/* This function is only called on the boot processor */
void __init time_init(void)
{
time_t sec, old_sec;
unsigned old_stamp, stamp, elapsed;
if (ppc_md.time_init != NULL)
time_offset = ppc_md.time_init();
if (__USE_RTC()) {
/* 601 processor: dec counts down by 128 every 128ns */
tb_ticks_per_jiffy = DECREMENTER_COUNT_601;
/* mulhwu_scale_factor(1000000000, 1000000) is 0x418937 */
tb_to_us = 0x418937;
} else {
ppc_md.calibrate_decr();
}
/* Now that the decrementer is calibrated, it can be used in case the
* clock is stuck, but the fact that we have to handle the 601
* makes things more complex. Repeatedly read the RTC until the
* next second boundary to try to achieve some precision. If there
* is no RTC, we still need to set tb_last_stamp and
* last_jiffy_stamp(cpu 0) to the current stamp.
*/
stamp = get_native_tbl();
if (ppc_md.get_rtc_time) {
sec = ppc_md.get_rtc_time();
elapsed = 0;
do {
old_stamp = stamp;
old_sec = sec;
stamp = get_native_tbl();
if (__USE_RTC() && stamp < old_stamp)
old_stamp -= 1000000000;
elapsed += stamp - old_stamp;
sec = ppc_md.get_rtc_time();
} while ( sec == old_sec && elapsed < 2*HZ*tb_ticks_per_jiffy);
if (sec == old_sec)
printk("Warning: real time clock seems stuck!\n");
xtime.tv_sec = sec;
xtime.tv_usec = 0;
/* No update now, we just read the time from the RTC ! */
last_rtc_update = xtime.tv_sec;
}
last_jiffy_stamp(0) = tb_last_stamp = stamp;
/* Not exact, but the timer interrupt takes care of this */
set_dec(tb_ticks_per_jiffy);
/* If platform provided a timezone (pmac), we correct the time
* using do_sys_settimeofday() which in turn calls warp_clock()
*/
if (time_offset) {
struct timezone tz;
tz.tz_minuteswest = -time_offset / 60;
tz.tz_dsttime = 0;
do_sys_settimeofday(NULL, &tz);
}
}
/* Timer interrupt helper function */
static inline int tb_delta(unsigned *jiffy_stamp) {
int delta;
if (__USE_RTC()) {
delta = get_rtcl();
if (delta < *jiffy_stamp) *jiffy_stamp -= 1000000000;
delta -= *jiffy_stamp;
} else {
delta = get_tbl() - *jiffy_stamp;
}
return delta;
}
unsigned long long sched_clock(void)
{
unsigned long lo, hi, hi2;
unsigned long long tb;
if (!__USE_RTC()) {
do {
hi = get_tbu();
lo = get_tbl();
hi2 = get_tbu();
} while (hi2 != hi);
tb = ((unsigned long long) hi << 32) | lo;
tb = (tb * tb_to_ns_scale) >> 10;
} else {
do {
