diff options
Diffstat (limited to 'kernel/time/clocksource.c')
| -rw-r--r-- | kernel/time/clocksource.c | 48 |
1 files changed, 34 insertions, 14 deletions
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index a20368e1a720..3b43159ab41f 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -108,7 +108,7 @@ static int finished_booting; #ifdef CONFIG_CLOCKSOURCE_WATCHDOG static void clocksource_watchdog_work(struct work_struct *work); -static void clocksource_select(void); +static void clocksource_select(bool force); static LIST_HEAD(watchdog_list); static struct clocksource *watchdog; @@ -422,7 +422,7 @@ static int clocksource_watchdog_kthread(void *data) { mutex_lock(&clocksource_mutex); if (__clocksource_watchdog_kthread()) - clocksource_select(); + clocksource_select(false); mutex_unlock(&clocksource_mutex); return 0; } @@ -562,11 +562,12 @@ static inline void clocksource_update_max_deferment(struct clocksource *cs) #ifndef CONFIG_ARCH_USES_GETTIMEOFFSET -static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur) +static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur, + bool force) { struct clocksource *cs; - if (!finished_booting || list_empty(&clocksource_list)) + if ((!finished_booting && !force) || list_empty(&clocksource_list)) return NULL; /* @@ -584,13 +585,13 @@ static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur) return NULL; } -static void __clocksource_select(bool skipcur) +static void __clocksource_select(bool skipcur, bool force) { bool oneshot = tick_oneshot_mode_active(); struct clocksource *best, *cs; /* Find the best suitable clocksource */ - best = clocksource_find_best(oneshot, skipcur); + best = clocksource_find_best(oneshot, skipcur, force); if (!best) return; @@ -630,22 +631,40 @@ static void __clocksource_select(bool skipcur) * Select the clocksource with the best rating, or the clocksource, * which is selected by userspace override. */ -static void clocksource_select(void) +static void clocksource_select(bool force) { - __clocksource_select(false); + return __clocksource_select(false, force); } static void clocksource_select_fallback(void) { - __clocksource_select(true); + __clocksource_select(true, false); } #else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */ -static inline void clocksource_select(void) { } + +static inline void clocksource_select(bool force) { } static inline void clocksource_select_fallback(void) { } #endif +/** + * clocksource_select_force - Force re-selection of the best clocksource + * among registered clocksources + * + * clocksource_select() can't select the best clocksource before + * calling clocksource_done_booting() and since clocksource_select() + * should be called with clocksource_mutex held, provide a new API + * can be called from other files to select best clockrouce irrespective + * of finished_booting flag. + */ +void clocksource_select_force(void) +{ + mutex_lock(&clocksource_mutex); + clocksource_select(true); + mutex_unlock(&clocksource_mutex); +} + /* * clocksource_done_booting - Called near the end of core bootup * @@ -662,7 +681,7 @@ static int __init clocksource_done_booting(void) * Run the watchdog first to eliminate unstable clock sources */ __clocksource_watchdog_kthread(); - clocksource_select(); + clocksource_select(false); mutex_unlock(&clocksource_mutex); return 0; } @@ -751,6 +770,7 @@ void __clocksource_update_freq_scale(struct clocksource *cs, u32 scale, u32 freq } EXPORT_SYMBOL_GPL(__clocksource_update_freq_scale); + /** * __clocksource_register_scale - Used to install new clocksources * @cs: clocksource to be registered @@ -772,7 +792,7 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); clocksource_enqueue_watchdog(cs); - clocksource_select(); + clocksource_select(false); clocksource_select_watchdog(false); mutex_unlock(&clocksource_mutex); return 0; @@ -795,7 +815,7 @@ void clocksource_change_rating(struct clocksource *cs, int rating) { mutex_lock(&clocksource_mutex); __clocksource_change_rating(cs, rating); - clocksource_select(); + clocksource_select(false); clocksource_select_watchdog(false); mutex_unlock(&clocksource_mutex); } @@ -899,7 +919,7 @@ static ssize_t sysfs_override_clocksource(struct device *dev, ret = sysfs_get_uname(buf, override_name, count); if (ret >= 0) - clocksource_select(); + clocksource_select(false); mutex_unlock(&clocksource_mutex); |