--- /dev/null
+/*
+ * linux/kernel/time/clockevents.c
+ *
+ * This file contains functions which manage clock event devices.
+ *
+ * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
+ *
+ * This code is licenced under the GPL version 2. For details see
+ * kernel-base/COPYING.
+ */
+
+#include <linux/clockchips.h>
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/module.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);
+/* 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;
+};
+
+static u64 cev_delta2ns(unsigned long latch, struct clock_event_device *evt,
+ bool ismax)
+{
+ u64 clc = (u64) latch << evt->shift;
+ u64 rnd;
+
+ if (unlikely(!evt->mult)) {
+ evt->mult = 1;
+ WARN_ON(1);
+ }
+ rnd = (u64) evt->mult - 1;
+
+ /*
+ * Upper bound sanity check. If the backwards conversion is
+ * not equal latch, we know that the above shift overflowed.
+ */
+ if ((clc >> evt->shift) != (u64)latch)
+ clc = ~0ULL;
+
+ /*
+ * Scaled math oddities:
+ *
+ * For mult <= (1 << shift) we can safely add mult - 1 to
+ * prevent integer rounding loss. So the backwards conversion
+ * from nsec to device ticks will be correct.
+ *
+ * For mult > (1 << shift), i.e. device frequency is > 1GHz we
+ * need to be careful. Adding mult - 1 will result in a value
+ * which when converted back to device ticks can be larger
+ * than latch by up to (mult - 1) >> shift. For the min_delta
+ * calculation we still want to apply this in order to stay
+ * above the minimum device ticks limit. For the upper limit
+ * we would end up with a latch value larger than the upper
+ * limit of the device, so we omit the add to stay below the
+ * device upper boundary.
+ *
+ * Also omit the add if it would overflow the u64 boundary.
+ */
+ if ((~0ULL - clc > rnd) &&
+ (!ismax || evt->mult <= (1ULL << evt->shift)))
+ clc += rnd;
+
+ do_div(clc, evt->mult);
+
+ /* Deltas less than 1usec are pointless noise */
+ return clc > 1000 ? clc : 1000;
+}
+
+/**
+ * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
+ * @latch: value to convert
+ * @evt: pointer to clock event device descriptor
+ *
+ * Math helper, returns latch value converted to nanoseconds (bound checked)
+ */
+u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt)
+{
+ return cev_delta2ns(latch, evt, false);
+}
+EXPORT_SYMBOL_GPL(clockevent_delta2ns);
+
+static int __clockevents_set_state(struct clock_event_device *dev,
+ enum clock_event_state state)
+{
+ /* Transition with legacy set_mode() callback */
+ if (dev->set_mode) {
+ /* Legacy callback doesn't support new modes */
+ if (state > CLOCK_EVT_STATE_ONESHOT)
+ return -ENOSYS;
+ /*
+ * 'clock_event_state' and 'clock_event_mode' have 1-to-1
+ * mapping until *_ONESHOT, and so a simple cast will work.
+ */
+ dev->set_mode((enum clock_event_mode)state, dev);
+ dev->mode = (enum clock_event_mode)state;
+ return 0;
+ }
+
+ if (dev->features & CLOCK_EVT_FEAT_DUMMY)
+ return 0;
+
+ /* Transition with new state-specific callbacks */
+ switch (state) {
+ case CLOCK_EVT_STATE_DETACHED:
+ /* The clockevent device is getting replaced. Shut it down. */
+
+ case CLOCK_EVT_STATE_SHUTDOWN:
+ return dev->set_state_shutdown(dev);
+
+ case CLOCK_EVT_STATE_PERIODIC:
+ /* Core internal bug */
+ if (!(dev->features & CLOCK_EVT_FEAT_PERIODIC))
+ return -ENOSYS;
+ return dev->set_state_periodic(dev);
+
+ case CLOCK_EVT_STATE_ONESHOT:
+ /* Core internal bug */
+ if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT))
+ return -ENOSYS;
+ return dev->set_state_oneshot(dev);
+
+ default:
+ return -ENOSYS;
+ }
+}
+
+/**
+ * clockevents_set_state - set the operating state of a clock event device
+ * @dev: device to modify
+ * @state: new state
+ *
+ * Must be called with interrupts disabled !
+ */
+void clockevents_set_state(struct clock_event_device *dev,
+ enum clock_event_state state)
+{
+ if (dev->state != state) {
+ if (__clockevents_set_state(dev, state))
+ return;
+
+ dev->state = state;
+
+ /*
+ * A nsec2cyc multiplicator of 0 is invalid and we'd crash
+ * on it, so fix it up and emit a warning:
+ */
+ if (state == CLOCK_EVT_STATE_ONESHOT) {
+ if (unlikely(!dev->mult)) {
+ dev->mult = 1;
+ WARN_ON(1);
+ }
+ }
+ }
+}
+
+/**
+ * clockevents_shutdown - shutdown the device and clear next_event
+ * @dev: device to shutdown
+ */
+void clockevents_shutdown(struct clock_event_device *dev)
+{
+ clockevents_set_state(dev, CLOCK_EVT_STATE_SHUTDOWN);
+ dev->next_event.tv64 = KTIME_MAX;
+}
+
+/**
+ * clockevents_tick_resume - Resume the tick device before using it again
+ * @dev: device to resume
+ */
+int clockevents_tick_resume(struct clock_event_device *dev)
+{
+ int ret = 0;
+
+ if (dev->set_mode) {
+ dev->set_mode(CLOCK_EVT_MODE_RESUME, dev);
+ dev->mode = CLOCK_EVT_MODE_RESUME;
+ } else if (dev->tick_resume) {
+ ret = dev->tick_resume(dev);
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST
+
+/* Limit min_delta to a jiffie */
+#define MIN_DELTA_LIMIT (NSEC_PER_SEC / HZ)
+
+/**
+ * clockevents_increase_min_delta - raise minimum delta of a clock event device
+ * @dev: device to increase the minimum delta
+ *
+ * Returns 0 on success, -ETIME when the minimum delta reached the limit.
+ */
+static int clockevents_increase_min_delta(struct clock_event_device *dev)
+{
+ /* Nothing to do if we already reached the limit */
+ if (dev->min_delta_ns >= MIN_DELTA_LIMIT) {
+ printk_deferred(KERN_WARNING
+ "CE: Reprogramming failure. Giving up\n");
+ dev->next_event.tv64 = KTIME_MAX;
+ return -ETIME;
+ }
+
+ if (dev->min_delta_ns < 5000)
+ dev->min_delta_ns = 5000;
+ else
+ dev->min_delta_ns += dev->min_delta_ns >> 1;
+
+ if (dev->min_delta_ns > MIN_DELTA_LIMIT)
+ dev->min_delta_ns = MIN_DELTA_LIMIT;
+
+ printk_deferred(KERN_WARNING
+ "CE: %s increased min_delta_ns to %llu nsec\n",
+ dev->name ? dev->name : "?",
+ (unsigned long long) dev->min_delta_ns);
+ return 0;
+}
+
+/**
+ * clockevents_program_min_delta - Set clock event device to the minimum delay.
+ * @dev: device to program
+ *
+ * Returns 0 on success, -ETIME when the retry loop failed.
+ */
+static int clockevents_program_min_delta(struct clock_event_device *dev)
+{
+ unsigned long long clc;
+ int64_t delta;
+ int i;
+
+ for (i = 0;;) {
+ delta = dev->min_delta_ns;
+ dev->next_event = ktime_add_ns(ktime_get(), delta);
+
+ if (dev->state == CLOCK_EVT_STATE_SHUTDOWN)
+ return 0;
+
+ dev->retries++;
+ clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
+ if (dev->set_next_event((unsigned long) clc, dev) == 0)
+ return 0;
+
+ if (++i > 2) {
+ /*
+ * We tried 3 times to program the device with the
+ * given min_delta_ns. Try to increase the minimum
+ * delta, if that fails as well get out of here.
+ */
+ if (clockevents_increase_min_delta(dev))
+ return -ETIME;
+ i = 0;
+ }
+ }
+}
+
+#else /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */
+
+/**
+ * clockevents_program_min_delta - Set clock event device to the minimum delay.
+ * @dev: device to program
+ *
+ * Returns 0 on success, -ETIME when the retry loop failed.
+ */
+static int clockevents_program_min_delta(struct clock_event_device *dev)
+{
+ unsigned long long clc;
+ int64_t delta;
+
+ delta = dev->min_delta_ns;
+ dev->next_event = ktime_add_ns(ktime_get(), delta);
+
+ if (dev->state == CLOCK_EVT_STATE_SHUTDOWN)
+ return 0;
+
+ dev->retries++;
+ clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
+ return dev->set_next_event((unsigned long) clc, dev);
+}
+
+#endif /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */
+
+/**
+ * clockevents_program_event - Reprogram the clock event device.
+ * @dev: device to program
+ * @expires: absolute expiry time (monotonic clock)
+ * @force: program minimum delay if expires can not be set
+ *
+ * Returns 0 on success, -ETIME when the event is in the past.
+ */
+int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
+ bool force)
+{
+ unsigned long long clc;
+ int64_t delta;
+ int rc;
+
+ if (unlikely(expires.tv64 < 0)) {
+ WARN_ON_ONCE(1);
+ return -ETIME;
+ }
+
+ dev->next_event = expires;
+
+ if (dev->state == CLOCK_EVT_STATE_SHUTDOWN)
+ return 0;
+
+ /* Shortcut for clockevent devices that can deal with ktime. */
+ if (dev->features & CLOCK_EVT_FEAT_KTIME)
+ return dev->set_next_ktime(expires, dev);
+
+ delta = ktime_to_ns(ktime_sub(expires, ktime_get()));
+ if (delta <= 0)
+ return force ? clockevents_program_min_delta(dev) : -ETIME;
+
+ delta = min(delta, (int64_t) dev->max_delta_ns);
+ delta = max(delta, (int64_t) dev->min_delta_ns);
+
+ clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
+ rc = dev->set_next_event((unsigned long) clc, dev);
+
+ return (rc && force) ? clockevents_program_min_delta(dev) : rc;
+}
+
+/*
+ * Called after a notify add to make devices available which were
+ * released from the notifier call.
+ */
+static void clockevents_notify_released(void)
+{
+ struct clock_event_device *dev;
+
+ 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);
+ }
+}
+
+/*
+ * 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->state != CLOCK_EVT_STATE_DETACHED)
+ 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;
+}
+
+/*
+ * Called with clockevents_mutex and clockevents_lock held
+ */
+static int __clockevents_try_unbind(struct clock_event_device *ced, int cpu)
+{
+ /* Fast track. Device is unused */
+ if (ced->state == CLOCK_EVT_STATE_DETACHED) {
+ list_del_init(&ced->list);
+ return 0;
+ }
+
+ return ced == per_cpu(tick_cpu_device, cpu).evtdev ? -EAGAIN : -EBUSY;
+}
+
+/*
+ * SMP function call to unbind a device
+ */
+static void __clockevents_unbind(void *arg)
+{
+ 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);
+}
+
+/*
+ * 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_device);
+
+/* Sanity check of state transition callbacks */
+static int clockevents_sanity_check(struct clock_event_device *dev)
+{
+ /* Legacy set_mode() callback */
+ if (dev->set_mode) {
+ /* We shouldn't be supporting new modes now */
+ WARN_ON(dev->set_state_periodic || dev->set_state_oneshot ||
+ dev->set_state_shutdown || dev->tick_resume);
+
+ BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
+ return 0;
+ }
+
+ if (dev->features & CLOCK_EVT_FEAT_DUMMY)
+ return 0;
+
+ /* New state-specific callbacks */
+ if (!dev->set_state_shutdown)
+ return -EINVAL;
+
+ if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
+ !dev->set_state_periodic)
+ return -EINVAL;
+
+ if ((dev->features & CLOCK_EVT_FEAT_ONESHOT) &&
+ !dev->set_state_oneshot)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * clockevents_register_device - register a clock event device
+ * @dev: device to register
+ */
+void clockevents_register_device(struct clock_event_device *dev)
+{
+ unsigned long flags;
+
+ BUG_ON(clockevents_sanity_check(dev));
+
+ /* Initialize state to DETACHED */
+ dev->state = CLOCK_EVT_STATE_DETACHED;
+
+ if (!dev->cpumask) {
+ WARN_ON(num_possible_cpus() > 1);
+ dev->cpumask = cpumask_of(smp_processor_id());
+ }
+
+ raw_spin_lock_irqsave(&clockevents_lock, flags);
+
+ list_add(&dev->list, &clockevent_devices);
+ tick_check_new_device(dev);
+ clockevents_notify_released();
+
+ raw_spin_unlock_irqrestore(&clockevents_lock, flags);
+}
+EXPORT_SYMBOL_GPL(clockevents_register_device);
+
+void clockevents_config(struct clock_event_device *dev, u32 freq)
+{
+ u64 sec;
+
+ if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT))
+ return;
+
+ /*
+ * Calculate the maximum number of seconds we can sleep. Limit
+ * to 10 minutes for hardware which can program more than
+ * 32bit ticks so we still get reasonable conversion values.
+ */
+ sec = dev->max_delta_ticks;
+ do_div(sec, freq);
+ if (!sec)
+ sec = 1;
+ else if (sec > 600 && dev->max_delta_ticks > UINT_MAX)
+ sec = 600;
+
+ clockevents_calc_mult_shift(dev, freq, sec);
+ dev->min_delta_ns = cev_delta2ns(dev->min_delta_ticks, dev, false);
+ dev->max_delta_ns = cev_delta2ns(dev->max_delta_ticks, dev, true);
+}
+
+/**
+ * clockevents_config_and_register - Configure and register a clock event device
+ * @dev: device to register
+ * @freq: The clock frequency
+ * @min_delta: The minimum clock ticks to program in oneshot mode
+ * @max_delta: The maximum clock ticks to program in oneshot mode
+ *
+ * min/max_delta can be 0 for devices which do not support oneshot mode.
+ */
+void clockevents_config_and_register(struct clock_event_device *dev,
+ u32 freq, unsigned long min_delta,
+ unsigned long max_delta)
+{
+ dev->min_delta_ticks = min_delta;
+ dev->max_delta_ticks = max_delta;
+ clockevents_config(dev, freq);
+ clockevents_register_device(dev);
+}
+EXPORT_SYMBOL_GPL(clockevents_config_and_register);
+
+int __clockevents_update_freq(struct clock_event_device *dev, u32 freq)
+{
+ clockevents_config(dev, freq);
+
+ if (dev->state == CLOCK_EVT_STATE_ONESHOT)
+ return clockevents_program_event(dev, dev->next_event, false);
+
+ if (dev->state == CLOCK_EVT_STATE_PERIODIC)
+ return __clockevents_set_state(dev, CLOCK_EVT_STATE_PERIODIC);
+
+ return 0;
+}
+
+/**
+ * clockevents_update_freq - Update frequency and reprogram a clock event device.
+ * @dev: device to modify
+ * @freq: new device frequency
+ *
+ * Reconfigure and reprogram a clock event device in oneshot
+ * mode. Must be called on the cpu for which the device delivers per
+ * cpu timer events. If called for the broadcast device the core takes
+ * care of serialization.
+ *
+ * Returns 0 on success, -ETIME when the event is in the past.
+ */
+int clockevents_update_freq(struct clock_event_device *dev, u32 freq)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+ ret = tick_broadcast_update_freq(dev, freq);
+ if (ret == -ENODEV)
+ ret = __clockevents_update_freq(dev, freq);
+ local_irq_restore(flags);
+ return ret;
+}
+
+/*
+ * Noop handler when we shut down an event device
+ */
+void clockevents_handle_noop(struct clock_event_device *dev)
+{
+}
+
+/**
+ * clockevents_exchange_device - release and request clock devices
+ * @old: device to release (can be NULL)
+ * @new: device to request (can be NULL)
+ *
+ * Called from various tick functions with clockevents_lock held and
+ * interrupts disabled.
+ */
+void clockevents_exchange_device(struct clock_event_device *old,
+ struct clock_event_device *new)
+{
+ /*
+ * Caller releases a clock event device. We queue it into the
+ * released list and do a notify add later.
+ */
+ if (old) {
+ module_put(old->owner);
+ clockevents_set_state(old, CLOCK_EVT_STATE_DETACHED);
+ list_del(&old->list);
+ list_add(&old->list, &clockevents_released);
+ }
+
+ if (new) {
+ BUG_ON(new->state != CLOCK_EVT_STATE_DETACHED);
+ clockevents_shutdown(new);
+ }
+}
+
+/**
+ * clockevents_suspend - suspend clock devices
+ */
+void clockevents_suspend(void)
+{
+ struct clock_event_device *dev;
+
+ list_for_each_entry_reverse(dev, &clockevent_devices, list)
+ if (dev->suspend)
+ dev->suspend(dev);
+}
+
+/**
+ * clockevents_resume - resume clock devices
+ */
+void clockevents_resume(void)
+{
+ struct clock_event_device *dev;
+
+ list_for_each_entry(dev, &clockevent_devices, list)
+ if (dev->resume)
+ dev->resume(dev);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+/**
+ * tick_cleanup_dead_cpu - Cleanup the tick and clockevents of a dead cpu
+ */
+void tick_cleanup_dead_cpu(int cpu)
+{
+ struct clock_event_device *dev, *tmp;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&clockevents_lock, flags);
+
+ tick_shutdown_broadcast_oneshot(cpu);
+ tick_shutdown_broadcast(cpu);
+ tick_shutdown(cpu);
+ /*
+ * Unregister the clock event devices which were
+ * released from the users in the notify chain.
+ */
+ list_for_each_entry_safe(dev, tmp, &clockevents_released, list)
+ list_del(&dev->list);
+ /*
+ * Now check whether the CPU has left unused per cpu devices
+ */
+ list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) {
+ if (cpumask_test_cpu(cpu, dev->cpumask) &&
+ cpumask_weight(dev->cpumask) == 1 &&
+ !tick_is_broadcast_device(dev)) {
+ BUG_ON(dev->state != CLOCK_EVT_STATE_DETACHED);
+ list_del(&dev->list);
+ }
+ }
+ raw_spin_unlock_irqrestore(&clockevents_lock, flags);
+}
+#endif
+
+#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];
+ ssize_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 */
Code Review / kvmfornfv.git / blobdiff