#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/efi.h>
-#include <linux/profile.h>
#include <linux/timex.h>
+#include <linux/clocksource.h>
#include <asm/machvec.h>
#include <asm/delay.h>
#include <asm/sections.h>
#include <asm/system.h>
+#include "fsyscall_gtod_data.h"
+
+static cycle_t itc_get_cycles(void);
+
+struct fsyscall_gtod_data_t fsyscall_gtod_data = {
+ .lock = SEQLOCK_UNLOCKED,
+};
+
+struct itc_jitter_data_t itc_jitter_data;
+
volatile int time_keeper_id = 0; /* smp_processor_id() of time-keeper */
#ifdef CONFIG_IA64_DEBUG_IRQ
#endif
-static struct time_interpolator itc_interpolator = {
- .shift = 16,
- .mask = 0xffffffffffffffffLL,
- .source = TIME_SOURCE_CPU
+static struct clocksource clocksource_itc = {
+ .name = "itc",
+ .rating = 350,
+ .read = itc_get_cycles,
+ .mask = CLOCKSOURCE_MASK(64),
+ .mult = 0, /*to be caluclated*/
+ .shift = 16,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
+static struct clocksource *itc_clocksource;
static irqreturn_t
timer_interrupt (int irq, void *dev_id)
if (time_after(new_itm, ia64_get_itc()))
break;
+
+ /*
+ * Allow IPIs to interrupt the timer loop.
+ */
+ local_irq_enable();
+ local_irq_disable();
}
do {
+ itc_freq/2)/itc_freq;
if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
- itc_interpolator.frequency = local_cpu_data->itc_freq;
- itc_interpolator.drift = itc_drift;
#ifdef CONFIG_SMP
/* On IA64 in an SMP configuration ITCs are never accurately synchronized.
* Jitter compensation requires a cmpxchg which may limit
* even going backward) if the ITC offsets between the individual CPUs
* are too large.
*/
- if (!nojitter) itc_interpolator.jitter = 1;
+ if (!nojitter)
+ itc_jitter_data.itc_jitter = 1;
#endif
- register_time_interpolator(&itc_interpolator);
- }
+ } else
+ /*
+ * ITC is drifty and we have not synchronized the ITCs in smpboot.c.
+ * ITC values may fluctuate significantly between processors.
+ * Clock should not be used for hrtimers. Mark itc as only
+ * useful for boot and testing.
+ *
+ * Note that jitter compensation is off! There is no point of
+ * synchronizing ITCs since they may be large differentials
+ * that change over time.
+ *
+ * The only way to fix this would be to repeatedly sync the
+ * ITCs. Until that time we have to avoid ITC.
+ */
+ clocksource_itc.rating = 50;
/* Setup the CPU local timer tick */
ia64_cpu_local_tick();
+
+ if (!itc_clocksource) {
+ /* Sort out mult/shift values: */
+ clocksource_itc.mult =
+ clocksource_hz2mult(local_cpu_data->itc_freq,
+ clocksource_itc.shift);
+ clocksource_register(&clocksource_itc);
+ itc_clocksource = &clocksource_itc;
+ }
}
+static cycle_t itc_get_cycles(void)
+{
+ u64 lcycle, now, ret;
+
+ if (!itc_jitter_data.itc_jitter)
+ return get_cycles();
+
+ lcycle = itc_jitter_data.itc_lastcycle;
+ now = get_cycles();
+ if (lcycle && time_after(lcycle, now))
+ return lcycle;
+
+ /*
+ * Keep track of the last timer value returned.
+ * In an SMP environment, you could lose out in contention of
+ * cmpxchg. If so, your cmpxchg returns new value which the
+ * winner of contention updated to. Use the new value instead.
+ */
+ ret = cmpxchg(&itc_jitter_data.itc_lastcycle, lcycle, now);
+ if (unlikely(ret != lcycle))
+ return ret;
+
+ return now;
+}
+
+
static struct irqaction timer_irqaction = {
.handler = timer_interrupt,
- .flags = IRQF_DISABLED,
+ .flags = IRQF_DISABLED | IRQF_IRQPOLL,
.name = "timer"
};
}
EXPORT_SYMBOL(udelay);
-static unsigned long long ia64_itc_printk_clock(void)
+/* IA64 doesn't cache the timezone */
+void update_vsyscall_tz(void)
{
- if (ia64_get_kr(IA64_KR_PER_CPU_DATA))
- return sched_clock();
- return 0;
}
-static unsigned long long ia64_default_printk_clock(void)
+void update_vsyscall(struct timespec *wall, struct clocksource *c)
{
- return (unsigned long long)(jiffies_64 - INITIAL_JIFFIES) *
- (1000000000/HZ);
-}
-
-unsigned long long (*ia64_printk_clock)(void) = &ia64_default_printk_clock;
+ unsigned long flags;
+
+ write_seqlock_irqsave(&fsyscall_gtod_data.lock, flags);
+
+ /* copy fsyscall clock data */
+ fsyscall_gtod_data.clk_mask = c->mask;
+ fsyscall_gtod_data.clk_mult = c->mult;
+ fsyscall_gtod_data.clk_shift = c->shift;
+ fsyscall_gtod_data.clk_fsys_mmio = c->fsys_mmio;
+ fsyscall_gtod_data.clk_cycle_last = c->cycle_last;
+
+ /* copy kernel time structures */
+ fsyscall_gtod_data.wall_time.tv_sec = wall->tv_sec;
+ fsyscall_gtod_data.wall_time.tv_nsec = wall->tv_nsec;
+ fsyscall_gtod_data.monotonic_time.tv_sec = wall_to_monotonic.tv_sec
+ + wall->tv_sec;
+ fsyscall_gtod_data.monotonic_time.tv_nsec = wall_to_monotonic.tv_nsec
+ + wall->tv_nsec;
+
+ /* normalize */
+ while (fsyscall_gtod_data.monotonic_time.tv_nsec >= NSEC_PER_SEC) {
+ fsyscall_gtod_data.monotonic_time.tv_nsec -= NSEC_PER_SEC;
+ fsyscall_gtod_data.monotonic_time.tv_sec++;
+ }
-unsigned long long printk_clock(void)
-{
- return ia64_printk_clock();
+ write_sequnlock_irqrestore(&fsyscall_gtod_data.lock, flags);
}
-void __init
-ia64_setup_printk_clock(void)
-{
- if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT))
- ia64_printk_clock = ia64_itc_printk_clock;
-}