diff options
| -rw-r--r-- | include/linux/clockchips.h | 142 | ||||
| -rw-r--r-- | include/linux/hrtimer.h | 5 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 13 | ||||
| -rw-r--r-- | kernel/time/Makefile | 2 | ||||
| -rw-r--r-- | kernel/time/clockevents.c | 345 | ||||
| -rw-r--r-- | kernel/timer.c | 4 |
6 files changed, 497 insertions, 14 deletions
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h new file mode 100644 index 000000000000..4ea7e7bcfafe --- /dev/null +++ b/include/linux/clockchips.h @@ -0,0 +1,142 @@ +/* linux/include/linux/clockchips.h + * + * This file contains the structure definitions for clockchips. + * + * If you are not a clockchip, or the time of day code, you should + * not be including this file! + */ +#ifndef _LINUX_CLOCKCHIPS_H +#define _LINUX_CLOCKCHIPS_H + +#ifdef CONFIG_GENERIC_CLOCKEVENTS + +#include <linux/clocksource.h> +#include <linux/cpumask.h> +#include <linux/ktime.h> +#include <linux/notifier.h> + +struct clock_event_device; + +/* Clock event mode commands */ +enum clock_event_mode { + CLOCK_EVT_MODE_UNUSED = 0, + CLOCK_EVT_MODE_SHUTDOWN, + CLOCK_EVT_MODE_PERIODIC, + CLOCK_EVT_MODE_ONESHOT, +}; + +/* Clock event notification values */ +enum clock_event_nofitiers { + CLOCK_EVT_NOTIFY_ADD, + CLOCK_EVT_NOTIFY_BROADCAST_ON, + CLOCK_EVT_NOTIFY_BROADCAST_OFF, + CLOCK_EVT_NOTIFY_BROADCAST_ENTER, + CLOCK_EVT_NOTIFY_BROADCAST_EXIT, + CLOCK_EVT_NOTIFY_SUSPEND, + CLOCK_EVT_NOTIFY_RESUME, + CLOCK_EVT_NOTIFY_CPU_DEAD, +}; + +/* + * Clock event features + */ +#define CLOCK_EVT_FEAT_PERIODIC 0x000001 +#define CLOCK_EVT_FEAT_ONESHOT 0x000002 +/* + * x86(64) specific misfeatures: + * + * - Clockevent source stops in C3 State and needs broadcast support. + * - Local APIC timer is used as a dummy device. + */ +#define CLOCK_EVT_FEAT_C3STOP 0x000004 +#define CLOCK_EVT_FEAT_DUMMY 0x000008 + +/** + * struct clock_event_device - clock event device descriptor + * @name: ptr to clock event name + * @hints: usage hints + * @max_delta_ns: maximum delta value in ns + * @min_delta_ns: minimum delta value in ns + * @mult: nanosecond to cycles multiplier + * @shift: nanoseconds to cycles divisor (power of two) + * @rating: variable to rate clock event devices + * @irq: irq number (only for non cpu local devices) + * @cpumask: cpumask to indicate for which cpus this device works + * @set_next_event: set next event + * @set_mode: set mode function + * @evthandler: Assigned by the framework to be called by the low + * level handler of the event source + * @broadcast: function to broadcast events + * @list: list head for the management code + * @mode: operating mode assigned by the management code + * @next_event: local storage for the next event in oneshot mode + */ +struct clock_event_device { + const char *name; + unsigned int features; + unsigned long max_delta_ns; + unsigned long min_delta_ns; + unsigned long mult; + int shift; + int rating; + int irq; + cpumask_t cpumask; + int (*set_next_event)(unsigned long evt, + struct clock_event_device *); + void (*set_mode)(enum clock_event_mode mode, + struct clock_event_device *); + void (*event_handler)(struct clock_event_device *); + void (*broadcast)(cpumask_t mask); + struct list_head list; + enum clock_event_mode mode; + ktime_t next_event; +}; + +/* + * Calculate a multiplication factor for scaled math, which is used to convert + * nanoseconds based values to clock ticks: + * + * clock_ticks = (nanoseconds * factor) >> shift. + * + * div_sc is the rearranged equation to calculate a factor from a given clock + * ticks / nanoseconds ratio: + * + * factor = (clock_ticks << shift) / nanoseconds + */ +static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec, + int shift) +{ + uint64_t tmp = ((uint64_t)ticks) << shift; + + do_div(tmp, nsec); + return (unsigned long) tmp; +} + +/* Clock event layer functions */ +extern unsigned long clockevent_delta2ns(unsigned long latch, + struct clock_event_device *evt); +extern void clockevents_register_device(struct clock_event_device *dev); + +extern void clockevents_exchange_device(struct clock_event_device *old, + struct clock_event_device *new); +extern +struct clock_event_device *clockevents_request_device(unsigned int features, + cpumask_t cpumask); +extern void clockevents_release_device(struct clock_event_device *dev); +extern void clockevents_set_mode(struct clock_event_device *dev, + enum clock_event_mode mode); +extern int clockevents_register_notifier(struct notifier_block *nb); +extern void clockevents_unregister_notifier(struct notifier_block *nb); +extern int clockevents_program_event(struct clock_event_device *dev, + ktime_t expires, ktime_t now); + +extern void clockevents_notify(unsigned long reason, void *arg); + +#else + +static inline void clockevents_resume_events(void) { } +#define clockevents_notify(reason, arg) do { } while (0) + +#endif + +#endif diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 9041405d0b71..a759636fd09f 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -144,6 +144,8 @@ struct hrtimer_cpu_base { * is expired in the next softirq when the clock was advanced. */ #define clock_was_set() do { } while (0) +extern ktime_t ktime_get(void); +extern ktime_t ktime_get_real(void); /* Exported timer functions: */ @@ -196,9 +198,6 @@ extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, /* Soft interrupt function to run the hrtimer queues: */ extern void hrtimer_run_queues(void); -/* Resume notification */ -void hrtimer_notify_resume(void); - /* Bootup initialization: */ extern void __init hrtimers_init(void); diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index eca0f5593a75..a2310d1bebe1 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -46,7 +46,7 @@ * * returns the time in ktime_t format */ -static ktime_t ktime_get(void) +ktime_t ktime_get(void) { struct timespec now; @@ -60,7 +60,7 @@ static ktime_t ktime_get(void) * * returns the time in ktime_t format */ -static ktime_t ktime_get_real(void) +ktime_t ktime_get_real(void) { struct timespec now; @@ -311,14 +311,6 @@ static unsigned long ktime_divns(const ktime_t kt, s64 div) #endif /* BITS_PER_LONG >= 64 */ /* - * Timekeeping resumed notification - */ -void hrtimer_notify_resume(void) -{ - clock_was_set(); -} - -/* * Counterpart to lock_timer_base above: */ static inline @@ -889,6 +881,7 @@ static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self, #ifdef CONFIG_HOTPLUG_CPU case CPU_DEAD: + clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu); migrate_hrtimers(cpu); break; #endif diff --git a/kernel/time/Makefile b/kernel/time/Makefile index 61a3907d16fb..2bf1805914d0 100644 --- a/kernel/time/Makefile +++ b/kernel/time/Makefile @@ -1 +1,3 @@ obj-y += ntp.o clocksource.o jiffies.o + +obj-$(CONFIG_GENERIC_CLOCKEVENTS) += clockevents.o diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c new file mode 100644 index 000000000000..67932ea78c17 --- /dev/null +++ b/kernel/time/clockevents.c @@ -0,0 +1,345 @@ +/* + * 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/notifier.h> +#include <linux/smp.h> +#include <linux/sysdev.h> + +/* The registered clock event devices */ +static LIST_HEAD(clockevent_devices); +static LIST_HEAD(clockevents_released); + +/* Notification for clock events */ +static RAW_NOTIFIER_HEAD(clockevents_chain); + +/* Protection for the above */ +static DEFINE_SPINLOCK(clockevents_lock); + +/** + * 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) + */ +unsigned long clockevent_delta2ns(unsigned long latch, + struct clock_event_device *evt) +{ + u64 clc = ((u64) latch << evt->shift); + + do_div(clc, evt->mult); + if (clc < 1000) + clc = 1000; + if (clc > LONG_MAX) + clc = LONG_MAX; + + return (unsigned long) clc; +} + +/** + * clockevents_set_mode - set the operating mode of a clock event device + * @dev: device to modify + * @mode: new mode + * + * Must be called with interrupts disabled ! + */ +void clockevents_set_mode(struct clock_event_device *dev, + enum clock_event_mode mode) +{ + if (dev->mode != mode) { + dev->set_mode(mode, dev); + dev->mode = mode; + } +} + +/** + * clockevents_program_event - Reprogram the clock event device. + * @expires: absolute expiry time (monotonic clock) + * + * Returns 0 on success, -ETIME when the event is in the past. + */ +int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, + ktime_t now) +{ + unsigned long long clc; + int64_t delta; + + delta = ktime_to_ns(ktime_sub(expires, now)); + + if (delta <= 0) + return -ETIME; + + dev->next_event = expires; + + if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) + return 0; + + if (delta > dev->max_delta_ns) + delta = dev->max_delta_ns; + if (delta < dev->min_delta_ns) + delta = dev->min_delta_ns; + + clc = delta * dev->mult; + clc >>= dev->shift; + + return dev->set_next_event((unsigned long) clc, dev); +} + +/** + * clockevents_register_notifier - register a clock events change listener + */ +int clockevents_register_notifier(struct notifier_block *nb) +{ + int ret; + + spin_lock(&clockevents_lock); + ret = raw_notifier_chain_register(&clockevents_chain, nb); + spin_unlock(&clockevents_lock); + + return ret; +} + +/** + * clockevents_unregister_notifier - unregister a clock events change listener + */ +void clockevents_unregister_notifier(struct notifier_block *nb) +{ + spin_lock(&clockevents_lock); + raw_notifier_chain_unregister(&clockevents_chain, nb); + spin_unlock(&clockevents_lock); +} + +/* + * Notify about a clock event change. Called with clockevents_lock + * held. + */ +static void clockevents_do_notify(unsigned long reason, void *dev) +{ + raw_notifier_call_chain(&clockevents_chain, reason, dev); +} + +/* + * Called after a notify add to make devices availble 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); + clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); + } +} + +/** + * clockevents_register_device - register a clock event device + * @dev: device to register + */ +void clockevents_register_device(struct clock_event_device *dev) +{ + BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); + + spin_lock(&clockevents_lock); + + list_add(&dev->list, &clockevent_devices); + clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); + clockevents_notify_released(); + + spin_unlock(&clockevents_lock); +} + +/* + * Noop handler when we shut down an event device + */ +static 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 the notifier chain. clockevents_lock is held already + */ +void clockevents_exchange_device(struct clock_event_device *old, + struct clock_event_device *new) +{ + unsigned long flags; + + local_irq_save(flags); + /* + * Caller releases a clock event device. We queue it into the + * released list and do a notify add later. + */ + if (old) { + old->event_handler = clockevents_handle_noop; + clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED); + list_del(&old->list); + list_add(&old->list, &clockevents_released); + } + + if (new) { + BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED); + clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN); + } + local_irq_restore(flags); +} + +/** + * clockevents_request_device + */ +struct clock_event_device *clockevents_request_device(unsigned int features, + cpumask_t cpumask) +{ + struct clock_event_device *cur, *dev = NULL; + struct list_head *tmp; + + spin_lock(&clockevents_lock); + + list_for_each(tmp, &clockevent_devices) { + cur = list_entry(tmp, struct clock_event_device, list); + + if ((cur->features & features) == features && + cpus_equal(cpumask, cur->cpumask)) { + if (!dev || dev->rating < cur->rating) + dev = cur; + } + } + + clockevents_exchange_device(NULL, dev); + + spin_unlock(&clockevents_lock); + + return dev; +} + +/** + * clockevents_release_device + */ +void clockevents_release_device(struct clock_event_device *dev) +{ + spin_lock(&clockevents_lock); + + clockevents_exchange_device(dev, NULL); + clockevents_notify_released(); + + spin_unlock(&clockevents_lock); +} + +/** + * clockevents_notify - notification about relevant events + */ +void clockevents_notify(unsigned long reason, void *arg) +{ + spin_lock(&clockevents_lock); + clockevents_do_notify(reason, arg); + + switch (reason) { + case CLOCK_EVT_NOTIFY_CPU_DEAD: + /* + * Unregister the clock event devices which were + * released from the users in the notify chain. + */ + while (!list_empty(&clockevents_released)) { + struct clock_event_device *dev; + + dev = list_entry(clockevents_released.next, + struct clock_event_device, list); + list_del(&dev->list); + } + break; + default: + break; + } + spin_unlock(&clockevents_lock); +} +EXPORT_SYMBOL_GPL(clockevents_notify); + +#ifdef CONFIG_SYSFS + +/** + * clockevents_show_registered - sysfs interface for listing clockevents + * @dev: unused + * @buf: char buffer to be filled with clock events list + * + * Provides sysfs interface for listing registered clock event devices + */ +static ssize_t clockevents_show_registered(struct sys_device *dev, char *buf) +{ + struct list_head *tmp; + char *p = buf; + int cpu; + + spin_lock(&clockevents_lock); + + list_for_each(tmp, &clockevent_devices) { + struct clock_event_device *ce; + + ce = list_entry(tmp, struct clock_event_device, list); + p += sprintf(p, "%-20s F:%04x M:%d", ce->name, + ce->features, ce->mode); + p += sprintf(p, " C:"); + if (!cpus_equal(ce->cpumask, cpu_possible_map)) { + for_each_cpu_mask(cpu, ce->cpumask) + p += sprintf(p, " %d", cpu); + } else { + /* + * FIXME: Add the cpu which is handling this sucker + */ + } + p += sprintf(p, "\n"); + } + + spin_unlock(&clockevents_lock); + + return p - buf; +} + +/* + * Sysfs setup bits: + */ +static SYSDEV_ATTR(registered, 0600, + clockevents_show_registered, NULL); + +static struct sysdev_class clockevents_sysclass = { + set_kset_name("clockevents"), +}; + +static struct sys_device clockevents_sys_device = { + .id = 0, + .cls = &clockevents_sysclass, +}; + +static int __init clockevents_sysfs_init(void) +{ + int error = sysdev_class_register(&clockevents_sysclass); + + if (!error) + error = sysdev_register(&clockevents_sys_device); + if (!error) + error = sysdev_create_file( + &clockevents_sys_device, + &attr_registered); + return error; +} +device_initcall(clockevents_sysfs_init); +#endif diff --git a/kernel/timer.c b/kernel/timer.c index 6d843e100e75..7d522bdf8265 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -34,6 +34,7 @@ #include <linux/cpu.h> #include <linux/syscalls.h> #include <linux/delay.h> +#include <linux/clockchips.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -970,7 +971,8 @@ static int timekeeping_resume(struct sys_device *dev) write_sequnlock_irqrestore(&xtime_lock, flags); touch_softlockup_watchdog(); - hrtimer_notify_resume(); + /* Resume hrtimers */ + clock_was_set(); return 0; } |