#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/hrtimer.h>
-#include <linux/irq.h>
+#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/profile.h>
#include <linux/sched.h>
*/
struct tick_device tick_broadcast_device;
-static cpumask_t tick_broadcast_mask;
+/* FIXME: Use cpumask_var_t. */
+static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS);
+static DECLARE_BITMAP(tmpmask, NR_CPUS);
static DEFINE_SPINLOCK(tick_broadcast_lock);
+static int tick_broadcast_force;
+
+#ifdef CONFIG_TICK_ONESHOT
+static void tick_broadcast_clear_oneshot(int cpu);
+#else
+static inline void tick_broadcast_clear_oneshot(int cpu) { }
+#endif
/*
* Debugging: see timer_list.c
return &tick_broadcast_device;
}
-cpumask_t *tick_get_broadcast_mask(void)
+struct cpumask *tick_get_broadcast_mask(void)
{
- return &tick_broadcast_mask;
+ return to_cpumask(tick_broadcast_mask);
}
/*
*/
static void tick_broadcast_start_periodic(struct clock_event_device *bc)
{
- if (bc && bc->mode == CLOCK_EVT_MODE_SHUTDOWN)
+ if (bc)
tick_setup_periodic(bc, 1);
}
*/
int tick_check_broadcast_device(struct clock_event_device *dev)
{
- if (tick_broadcast_device.evtdev ||
- (dev->features & CLOCK_EVT_FEAT_C3STOP))
+ if ((tick_broadcast_device.evtdev &&
+ tick_broadcast_device.evtdev->rating >= dev->rating) ||
+ (dev->features & CLOCK_EVT_FEAT_C3STOP))
return 0;
clockevents_exchange_device(NULL, dev);
tick_broadcast_device.evtdev = dev;
- if (!cpus_empty(tick_broadcast_mask))
+ if (!cpumask_empty(tick_get_broadcast_mask()))
tick_broadcast_start_periodic(dev);
return 1;
}
*/
if (!tick_device_is_functional(dev)) {
dev->event_handler = tick_handle_periodic;
- cpu_set(cpu, tick_broadcast_mask);
+ cpumask_set_cpu(cpu, tick_get_broadcast_mask());
tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
ret = 1;
- }
+ } else {
+ /*
+ * When the new device is not affected by the stop
+ * feature and the cpu is marked in the broadcast mask
+ * then clear the broadcast bit.
+ */
+ if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) {
+ int cpu = smp_processor_id();
+ cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
+ tick_broadcast_clear_oneshot(cpu);
+ }
+ }
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
return ret;
}
/*
- * Broadcast the event to the cpus, which are set in the mask
+ * Broadcast the event to the cpus, which are set in the mask (mangled).
*/
-int tick_do_broadcast(cpumask_t mask)
+static void tick_do_broadcast(struct cpumask *mask)
{
- int ret = 0, cpu = smp_processor_id();
+ int cpu = smp_processor_id();
struct tick_device *td;
/*
* Check, if the current cpu is in the mask
*/
- if (cpu_isset(cpu, mask)) {
- cpu_clear(cpu, mask);
+ if (cpumask_test_cpu(cpu, mask)) {
+ cpumask_clear_cpu(cpu, mask);
td = &per_cpu(tick_cpu_device, cpu);
td->evtdev->event_handler(td->evtdev);
- ret = 1;
}
- if (!cpus_empty(mask)) {
+ if (!cpumask_empty(mask)) {
/*
* It might be necessary to actually check whether the devices
* have different broadcast functions. For now, just use the
* one of the first device. This works as long as we have this
* misfeature only on x86 (lapic)
*/
- cpu = first_cpu(mask);
- td = &per_cpu(tick_cpu_device, cpu);
+ td = &per_cpu(tick_cpu_device, cpumask_first(mask));
td->evtdev->broadcast(mask);
- ret = 1;
}
- return ret;
}
/*
*/
static void tick_do_periodic_broadcast(void)
{
- cpumask_t mask;
-
spin_lock(&tick_broadcast_lock);
- cpus_and(mask, cpu_online_map, tick_broadcast_mask);
- tick_do_broadcast(mask);
+ cpumask_and(to_cpumask(tmpmask),
+ cpu_online_mask, tick_get_broadcast_mask());
+ tick_do_broadcast(to_cpumask(tmpmask));
spin_unlock(&tick_broadcast_lock);
}
*/
static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
{
- dev->next_event.tv64 = KTIME_MAX;
+ ktime_t next;
tick_do_periodic_broadcast();
/*
* 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;
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);
bc = tick_broadcast_device.evtdev;
/*
- * Is the device in broadcast mode forever or is it not
- * affected by the powerstate ?
+ * Is the device not affected by the powerstate ?
*/
- if (!dev || !tick_device_is_functional(dev) ||
- !(dev->features & CLOCK_EVT_FEAT_C3STOP))
+ if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP))
+ goto out;
+
+ if (!tick_device_is_functional(dev))
goto out;
- if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_ON) {
- if (!cpu_isset(cpu, tick_broadcast_mask)) {
- cpu_set(cpu, tick_broadcast_mask);
- if (td->mode == TICKDEV_MODE_PERIODIC)
- clockevents_set_mode(dev,
- CLOCK_EVT_MODE_SHUTDOWN);
+ bc_stopped = cpumask_empty(tick_get_broadcast_mask());
+
+ switch (*reason) {
+ case CLOCK_EVT_NOTIFY_BROADCAST_ON:
+ case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
+ if (!cpumask_test_cpu(cpu, tick_get_broadcast_mask())) {
+ cpumask_set_cpu(cpu, tick_get_broadcast_mask());
+ if (tick_broadcast_device.mode ==
+ TICKDEV_MODE_PERIODIC)
+ clockevents_shutdown(dev);
}
- } else {
- if (cpu_isset(cpu, tick_broadcast_mask)) {
- cpu_clear(cpu, tick_broadcast_mask);
- if (td->mode == TICKDEV_MODE_PERIODIC)
+ if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)
+ tick_broadcast_force = 1;
+ break;
+ case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
+ if (!tick_broadcast_force &&
+ cpumask_test_cpu(cpu, tick_get_broadcast_mask())) {
+ cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
+ if (tick_broadcast_device.mode ==
+ TICKDEV_MODE_PERIODIC)
tick_setup_periodic(dev, 0);
}
+ break;
}
- if (cpus_empty(tick_broadcast_mask))
- clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
- else {
+ if (cpumask_empty(tick_get_broadcast_mask())) {
+ if (!bc_stopped)
+ clockevents_shutdown(bc);
+ } else if (bc_stopped) {
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
else
*/
void tick_broadcast_on_off(unsigned long reason, int *oncpu)
{
- int cpu = get_cpu();
-
- if (cpu == *oncpu)
- tick_do_broadcast_on_off(&reason);
+ if (!cpumask_test_cpu(*oncpu, cpu_online_mask))
+ printk(KERN_ERR "tick-broadcast: ignoring broadcast for "
+ "offline CPU #%d\n", *oncpu);
else
smp_call_function_single(*oncpu, tick_do_broadcast_on_off,
- &reason, 1, 1);
- put_cpu();
+ &reason, 1);
}
/*
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
- cpu_clear(cpu, tick_broadcast_mask);
+ cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
- if (bc && cpus_empty(tick_broadcast_mask))
- clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+ if (bc && cpumask_empty(tick_get_broadcast_mask()))
+ clockevents_shutdown(bc);
}
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
- if (bc && tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
- clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+ if (bc)
+ clockevents_shutdown(bc);
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
bc = tick_broadcast_device.evtdev;
if (bc) {
+ clockevents_set_mode(bc, CLOCK_EVT_MODE_RESUME);
+
switch (tick_broadcast_device.mode) {
case TICKDEV_MODE_PERIODIC:
- if(!cpus_empty(tick_broadcast_mask))
+ if (!cpumask_empty(tick_get_broadcast_mask()))
tick_broadcast_start_periodic(bc);
- broadcast = cpu_isset(smp_processor_id(),
- tick_broadcast_mask);
+ broadcast = cpumask_test_cpu(smp_processor_id(),
+ tick_get_broadcast_mask());
break;
case TICKDEV_MODE_ONESHOT:
broadcast = tick_resume_broadcast_oneshot(bc);
#ifdef CONFIG_TICK_ONESHOT
-static cpumask_t tick_broadcast_oneshot_mask;
+/* FIXME: use cpumask_var_t. */
+static DECLARE_BITMAP(tick_broadcast_oneshot_mask, NR_CPUS);
/*
- * Debugging: see timer_list.c
+ * Exposed for debugging: see timer_list.c
*/
-cpumask_t *tick_get_broadcast_oneshot_mask(void)
+struct cpumask *tick_get_broadcast_oneshot_mask(void)
{
- return &tick_broadcast_oneshot_mask;
+ return to_cpumask(tick_broadcast_oneshot_mask);
}
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)
{
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
-
- if(!cpus_empty(tick_broadcast_oneshot_mask))
- tick_broadcast_set_event(ktime_get(), 1);
-
- return cpu_isset(smp_processor_id(), tick_broadcast_oneshot_mask);
+ return 0;
}
/*
- * Reprogram the broadcast device:
- *
- * Called with tick_broadcast_lock held and interrupts disabled.
+ * Called from irq_enter() when idle was interrupted to reenable the
+ * per cpu device.
*/
-static int tick_broadcast_reprogram(void)
+void tick_check_oneshot_broadcast(int cpu)
{
- ktime_t expires = { .tv64 = KTIME_MAX };
- struct tick_device *td;
- int cpu;
+ if (cpumask_test_cpu(cpu, to_cpumask(tick_broadcast_oneshot_mask))) {
+ struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
- /*
- * Find the event which expires next:
- */
- for (cpu = first_cpu(tick_broadcast_oneshot_mask); cpu != NR_CPUS;
- cpu = next_cpu(cpu, tick_broadcast_oneshot_mask)) {
- td = &per_cpu(tick_cpu_device, cpu);
- if (td->evtdev->next_event.tv64 < expires.tv64)
- expires = td->evtdev->next_event;
+ clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT);
}
-
- if (expires.tv64 == KTIME_MAX)
- return 0;
-
- return tick_broadcast_set_event(expires, 0);
}
/*
static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
{
struct tick_device *td;
- cpumask_t mask;
- ktime_t now;
+ ktime_t now, next_event;
int cpu;
spin_lock(&tick_broadcast_lock);
again:
dev->next_event.tv64 = KTIME_MAX;
- mask = CPU_MASK_NONE;
+ next_event.tv64 = KTIME_MAX;
+ cpumask_clear(to_cpumask(tmpmask));
now = ktime_get();
/* Find all expired events */
- for (cpu = first_cpu(tick_broadcast_oneshot_mask); cpu != NR_CPUS;
- cpu = next_cpu(cpu, tick_broadcast_oneshot_mask)) {
+ for_each_cpu(cpu, tick_get_broadcast_oneshot_mask()) {
td = &per_cpu(tick_cpu_device, cpu);
if (td->evtdev->next_event.tv64 <= now.tv64)
- cpu_set(cpu, mask);
+ cpumask_set_cpu(cpu, to_cpumask(tmpmask));
+ else if (td->evtdev->next_event.tv64 < next_event.tv64)
+ next_event.tv64 = td->evtdev->next_event.tv64;
}
/*
- * Wakeup the cpus which have an expired event. The broadcast
- * device is reprogrammed in the return from idle code.
+ * Wakeup the cpus which have an expired event.
+ */
+ tick_do_broadcast(to_cpumask(tmpmask));
+
+ /*
+ * Two reasons for reprogram:
+ *
+ * - The global event did not expire any CPU local
+ * events. This happens in dyntick mode, as the maximum PIT
+ * delta is quite small.
+ *
+ * - There are pending events on sleeping CPUs which were not
+ * in the event mask
*/
- if (!tick_do_broadcast(mask)) {
+ if (next_event.tv64 != KTIME_MAX) {
/*
- * The global event did not expire any CPU local
- * events. This happens in dyntick mode, as the
- * maximum PIT delta is quite small.
+ * Rearm the broadcast device. If event expired,
+ * repeat the above
*/
- if (tick_broadcast_reprogram())
+ if (tick_broadcast_set_event(next_event, 0))
goto again;
}
spin_unlock(&tick_broadcast_lock);
goto out;
if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) {
- if (!cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
- cpu_set(cpu, tick_broadcast_oneshot_mask);
+ if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
+ cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask());
clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
if (dev->next_event.tv64 < bc->next_event.tv64)
tick_broadcast_set_event(dev->next_event, 1);
}
} else {
- if (cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
- cpu_clear(cpu, tick_broadcast_oneshot_mask);
+ if (cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
+ cpumask_clear_cpu(cpu,
+ tick_get_broadcast_oneshot_mask());
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
if (dev->next_event.tv64 != KTIME_MAX)
tick_program_event(dev->next_event, 1);
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
+/*
+ * Reset the one shot broadcast for a cpu
+ *
+ * Called with tick_broadcast_lock held
+ */
+static void tick_broadcast_clear_oneshot(int cpu)
+{
+ cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask());
+}
+
+static void tick_broadcast_init_next_event(struct cpumask *mask,
+ ktime_t expires)
+{
+ struct tick_device *td;
+ int cpu;
+
+ for_each_cpu(cpu, mask) {
+ td = &per_cpu(tick_cpu_device, cpu);
+ if (td->evtdev)
+ td->evtdev->next_event = expires;
+ }
+}
+
/**
- * tick_broadcast_setup_highres - setup the broadcast device for highres
+ * tick_broadcast_setup_oneshot - setup the broadcast device
*/
void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
- if (bc->mode != CLOCK_EVT_MODE_ONESHOT) {
+ /* 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();
+
bc->event_handler = tick_handle_oneshot_broadcast;
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
- bc->next_event.tv64 = KTIME_MAX;
+
+ /* 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.
+ */
+ cpumask_copy(to_cpumask(tmpmask), tick_get_broadcast_mask());
+ cpumask_clear_cpu(cpu, to_cpumask(tmpmask));
+ cpumask_or(tick_get_broadcast_oneshot_mask(),
+ tick_get_broadcast_oneshot_mask(),
+ to_cpumask(tmpmask));
+
+ if (was_periodic && !cpumask_empty(to_cpumask(tmpmask))) {
+ tick_broadcast_init_next_event(to_cpumask(tmpmask),
+ tick_next_period);
+ tick_broadcast_set_event(tick_next_period, 1);
+ } else
+ bc->next_event.tv64 = KTIME_MAX;
}
}
*/
void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
{
- struct clock_event_device *bc;
unsigned long flags;
unsigned int cpu = *cpup;
spin_lock_irqsave(&tick_broadcast_lock, flags);
- bc = tick_broadcast_device.evtdev;
- cpu_clear(cpu, tick_broadcast_oneshot_mask);
-
- if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT) {
- if (bc && cpus_empty(tick_broadcast_oneshot_mask))
- clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
- }
+ /*
+ * Clear the broadcast mask flag for the dead cpu, but do not
+ * stop the broadcast device!
+ */
+ cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask());
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
+/*
+ * Check, whether the broadcast device is in one shot mode
+ */
+int tick_broadcast_oneshot_active(void)
+{
+ return tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT;
+}
+
#endif