/* $NetBSD: subr_time.c,v 1.41 2024/12/22 23:24:20 riastradh Exp $ */

/* $NetBSD: subr_time.c,v 1.41 2024/12/22 23:24:20 riastradh Exp $ */

/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
* @(#)kern_time.c 8.4 (Berkeley) 5/26/95
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_time.c,v 1.41 2024/12/22 23:24:20 riastradh Exp $");

#include <sys/param.h>
#include <sys/types.h>

#include <sys/intr.h>
#include <sys/kauth.h>
#include <sys/kernel.h>
#include <sys/lwp.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/timetc.h>
#include <sys/timex.h>

/*
* Compute number of hz until specified time. Used to compute second
* argument to callout_reset() from an absolute time.
*/
int
tvhzto(const struct timeval *tvp)
{
struct timeval now, tv;

tv = *tvp; /* Don't modify original tvp. */
getmicrotime(&now);
timersub(&tv, &now, &tv);
return tvtohz(&tv);
}

int
tshzto(const struct timespec *tsp)
{
struct timespec now, ts;

ts = *tsp; /* Don't modify original tsp. */
getnanotime(&now);
timespecsub(&ts, &now, &ts);
return tstohz(&ts);
}

int
tshztoup(const struct timespec *tsp)
{
struct timespec now, ts;

ts = *tsp; /* Don't modify original tsp. */
getnanouptime(&now);
timespecsub(&ts, &now, &ts);
return tstohz(&ts);
}

/*
* Compute number of ticks in the specified amount of time.
*/
int
tstohz(const struct timespec *ts)
{
struct timeval tv;

/*
* usec has great enough resolution for hz, so convert to a
* timeval and use tvtohz() above.
*/
TIMESPEC_TO_TIMEVAL(&tv, ts);
return tvtohz(&tv);
}

int
inittimeleft(struct timespec *ts, struct timespec *sleepts)
{

if (itimespecfix(ts)) {
return -1;
}
KASSERT(ts->tv_sec >= 0);
getnanouptime(sleepts);
return 0;
}

int
gettimeleft(struct timespec *ts, struct timespec *sleepts)
{
struct timespec now, sleptts;

KASSERT(ts->tv_sec >= 0);

/*
* Reduce ts by elapsed time based on monotonic time scale.
*/
getnanouptime(&now);
KASSERT(timespeccmp(sleepts, &now, <=));
timespecsub(&now, sleepts, &sleptts);
*sleepts = now;

if (timespeccmp(ts, &sleptts, <=)) { /* timed out */
timespecclear(ts);
return 0;
}
timespecsub(ts, &sleptts, ts);

return tstohz(ts);
}

void
clock_timeleft(clockid_t clockid, struct timespec *ts, struct timespec *sleepts)
{
struct timespec sleptts;

clock_gettime1(clockid, &sleptts);
timespecadd(ts, sleepts, ts);
timespecsub(ts, &sleptts, ts);
*sleepts = sleptts;
}

int
clock_gettime1(clockid_t clock_id, struct timespec *ts)
{
int error;
struct proc *p;

#define CPUCLOCK_ID_MASK (~(CLOCK_THREAD_CPUTIME_ID|CLOCK_PROCESS_CPUTIME_ID))
if (clock_id & CLOCK_PROCESS_CPUTIME_ID) {
pid_t pid = clock_id & CPUCLOCK_ID_MASK;
struct timeval cputime;

mutex_enter(&proc_lock);
p = pid == 0 ? curproc : proc_find(pid);
if (p == NULL) {
mutex_exit(&proc_lock);
return ESRCH;
}
mutex_enter(p->p_lock);
calcru(p, /*usertime*/NULL, /*systime*/NULL, /*intrtime*/NULL,
&cputime);
mutex_exit(p->p_lock);
mutex_exit(&proc_lock);

// XXX: Perhaps create a special kauth type
error = kauth_authorize_process(kauth_cred_get(),
KAUTH_PROCESS_PTRACE, p,
KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
if (error)
return error;

TIMEVAL_TO_TIMESPEC(&cputime, ts);
return 0;
} else if (clock_id & CLOCK_THREAD_CPUTIME_ID) {
struct lwp *l;
lwpid_t lid = clock_id & CPUCLOCK_ID_MASK;
struct bintime tm = {0, 0};

p = curproc;
mutex_enter(p->p_lock);
l = lid == 0 ? curlwp : lwp_find(p, lid);
if (l == NULL) {
mutex_exit(p->p_lock);
return ESRCH;
}
addrulwp(l, &tm);
mutex_exit(p->p_lock);

bintime2timespec(&tm, ts);
return 0;
}

switch (clock_id) {
case CLOCK_REALTIME:
nanotime(ts);
break;
case CLOCK_MONOTONIC:
nanouptime(ts);
break;
default:
return EINVAL;
}

return 0;
}

/*
* Calculate delta and convert from struct timespec to the ticks.
*/
int
ts2timo(clockid_t clock_id, int flags, struct timespec *ts,
int *timo, struct timespec *start)
{
int error;
struct timespec tsd;

if (ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000L)
return EINVAL;

if ((flags & TIMER_ABSTIME) != 0 || start != NULL) {
error = clock_gettime1(clock_id, &tsd);
if (error != 0)
return error;
if (start != NULL)
*start = tsd;
}

if ((flags & TIMER_ABSTIME) != 0) {
if (!timespecsubok(ts, &tsd))
return EINVAL;
timespecsub(ts, &tsd, &tsd);
ts = &tsd;
}

error = itimespecfix(ts);
if (error != 0)
return error;

if (ts->tv_sec == 0 && ts->tv_nsec == 0)
return ETIMEDOUT;

*timo = tstohz(ts);
KASSERT(*timo > 0);

return 0;
}