/* * Get the TOD clock running. */ static u64 __init reset_tod_clock(void) { u64 time; etr_reset(); if (store_clock(&time) == 0) return time; /* TOD clock not running. Set the clock to Unix Epoch. */ if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0) panic("TOD clock not operational."); return TOD_UNIX_EPOCH; }
/* * Initialize the TOD clock and the CPU timer of * the boot cpu. */ void __init time_init(void) { struct timespec ts; unsigned long flags; cycle_t now; /* Reset time synchronization interfaces. */ etr_reset(); stp_reset(); /* request the clock comparator external interrupt */ if (register_early_external_interrupt(0x1004, clock_comparator_interrupt, &ext_int_info_cc) != 0) panic("Couldn't request external interrupt 0x1004"); /* request the timing alert external interrupt */ if (register_early_external_interrupt(0x1406, timing_alert_interrupt, &ext_int_etr_cc) != 0) panic("Couldn't request external interrupt 0x1406"); if (clocksource_register(&clocksource_tod) != 0) panic("Could not register TOD clock source"); /* * The TOD clock is an accurate clock. The xtime should be * initialized in a way that the difference between TOD and * xtime is reasonably small. Too bad that timekeeping_init * sets xtime.tv_nsec to zero. In addition the clock source * change from the jiffies clock source to the TOD clock * source add another error of up to 1/HZ second. The same * function sets wall_to_monotonic to a value that is too * small for /proc/uptime to be accurate. * Reset xtime and wall_to_monotonic to sane values. */ write_seqlock_irqsave(&xtime_lock, flags); now = get_clock(); tod_to_timeval(now - TOD_UNIX_EPOCH, &xtime); clocksource_tod.cycle_last = now; clocksource_tod.raw_time = xtime; tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, &ts); set_normalized_timespec(&wall_to_monotonic, -ts.tv_sec, -ts.tv_nsec); write_sequnlock_irqrestore(&xtime_lock, flags); /* Enable TOD clock interrupts on the boot cpu. */ init_cpu_timer(); /* Enable cpu timer interrupts on the boot cpu. */ vtime_init(); }
/* * Initialize the TOD clock and the CPU timer of * the boot cpu. */ void __init time_init(void) { /* Reset time synchronization interfaces. */ etr_reset(); stp_reset(); /* request the clock comparator external interrupt */ if (register_external_interrupt(0x1004, clock_comparator_interrupt)) panic("Couldn't request external interrupt 0x1004"); /* request the timing alert external interrupt */ if (register_external_interrupt(0x1406, timing_alert_interrupt)) panic("Couldn't request external interrupt 0x1406"); if (clocksource_register(&clocksource_tod) != 0) panic("Could not register TOD clock source"); /* Enable TOD clock interrupts on the boot cpu. */ init_cpu_timer(); /* Enable cpu timer interrupts on the boot cpu. */ vtime_init(); }