[PATCH 07/35] clockevents: Make suspend/resume calls explicit
From: Peter Zijlstra
Date: Mon Feb 16 2015 - 08:19:39 EST
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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 <tglx@xxxxxxxxxxxxx>
---
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 <linux/types.h>
-#include <linux/clockchips.h>
+#include <linux/tick.h>
#include <xen/interface/xen.h>
#include <xen/grant_table.h>
@@ -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();
--
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