clockevents.c revision 1b054b67d3bfc6dca9f634c104780f3f24ff3eec
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 228e1a928a2ed7e8d5cad97c8e985294b4caedd168H Hartley Sweeten#include "tick-internal.h" 238e1a928a2ed7e8d5cad97c8e985294b4caedd168H Hartley Sweeten 24d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* The registered clock event devices */ 25d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic LIST_HEAD(clockevent_devices); 26d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic LIST_HEAD(clockevents_released); 27d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 28d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* Notification for clock events */ 29d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic RAW_NOTIFIER_HEAD(clockevents_chain); 30d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 31d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* Protection for the above */ 32b5f91da0a6973bb6f9ff3b91b0e92c0773a458f3Thomas Gleixnerstatic DEFINE_RAW_SPINLOCK(clockevents_lock); 33d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 34d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 35d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds 36d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @latch: value to convert 37d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @evt: pointer to clock event device descriptor 38d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 39d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Math helper, returns latch value converted to nanoseconds (bound checked) 40d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 4197813f2fe77804a4464564c75ba8d8826377feeaJon Hunteru64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt) 42d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 4397813f2fe77804a4464564c75ba8d8826377feeaJon Hunter u64 clc = (u64) latch << evt->shift; 44d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 4545fe4fe19120a22f7339f5bb110447170c25fca9Ingo Molnar if (unlikely(!evt->mult)) { 4645fe4fe19120a22f7339f5bb110447170c25fca9Ingo Molnar evt->mult = 1; 4745fe4fe19120a22f7339f5bb110447170c25fca9Ingo Molnar WARN_ON(1); 4845fe4fe19120a22f7339f5bb110447170c25fca9Ingo Molnar } 4945fe4fe19120a22f7339f5bb110447170c25fca9Ingo Molnar 50d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner do_div(clc, evt->mult); 51d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (clc < 1000) 52d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clc = 1000; 5397813f2fe77804a4464564c75ba8d8826377feeaJon Hunter if (clc > KTIME_MAX) 5497813f2fe77804a4464564c75ba8d8826377feeaJon Hunter clc = KTIME_MAX; 55d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 5697813f2fe77804a4464564c75ba8d8826377feeaJon Hunter return clc; 57d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 58c81fc2c331b8514ad112054cd2d87e6ec132286bMagnus DammEXPORT_SYMBOL_GPL(clockevent_delta2ns); 59d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 60d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 61d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_set_mode - set the operating mode of a clock event device 62d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @dev: device to modify 63d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @mode: new mode 64d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 65d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Must be called with interrupts disabled ! 66d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 67d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_set_mode(struct clock_event_device *dev, 68d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner enum clock_event_mode mode) 69d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 70d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (dev->mode != mode) { 71d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev->set_mode(mode, dev); 72d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev->mode = mode; 732d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm 742d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm /* 752d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm * A nsec2cyc multiplicator of 0 is invalid and we'd crash 762d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm * on it, so fix it up and emit a warning: 772d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm */ 782d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm if (mode == CLOCK_EVT_MODE_ONESHOT) { 792d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm if (unlikely(!dev->mult)) { 802d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm dev->mult = 1; 812d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm WARN_ON(1); 822d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm } 832d68259db26ad57fd9643f1c69b5181ec9836ca9Magnus Damm } 84d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 85d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 86d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 87d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 882344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner * clockevents_shutdown - shutdown the device and clear next_event 892344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner * @dev: device to shutdown 902344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner */ 912344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixnervoid clockevents_shutdown(struct clock_event_device *dev) 922344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner{ 932344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); 942344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner dev->next_event.tv64 = KTIME_MAX; 952344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner} 962344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner 972344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner/** 98d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_program_event - Reprogram the clock event device. 99d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @expires: absolute expiry time (monotonic clock) 100d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 101d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Returns 0 on success, -ETIME when the event is in the past. 102d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 103d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerint clockevents_program_event(struct clock_event_device *dev, ktime_t expires, 104d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner ktime_t now) 105d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 106d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner unsigned long long clc; 107d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner int64_t delta; 108d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 109167b1de3ee4e50d65a2bd0a2667c9cd48faf54f3Thomas Gleixner if (unlikely(expires.tv64 < 0)) { 110167b1de3ee4e50d65a2bd0a2667c9cd48faf54f3Thomas Gleixner WARN_ON_ONCE(1); 111167b1de3ee4e50d65a2bd0a2667c9cd48faf54f3Thomas Gleixner return -ETIME; 112167b1de3ee4e50d65a2bd0a2667c9cd48faf54f3Thomas Gleixner } 113167b1de3ee4e50d65a2bd0a2667c9cd48faf54f3Thomas Gleixner 114d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner delta = ktime_to_ns(ktime_sub(expires, now)); 115d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 116d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (delta <= 0) 117d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return -ETIME; 118d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 119d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev->next_event = expires; 120d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 121d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) 122d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return 0; 123d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 124d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (delta > dev->max_delta_ns) 125d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner delta = dev->max_delta_ns; 126d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (delta < dev->min_delta_ns) 127d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner delta = dev->min_delta_ns; 128d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 129d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clc = delta * dev->mult; 130d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clc >>= dev->shift; 131d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 132d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return dev->set_next_event((unsigned long) clc, dev); 133d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 134d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 135d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 136d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_register_notifier - register a clock events change listener 137d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 138d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerint clockevents_register_notifier(struct notifier_block *nb) 139d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 140f833bab87fca5c3ce13778421b1365845843b976Suresh Siddha unsigned long flags; 141d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner int ret; 142d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 143b5f91da0a6973bb6f9ff3b91b0e92c0773a458f3Thomas Gleixner raw_spin_lock_irqsave(&clockevents_lock, flags); 144d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner ret = raw_notifier_chain_register(&clockevents_chain, nb); 145b5f91da0a6973bb6f9ff3b91b0e92c0773a458f3Thomas Gleixner raw_spin_unlock_irqrestore(&clockevents_lock, flags); 146d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 147d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner return ret; 148d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 149d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 150d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 151d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Notify about a clock event change. Called with clockevents_lock 152d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * held. 153d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 154d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic void clockevents_do_notify(unsigned long reason, void *dev) 155d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 156d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner raw_notifier_call_chain(&clockevents_chain, reason, dev); 157d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 158d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 159d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 1603eb056764dd806bbe84eb604e45e7470feeaafd8Li Zefan * Called after a notify add to make devices available which were 161d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * released from the notifier call. 162d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 163d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnerstatic void clockevents_notify_released(void) 164d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 165d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *dev; 166d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 167d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner while (!list_empty(&clockevents_released)) { 168d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner dev = list_entry(clockevents_released.next, 169d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device, list); 170d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_del(&dev->list); 171d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_add(&dev->list, &clockevent_devices); 172d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); 173d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 174d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 175d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 176d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 177d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_register_device - register a clock event device 178d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @dev: device to register 179d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 180d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_register_device(struct clock_event_device *dev) 181d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 182f833bab87fca5c3ce13778421b1365845843b976Suresh Siddha unsigned long flags; 183f833bab87fca5c3ce13778421b1365845843b976Suresh Siddha 184d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); 1851b054b67d3bfc6dca9f634c104780f3f24ff3eecThomas Gleixner if (!dev->cpumask) { 1861b054b67d3bfc6dca9f634c104780f3f24ff3eecThomas Gleixner WARN_ON(num_possible_cpus() > 1); 1871b054b67d3bfc6dca9f634c104780f3f24ff3eecThomas Gleixner dev->cpumask = cpumask_of(smp_processor_id()); 1881b054b67d3bfc6dca9f634c104780f3f24ff3eecThomas Gleixner } 189320ab2b0b1e08e3805a3e1084a2f0eb1938d5d67Rusty Russell 190b5f91da0a6973bb6f9ff3b91b0e92c0773a458f3Thomas Gleixner raw_spin_lock_irqsave(&clockevents_lock, flags); 191d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 192d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_add(&dev->list, &clockevent_devices); 193d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); 194d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_notify_released(); 195d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 196b5f91da0a6973bb6f9ff3b91b0e92c0773a458f3Thomas Gleixner raw_spin_unlock_irqrestore(&clockevents_lock, flags); 197d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 198c81fc2c331b8514ad112054cd2d87e6ec132286bMagnus DammEXPORT_SYMBOL_GPL(clockevents_register_device); 199d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 20057f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixnerstatic void clockevents_config(struct clock_event_device *dev, 20157f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner u32 freq) 20257f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner{ 203c0e299b1a91cbdb21ae08e382a4176200398bc36Thomas Gleixner u64 sec; 20457f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner 20557f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) 20657f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner return; 20757f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner 20857f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner /* 20957f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * Calculate the maximum number of seconds we can sleep. Limit 21057f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * to 10 minutes for hardware which can program more than 21157f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * 32bit ticks so we still get reasonable conversion values. 21257f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner */ 21357f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner sec = dev->max_delta_ticks; 21457f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner do_div(sec, freq); 21557f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner if (!sec) 21657f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner sec = 1; 21757f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner else if (sec > 600 && dev->max_delta_ticks > UINT_MAX) 21857f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner sec = 600; 21957f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner 22057f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner clockevents_calc_mult_shift(dev, freq, sec); 22157f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner dev->min_delta_ns = clockevent_delta2ns(dev->min_delta_ticks, dev); 22257f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner dev->max_delta_ns = clockevent_delta2ns(dev->max_delta_ticks, dev); 22357f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner} 22457f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner 22557f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner/** 22657f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * clockevents_config_and_register - Configure and register a clock event device 22757f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * @dev: device to register 22857f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * @freq: The clock frequency 22957f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * @min_delta: The minimum clock ticks to program in oneshot mode 23057f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * @max_delta: The maximum clock ticks to program in oneshot mode 23157f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * 23257f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner * min/max_delta can be 0 for devices which do not support oneshot mode. 23357f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner */ 23457f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixnervoid clockevents_config_and_register(struct clock_event_device *dev, 23557f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner u32 freq, unsigned long min_delta, 23657f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner unsigned long max_delta) 23757f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner{ 23857f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner dev->min_delta_ticks = min_delta; 23957f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner dev->max_delta_ticks = max_delta; 24057f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner clockevents_config(dev, freq); 24157f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner clockevents_register_device(dev); 24257f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner} 24357f0fcbe1dea8a36c9d1673086326059991c5f81Thomas Gleixner 24480b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner/** 24580b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * clockevents_update_freq - Update frequency and reprogram a clock event device. 24680b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * @dev: device to modify 24780b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * @freq: new device frequency 24880b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * 24980b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * Reconfigure and reprogram a clock event device in oneshot 25080b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * mode. Must be called on the cpu for which the device delivers per 25180b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * cpu timer events with interrupts disabled! Returns 0 on success, 25280b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner * -ETIME when the event is in the past. 25380b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner */ 25480b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixnerint clockevents_update_freq(struct clock_event_device *dev, u32 freq) 25580b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner{ 25680b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner clockevents_config(dev, freq); 25780b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner 25880b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner if (dev->mode != CLOCK_EVT_MODE_ONESHOT) 25980b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner return 0; 26080b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner 26180b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner return clockevents_program_event(dev, dev->next_event, ktime_get()); 26280b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner} 26380b816b736cfa5b9582279127099b20a479ab7d9Thomas Gleixner 264d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/* 265d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Noop handler when we shut down an event device 266d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 2677c1e76897492d92b6a1c2d6892494d39ded9680cVenkatesh Pallipadivoid clockevents_handle_noop(struct clock_event_device *dev) 268d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 269d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 270d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 271d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 272d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_exchange_device - release and request clock devices 273d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @old: device to release (can be NULL) 274d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * @new: device to request (can be NULL) 275d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * 276d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Called from the notifier chain. clockevents_lock is held already 277d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 278d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_exchange_device(struct clock_event_device *old, 279d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner struct clock_event_device *new) 280d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 281d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner unsigned long flags; 282d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 283d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner local_irq_save(flags); 284d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner /* 285d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Caller releases a clock event device. We queue it into the 286d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * released list and do a notify add later. 287d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 288d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (old) { 289d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED); 290d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_del(&old->list); 291d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner list_add(&old->list, &clockevents_released); 292d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 293d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 294d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner if (new) { 295d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED); 2962344abbcbdb82140050e8be29d3d55e4f6fe860bThomas Gleixner clockevents_shutdown(new); 297d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 298d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner local_irq_restore(flags); 299d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 300d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 301de68d9b173ee657115dd0e584c2365b7954253a5Thomas Gleixner#ifdef CONFIG_GENERIC_CLOCKEVENTS 302d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner/** 303d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * clockevents_notify - notification about relevant events 304d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 305d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixnervoid clockevents_notify(unsigned long reason, void *arg) 306d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner{ 307bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner struct clock_event_device *dev, *tmp; 308f833bab87fca5c3ce13778421b1365845843b976Suresh Siddha unsigned long flags; 309bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner int cpu; 3100b858e6ff9a38b987a83d22e6f2a2f621c80608dLi Zefan 311b5f91da0a6973bb6f9ff3b91b0e92c0773a458f3Thomas Gleixner raw_spin_lock_irqsave(&clockevents_lock, flags); 312d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner clockevents_do_notify(reason, arg); 313d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner 314d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner switch (reason) { 315d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner case CLOCK_EVT_NOTIFY_CPU_DEAD: 316d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner /* 317d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * Unregister the clock event devices which were 318d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner * released from the users in the notify chain. 319d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner */ 320bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner list_for_each_entry_safe(dev, tmp, &clockevents_released, list) 321bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner list_del(&dev->list); 322bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner /* 323bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner * Now check whether the CPU has left unused per cpu devices 324bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner */ 325bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner cpu = *((int *)arg); 326bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) { 327bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner if (cpumask_test_cpu(cpu, dev->cpumask) && 328ea9d8e3f45404d411c00ae67b45cc35c58265bb7Xiaotian Feng cpumask_weight(dev->cpumask) == 1 && 329ea9d8e3f45404d411c00ae67b45cc35c58265bb7Xiaotian Feng !tick_is_broadcast_device(dev)) { 330bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); 331bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner list_del(&dev->list); 332bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner } 333bb6eddf7676e1c1f3e637aa93c5224488d99036fThomas Gleixner } 334d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner break; 335d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner default: 336d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner break; 337d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner } 338b5f91da0a6973bb6f9ff3b91b0e92c0773a458f3Thomas Gleixner raw_spin_unlock_irqrestore(&clockevents_lock, flags); 339d316c57ff6bfad9557462b9100f25c6260d2b774Thomas Gleixner} 340d316c57ff6bfad9557462b9100f25c6260d2b774Thomas GleixnerEXPORT_SYMBOL_GPL(clockevents_notify); 341de68d9b173ee657115dd0e584c2365b7954253a5Thomas Gleixner#endif 342