/* powerpc clocksource/clockevent code */
+#include <linux/clockchips.h>
#include <linux/clocksource.h>
static cycle_t rtc_read(void);
.read = timebase_read,
};
+#define DECREMENTER_MAX 0x7fffffff
+
+static int decrementer_set_next_event(unsigned long evt,
+ struct clock_event_device *dev);
+static void decrementer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev);
+
+static struct clock_event_device decrementer_clockevent = {
+ .name = "decrementer",
+ .rating = 200,
+ .shift = 32,
+ .mult = 0, /* To be filled in */
+ .irq = 0,
+ .set_next_event = decrementer_set_next_event,
+ .set_mode = decrementer_set_mode,
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+};
+
+static DEFINE_PER_CPU(struct clock_event_device, decrementers);
+void init_decrementer_clockevent(void);
+static DEFINE_PER_CPU(u64, decrementer_next_tb);
+
#ifdef CONFIG_PPC_ISERIES
static unsigned long __initdata iSeries_recal_titan;
static signed long __initdata iSeries_recal_tb;
void timer_interrupt(struct pt_regs * regs)
{
struct pt_regs *old_regs;
- int next_dec;
int cpu = smp_processor_id();
- unsigned long ticks;
- u64 tb_next_jiffy;
+ struct clock_event_device *evt = &per_cpu(decrementers, cpu);
+ u64 now;
+
+ /* Ensure a positive value is written to the decrementer, or else
+ * some CPUs will continuue to take decrementer exceptions */
+ set_dec(DECREMENTER_MAX);
#ifdef CONFIG_PPC32
if (atomic_read(&ppc_n_lost_interrupts) != 0)
do_IRQ(regs);
#endif
+ now = get_tb_or_rtc();
+ if (now < per_cpu(decrementer_next_tb, cpu)) {
+ /* not time for this event yet */
+ now = per_cpu(decrementer_next_tb, cpu) - now;
+ if (now <= DECREMENTER_MAX)
+ set_dec((unsigned int)now - 1);
+ return;
+ }
old_regs = set_irq_regs(regs);
irq_enter();
- profile_tick(CPU_PROFILING);
calculate_steal_time();
#ifdef CONFIG_PPC_ISERIES
get_lppaca()->int_dword.fields.decr_int = 0;
#endif
- while ((ticks = tb_ticks_since(per_cpu(last_jiffy, cpu)))
- >= tb_ticks_per_jiffy) {
- /* Update last_jiffy */
- per_cpu(last_jiffy, cpu) += tb_ticks_per_jiffy;
- /* Handle RTCL overflow on 601 */
- if (__USE_RTC() && per_cpu(last_jiffy, cpu) >= 1000000000)
- per_cpu(last_jiffy, cpu) -= 1000000000;
-
- /*
- * We cannot disable the decrementer, so in the period
- * between this cpu's being marked offline in cpu_online_map
- * and calling stop-self, it is taking timer interrupts.
- * Avoid calling into the scheduler rebalancing code if this
- * is the case.
- */
- if (!cpu_is_offline(cpu))
- account_process_time(regs);
-
- /*
- * No need to check whether cpu is offline here; boot_cpuid
- * should have been fixed up by now.
- */
- if (cpu != boot_cpuid)
- continue;
+ /*
+ * We cannot disable the decrementer, so in the period
+ * between this cpu's being marked offline in cpu_online_map
+ * and calling stop-self, it is taking timer interrupts.
+ * Avoid calling into the scheduler rebalancing code if this
+ * is the case.
+ */
+ if (!cpu_is_offline(cpu))
+ account_process_time(regs);
- write_seqlock(&xtime_lock);
- tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
- if (__USE_RTC() && tb_next_jiffy >= 1000000000)
- tb_next_jiffy -= 1000000000;
- if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
- tb_last_jiffy = tb_next_jiffy;
- do_timer(1);
- }
- write_sequnlock(&xtime_lock);
- }
-
- next_dec = tb_ticks_per_jiffy - ticks;
- set_dec(next_dec);
+ if (evt->event_handler)
+ evt->event_handler(evt);
+ else
+ evt->set_next_event(DECREMENTER_MAX, evt);
#ifdef CONFIG_PPC_ISERIES
if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
clock->name, clock->mult, clock->shift);
}
+static int decrementer_set_next_event(unsigned long evt,
+ struct clock_event_device *dev)
+{
+ __get_cpu_var(decrementer_next_tb) = get_tb_or_rtc() + evt;
+ /* The decrementer interrupts on the 0 -> -1 transition */
+ if (evt)
+ --evt;
+ set_dec(evt);
+ return 0;
+}
+
+static void decrementer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev)
+{
+ if (mode != CLOCK_EVT_MODE_ONESHOT)
+ decrementer_set_next_event(DECREMENTER_MAX, dev);
+}
+
+static void register_decrementer_clockevent(int cpu)
+{
+ struct clock_event_device *dec = &per_cpu(decrementers, cpu);
+
+ *dec = decrementer_clockevent;
+ dec->cpumask = cpumask_of_cpu(cpu);
+
+ printk(KERN_ERR "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n",
+ dec->name, dec->mult, dec->shift, cpu);
+
+ clockevents_register_device(dec);
+}
+
+void init_decrementer_clockevent(void)
+{
+ int cpu = smp_processor_id();
+
+ decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC,
+ decrementer_clockevent.shift);
+ decrementer_clockevent.max_delta_ns =
+ clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
+ decrementer_clockevent.min_delta_ns = 1000;
+
+ register_decrementer_clockevent(cpu);
+}
+
+void secondary_cpu_time_init(void)
+{
+ /* FIME: Should make unrelatred change to move snapshot_timebase
+ * call here ! */
+ register_decrementer_clockevent(smp_processor_id());
+}
+
/* This function is only called on the boot processor */
void __init time_init(void)
{
if (!firmware_has_feature(FW_FEATURE_ISERIES))
clocksource_init();
- /* Not exact, but the timer interrupt takes care of this */
- set_dec(tb_ticks_per_jiffy);
+ init_decrementer_clockevent();
}
projects / linux-2.6 / blobdiff