From 4ffee521f36390c7720d493591b764ca35c8030b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 25 Mar 2015 13:09:16 +0100 Subject: [PATCH] clockevents: Make suspend/resume calls explicit clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the suspend/resume() calls and invoke them directly from the call sites. No locking required at this point because these calls happen with interrupts disabled and a single cpu online. Signed-off-by: Thomas Gleixner [ Rebased on top of 4.0-rc5. ] Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/713674030.jVm1qaHuPf@vostro.rjw.lan [ Rebased on top of latest timers/core. ] Signed-off-by: Ingo Molnar --- arch/x86/xen/suspend.c | 11 ++++------- include/linux/clockchips.h | 2 -- include/linux/tick.h | 3 +++ kernel/time/clockevents.c | 9 --------- kernel/time/tick-common.c | 26 +++++++++++++++++++++++--- kernel/time/tick-internal.h | 3 ++- kernel/time/timekeeping.c | 6 ++---- 7 files changed, 34 insertions(+), 26 deletions(-) diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index c4df9dbd63b7..033e428581f4 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -1,5 +1,5 @@ #include -#include +#include #include #include @@ -81,17 +81,14 @@ void xen_arch_post_suspend(int cancelled) static void xen_vcpu_notify_restore(void *data) { - unsigned long reason = (unsigned long)data; - /* Boot processor notified via generic timekeeping_resume() */ - if ( smp_processor_id() == 0) + if (smp_processor_id() == 0) return; - clockevents_notify(reason, NULL); + tick_resume(); } void xen_arch_resume(void) { - on_each_cpu(xen_vcpu_notify_restore, - (void *)CLOCK_EVT_NOTIFY_RESUME, 1); + on_each_cpu(xen_vcpu_notify_restore, NULL, 1); } diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index bc3af821350b..50ce9750754f 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -16,8 +16,6 @@ enum clock_event_nofitiers { CLOCK_EVT_NOTIFY_BROADCAST_FORCE, CLOCK_EVT_NOTIFY_BROADCAST_ENTER, CLOCK_EVT_NOTIFY_BROADCAST_EXIT, - CLOCK_EVT_NOTIFY_SUSPEND, - CLOCK_EVT_NOTIFY_RESUME, CLOCK_EVT_NOTIFY_CPU_DYING, CLOCK_EVT_NOTIFY_CPU_DEAD, }; diff --git a/include/linux/tick.h b/include/linux/tick.h index f9a2d2687a46..7e07e0e3d898 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -29,10 +29,13 @@ extern struct tick_device *tick_get_device(int cpu); extern void __init tick_init(void); extern void tick_freeze(void); extern void tick_unfreeze(void); +/* Should be core only, but XEN resume magic abuses this interface */ +extern void tick_resume(void); #else /* CONFIG_GENERIC_CLOCKEVENTS */ static inline void tick_init(void) { } static inline void tick_freeze(void) { } static inline void tick_unfreeze(void) { } +static inline void tick_resume(void) { } #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ #ifdef CONFIG_TICK_ONESHOT diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index b73002718536..7af614829da1 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -670,15 +670,6 @@ int clockevents_notify(unsigned long reason, void *arg) tick_handover_do_timer(arg); break; - case CLOCK_EVT_NOTIFY_SUSPEND: - tick_suspend(); - tick_suspend_broadcast(); - break; - - case CLOCK_EVT_NOTIFY_RESUME: - tick_resume(); - break; - case CLOCK_EVT_NOTIFY_CPU_DEAD: tick_shutdown_broadcast_oneshot(arg); tick_shutdown_broadcast(arg); diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index a5b877130ae9..1a60c2ae96a8 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -373,18 +373,39 @@ void tick_shutdown(unsigned int *cpup) } } +/** + * tick_suspend - Suspend the tick and the broadcast device + * + * Called from syscore_suspend() via timekeeping_suspend with only one + * CPU online and interrupts disabled or from tick_unfreeze() under + * tick_freeze_lock. + * + * No locks required. Nothing can change the per cpu device. + */ void tick_suspend(void) { struct tick_device *td = this_cpu_ptr(&tick_cpu_device); clockevents_shutdown(td->evtdev); + tick_suspend_broadcast(); } +/** + * tick_resume - Resume the tick and the broadcast device + * + * Called from syscore_resume() via timekeeping_resume with only one + * CPU online and interrupts disabled or from tick_unfreeze() under + * tick_freeze_lock. + * + * No locks required. Nothing can change the per cpu device. + */ void tick_resume(void) { - struct tick_device *td = this_cpu_ptr(&tick_cpu_device); - int broadcast = tick_resume_broadcast(); + struct tick_device *td; + int broadcast; + broadcast = tick_resume_broadcast(); + td = this_cpu_ptr(&tick_cpu_device); clockevents_tick_resume(td->evtdev); if (!broadcast) { @@ -416,7 +437,6 @@ void tick_freeze(void) timekeeping_suspend(); } else { tick_suspend(); - tick_suspend_broadcast(); } raw_spin_unlock(&tick_freeze_lock); diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index dd2c45d057b9..85a957195bf6 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -23,7 +23,6 @@ extern void tick_check_new_device(struct clock_event_device *dev); extern void tick_handover_do_timer(int *cpup); extern void tick_shutdown(unsigned int *cpup); extern void tick_suspend(void); -extern void tick_resume(void); extern bool tick_check_replacement(struct clock_event_device *curdev, struct clock_event_device *newdev); extern void tick_install_replacement(struct clock_event_device *dev); @@ -42,6 +41,8 @@ extern void clockevents_exchange_device(struct clock_event_device *old, extern void clockevents_handle_noop(struct clock_event_device *dev); extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq); extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt); +#else +static inline void tick_suspend(void) { } #endif /* GENERIC_CLOCKEVENTS */ /* Oneshot related functions */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index c3fcff06d30a..5b12292b343a 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1389,9 +1389,7 @@ void timekeeping_resume(void) touch_softlockup_watchdog(); - clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); - - /* Resume hrtimers */ + tick_resume(); hrtimers_resume(); } @@ -1444,7 +1442,7 @@ int timekeeping_suspend(void) write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); - clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); + tick_suspend(); clocksource_suspend(); clockevents_suspend(); -- GitLab