#include <linux/hrtimer.h>
#include <linux/init.h>
#include <linux/module.h>
-#include <linux/notifier.h>
#include <linux/smp.h>
+#include <linux/device.h>
#include "tick-internal.h"
/* The registered clock event devices */
static LIST_HEAD(clockevent_devices);
static LIST_HEAD(clockevents_released);
-
-/* Notification for clock events */
-static RAW_NOTIFIER_HEAD(clockevents_chain);
-
/* Protection for the above */
static DEFINE_RAW_SPINLOCK(clockevents_lock);
+/* Protection for unbind operations */
+static DEFINE_MUTEX(clockevents_mutex);
+
+struct ce_unbind {
+ struct clock_event_device *ce;
+ int res;
+};
/**
* clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
return (rc && force) ? clockevents_program_min_delta(dev) : rc;
}
-/**
- * clockevents_register_notifier - register a clock events change listener
+/*
+ * Called after a notify add to make devices available which were
+ * released from the notifier call.
*/
-int clockevents_register_notifier(struct notifier_block *nb)
+static void clockevents_notify_released(void)
{
- unsigned long flags;
- int ret;
+ struct clock_event_device *dev;
- raw_spin_lock_irqsave(&clockevents_lock, flags);
- ret = raw_notifier_chain_register(&clockevents_chain, nb);
- raw_spin_unlock_irqrestore(&clockevents_lock, flags);
+ while (!list_empty(&clockevents_released)) {
+ dev = list_entry(clockevents_released.next,
+ struct clock_event_device, list);
+ list_del(&dev->list);
+ list_add(&dev->list, &clockevent_devices);
+ tick_check_new_device(dev);
+ }
+}
- return ret;
+/*
+ * Try to install a replacement clock event device
+ */
+static int clockevents_replace(struct clock_event_device *ced)
+{
+ struct clock_event_device *dev, *newdev = NULL;
+
+ list_for_each_entry(dev, &clockevent_devices, list) {
+ if (dev == ced || dev->mode != CLOCK_EVT_MODE_UNUSED)
+ continue;
+
+ if (!tick_check_replacement(newdev, dev))
+ continue;
+
+ if (!try_module_get(dev->owner))
+ continue;
+
+ if (newdev)
+ module_put(newdev->owner);
+ newdev = dev;
+ }
+ if (newdev) {
+ tick_install_replacement(newdev);
+ list_del_init(&ced->list);
+ }
+ return newdev ? 0 : -EBUSY;
}
/*
- * Notify about a clock event change. Called with clockevents_lock
- * held.
+ * Called with clockevents_mutex and clockevents_lock held
*/
-static void clockevents_do_notify(unsigned long reason, void *dev)
+static int __clockevents_try_unbind(struct clock_event_device *ced, int cpu)
{
- raw_notifier_call_chain(&clockevents_chain, reason, dev);
+ /* Fast track. Device is unused */
+ if (ced->mode == CLOCK_EVT_MODE_UNUSED) {
+ list_del_init(&ced->list);
+ return 0;
+ }
+
+ return ced == per_cpu(tick_cpu_device, cpu).evtdev ? -EAGAIN : -EBUSY;
}
/*
- * Called after a notify add to make devices available which were
- * released from the notifier call.
+ * SMP function call to unbind a device
*/
-static void clockevents_notify_released(void)
+static void __clockevents_unbind(void *arg)
{
- struct clock_event_device *dev;
+ struct ce_unbind *cu = arg;
+ int res;
+
+ raw_spin_lock(&clockevents_lock);
+ res = __clockevents_try_unbind(cu->ce, smp_processor_id());
+ if (res == -EAGAIN)
+ res = clockevents_replace(cu->ce);
+ cu->res = res;
+ raw_spin_unlock(&clockevents_lock);
+}
- while (!list_empty(&clockevents_released)) {
- dev = list_entry(clockevents_released.next,
- struct clock_event_device, list);
- list_del(&dev->list);
- list_add(&dev->list, &clockevent_devices);
- clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
- }
+/*
+ * Issues smp function call to unbind a per cpu device. Called with
+ * clockevents_mutex held.
+ */
+static int clockevents_unbind(struct clock_event_device *ced, int cpu)
+{
+ struct ce_unbind cu = { .ce = ced, .res = -ENODEV };
+
+ smp_call_function_single(cpu, __clockevents_unbind, &cu, 1);
+ return cu.res;
}
+/*
+ * Unbind a clockevents device.
+ */
+int clockevents_unbind_device(struct clock_event_device *ced, int cpu)
+{
+ int ret;
+
+ mutex_lock(&clockevents_mutex);
+ ret = clockevents_unbind(ced, cpu);
+ mutex_unlock(&clockevents_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clockevents_unbind);
+
/**
* clockevents_register_device - register a clock event device
* @dev: device to register
raw_spin_lock_irqsave(&clockevents_lock, flags);
list_add(&dev->list, &clockevent_devices);
- clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+ tick_check_new_device(dev);
clockevents_notify_released();
raw_spin_unlock_irqrestore(&clockevents_lock, flags);
* released list and do a notify add later.
*/
if (old) {
+ module_put(old->owner);
clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
list_del(&old->list);
list_add(&old->list, &clockevents_released);
int cpu;
raw_spin_lock_irqsave(&clockevents_lock, flags);
- clockevents_do_notify(reason, arg);
switch (reason) {
+ case CLOCK_EVT_NOTIFY_BROADCAST_ON:
+ case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
+ case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
+ tick_broadcast_on_off(reason, arg);
+ break;
+
+ case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
+ case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
+ tick_broadcast_oneshot_control(reason);
+ break;
+
+ case CLOCK_EVT_NOTIFY_CPU_DYING:
+ tick_handover_do_timer(arg);
+ break;
+
+ case CLOCK_EVT_NOTIFY_SUSPEND:
+ tick_suspend();
+ tick_suspend_broadcast();
+ break;
+
+ case CLOCK_EVT_NOTIFY_RESUME:
+ tick_resume();
+ break;
+
case CLOCK_EVT_NOTIFY_CPU_DEAD:
+ tick_shutdown_broadcast_oneshot(arg);
+ tick_shutdown_broadcast(arg);
+ tick_shutdown(arg);
/*
* Unregister the clock event devices which were
* released from the users in the notify chain.
raw_spin_unlock_irqrestore(&clockevents_lock, flags);
}
EXPORT_SYMBOL_GPL(clockevents_notify);
+
+#ifdef CONFIG_SYSFS
+struct bus_type clockevents_subsys = {
+ .name = "clockevents",
+ .dev_name = "clockevent",
+};
+
+static DEFINE_PER_CPU(struct device, tick_percpu_dev);
+static struct tick_device *tick_get_tick_dev(struct device *dev);
+
+static ssize_t sysfs_show_current_tick_dev(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tick_device *td;
+ ssize_t count = 0;
+
+ raw_spin_lock_irq(&clockevents_lock);
+ td = tick_get_tick_dev(dev);
+ if (td && td->evtdev)
+ count = snprintf(buf, PAGE_SIZE, "%s\n", td->evtdev->name);
+ raw_spin_unlock_irq(&clockevents_lock);
+ return count;
+}
+static DEVICE_ATTR(current_device, 0444, sysfs_show_current_tick_dev, NULL);
+
+/* We don't support the abomination of removable broadcast devices */
+static ssize_t sysfs_unbind_tick_dev(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ char name[CS_NAME_LEN];
+ size_t ret = sysfs_get_uname(buf, name, count);
+ struct clock_event_device *ce;
+
+ if (ret < 0)
+ return ret;
+
+ ret = -ENODEV;
+ mutex_lock(&clockevents_mutex);
+ raw_spin_lock_irq(&clockevents_lock);
+ list_for_each_entry(ce, &clockevent_devices, list) {
+ if (!strcmp(ce->name, name)) {
+ ret = __clockevents_try_unbind(ce, dev->id);
+ break;
+ }
+ }
+ raw_spin_unlock_irq(&clockevents_lock);
+ /*
+ * We hold clockevents_mutex, so ce can't go away
+ */
+ if (ret == -EAGAIN)
+ ret = clockevents_unbind(ce, dev->id);
+ mutex_unlock(&clockevents_mutex);
+ return ret ? ret : count;
+}
+static DEVICE_ATTR(unbind_device, 0200, NULL, sysfs_unbind_tick_dev);
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+static struct device tick_bc_dev = {
+ .init_name = "broadcast",
+ .id = 0,
+ .bus = &clockevents_subsys,
+};
+
+static struct tick_device *tick_get_tick_dev(struct device *dev)
+{
+ return dev == &tick_bc_dev ? tick_get_broadcast_device() :
+ &per_cpu(tick_cpu_device, dev->id);
+}
+
+static __init int tick_broadcast_init_sysfs(void)
+{
+ int err = device_register(&tick_bc_dev);
+
+ if (!err)
+ err = device_create_file(&tick_bc_dev, &dev_attr_current_device);
+ return err;
+}
+#else
+static struct tick_device *tick_get_tick_dev(struct device *dev)
+{
+ return &per_cpu(tick_cpu_device, dev->id);
+}
+static inline int tick_broadcast_init_sysfs(void) { return 0; }
#endif
+
+static int __init tick_init_sysfs(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct device *dev = &per_cpu(tick_percpu_dev, cpu);
+ int err;
+
+ dev->id = cpu;
+ dev->bus = &clockevents_subsys;
+ err = device_register(dev);
+ if (!err)
+ err = device_create_file(dev, &dev_attr_current_device);
+ if (!err)
+ err = device_create_file(dev, &dev_attr_unbind_device);
+ if (err)
+ return err;
+ }
+ return tick_broadcast_init_sysfs();
+}
+
+static int __init clockevents_init_sysfs(void)
+{
+ int err = subsys_system_register(&clockevents_subsys, NULL);
+
+ if (!err)
+ err = tick_init_sysfs();
+ return err;
+}
+device_initcall(clockevents_init_sysfs);
+#endif /* SYSFS */
+
+#endif /* GENERIC_CLOCK_EVENTS */
projects / karo-tx-linux.git / blobdiff