National Security, LLC.
 *  Produced at Lawrence Livermore National Laboratory
 *  Written by:
 *          Brian Behlendorf <behlendorf1@llnl.gov>,
 *          Herb Wartens <wartens2@llnl.gov>,
 *          Jim Garlick <garlick@llnl.gov>
 *  UCRL-CODE-235197
 *
 *  This is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This is distributed in the hope that it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
 */

#include <sys/sysmacros.h>
#include <sys/time.h>

#ifdef HAVE_MONOTONIC_CLOCK
extern unsigned long long monotonic_clock(void);
#endif

#ifdef DEBUG_SUBSYSTEM
#undef DEBUG_SUBSYSTEM
#endif

#define DEBUG_SUBSYSTEM S_TIME

void
__gethrestime(timestruc_t *ts)
{
        struct timeval tv;

	do_gettimeofday(&tv);
	ts->tv_sec = tv.tv_sec;
	ts->tv_nsec = tv.tv_usec * NSEC_PER_USEC;
}
EXPORT_SYMBOL(__gethrestime);

/* Use monotonic_clock() by default. It's faster and is available on older
 * kernels, but few architectures have them, so we must fallback to
 * do_posix_clock_monotonic_gettime().
 */
hrtime_t
__gethrtime(void) {
#ifdef HAVE_MONOTONIC_CLOCK
        unsigned long long res = monotonic_clock();

        /* Deal with signed/unsigned mismatch */
        return (hrtime_t)(res & ~(1ULL << 63));
#else
        uint64_t j = get_jiffies_64();

        return (hrtime_t)(j * NSEC_PER_SEC / HZ);
#endif
}
EXPORT_SYMBOL(__gethrtime);

/* set_normalized_timespec() API changes
 * 2.6.0  - 2.6.15: Inline function provided by linux/time.h
 * 2.6.16 - 2.6.25: Function prototype defined but not exported
 * 2.6.26 - 2.6.x:  Function defined and exported
 */
#if !defined(HAVE_SET_NORMALIZED_TIMESPEC_INLINE) && \
    !defined(HAVE_SET_NORMALIZED_TIMESPEC_EXPORT)
void
set_normalized_timespec(struct timespec *ts, time_t sec, long nsec)
{
	while (nsec >= NSEC_PER_SEC) {
	        nsec -= NSEC_PER_SEC;
	        ++sec;
	}
	while (nsec < 0) {
	        nsec += NSEC_PER_SEC;
	        --sec;
	}
	ts->tv_sec = sec;
	ts->tv_nsec = nsec;
}
EXPORT_SYMBOL(set_normalized_timespec);
#endif