clockevents.c revision d316c57ff6bfad9557462b9100f25c6260d2b774
1d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 2d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * linux/kernel/time/clockevents.c 3d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 4d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * This file contains functions which manage clock event devices. 5d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 6d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> 7d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar 8d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner 9d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 10d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * This code is licenced under the GPL version 2. For details see 11d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * kernel-base/COPYING. 12d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 13d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 14d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#include <linux/clockchips.h> 15d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#include <linux/hrtimer.h> 16d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#include <linux/init.h> 17d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#include <linux/module.h> 18d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#include <linux/notifier.h> 19d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#include <linux/smp.h> 20d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#include <linux/sysdev.h> 21d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 22d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* The registered clock event devices */ 23d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic LIST_HEAD(clockevent_devices); 24d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic LIST_HEAD(clockevents_released); 25d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 26d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* Notification for clock events */ 27d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic RAW_NOTIFIER_HEAD(clockevents_chain); 28d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 29d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* Protection for the above */ 30d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic DEFINE_SPINLOCK(clockevents_lock); 31d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 32d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 33d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds 34d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @latch: value to convert 35d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @evt: pointer to clock event device descriptor 36d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 37d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Math helper, returns latch value converted to nanoseconds (bound checked) 38d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 39d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerunsigned long clockevent_delta2ns(unsigned long latch, 40d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *evt) 41d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 42d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner u64 clc = ((u64) latch << evt->shift); 43d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 44d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner do_div(clc, evt->mult); 45d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (clc < 1000) 46d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clc = 1000; 47d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (clc > LONG_MAX) 48d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clc = LONG_MAX; 49d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 50d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return (unsigned long) clc; 51d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 52d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 53d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 54d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_set_mode - set the operating mode of a clock event device 55d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @dev: device to modify 56d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @mode: new mode 57d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 58d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Must be called with interrupts disabled ! 59d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 60d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_set_mode(struct clock_event_device *dev, 61d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner enum clock_event_mode mode) 62d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 63d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (dev->mode != mode) { 64d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev->set_mode(mode, dev); 65d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev->mode = mode; 66d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 67d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 68d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 69d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 70d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_program_event - Reprogram the clock event device. 71d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @expires: absolute expiry time (monotonic clock) 72d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 73d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Returns 0 on success, -ETIME when the event is in the past. 74d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 75d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerint clockevents_program_event(struct clock_event_device *dev, ktime_t expires, 76d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner ktime_t now) 77d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 78d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner unsigned long long clc; 79d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner int64_t delta; 80d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 81d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner delta = ktime_to_ns(ktime_sub(expires, now)); 82d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 83d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (delta <= 0) 84d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return -ETIME; 85d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 86d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev->next_event = expires; 87d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 88d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) 89d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return 0; 90d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 91d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (delta > dev->max_delta_ns) 92d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner delta = dev->max_delta_ns; 93d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (delta < dev->min_delta_ns) 94d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner delta = dev->min_delta_ns; 95d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 96d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clc = delta * dev->mult; 97d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clc >>= dev->shift; 98d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 99d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return dev->set_next_event((unsigned long) clc, dev); 100d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 101d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 102d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 103d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_register_notifier - register a clock events change listener 104d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 105d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerint clockevents_register_notifier(struct notifier_block *nb) 106d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 107d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner int ret; 108d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 109d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_lock(&clockevents_lock); 110d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner ret = raw_notifier_chain_register(&clockevents_chain, nb); 111d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_unlock(&clockevents_lock); 112d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 113d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return ret; 114d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 115d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 116d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 117d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_unregister_notifier - unregister a clock events change listener 118d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 119d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_unregister_notifier(struct notifier_block *nb) 120d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 121d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_lock(&clockevents_lock); 122d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner raw_notifier_chain_unregister(&clockevents_chain, nb); 123d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_unlock(&clockevents_lock); 124d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 125d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 126d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 127d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Notify about a clock event change. Called with clockevents_lock 128d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * held. 129d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 130d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic void clockevents_do_notify(unsigned long reason, void *dev) 131d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 132d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner raw_notifier_call_chain(&clockevents_chain, reason, dev); 133d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 134d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 135d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 136d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Called after a notify add to make devices availble which were 137d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * released from the notifier call. 138d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 139d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic void clockevents_notify_released(void) 140d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 141d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *dev; 142d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 143d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner while (!list_empty(&clockevents_released)) { 144d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev = list_entry(clockevents_released.next, 145d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device, list); 146d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_del(&dev->list); 147d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_add(&dev->list, &clockevent_devices); 148d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); 149d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 150d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 151d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 152d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 153d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_register_device - register a clock event device 154d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @dev: device to register 155d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 156d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_register_device(struct clock_event_device *dev) 157d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 158d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); 159d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 160d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_lock(&clockevents_lock); 161d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 162d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_add(&dev->list, &clockevent_devices); 163d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); 164d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_notify_released(); 165d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 166d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_unlock(&clockevents_lock); 167d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 168d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 169d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 170d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Noop handler when we shut down an event device 171d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 172d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic void clockevents_handle_noop(struct clock_event_device *dev) 173d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 174d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 175d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 176d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 177d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_exchange_device - release and request clock devices 178d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @old: device to release (can be NULL) 179d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @new: device to request (can be NULL) 180d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 181d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Called from the notifier chain. clockevents_lock is held already 182d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 183d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_exchange_device(struct clock_event_device *old, 184d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *new) 185d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 186d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner unsigned long flags; 187d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 188d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner local_irq_save(flags); 189d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner /* 190d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Caller releases a clock event device. We queue it into the 191d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * released list and do a notify add later. 192d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 193d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (old) { 194d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner old->event_handler = clockevents_handle_noop; 195d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED); 196d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_del(&old->list); 197d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_add(&old->list, &clockevents_released); 198d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 199d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 200d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (new) { 201d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED); 202d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN); 203d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 204d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner local_irq_restore(flags); 205d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 206d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 207d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 208d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_request_device 209d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 210d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstruct clock_event_device *clockevents_request_device(unsigned int features, 211d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner cpumask_t cpumask) 212d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 213d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *cur, *dev = NULL; 214d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct list_head *tmp; 215d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 216d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_lock(&clockevents_lock); 217d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 218d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_for_each(tmp, &clockevent_devices) { 219d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner cur = list_entry(tmp, struct clock_event_device, list); 220d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 221d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if ((cur->features & features) == features && 222d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner cpus_equal(cpumask, cur->cpumask)) { 223d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (!dev || dev->rating < cur->rating) 224d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev = cur; 225d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 226d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 227d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 228d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_exchange_device(NULL, dev); 229d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 230d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_unlock(&clockevents_lock); 231d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 232d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return dev; 233d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 234d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 235d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 236d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_release_device 237d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 238d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_release_device(struct clock_event_device *dev) 239d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 240d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_lock(&clockevents_lock); 241d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 242d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_exchange_device(dev, NULL); 243d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_notify_released(); 244d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 245d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_unlock(&clockevents_lock); 246d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 247d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 248d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 249d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_notify - notification about relevant events 250d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 251d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_notify(unsigned long reason, void *arg) 252d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 253d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_lock(&clockevents_lock); 254d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_do_notify(reason, arg); 255d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 256d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner switch (reason) { 257d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner case CLOCK_EVT_NOTIFY_CPU_DEAD: 258d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner /* 259d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Unregister the clock event devices which were 260d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * released from the users in the notify chain. 261d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 262d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner while (!list_empty(&clockevents_released)) { 263d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *dev; 264d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 265d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev = list_entry(clockevents_released.next, 266d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device, list); 267d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_del(&dev->list); 268d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 269d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner break; 270d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner default: 271d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner break; 272d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 273d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_unlock(&clockevents_lock); 274d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 275d316c57ff6bfad9557462b9100f25c6260d2b774Thomas GleixnerEXPORT_SYMBOL_GPL(clockevents_notify); 276d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 277d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#ifdef CONFIG_SYSFS 278d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 279d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 280d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_show_registered - sysfs interface for listing clockevents 281d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @dev: unused 282d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @buf: char buffer to be filled with clock events list 283d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 284d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Provides sysfs interface for listing registered clock event devices 285d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 286d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic ssize_t clockevents_show_registered(struct sys_device *dev, char *buf) 287d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 288d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct list_head *tmp; 289d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner char *p = buf; 290d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner int cpu; 291d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 292d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_lock(&clockevents_lock); 293d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 294d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_for_each(tmp, &clockevent_devices) { 295d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *ce; 296d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 297d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner ce = list_entry(tmp, struct clock_event_device, list); 298d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner p += sprintf(p, "%-20s F:%04x M:%d", ce->name, 299d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner ce->features, ce->mode); 300d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner p += sprintf(p, " C:"); 301d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (!cpus_equal(ce->cpumask, cpu_possible_map)) { 302d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner for_each_cpu_mask(cpu, ce->cpumask) 303d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner p += sprintf(p, " %d", cpu); 304d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } else { 305d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner /* 306d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * FIXME: Add the cpu which is handling this sucker 307d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 308d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 309d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner p += sprintf(p, "\n"); 310d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 311d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 312d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner spin_unlock(&clockevents_lock); 313d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 314d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return p - buf; 315d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 316d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 317d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 318d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Sysfs setup bits: 319d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 320d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic SYSDEV_ATTR(registered, 0600, 321d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_show_registered, NULL); 322d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 323d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic struct sysdev_class clockevents_sysclass = { 324d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner set_kset_name("clockevents"), 325d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner}; 326d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 327d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic struct sys_device clockevents_sys_device = { 328d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner .id = 0, 329d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner .cls = &clockevents_sysclass, 330d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner}; 331d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 332d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic int __init clockevents_sysfs_init(void) 333d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 334d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner int error = sysdev_class_register(&clockevents_sysclass); 335d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 336d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (!error) 337d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner error = sysdev_register(&clockevents_sys_device); 338d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (!error) 339d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner error = sysdev_create_file( 340d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner &clockevents_sys_device, 341d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner &attr_registered); 342d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return error; 343d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 344d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerdevice_initcall(clockevents_sysfs_init); 345d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner#endif 346