| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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 |
| */ |
| |
| #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 (WARN_ON(!evt->mult)) |
| evt->mult = 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_switch_state(struct clock_event_device *dev, |
| enum clock_event_state state) |
| { |
| 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: |
| if (dev->set_state_shutdown) |
| return dev->set_state_shutdown(dev); |
| return 0; |
| |
| case CLOCK_EVT_STATE_PERIODIC: |
| /* Core internal bug */ |
| if (!(dev->features & CLOCK_EVT_FEAT_PERIODIC)) |
| return -ENOSYS; |
| if (dev->set_state_periodic) |
| return dev->set_state_periodic(dev); |
| return 0; |
| |
| case CLOCK_EVT_STATE_ONESHOT: |
| /* Core internal bug */ |
| if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) |
| return -ENOSYS; |
| if (dev->set_state_oneshot) |
| return dev->set_state_oneshot(dev); |
| return 0; |
| |
| case CLOCK_EVT_STATE_ONESHOT_STOPPED: |
| /* Core internal bug */ |
| if (WARN_ONCE(!clockevent_state_oneshot(dev), |
| "Current state: %d\n", |
| clockevent_get_state(dev))) |
| return -EINVAL; |
| |
| if (dev->set_state_oneshot_stopped) |
| return dev->set_state_oneshot_stopped(dev); |
| else |
| return -ENOSYS; |
| |
| default: |
| return -ENOSYS; |
| } |
| } |
| |
| /** |
| * clockevents_switch_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_switch_state(struct clock_event_device *dev, |
| enum clock_event_state state) |
| { |
| if (clockevent_get_state(dev) != state) { |
| if (__clockevents_switch_state(dev, state)) |
| return; |
| |
| clockevent_set_state(dev, state); |
| |
| /* |
| * A nsec2cyc multiplicator of 0 is invalid and we'd crash |
| * on it, so fix it up and emit a warning: |
| */ |
| if (clockevent_state_oneshot(dev)) { |
| if (WARN_ON(!dev->mult)) |
| dev->mult = 1; |
| } |
| } |
| } |
| |
| /** |
| * clockevents_shutdown - shutdown the device and clear next_event |
| * @dev: device to shutdown |
| */ |
| void clockevents_shutdown(struct clock_event_device *dev) |
| { |
| clockevents_switch_state(dev, CLOCK_EVT_STATE_SHUTDOWN); |
| dev->next_event = 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->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 = 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 (clockevent_state_shutdown(dev)) |
| 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 = 0; |
| int i; |
| |
| for (i = 0; i < 10; i++) { |
| delta += dev->min_delta_ns; |
| dev->next_event = ktime_add_ns(ktime_get(), delta); |
| |
| if (clockevent_state_shutdown(dev)) |
| 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; |
| } |
| return -ETIME; |
| } |
| |
| #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 (WARN_ON_ONCE(expires < 0)) |
| return -ETIME; |
| |
| dev->next_event = expires; |
| |
| if (clockevent_state_shutdown(dev)) |
| return 0; |
| |
| /* We must be in ONESHOT state here */ |
| WARN_ONCE(!clockevent_state_oneshot(dev), "Current state: %d\n", |
| clockevent_get_state(dev)); |
| |
| /* 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 || !clockevent_state_detached(dev)) |
| 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 (clockevent_state_detached(ced)) { |
| 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); |
| |
| /** |
| * clockevents_register_device - register a clock event device |
| * @dev: device to register |
| */ |
| void clockevents_register_device(struct clock_event_device *dev) |
| { |
| unsigned long flags; |
| |
| /* Initialize state to DETACHED */ |
| clockevent_set_state(dev, CLOCK_EVT_STATE_DETACHED); |
| |
| if (!dev->cpumask) { |
| WARN_ON(num_possible_cpus() > 1); |
| dev->cpumask = cpumask_of(smp_processor_id()); |
| } |
| |
| if (dev->cpumask == cpu_all_mask) { |
| WARN(1, "%s cpumask == cpu_all_mask, using cpu_possible_mask instead\n", |
| dev->name); |
| dev->cpumask = cpu_possible_mask; |
| } |
| |
| 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); |
| |
| static 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 (clockevent_state_oneshot(dev)) |
| return clockevents_program_event(dev, dev->next_event, false); |
| |
| if (clockevent_state_periodic(dev)) |
| return __clockevents_switch_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_switch_state(old, CLOCK_EVT_STATE_DETACHED); |
| list_del(&old->list); |
| list_add(&old->list, &clockevents_released); |
| } |
| |
| if (new) { |
| BUG_ON(!clockevent_state_detached(new)); |
| 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 && !clockevent_state_detached(dev)) |
| 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 && !clockevent_state_detached(dev)) |
| 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(!clockevent_state_detached(dev)); |
| list_del(&dev->list); |
| } |
| } |
| raw_spin_unlock_irqrestore(&clockevents_lock, flags); |
| } |
| #endif |
| |
| #ifdef CONFIG_SYSFS |
| static 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 */ |