A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-28 02:32:09 -04:00
Code Issues Projects Releases Packages Wiki Activity

Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

Browse source 
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (34 commits)
  time: Prevent 32 bit overflow with set_normalized_timespec()
  clocksource: Delay clocksource down rating to late boot
  clocksource: clocksource_select must be called with mutex locked
  clocksource: Resolve cpu hotplug dead lock with TSC unstable, fix crash
  timers: Drop a function prototype
  clocksource: Resolve cpu hotplug dead lock with TSC unstable
  timer.c: Fix S/390 comments
  timekeeping: Fix invalid getboottime() value
  timekeeping: Fix up read_persistent_clock() breakage on sh
  timekeeping: Increase granularity of read_persistent_clock(), build fix
  time: Introduce CLOCK_REALTIME_COARSE
  x86: Do not unregister PIT clocksource on PIT oneshot setup/shutdown
  clocksource: Avoid clocksource watchdog circular locking dependency
  clocksource: Protect the watchdog rating changes with clocksource_mutex
  clocksource: Call clocksource_change_rating() outside of watchdog_lock
  timekeeping: Introduce read_boot_clock
  timekeeping: Increase granularity of read_persistent_clock()
  timekeeping: Update clocksource with stop_machine
  timekeeping: Add timekeeper read_clock helper functions
  timekeeping: Move NTP adjusted clock multiplier to struct timekeeper
  ...

Fix trivial conflict due to MIPS lemote -> loongson renaming.
This commit is contained in:
Linus Torvalds 2009-09-18 09:15:24 -07:00
commit a03fdb7612
32 changed files with 917 additions and 640 deletions
Download patch file Download diff file Expand all files Collapse all files

545
kernel/time/clocksource.c
View file

@ -21,7 +21,6 @@
*
* TODO WishList:
* o Allow clocksource drivers to be unregistered
* o get rid of clocksource_jiffies extern
*/
#include <linux/clocksource.h>
@ -30,6 +29,7 @@
#include <linux/module.h>
#include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
#include <linux/tick.h>
#include <linux/kthread.h>
void timecounter_init(struct timecounter *tc,
const struct cyclecounter *cc,
@ -107,50 +107,35 @@ u64 timecounter_cyc2time(struct timecounter *tc,
}
EXPORT_SYMBOL(timecounter_cyc2time);
/* XXX - Would like a better way for initializing curr_clocksource */
extern struct clocksource clocksource_jiffies;
/*[Clocksource internal variables]---------
* curr_clocksource:
* currently selected clocksource. Initialized to clocksource_jiffies.
* next_clocksource:
* pending next selected clocksource.
* currently selected clocksource.
* clocksource_list:
* linked list with the registered clocksources
* clocksource_lock:
* protects manipulations to curr_clocksource and next_clocksource
* and the clocksource_list
* clocksource_mutex:
* protects manipulations to curr_clocksource and the clocksource_list
* override_name:
* Name of the user-specified clocksource.
*/
static struct clocksource *curr_clocksource = &clocksource_jiffies;
static struct clocksource *next_clocksource;
static struct clocksource *clocksource_override;
static struct clocksource *curr_clocksource;
static LIST_HEAD(clocksource_list);
static DEFINE_SPINLOCK(clocksource_lock);
static DEFINE_MUTEX(clocksource_mutex);
static char override_name[32];
static int finished_booting;
/* clocksource_done_booting - Called near the end of core bootup
*
* Hack to avoid lots of clocksource churn at boot time.
* We use fs_initcall because we want this to start before
* device_initcall but after subsys_initcall.
*/
static int __init clocksource_done_booting(void)
{
finished_booting = 1;
return 0;
}
fs_initcall(clocksource_done_booting);
#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
static void clocksource_watchdog_work(struct work_struct *work);
static LIST_HEAD(watchdog_list);
static struct clocksource *watchdog;
static struct timer_list watchdog_timer;
static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
static DEFINE_SPINLOCK(watchdog_lock);
static cycle_t watchdog_last;
static unsigned long watchdog_resumed;
static int watchdog_running;
static int clocksource_watchdog_kthread(void *data);
static void __clocksource_change_rating(struct clocksource *cs, int rating);
/*
* Interval: 0.5sec Threshold: 0.0625s
@ -158,135 +143,249 @@ static unsigned long watchdog_resumed;
#define WATCHDOG_INTERVAL (HZ >> 1)
#define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4)
static void clocksource_ratewd(struct clocksource *cs, int64_t delta)
static void clocksource_watchdog_work(struct work_struct *work)
{
if (delta > -WATCHDOG_THRESHOLD && delta < WATCHDOG_THRESHOLD)
return;
/*
* If kthread_run fails the next watchdog scan over the
* watchdog_list will find the unstable clock again.
*/
kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog");
}
static void __clocksource_unstable(struct clocksource *cs)
{
cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
cs->flags |= CLOCK_SOURCE_UNSTABLE;
if (finished_booting)
schedule_work(&watchdog_work);
}
static void clocksource_unstable(struct clocksource *cs, int64_t delta)
{
printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n",
cs->name, delta);
cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
clocksource_change_rating(cs, 0);
list_del(&cs->wd_list);
__clocksource_unstable(cs);
}
/**
* clocksource_mark_unstable - mark clocksource unstable via watchdog
* @cs: clocksource to be marked unstable
*
* This function is called instead of clocksource_change_rating from
* cpu hotplug code to avoid a deadlock between the clocksource mutex
* and the cpu hotplug mutex. It defers the update of the clocksource
* to the watchdog thread.
*/
void clocksource_mark_unstable(struct clocksource *cs)
{
unsigned long flags;
spin_lock_irqsave(&watchdog_lock, flags);
if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {
if (list_empty(&cs->wd_list))
list_add(&cs->wd_list, &watchdog_list);
__clocksource_unstable(cs);
}
spin_unlock_irqrestore(&watchdog_lock, flags);
}
static void clocksource_watchdog(unsigned long data)
{
struct clocksource *cs, *tmp;
struct clocksource *cs;
cycle_t csnow, wdnow;
int64_t wd_nsec, cs_nsec;
int resumed;
int next_cpu;
spin_lock(&watchdog_lock);
resumed = test_and_clear_bit(0, &watchdog_resumed);
if (!watchdog_running)
goto out;
wdnow = watchdog->read(watchdog);
wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
wd_nsec = clocksource_cyc2ns((wdnow - watchdog_last) & watchdog->mask,
watchdog->mult, watchdog->shift);
watchdog_last = wdnow;
list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
list_for_each_entry(cs, &watchdog_list, wd_list) {
/* Clocksource already marked unstable? */
if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
if (finished_booting)
schedule_work(&watchdog_work);
continue;
}
csnow = cs->read(cs);
if (unlikely(resumed)) {
/* Clocksource initialized ? */
if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
cs->flags |= CLOCK_SOURCE_WATCHDOG;
cs->wd_last = csnow;
continue;
}
/* Initialized ? */
if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
if ((cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
(watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
/*
* We just marked the clocksource as
* highres-capable, notify the rest of the
* system as well so that we transition
* into high-res mode:
*/
tick_clock_notify();
}
cs->flags |= CLOCK_SOURCE_WATCHDOG;
cs->wd_last = csnow;
} else {
cs_nsec = cyc2ns(cs, (csnow - cs->wd_last) & cs->mask);
cs->wd_last = csnow;
/* Check the delta. Might remove from the list ! */
clocksource_ratewd(cs, cs_nsec - wd_nsec);
/* Check the deviation from the watchdog clocksource. */
cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) &
cs->mask, cs->mult, cs->shift);
cs->wd_last = csnow;
if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
clocksource_unstable(cs, cs_nsec - wd_nsec);
continue;
}
if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
(cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
(watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
/*
* We just marked the clocksource as highres-capable,
* notify the rest of the system as well so that we
* transition into high-res mode:
*/
tick_clock_notify();
}
}
if (!list_empty(&watchdog_list)) {
/*
* Cycle through CPUs to check if the CPUs stay
* synchronized to each other.
*/
int next_cpu = cpumask_next(raw_smp_processor_id(),
cpu_online_mask);
if (next_cpu >= nr_cpu_ids)
next_cpu = cpumask_first(cpu_online_mask);
watchdog_timer.expires += WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer, next_cpu);
}
/*
* Cycle through CPUs to check if the CPUs stay synchronized
* to each other.
*/
next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
if (next_cpu >= nr_cpu_ids)
next_cpu = cpumask_first(cpu_online_mask);
watchdog_timer.expires += WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer, next_cpu);
out:
spin_unlock(&watchdog_lock);
}
static void clocksource_resume_watchdog(void)
static inline void clocksource_start_watchdog(void)
{
set_bit(0, &watchdog_resumed);
if (watchdog_running || !watchdog || list_empty(&watchdog_list))
return;
init_timer(&watchdog_timer);
watchdog_timer.function = clocksource_watchdog;
watchdog_last = watchdog->read(watchdog);
watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask));
watchdog_running = 1;
}
static void clocksource_check_watchdog(struct clocksource *cs)
static inline void clocksource_stop_watchdog(void)
{
if (!watchdog_running || (watchdog && !list_empty(&watchdog_list)))
return;
del_timer(&watchdog_timer);
watchdog_running = 0;
}
static inline void clocksource_reset_watchdog(void)
{
struct clocksource *cs;
list_for_each_entry(cs, &watchdog_list, wd_list)
cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
}
static void clocksource_resume_watchdog(void)
{
unsigned long flags;
spin_lock_irqsave(&watchdog_lock, flags);
clocksource_reset_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
}
static void clocksource_enqueue_watchdog(struct clocksource *cs)
{
struct clocksource *cse;
unsigned long flags;
spin_lock_irqsave(&watchdog_lock, flags);
if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
int started = !list_empty(&watchdog_list);
/* cs is a clocksource to be watched. */
list_add(&cs->wd_list, &watchdog_list);
if (!started && watchdog) {
watchdog_last = watchdog->read(watchdog);
watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer,
cpumask_first(cpu_online_mask));
}
cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
} else {
/* cs is a watchdog. */
if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
/* Pick the best watchdog. */
if (!watchdog || cs->rating > watchdog->rating) {
if (watchdog)
del_timer(&watchdog_timer);
watchdog = cs;
init_timer(&watchdog_timer);
watchdog_timer.function = clocksource_watchdog;
/* Reset watchdog cycles */
list_for_each_entry(cse, &watchdog_list, wd_list)
cse->flags &= ~CLOCK_SOURCE_WATCHDOG;
/* Start if list is not empty */
if (!list_empty(&watchdog_list)) {
watchdog_last = watchdog->read(watchdog);
watchdog_timer.expires =
jiffies + WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer,
cpumask_first(cpu_online_mask));
}
clocksource_reset_watchdog();
}
}
/* Check if the watchdog timer needs to be started. */
clocksource_start_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
}
#else
static void clocksource_check_watchdog(struct clocksource *cs)
static void clocksource_dequeue_watchdog(struct clocksource *cs)
{
struct clocksource *tmp;
unsigned long flags;
spin_lock_irqsave(&watchdog_lock, flags);
if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
/* cs is a watched clocksource. */
list_del_init(&cs->wd_list);
} else if (cs == watchdog) {
/* Reset watchdog cycles */
clocksource_reset_watchdog();
/* Current watchdog is removed. Find an alternative. */
watchdog = NULL;
list_for_each_entry(tmp, &clocksource_list, list) {
if (tmp == cs || tmp->flags & CLOCK_SOURCE_MUST_VERIFY)
continue;
if (!watchdog || tmp->rating > watchdog->rating)
watchdog = tmp;
}
}
cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
/* Check if the watchdog timer needs to be stopped. */
clocksource_stop_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
}
static int clocksource_watchdog_kthread(void *data)
{
struct clocksource *cs, *tmp;
unsigned long flags;
LIST_HEAD(unstable);
mutex_lock(&clocksource_mutex);
spin_lock_irqsave(&watchdog_lock, flags);
list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list)
if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
list_del_init(&cs->wd_list);
list_add(&cs->wd_list, &unstable);
}
/* Check if the watchdog timer needs to be stopped. */
clocksource_stop_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
/* Needs to be done outside of watchdog lock */
list_for_each_entry_safe(cs, tmp, &unstable, wd_list) {
list_del_init(&cs->wd_list);
__clocksource_change_rating(cs, 0);
}
mutex_unlock(&clocksource_mutex);
return 0;
}
#else /* CONFIG_CLOCKSOURCE_WATCHDOG */
static void clocksource_enqueue_watchdog(struct clocksource *cs)
{
if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
}
static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { }
static inline void clocksource_resume_watchdog(void) { }
#endif
static inline int clocksource_watchdog_kthread(void *data) { return 0; }
#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */
/**
* clocksource_resume - resume the clocksource(s)
@ -294,18 +393,16 @@ static inline void clocksource_resume_watchdog(void) { }
void clocksource_resume(void)
{
struct clocksource *cs;
unsigned long flags;
spin_lock_irqsave(&clocksource_lock, flags);
mutex_lock(&clocksource_mutex);
list_for_each_entry(cs, &clocksource_list, list) {
list_for_each_entry(cs, &clocksource_list, list)
if (cs->resume)
cs->resume();
}
clocksource_resume_watchdog();
spin_unlock_irqrestore(&clocksource_lock, flags);
mutex_unlock(&clocksource_mutex);
}
/**
@ -320,75 +417,94 @@ void clocksource_touch_watchdog(void)
clocksource_resume_watchdog();
}
/**
* clocksource_get_next - Returns the selected clocksource
*
*/
struct clocksource *clocksource_get_next(void)
{
unsigned long flags;
spin_lock_irqsave(&clocksource_lock, flags);
if (next_clocksource && finished_booting) {
curr_clocksource = next_clocksource;
next_clocksource = NULL;
}
spin_unlock_irqrestore(&clocksource_lock, flags);
return curr_clocksource;
}
#ifdef CONFIG_GENERIC_TIME
/**
* select_clocksource - Selects the best registered clocksource.
* clocksource_select - Select the best clocksource available
*
* Private function. Must hold clocksource_lock when called.
* Private function. Must hold clocksource_mutex when called.
*
* Select the clocksource with the best rating, or the clocksource,
* which is selected by userspace override.
*/
static struct clocksource *select_clocksource(void)
static void clocksource_select(void)
{
struct clocksource *next;
struct clocksource *best, *cs;
if (list_empty(&clocksource_list))
return NULL;
if (clocksource_override)
next = clocksource_override;
else
next = list_entry(clocksource_list.next, struct clocksource,
list);
if (next == curr_clocksource)
return NULL;
return next;
if (!finished_booting || list_empty(&clocksource_list))
return;
/* First clocksource on the list has the best rating. */
best = list_first_entry(&clocksource_list, struct clocksource, list);
/* Check for the override clocksource. */
list_for_each_entry(cs, &clocksource_list, list) {
if (strcmp(cs->name, override_name) != 0)
continue;
/*
* Check to make sure we don't switch to a non-highres
* capable clocksource if the tick code is in oneshot
* mode (highres or nohz)
*/
if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
tick_oneshot_mode_active()) {
/* Override clocksource cannot be used. */
printk(KERN_WARNING "Override clocksource %s is not "
"HRT compatible. Cannot switch while in "
"HRT/NOHZ mode\n", cs->name);
override_name[0] = 0;
} else
/* Override clocksource can be used. */
best = cs;
break;
}
if (curr_clocksource != best) {
printk(KERN_INFO "Switching to clocksource %s\n", best->name);
curr_clocksource = best;
timekeeping_notify(curr_clocksource);
}
}
#else /* CONFIG_GENERIC_TIME */
static inline void clocksource_select(void) { }
#endif
/*
* clocksource_done_booting - Called near the end of core bootup
*
* Hack to avoid lots of clocksource churn at boot time.
* We use fs_initcall because we want this to start before
* device_initcall but after subsys_initcall.
*/
static int __init clocksource_done_booting(void)
{
finished_booting = 1;
/*
* Run the watchdog first to eliminate unstable clock sources
*/
clocksource_watchdog_kthread(NULL);
mutex_lock(&clocksource_mutex);
clocksource_select();
mutex_unlock(&clocksource_mutex);
return 0;
}
fs_initcall(clocksource_done_booting);
/*
* Enqueue the clocksource sorted by rating
*/
static int clocksource_enqueue(struct clocksource *c)
static void clocksource_enqueue(struct clocksource *cs)
{
struct list_head *tmp, *entry = &clocksource_list;
struct list_head *entry = &clocksource_list;
struct clocksource *tmp;
list_for_each(tmp, &clocksource_list) {
struct clocksource *cs;
cs = list_entry(tmp, struct clocksource, list);
if (cs == c)
return -EBUSY;
list_for_each_entry(tmp, &clocksource_list, list)
/* Keep track of the place, where to insert */
if (cs->rating >= c->rating)
entry = tmp;
}
list_add(&c->list, entry);
if (strlen(c->name) == strlen(override_name) &&
!strcmp(c->name, override_name))
clocksource_override = c;
return 0;
if (tmp->rating >= cs->rating)
entry = &tmp->list;
list_add(&cs->list, entry);
}
/**
@ -397,52 +513,48 @@ static int clocksource_enqueue(struct clocksource *c)
*
* Returns -EBUSY if registration fails, zero otherwise.
*/
int clocksource_register(struct clocksource *c)
int clocksource_register(struct clocksource *cs)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&clocksource_lock, flags);
ret = clocksource_enqueue(c);
if (!ret)
next_clocksource = select_clocksource();
spin_unlock_irqrestore(&clocksource_lock, flags);
if (!ret)
clocksource_check_watchdog(c);
return ret;
mutex_lock(&clocksource_mutex);
clocksource_enqueue(cs);
clocksource_select();
clocksource_enqueue_watchdog(cs);
mutex_unlock(&clocksource_mutex);
return 0;
}
EXPORT_SYMBOL(clocksource_register);
/**
* clocksource_change_rating - Change the rating of a registered clocksource
*
*/
void clocksource_change_rating(struct clocksource *cs, int rating)
static void __clocksource_change_rating(struct clocksource *cs, int rating)
{
unsigned long flags;
spin_lock_irqsave(&clocksource_lock, flags);
list_del(&cs->list);
cs->rating = rating;
clocksource_enqueue(cs);
next_clocksource = select_clocksource();
spin_unlock_irqrestore(&clocksource_lock, flags);
clocksource_select();
}
/**
* clocksource_change_rating - Change the rating of a registered clocksource
*/
void clocksource_change_rating(struct clocksource *cs, int rating)
{
mutex_lock(&clocksource_mutex);
__clocksource_change_rating(cs, rating);
mutex_unlock(&clocksource_mutex);
}
EXPORT_SYMBOL(clocksource_change_rating);
/**
* clocksource_unregister - remove a registered clocksource
*/
void clocksource_unregister(struct clocksource *cs)
{
unsigned long flags;
spin_lock_irqsave(&clocksource_lock, flags);
mutex_lock(&clocksource_mutex);
clocksource_dequeue_watchdog(cs);
list_del(&cs->list);
if (clocksource_override == cs)
clocksource_override = NULL;
next_clocksource = select_clocksource();
spin_unlock_irqrestore(&clocksource_lock, flags);
clocksource_select();
mutex_unlock(&clocksource_mutex);
}
EXPORT_SYMBOL(clocksource_unregister);
#ifdef CONFIG_SYSFS
/**
@ -458,9 +570,9 @@ sysfs_show_current_clocksources(struct sys_device *dev,
{
ssize_t count = 0;
spin_lock_irq(&clocksource_lock);
mutex_lock(&clocksource_mutex);
count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name);
spin_unlock_irq(&clocksource_lock);
mutex_unlock(&clocksource_mutex);
return count;
}
@ -478,9 +590,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
struct sysdev_attribute *attr,
const char *buf, size_t count)
{
struct clocksource *ovr = NULL;
size_t ret = count;
int len;
/* strings from sysfs write are not 0 terminated! */
if (count >= sizeof(override_name))
@ -490,44 +600,14 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
if (buf[count-1] == '\n')
count--;
spin_lock_irq(&clocksource_lock);
mutex_lock(&clocksource_mutex);
if (count > 0)
memcpy(override_name, buf, count);
override_name[count] = 0;
clocksource_select();
len = strlen(override_name);
if (len) {
struct clocksource *cs;
ovr = clocksource_override;
/* try to select it: */
list_for_each_entry(cs, &clocksource_list, list) {
if (strlen(cs->name) == len &&
!strcmp(cs->name, override_name))
ovr = cs;
}
}
/*
* Check to make sure we don't switch to a non-highres capable
* clocksource if the tick code is in oneshot mode (highres or nohz)
*/
if (tick_oneshot_mode_active() && ovr &&
!(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {
printk(KERN_WARNING "%s clocksource is not HRT compatible. "
"Cannot switch while in HRT/NOHZ mode\n", ovr->name);
ovr = NULL;
override_name[0] = 0;
}
/* Reselect, when the override name has changed */
if (ovr != clocksource_override) {
clocksource_override = ovr;
next_clocksource = select_clocksource();
}
spin_unlock_irq(&clocksource_lock);
mutex_unlock(&clocksource_mutex);
return ret;
}
@ -547,7 +627,7 @@ sysfs_show_available_clocksources(struct sys_device *dev,
struct clocksource *src;
ssize_t count = 0;
spin_lock_irq(&clocksource_lock);
mutex_lock(&clocksource_mutex);
list_for_each_entry(src, &clocksource_list, list) {
/*
* Don't show non-HRES clocksource if the tick code is
@ -559,7 +639,7 @@ sysfs_show_available_clocksources(struct sys_device *dev,
max((ssize_t)PAGE_SIZE - count, (ssize_t)0),
"%s ", src->name);
}
spin_unlock_irq(&clocksource_lock);
mutex_unlock(&clocksource_mutex);
count += snprintf(buf + count,
max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n");
@ -614,11 +694,10 @@ device_initcall(init_clocksource_sysfs);
*/
static int __init boot_override_clocksource(char* str)
{
unsigned long flags;
spin_lock_irqsave(&clocksource_lock, flags);
mutex_lock(&clocksource_mutex);
if (str)
strlcpy(override_name, str, sizeof(override_name));
spin_unlock_irqrestore(&clocksource_lock, flags);
mutex_unlock(&clocksource_mutex);
return 1;
}

6
kernel/time/jiffies.c
View file

@ -61,7 +61,6 @@ struct clocksource clocksource_jiffies = {
.read = jiffies_read,
.mask = 0xffffffff, /*32bits*/
.mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */
.mult_orig = NSEC_PER_JIFFY << JIFFIES_SHIFT,
.shift = JIFFIES_SHIFT,
};
@ -71,3 +70,8 @@ static int __init init_jiffies_clocksource(void)
}
core_initcall(init_jiffies_clocksource);
struct clocksource * __init __weak clocksource_default_clock(void)
{
return &clocksource_jiffies;
}

7
kernel/time/ntp.c
View file

@ -194,8 +194,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
case TIME_OK:
break;
case TIME_INS:
xtime.tv_sec--;
wall_to_monotonic.tv_sec++;
timekeeping_leap_insert(-1);
time_state = TIME_OOP;
printk(KERN_NOTICE
"Clock: inserting leap second 23:59:60 UTC\n");
@ -203,9 +202,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
res = HRTIMER_RESTART;
break;
case TIME_DEL:
xtime.tv_sec++;
timekeeping_leap_insert(1);
time_tai--;
wall_to_monotonic.tv_sec--;
time_state = TIME_WAIT;
printk(KERN_NOTICE
"Clock: deleting leap second 23:59:59 UTC\n");
@ -219,7 +217,6 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
time_state = TIME_OK;
break;
}
update_vsyscall(&xtime, clock);
write_sequnlock(&xtime_lock);

549
kernel/time/timekeeping.c
View file

@ -18,7 +18,117 @@
#include <linux/jiffies.h>
#include <linux/time.h>
#include <linux/tick.h>
#include <linux/stop_machine.h>
/* Structure holding internal timekeeping values. */
struct timekeeper {
/* Current clocksource used for timekeeping. */
struct clocksource *clock;
/* The shift value of the current clocksource. */
int shift;
/* Number of clock cycles in one NTP interval. */
cycle_t cycle_interval;
/* Number of clock shifted nano seconds in one NTP interval. */
u64 xtime_interval;
/* Raw nano seconds accumulated per NTP interval. */
u32 raw_interval;
/* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */
u64 xtime_nsec;
/* Difference between accumulated time and NTP time in ntp
* shifted nano seconds. */
s64 ntp_error;
/* Shift conversion between clock shifted nano seconds and
* ntp shifted nano seconds. */
int ntp_error_shift;
/* NTP adjusted clock multiplier */
u32 mult;
};
struct timekeeper timekeeper;
/**
* timekeeper_setup_internals - Set up internals to use clocksource clock.
*
* @clock: Pointer to clocksource.
*
* Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
* pair and interval request.
*
* Unless you're the timekeeping code, you should not be using this!
*/
static void timekeeper_setup_internals(struct clocksource *clock)
{
cycle_t interval;
u64 tmp;
timekeeper.clock = clock;
clock->cycle_last = clock->read(clock);
/* Do the ns -> cycle conversion first, using original mult */
tmp = NTP_INTERVAL_LENGTH;
tmp <<= clock->shift;
tmp += clock->mult/2;
do_div(tmp, clock->mult);
if (tmp == 0)
tmp = 1;
interval = (cycle_t) tmp;
timekeeper.cycle_interval = interval;
/* Go back from cycles -> shifted ns */
timekeeper.xtime_interval = (u64) interval * clock->mult;
timekeeper.raw_interval =
((u64) interval * clock->mult) >> clock->shift;
timekeeper.xtime_nsec = 0;
timekeeper.shift = clock->shift;
timekeeper.ntp_error = 0;
timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
/*
* The timekeeper keeps its own mult values for the currently
* active clocksource. These value will be adjusted via NTP
* to counteract clock drifting.
*/
timekeeper.mult = clock->mult;
}
/* Timekeeper helper functions. */
static inline s64 timekeeping_get_ns(void)
{
cycle_t cycle_now, cycle_delta;
struct clocksource *clock;
/* read clocksource: */
clock = timekeeper.clock;
cycle_now = clock->read(clock);
/* calculate the delta since the last update_wall_time: */
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
/* return delta convert to nanoseconds using ntp adjusted mult. */
return clocksource_cyc2ns(cycle_delta, timekeeper.mult,
timekeeper.shift);
}
static inline s64 timekeeping_get_ns_raw(void)
{
cycle_t cycle_now, cycle_delta;
struct clocksource *clock;
/* read clocksource: */
clock = timekeeper.clock;
cycle_now = clock->read(clock);
/* calculate the delta since the last update_wall_time: */
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
/* return delta convert to nanoseconds using ntp adjusted mult. */
return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
}
/*
* This read-write spinlock protects us from races in SMP while
@ -44,7 +154,12 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
*/
struct timespec xtime __attribute__ ((aligned (16)));
struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
static unsigned long total_sleep_time; /* seconds */
static struct timespec total_sleep_time;
/*
* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
*/
struct timespec raw_time;
/* flag for if timekeeping is suspended */
int __read_mostly timekeeping_suspended;
@ -56,35 +171,44 @@ void update_xtime_cache(u64 nsec)
timespec_add_ns(&xtime_cache, nsec);
}
struct clocksource *clock;
/* must hold xtime_lock */
void timekeeping_leap_insert(int leapsecond)
{
xtime.tv_sec += leapsecond;
wall_to_monotonic.tv_sec -= leapsecond;
update_vsyscall(&xtime, timekeeper.clock);
}
#ifdef CONFIG_GENERIC_TIME
/**
* clocksource_forward_now - update clock to the current time
* timekeeping_forward_now - update clock to the current time
*
* Forward the current clock to update its state since the last call to
* update_wall_time(). This is useful before significant clock changes,
* as it avoids having to deal with this time offset explicitly.
*/
static void clocksource_forward_now(void)
static void timekeeping_forward_now(void)
{
cycle_t cycle_now, cycle_delta;
struct clocksource *clock;
s64 nsec;
cycle_now = clocksource_read(clock);
clock = timekeeper.clock;
cycle_now = clock->read(clock);
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
clock->cycle_last = cycle_now;
nsec = cyc2ns(clock, cycle_delta);
nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult,
timekeeper.shift);
/* If arch requires, add in gettimeoffset() */
nsec += arch_gettimeoffset();
timespec_add_ns(&xtime, nsec);
nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
clock->raw_time.tv_nsec += nsec;
nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
timespec_add_ns(&raw_time, nsec);
}
/**
@ -95,7 +219,6 @@ static void clocksource_forward_now(void)
*/
void getnstimeofday(struct timespec *ts)
{
cycle_t cycle_now, cycle_delta;
unsigned long seq;
s64 nsecs;
@ -105,15 +228,7 @@ void getnstimeofday(struct timespec *ts)
seq = read_seqbegin(&xtime_lock);
*ts = xtime;
/* read clocksource: */
cycle_now = clocksource_read(clock);
/* calculate the delta since the last update_wall_time: */
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
/* convert to nanoseconds: */
nsecs = cyc2ns(clock, cycle_delta);
nsecs = timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
@ -125,6 +240,57 @@ void getnstimeofday(struct timespec *ts)
EXPORT_SYMBOL(getnstimeofday);
ktime_t ktime_get(void)
{
unsigned int seq;
s64 secs, nsecs;
WARN_ON(timekeeping_suspended);
do {
seq = read_seqbegin(&xtime_lock);
secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
nsecs += timekeeping_get_ns();
} while (read_seqretry(&xtime_lock, seq));
/*
* Use ktime_set/ktime_add_ns to create a proper ktime on
* 32-bit architectures without CONFIG_KTIME_SCALAR.
*/
return ktime_add_ns(ktime_set(secs, 0), nsecs);
}
EXPORT_SYMBOL_GPL(ktime_get);
/**
* ktime_get_ts - get the monotonic clock in timespec format
* @ts: pointer to timespec variable
*
* The function calculates the monotonic clock from the realtime
* clock and the wall_to_monotonic offset and stores the result
* in normalized timespec format in the variable pointed to by @ts.
*/
void ktime_get_ts(struct timespec *ts)
{
struct timespec tomono;
unsigned int seq;
s64 nsecs;
WARN_ON(timekeeping_suspended);
do {
seq = read_seqbegin(&xtime_lock);
*ts = xtime;
tomono = wall_to_monotonic;
nsecs = timekeeping_get_ns();
} while (read_seqretry(&xtime_lock, seq));
set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
ts->tv_nsec + tomono.tv_nsec + nsecs);
}
EXPORT_SYMBOL_GPL(ktime_get_ts);
/**
* do_gettimeofday - Returns the time of day in a timeval
* @tv: pointer to the timeval to be set
@ -157,7 +323,7 @@ int do_settimeofday(struct timespec *tv)
write_seqlock_irqsave(&xtime_lock, flags);
clocksource_forward_now();
timekeeping_forward_now();
ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec;
ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec;
@ -167,10 +333,10 @@ int do_settimeofday(struct timespec *tv)
update_xtime_cache(0);
clock->error = 0;
timekeeper.ntp_error = 0;
ntp_clear();
update_vsyscall(&xtime, clock);
update_vsyscall(&xtime, timekeeper.clock);
write_sequnlock_irqrestore(&xtime_lock, flags);
@ -187,44 +353,97 @@ EXPORT_SYMBOL(do_settimeofday);
*
* Accumulates current time interval and initializes new clocksource
*/
static void change_clocksource(void)
static int change_clocksource(void *data)
{
struct clocksource *new, *old;
new = clocksource_get_next();
new = (struct clocksource *) data;
if (clock == new)
return;
clocksource_forward_now();
if (clocksource_enable(new))
return;
new->raw_time = clock->raw_time;
old = clock;
clock = new;
clocksource_disable(old);
clock->cycle_last = 0;
clock->cycle_last = clocksource_read(clock);
clock->error = 0;
clock->xtime_nsec = 0;
clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
tick_clock_notify();
/*
* We're holding xtime lock and waking up klogd would deadlock
* us on enqueue. So no printing!
printk(KERN_INFO "Time: %s clocksource has been installed.\n",
clock->name);
*/
timekeeping_forward_now();
if (!new->enable || new->enable(new) == 0) {
old = timekeeper.clock;
timekeeper_setup_internals(new);
if (old->disable)
old->disable(old);
}
return 0;
}
#else
static inline void clocksource_forward_now(void) { }
static inline void change_clocksource(void) { }
#endif
/**
* timekeeping_notify - Install a new clock source
* @clock: pointer to the clock source
*
* This function is called from clocksource.c after a new, better clock
* source has been registered. The caller holds the clocksource_mutex.
*/
void timekeeping_notify(struct clocksource *clock)
{
if (timekeeper.clock == clock)
return;
stop_machine(change_clocksource, clock, NULL);
tick_clock_notify();
}
#else /* GENERIC_TIME */
static inline void timekeeping_forward_now(void) { }
/**
* ktime_get - get the monotonic time in ktime_t format
*
* returns the time in ktime_t format
*/
ktime_t ktime_get(void)
{
struct timespec now;
ktime_get_ts(&now);
return timespec_to_ktime(now);
}
EXPORT_SYMBOL_GPL(ktime_get);
/**
* ktime_get_ts - get the monotonic clock in timespec format
* @ts: pointer to timespec variable
*
* The function calculates the monotonic clock from the realtime
* clock and the wall_to_monotonic offset and stores the result
* in normalized timespec format in the variable pointed to by @ts.
*/
void ktime_get_ts(struct timespec *ts)
{
struct timespec tomono;
unsigned long seq;
do {
seq = read_seqbegin(&xtime_lock);
getnstimeofday(ts);
tomono = wall_to_monotonic;
} while (read_seqretry(&xtime_lock, seq));
set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
ts->tv_nsec + tomono.tv_nsec);
}
EXPORT_SYMBOL_GPL(ktime_get_ts);
#endif /* !GENERIC_TIME */
/**
* ktime_get_real - get the real (wall-) time in ktime_t format
*
* returns the time in ktime_t format
*/
ktime_t ktime_get_real(void)
{
struct timespec now;
getnstimeofday(&now);
return timespec_to_ktime(now);
}
EXPORT_SYMBOL_GPL(ktime_get_real);
/**
* getrawmonotonic - Returns the raw monotonic time in a timespec
@ -236,21 +455,11 @@ void getrawmonotonic(struct timespec *ts)
{
unsigned long seq;
s64 nsecs;
cycle_t cycle_now, cycle_delta;
do {
seq = read_seqbegin(&xtime_lock);
/* read clocksource: */
cycle_now = clocksource_read(clock);
/* calculate the delta since the last update_wall_time: */
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
/* convert to nanoseconds: */
nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
*ts = clock->raw_time;
nsecs = timekeeping_get_ns_raw();
*ts = raw_time;
} while (read_seqretry(&xtime_lock, seq));
@ -270,7 +479,7 @@ int timekeeping_valid_for_hres(void)
do {
seq = read_seqbegin(&xtime_lock);
ret = clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
} while (read_seqretry(&xtime_lock, seq));
@ -278,17 +487,33 @@ int timekeeping_valid_for_hres(void)
}
/**
* read_persistent_clock - Return time in seconds from the persistent clock.
* read_persistent_clock - Return time from the persistent clock.
*
* Weak dummy function for arches that do not yet support it.
* Returns seconds from epoch using the battery backed persistent clock.
* Returns zero if unsupported.
* Reads the time from the battery backed persistent clock.
* Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
*
* XXX - Do be sure to remove it once all arches implement it.
*/
unsigned long __attribute__((weak)) read_persistent_clock(void)
void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
{
return 0;
ts->tv_sec = 0;
ts->tv_nsec = 0;
}
/**
* read_boot_clock - Return time of the system start.
*
* Weak dummy function for arches that do not yet support it.
* Function to read the exact time the system has been started.
* Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
*
* XXX - Do be sure to remove it once all arches implement it.
*/
void __attribute__((weak)) read_boot_clock(struct timespec *ts)
{
ts->tv_sec = 0;
ts->tv_nsec = 0;
}
/*
@ -296,29 +521,40 @@ unsigned long __attribute__((weak)) read_persistent_clock(void)
*/
void __init timekeeping_init(void)
{
struct clocksource *clock;
unsigned long flags;
unsigned long sec = read_persistent_clock();
struct timespec now, boot;
read_persistent_clock(&now);
read_boot_clock(&boot);
write_seqlock_irqsave(&xtime_lock, flags);
ntp_init();
clock = clocksource_get_next();
clocksource_enable(clock);
clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
clock->cycle_last = clocksource_read(clock);
clock = clocksource_default_clock();
if (clock->enable)
clock->enable(clock);
timekeeper_setup_internals(clock);
xtime.tv_sec = sec;
xtime.tv_nsec = 0;
xtime.tv_sec = now.tv_sec;
xtime.tv_nsec = now.tv_nsec;
raw_time.tv_sec = 0;
raw_time.tv_nsec = 0;
if (boot.tv_sec == 0 && boot.tv_nsec == 0) {
boot.tv_sec = xtime.tv_sec;
boot.tv_nsec = xtime.tv_nsec;
}
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
-boot.tv_sec, -boot.tv_nsec);
update_xtime_cache(0);
total_sleep_time = 0;
total_sleep_time.tv_sec = 0;
total_sleep_time.tv_nsec = 0;
write_sequnlock_irqrestore(&xtime_lock, flags);
}
/* time in seconds when suspend began */
static unsigned long timekeeping_suspend_time;
static struct timespec timekeeping_suspend_time;
/**
* timekeeping_resume - Resumes the generic timekeeping subsystem.
@ -331,24 +567,24 @@ static unsigned long timekeeping_suspend_time;
static int timekeeping_resume(struct sys_device *dev)
{
unsigned long flags;
unsigned long now = read_persistent_clock();
struct timespec ts;
read_persistent_clock(&ts);
clocksource_resume();
write_seqlock_irqsave(&xtime_lock, flags);
if (now && (now > timekeeping_suspend_time)) {
unsigned long sleep_length = now - timekeeping_suspend_time;
xtime.tv_sec += sleep_length;
wall_to_monotonic.tv_sec -= sleep_length;
total_sleep_time += sleep_length;
if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
ts = timespec_sub(ts, timekeeping_suspend_time);
xtime = timespec_add_safe(xtime, ts);
wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
total_sleep_time = timespec_add_safe(total_sleep_time, ts);
}
update_xtime_cache(0);
/* re-base the last cycle value */
clock->cycle_last = 0;
clock->cycle_last = clocksource_read(clock);
clock->error = 0;
timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
timekeeper.ntp_error = 0;
timekeeping_suspended = 0;
write_sequnlock_irqrestore(&xtime_lock, flags);
@ -366,10 +602,10 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
{
unsigned long flags;
timekeeping_suspend_time = read_persistent_clock();
read_persistent_clock(&timekeeping_suspend_time);
write_seqlock_irqsave(&xtime_lock, flags);
clocksource_forward_now();
timekeeping_forward_now();
timekeeping_suspended = 1;
write_sequnlock_irqrestore(&xtime_lock, flags);
@ -404,7 +640,7 @@ device_initcall(timekeeping_init_device);
* If the error is already larger, we look ahead even further
* to compensate for late or lost adjustments.
*/
static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
s64 *offset)
{
s64 tick_error, i;
@ -420,7 +656,7 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
* here. This is tuned so that an error of about 1 msec is adjusted
* within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
*/
error2 = clock->error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
error2 = abs(error2);
for (look_ahead = 0; error2 > 0; look_ahead++)
error2 >>= 2;
@ -429,8 +665,8 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
* Now calculate the error in (1 << look_ahead) ticks, but first
* remove the single look ahead already included in the error.
*/
tick_error = tick_length >> (NTP_SCALE_SHIFT - clock->shift + 1);
tick_error -= clock->xtime_interval >> 1;
tick_error = tick_length >> (timekeeper.ntp_error_shift + 1);
tick_error -= timekeeper.xtime_interval >> 1;
error = ((error - tick_error) >> look_ahead) + tick_error;
/* Finally calculate the adjustment shift value. */
@ -455,18 +691,18 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
* this is optimized for the most common adjustments of -1,0,1,
* for other values we can do a bit more work.
*/
static void clocksource_adjust(s64 offset)
static void timekeeping_adjust(s64 offset)
{
s64 error, interval = clock->cycle_interval;
s64 error, interval = timekeeper.cycle_interval;
int adj;
error = clock->error >> (NTP_SCALE_SHIFT - clock->shift - 1);
error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1);
if (error > interval) {
error >>= 2;
if (likely(error <= interval))
adj = 1;
else
adj = clocksource_bigadjust(error, &interval, &offset);
adj = timekeeping_bigadjust(error, &interval, &offset);
} else if (error < -interval) {
error >>= 2;
if (likely(error >= -interval)) {
@ -474,15 +710,15 @@ static void clocksource_adjust(s64 offset)
interval = -interval;
offset = -offset;
} else
adj = clocksource_bigadjust(error, &interval, &offset);
adj = timekeeping_bigadjust(error, &interval, &offset);
} else
return;
clock->mult += adj;
clock->xtime_interval += interval;
clock->xtime_nsec -= offset;
clock->error -= (interval - offset) <<
(NTP_SCALE_SHIFT - clock->shift);
timekeeper.mult += adj;
timekeeper.xtime_interval += interval;
timekeeper.xtime_nsec -= offset;
timekeeper.ntp_error -= (interval - offset) <<
timekeeper.ntp_error_shift;
}
/**
@ -492,53 +728,59 @@ static void clocksource_adjust(s64 offset)
*/
void update_wall_time(void)
{
struct clocksource *clock;
cycle_t offset;
u64 nsecs;
/* Make sure we're fully resumed: */
if (unlikely(timekeeping_suspended))
return;
clock = timekeeper.clock;
#ifdef CONFIG_GENERIC_TIME
offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask;
offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
#else
offset = clock->cycle_interval;
offset = timekeeper.cycle_interval;
#endif
clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift;
timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
/* normally this loop will run just once, however in the
* case of lost or late ticks, it will accumulate correctly.
*/
while (offset >= clock->cycle_interval) {
/* accumulate one interval */
offset -= clock->cycle_interval;
clock->cycle_last += clock->cycle_interval;
while (offset >= timekeeper.cycle_interval) {
u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
clock->xtime_nsec += clock->xtime_interval;
if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) {
clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift;
/* accumulate one interval */
offset -= timekeeper.cycle_interval;
clock->cycle_last += timekeeper.cycle_interval;
timekeeper.xtime_nsec += timekeeper.xtime_interval;
if (timekeeper.xtime_nsec >= nsecps) {
timekeeper.xtime_nsec -= nsecps;
xtime.tv_sec++;
second_overflow();
}
clock->raw_time.tv_nsec += clock->raw_interval;
if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) {
clock->raw_time.tv_nsec -= NSEC_PER_SEC;
clock->raw_time.tv_sec++;
raw_time.tv_nsec += timekeeper.raw_interval;
if (raw_time.tv_nsec >= NSEC_PER_SEC) {
raw_time.tv_nsec -= NSEC_PER_SEC;
raw_time.tv_sec++;
}
/* accumulate error between NTP and clock interval */
clock->error += tick_length;
clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift);
timekeeper.ntp_error += tick_length;
timekeeper.ntp_error -= timekeeper.xtime_interval <<
timekeeper.ntp_error_shift;
}
/* correct the clock when NTP error is too big */
clocksource_adjust(offset);
timekeeping_adjust(offset);
/*
* Since in the loop above, we accumulate any amount of time
* in xtime_nsec over a second into xtime.tv_sec, its possible for
* xtime_nsec to be fairly small after the loop. Further, if we're
* slightly speeding the clocksource up in clocksource_adjust(),
* slightly speeding the clocksource up in timekeeping_adjust(),
* its possible the required corrective factor to xtime_nsec could
* cause it to underflow.
*
@ -550,24 +792,25 @@ void update_wall_time(void)
* We'll correct this error next time through this function, when
* xtime_nsec is not as small.
*/
if (unlikely((s64)clock->xtime_nsec < 0)) {
s64 neg = -(s64)clock->xtime_nsec;
clock->xtime_nsec = 0;
clock->error += neg << (NTP_SCALE_SHIFT - clock->shift);
if (unlikely((s64)timekeeper.xtime_nsec < 0)) {
s64 neg = -(s64)timekeeper.xtime_nsec;
timekeeper.xtime_nsec = 0;
timekeeper.ntp_error += neg << timekeeper.ntp_error_shift;
}
/* store full nanoseconds into xtime after rounding it up and
* add the remainder to the error difference.
*/
xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1;
clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift;
clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift);
xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1;
timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift;
timekeeper.ntp_error += timekeeper.xtime_nsec <<
timekeeper.ntp_error_shift;
update_xtime_cache(cyc2ns(clock, offset));
nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift);
update_xtime_cache(nsecs);
/* check to see if there is a new clocksource to use */
change_clocksource();
update_vsyscall(&xtime, clock);
update_vsyscall(&xtime, timekeeper.clock);
}
/**
@ -583,9 +826,12 @@ void update_wall_time(void)
*/
void getboottime(struct timespec *ts)
{
set_normalized_timespec(ts,
- (wall_to_monotonic.tv_sec + total_sleep_time),
- wall_to_monotonic.tv_nsec);
struct timespec boottime = {
.tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec,
.tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec
};
set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
}
/**
@ -594,7 +840,7 @@ void getboottime(struct timespec *ts)
*/
void monotonic_to_bootbased(struct timespec *ts)
{
ts->tv_sec += total_sleep_time;
*ts = timespec_add_safe(*ts, total_sleep_time);
}
unsigned long get_seconds(void)
@ -603,6 +849,10 @@ unsigned long get_seconds(void)
}
EXPORT_SYMBOL(get_seconds);
struct timespec __current_kernel_time(void)
{
return xtime_cache;
}
struct timespec current_kernel_time(void)
{
@ -618,3 +868,20 @@ struct timespec current_kernel_time(void)
return now;
}
EXPORT_SYMBOL(current_kernel_time);
struct timespec get_monotonic_coarse(void)
{
struct timespec now, mono;
unsigned long seq;
do {
seq = read_seqbegin(&xtime_lock);
now = xtime_cache;
mono = wall_to_monotonic;
} while (read_seqretry(&xtime_lock, seq));
set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
now.tv_nsec + mono.tv_nsec);
return now;
}