From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932981AbbBPNTf (ORCPT ); Mon, 16 Feb 2015 08:19:35 -0500 Received: from casper.infradead.org ([85.118.1.10]:55421 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932575AbbBPNJ1 (ORCPT ); Mon, 16 Feb 2015 08:09:27 -0500 Message-Id: <20150216122412.384801895@infradead.org> User-Agent: quilt/0.61-1 Date: Mon, 16 Feb 2015 13:14:42 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, mingo@kernel.org, rjw@rjwysocki.net Cc: tglx@linutronix.de, peterz@infradead.org Subject: [PATCH 07/35] clockevents: Make suspend/resume calls explicit References: <20150216121435.203983131@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=clockevents-make-resume-call-explicit.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner 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 --- 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 | 23 +++++++++++++++++++++-- kernel/time/tick-internal.h | 3 ++- kernel/time/timekeeping.c | 6 ++---- 7 files changed, 32 insertions(+), 25 deletions(-) Index: linux/arch/x86/xen/suspend.c =================================================================== --- linux.orig/arch/x86/xen/suspend.c +++ linux/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); } Index: linux/include/linux/clockchips.h =================================================================== --- linux.orig/include/linux/clockchips.h +++ linux/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, }; Index: linux/include/linux/tick.h =================================================================== --- linux.orig/include/linux/tick.h +++ linux/include/linux/tick.h @@ -27,8 +27,11 @@ extern struct tick_device *tick_get_devi #ifdef CONFIG_GENERIC_CLOCKEVENTS extern void __init tick_init(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_resume(void) { } #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ #ifdef CONFIG_TICK_ONESHOT Index: linux/kernel/time/clockevents.c =================================================================== --- linux.orig/kernel/time/clockevents.c +++ linux/kernel/time/clockevents.c @@ -566,15 +566,6 @@ int clockevents_notify(unsigned long rea 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); Index: linux/kernel/time/tick-common.c =================================================================== --- linux.orig/kernel/time/tick-common.c +++ linux/kernel/time/tick-common.c @@ -372,18 +372,37 @@ 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. + * + * 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. + * + * 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_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME); if (!broadcast) { Index: linux/kernel/time/tick-internal.h =================================================================== --- linux.orig/kernel/time/tick-internal.h +++ linux/kernel/time/tick-internal.h @@ -23,7 +23,6 @@ extern void tick_check_new_device(struct 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); @@ -41,6 +40,8 @@ extern void clockevents_exchange_device( 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 */ Index: linux/kernel/time/timekeeping.c =================================================================== --- linux.orig/kernel/time/timekeeping.c +++ linux/kernel/time/timekeeping.c @@ -1245,9 +1245,7 @@ static void timekeeping_resume(void) touch_softlockup_watchdog(); - clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); - - /* Resume hrtimers */ + tick_resume(); hrtimers_resume(); } @@ -1299,7 +1297,7 @@ static 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();