coreboot-kgpe-d16/payloads/libpayload/libc/time.c

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/*
* This file is part of the libpayload project.
*
* Copyright (C) 2008 Advanced Micro Devices, Inc.
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/**
* @file libc/time.c
* General time functions
*/
#include <libpayload-config.h>
#include <libpayload.h>
#if CONFIG(LP_ARCH_X86) && CONFIG(LP_NVRAM)
#include <arch/rdtsc.h>
#endif
extern u32 cpu_khz;
static struct {
u64 ticks;
time_t secs;
suseconds_t usecs;
} clock;
static void update_clock(void)
{
u64 delta = timer_raw_value() - clock.ticks;
int secs;
static uint64_t ticks_per_sec = 0;
static uint64_t ticks_per_usec = 0;
if (!ticks_per_sec) {
ticks_per_sec = timer_hz();
ticks_per_usec = timer_hz() / 1000000;
}
clock.ticks += delta;
secs = (int) (delta / ticks_per_sec);
clock.secs += secs;
delta -= (secs * ticks_per_sec);
clock.usecs += (int)(delta / ticks_per_usec);
if (clock.usecs > 1000000) {
clock.usecs -= 1000000;
clock.secs++;
}
}
#if CONFIG(LP_NVRAM)
static unsigned int day_of_year(int mon, int day, int year)
{
static u8 mdays[12] = { 31, 28, 31, 30, 31, 30,
31, 31, 30, 31, 30, 31 };
int i, ret = 0;
for(i = 0; i < mon; i++) {
ret += mdays[i];
if (i == 1 && (year % 4))
ret++;
}
return (ret + day);
}
static void gettimeofday_init(void)
{
int days, delta;
struct tm tm;
rtc_read_clock(&tm);
clock.ticks = rdtsc();
/* Calculate the number of days in the year so far */
days = day_of_year(tm.tm_mon, tm.tm_mday, tm.tm_year + 1900);
delta = tm.tm_year - 70;
days += (delta * 365);
/* Figure leap years */
if (delta > 2)
days += (delta - 2) / 4;
clock.secs = (days * 86400) + (tm.tm_hour * 3600) +
(tm.tm_min * 60) + tm.tm_sec;
}
#else
static void gettimeofday_init(void)
{
/* Record the number of ticks */
clock.ticks = timer_raw_value();
}
#endif
/**
* Return the current time expressed as seconds from 00:00:00 UTC, 1 Jan 1970.
*
* @param tp When not NULL, set this to the current time in seconds.
* @return The current time in seconds.
*/
time_t time(time_t *tp)
{
/*
* Call the gtod init when we need it - this keeps the code from
* being included in the binary if we don't need it.
*/
if (!clock.ticks)
gettimeofday_init();
update_clock();
if (tp)
*tp = clock.secs;
return clock.secs;
}
/**
* Return the current time broken into a timeval structure.
*
* @param tv A pointer to a timeval structure.
* @param tz Added for compatibility - not used.
* @return 0 for success (this function cannot return non-zero currently).
*/
int gettimeofday(struct timeval *tv, void *tz)
{
tv->tv_sec = time(NULL);
tv->tv_usec = clock.usecs;
return 0;
}
__attribute__((weak))
void arch_ndelay(uint64_t ns)
{
uint64_t delta = ns * timer_hz() / NSECS_PER_SEC;
uint64_t start = timer_raw_value();
while (timer_raw_value() - start < delta) ;
}
u64 timer_us(u64 base)
{
static u64 hz;
// Only check timer_hz once. Assume it doesn't change.
if (hz == 0) {
hz = timer_hz();
if (hz < 1000000) {
printf("Timer frequency %lld is too low, "
"must be at least 1MHz.\n", hz);
halt();
}
}
return (1000000 * timer_raw_value()) / hz - base;
}