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-rw-r--r--arch/x86/kernel/hpet.c19
-rw-r--r--drivers/clocksource/acpi_pm.c54
-rw-r--r--include/linux/clockchips.h2
-rw-r--r--kernel/time/clockevents.c3
-rw-r--r--kernel/time/ntp.c2
-rw-r--r--kernel/time/tick-broadcast.c78
-rw-r--r--kernel/time/tick-common.c1
-rw-r--r--kernel/time/tick-internal.h2
-rw-r--r--kernel/time/tick-oneshot.c46
9 files changed, 151 insertions, 56 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 59fd3b6b130..73deaffadd0 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -210,8 +210,8 @@ static void hpet_legacy_clockevent_register(void)
/* Calculate the min / max delta */
hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
&hpet_clockevent);
- hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30,
- &hpet_clockevent);
+ /* 5 usec minimum reprogramming delta. */
+ hpet_clockevent.min_delta_ns = 5000;
/*
* Start hpet with the boot cpu mask and make it
@@ -270,15 +270,22 @@ static void hpet_legacy_set_mode(enum clock_event_mode mode,
}
static int hpet_legacy_next_event(unsigned long delta,
- struct clock_event_device *evt)
+ struct clock_event_device *evt)
{
- unsigned long cnt;
+ u32 cnt;
cnt = hpet_readl(HPET_COUNTER);
- cnt += delta;
+ cnt += (u32) delta;
hpet_writel(cnt, HPET_T0_CMP);
- return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0) ? -ETIME : 0;
+ /*
+ * We need to read back the CMP register to make sure that
+ * what we wrote hit the chip before we compare it to the
+ * counter.
+ */
+ WARN_ON((u32)hpet_readl(HPET_T0_CMP) != cnt);
+
+ return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
}
/*
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 5ca1d80de18..4eee533f3f4 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -21,6 +21,7 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/pci.h>
+#include <linux/delay.h>
#include <asm/io.h>
/*
@@ -151,13 +152,13 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE,
*/
static int verify_pmtmr_rate(void)
{
- u32 value1, value2;
+ cycle_t value1, value2;
unsigned long count, delta;
mach_prepare_counter();
- value1 = read_pmtmr();
+ value1 = clocksource_acpi_pm.read();
mach_countup(&count);
- value2 = read_pmtmr();
+ value2 = clocksource_acpi_pm.read();
delta = (value2 - value1) & ACPI_PM_MASK;
/* Check that the PMTMR delta is within 5% of what we expect */
@@ -175,10 +176,13 @@ static int verify_pmtmr_rate(void)
#define verify_pmtmr_rate() (0)
#endif
+/* Number of monotonicity checks to perform during initialization */
+#define ACPI_PM_MONOTONICITY_CHECKS 10
+
static int __init init_acpi_pm_clocksource(void)
{
- u32 value1, value2;
- unsigned int i;
+ cycle_t value1, value2;
+ unsigned int i, j, good = 0;
if (!pmtmr_ioport)
return -ENODEV;
@@ -187,24 +191,32 @@ static int __init init_acpi_pm_clocksource(void)
clocksource_acpi_pm.shift);
/* "verify" this timing source: */
- value1 = read_pmtmr();
- for (i = 0; i < 10000; i++) {
- value2 = read_pmtmr();
- if (value2 == value1)
- continue;
- if (value2 > value1)
- goto pm_good;
- if ((value2 < value1) && ((value2) < 0xFFF))
- goto pm_good;
- printk(KERN_INFO "PM-Timer had inconsistent results:"
- " 0x%#x, 0x%#x - aborting.\n", value1, value2);
- return -EINVAL;
+ for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
+ value1 = clocksource_acpi_pm.read();
+ for (i = 0; i < 10000; i++) {
+ value2 = clocksource_acpi_pm.read();
+ if (value2 == value1)
+ continue;
+ if (value2 > value1)
+ good++;
+ break;
+ if ((value2 < value1) && ((value2) < 0xFFF))
+ good++;
+ break;
+ printk(KERN_INFO "PM-Timer had inconsistent results:"
+ " 0x%#llx, 0x%#llx - aborting.\n",
+ value1, value2);
+ return -EINVAL;
+ }
+ udelay(300 * i);
+ }
+
+ if (good != ACPI_PM_MONOTONICITY_CHECKS) {
+ printk(KERN_INFO "PM-Timer failed consistency check "
+ " (0x%#llx) - aborting.\n", value1);
+ return -ENODEV;
}
- printk(KERN_INFO "PM-Timer had no reasonable result:"
- " 0x%#x - aborting.\n", value1);
- return -ENODEV;
-pm_good:
if (verify_pmtmr_rate() != 0)
return -ENODEV;
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index c33b0dc28e4..ed3a5d473e5 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -127,6 +127,8 @@ extern int clockevents_register_notifier(struct notifier_block *nb);
extern int clockevents_program_event(struct clock_event_device *dev,
ktime_t expires, ktime_t now);
+extern void clockevents_handle_noop(struct clock_event_device *dev);
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern void clockevents_notify(unsigned long reason, void *arg);
#else
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 3d1e3e1a197..1876b526c77 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -177,7 +177,7 @@ void clockevents_register_device(struct clock_event_device *dev)
/*
* Noop handler when we shut down an event device
*/
-static void clockevents_handle_noop(struct clock_event_device *dev)
+void clockevents_handle_noop(struct clock_event_device *dev)
{
}
@@ -199,7 +199,6 @@ void clockevents_exchange_device(struct clock_event_device *old,
* released list and do a notify add later.
*/
if (old) {
- old->event_handler = clockevents_handle_noop;
clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
list_del(&old->list);
list_add(&old->list, &clockevents_released);
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 5125ddd8196..1ad46f3df6e 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -245,7 +245,7 @@ static void sync_cmos_clock(unsigned long dummy)
if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
fail = update_persistent_clock(now);
- next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec;
+ next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
if (next.tv_nsec <= 0)
next.tv_nsec += NSEC_PER_SEC;
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 31463d370b9..2f5a38294bf 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -175,6 +175,8 @@ static void tick_do_periodic_broadcast(void)
*/
static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
{
+ ktime_t next;
+
tick_do_periodic_broadcast();
/*
@@ -185,10 +187,13 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
/*
* Setup the next period for devices, which do not have
- * periodic mode:
+ * periodic mode. We read dev->next_event first and add to it
+ * when the event alrady expired. clockevents_program_event()
+ * sets dev->next_event only when the event is really
+ * programmed to the device.
*/
- for (;;) {
- ktime_t next = ktime_add(dev->next_event, tick_period);
+ for (next = dev->next_event; ;) {
+ next = ktime_add(next, tick_period);
if (!clockevents_program_event(dev, next, ktime_get()))
return;
@@ -205,7 +210,7 @@ static void tick_do_broadcast_on_off(void *why)
struct clock_event_device *bc, *dev;
struct tick_device *td;
unsigned long flags, *reason = why;
- int cpu;
+ int cpu, bc_stopped;
spin_lock_irqsave(&tick_broadcast_lock, flags);
@@ -223,6 +228,8 @@ static void tick_do_broadcast_on_off(void *why)
if (!tick_device_is_functional(dev))
goto out;
+ bc_stopped = cpus_empty(tick_broadcast_mask);
+
switch (*reason) {
case CLOCK_EVT_NOTIFY_BROADCAST_ON:
case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
@@ -245,9 +252,10 @@ static void tick_do_broadcast_on_off(void *why)
break;
}
- if (cpus_empty(tick_broadcast_mask))
- clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
- else {
+ if (cpus_empty(tick_broadcast_mask)) {
+ if (!bc_stopped)
+ clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+ } else if (bc_stopped) {
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
else
@@ -364,16 +372,8 @@ cpumask_t *tick_get_broadcast_oneshot_mask(void)
static int tick_broadcast_set_event(ktime_t expires, int force)
{
struct clock_event_device *bc = tick_broadcast_device.evtdev;
- ktime_t now = ktime_get();
- int res;
-
- for(;;) {
- res = clockevents_program_event(bc, expires, now);
- if (!res || !force)
- return res;
- now = ktime_get();
- expires = ktime_add(now, ktime_set(0, bc->min_delta_ns));
- }
+
+ return tick_dev_program_event(bc, expires, force);
}
int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
@@ -491,14 +491,52 @@ static void tick_broadcast_clear_oneshot(int cpu)
cpu_clear(cpu, tick_broadcast_oneshot_mask);
}
+static void tick_broadcast_init_next_event(cpumask_t *mask, ktime_t expires)
+{
+ struct tick_device *td;
+ int cpu;
+
+ for_each_cpu_mask_nr(cpu, *mask) {
+ td = &per_cpu(tick_cpu_device, cpu);
+ if (td->evtdev)
+ td->evtdev->next_event = expires;
+ }
+}
+
/**
* tick_broadcast_setup_oneshot - setup the broadcast device
*/
void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
- bc->event_handler = tick_handle_oneshot_broadcast;
- clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
- bc->next_event.tv64 = KTIME_MAX;
+ /* Set it up only once ! */
+ if (bc->event_handler != tick_handle_oneshot_broadcast) {
+ int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC;
+ int cpu = smp_processor_id();
+ cpumask_t mask;
+
+ bc->event_handler = tick_handle_oneshot_broadcast;
+ clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
+
+ /* Take the do_timer update */
+ tick_do_timer_cpu = cpu;
+
+ /*
+ * We must be careful here. There might be other CPUs
+ * waiting for periodic broadcast. We need to set the
+ * oneshot_mask bits for those and program the
+ * broadcast device to fire.
+ */
+ mask = tick_broadcast_mask;
+ cpu_clear(cpu, mask);
+ cpus_or(tick_broadcast_oneshot_mask,
+ tick_broadcast_oneshot_mask, mask);
+
+ if (was_periodic && !cpus_empty(mask)) {
+ tick_broadcast_init_next_event(&mask, tick_next_period);
+ tick_broadcast_set_event(tick_next_period, 1);
+ } else
+ bc->next_event.tv64 = KTIME_MAX;
+ }
}
/*
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 80c4336f418..c4777193d56 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -161,6 +161,7 @@ static void tick_setup_device(struct tick_device *td,
} else {
handler = td->evtdev->event_handler;
next_event = td->evtdev->next_event;
+ td->evtdev->event_handler = clockevents_handle_noop;
}
td->evtdev = newdev;
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index f13f2b7f4fd..0ffc2918ea6 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -17,6 +17,8 @@ extern void tick_handle_periodic(struct clock_event_device *dev);
extern void tick_setup_oneshot(struct clock_event_device *newdev,
void (*handler)(struct clock_event_device *),
ktime_t nextevt);
+extern int tick_dev_program_event(struct clock_event_device *dev,
+ ktime_t expires, int force);
extern int tick_program_event(ktime_t expires, int force);
extern void tick_oneshot_notify(void);
extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index 450c04935b6..2e35501e61d 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -23,24 +23,58 @@
#include "tick-internal.h"
/**
- * tick_program_event
+ * tick_program_event internal worker function
*/
-int tick_program_event(ktime_t expires, int force)
+int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
+ int force)
{
- struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
ktime_t now = ktime_get();
+ int i;
- while (1) {
+ for (i = 0;;) {
int ret = clockevents_program_event(dev, expires, now);
if (!ret || !force)
return ret;
+
+ /*
+ * We tried 2 times to program the device with the given
+ * min_delta_ns. If that's not working then we double it
+ * and emit a warning.
+ */
+ if (++i > 2) {
+ printk(KERN_WARNING "CE: __tick_program_event of %s is "
+ "stuck %llx %llx\n", dev->name ? dev->name : "?",
+ now.tv64, expires.tv64);
+ printk(KERN_WARNING
+ "CE: increasing min_delta_ns %ld to %ld nsec\n",
+ dev->min_delta_ns, dev->min_delta_ns << 1);
+ WARN_ON(1);
+
+ /* Double the min. delta and try again */
+ if (!dev->min_delta_ns)
+ dev->min_delta_ns = 5000;
+ else
+ dev->min_delta_ns <<= 1;
+ i = 0;
+ }
+
now = ktime_get();
- expires = ktime_add(now, ktime_set(0, dev->min_delta_ns));
+ expires = ktime_add_ns(now, dev->min_delta_ns);
}
}
/**
+ * tick_program_event
+ */
+int tick_program_event(ktime_t expires, int force)
+{
+ struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+
+ return tick_dev_program_event(dev, expires, force);
+}
+
+/**
* tick_resume_onshot - resume oneshot mode
*/
void tick_resume_oneshot(void)
@@ -61,7 +95,7 @@ void tick_setup_oneshot(struct clock_event_device *newdev,
{
newdev->event_handler = handler;
clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT);
- clockevents_program_event(newdev, next_event, ktime_get());
+ tick_dev_program_event(newdev, next_event, 1);
}
/**