The patch titled
clockevents: Add broadcast support
has been added to the -mm tree. Its filename is
clockevents-add-broadcast-support.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: clockevents: Add broadcast support
x86 needs timer broadcasting for C-States which stop the local APIC timer
Add this functionality to clockevents, so highres/dyntick timers can work
on such systems.
Signed-of-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/clockchips.h | 21 +++
kernel/time/clockevents.c | 201 +++++++++++++++++++++++++++++++++--
2 files changed, 213 insertions(+), 9 deletions(-)
diff -puN include/linux/clockchips.h~clockevents-add-broadcast-support include/linux/clockchips.h
--- a/include/linux/clockchips.h~clockevents-add-broadcast-support
+++ a/include/linux/clockchips.h
@@ -114,9 +114,30 @@ extern int clockevents_set_next_event(kt
extern int clockevents_next_event_available(void);
extern void clockevents_resume_events(void);
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+extern void clockevents_set_broadcast(struct clock_event_device *evt,
+ int broadcast);
+extern void clockevents_set_global_broadcast(struct clock_event_device *evt,
+ int broadcast);
+extern int clockevents_register_broadcast(void (*fun)(cpumask_t *mask));
#else
+static inline void clockevents_set_broadcast(struct clock_event_device *evt,
+ int broadcast)
+{
+}
+#endif
+
+#else
+
# define clockevents_init() do { } while(0)
# define clockevents_resume_events() do { } while(0)
+
+struct clock_event_device;
+static inline void clockevents_set_broadcast(struct clock_event_device *evt,
+ int broadcast)
+{
+}
+
#endif
#endif
diff -puN kernel/time/clockevents.c~clockevents-add-broadcast-support kernel/time/clockevents.c
--- a/kernel/time/clockevents.c~clockevents-add-broadcast-support
+++ a/kernel/time/clockevents.c
@@ -49,6 +49,7 @@ struct local_events {
int installed;
struct event_descr events[MAX_CLOCK_EVENTS];
struct clock_event_device *nextevt;
+ ktime_t expires_next;
};
/* Variables related to the global event device */
@@ -66,6 +67,12 @@ static DEFINE_SPINLOCK(events_lock);
/* Variables related to the per cpu local event devices */
static DEFINE_PER_CPU(struct local_events, local_eventdevices);
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+static void clockevents_check_broadcast(struct event_descr *descr);
+#else
+static inline void clockevents_check_broadcast(struct event_descr *descr) { }
+#endif
+
/*
* Math helper. Convert a latch value (device ticks) to nanoseconds
*/
@@ -301,6 +308,7 @@ static void recalc_active_event(struct e
descr->event->name);
}
descr->real_caps = caps;
+ clockevents_check_broadcast(descr);
}
/*
@@ -464,6 +472,24 @@ int clockevents_init_next_event(void)
return ret;
}
+/*
+ * Reprogram the clock event device. Internal helper function
+ */
+static void do_clockevents_set_next_event(struct clock_event_device *nextevt,
+ int64_t delta)
+{
+ unsigned long long clc;
+
+ if (delta > nextevt->max_delta_ns)
+ delta = nextevt->max_delta_ns;
+ if (delta < nextevt->min_delta_ns)
+ delta = nextevt->min_delta_ns;
+
+ clc = delta * nextevt->mult;
+ clc >>= nextevt->shift;
+ nextevt->set_next_event((unsigned long)clc, nextevt);
+}
+
/**
* clockevents_set_next_event - Reprogram the clock event device.
* @expires: absolute expiry time (monotonic clock)
@@ -472,29 +498,186 @@ int clockevents_init_next_event(void)
*
* Returns 0 on success, -ETIME when the event is in the past and force is not
* set.
+ * Called with interrupts disabled.
*/
int clockevents_set_next_event(ktime_t expires, int force)
{
struct local_events *devices = &__get_cpu_var(local_eventdevices);
int64_t delta = ktime_to_ns(ktime_sub(expires, ktime_get()));
struct clock_event_device *nextevt = devices->nextevt;
- unsigned long long clc;
- if (delta <= 0 && !force)
+ if (delta <= 0 && !force) {
+ devices->expires_next.tv64 = KTIME_MAX;
return -ETIME;
+ }
- if (delta > nextevt->max_delta_ns)
- delta = nextevt->max_delta_ns;
- if (delta < nextevt->min_delta_ns)
- delta = nextevt->min_delta_ns;
+ devices->expires_next = expires;
- clc = delta * nextevt->mult;
- clc >>= nextevt->shift;
- nextevt->set_next_event((unsigned long)clc, devices->nextevt);
+ do_clockevents_set_next_event(nextevt, delta);
return 0;
}
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+
+static cpumask_t global_event_broadcast;
+static cpumask_t local_event_broadcast;
+static void (*broadcast_function)(cpumask_t *mask);
+static void (*global_event_handler)(struct pt_regs *regs);
+
+/**
+ * clockevents_set_broadcast - switch next event device from/to broadcast mode
+ *
+ * Called, when the PM code enters a state, where the next event device is
+ * switched off.
+ *
+ * Called with interrupts disabled !
+ */
+void clockevents_set_broadcast(struct clock_event_device *evt, int broadcast)
+{
+ struct local_events *devices = &__get_cpu_var(local_eventdevices);
+ struct clock_event_device *glblevt = global_eventdevice.event;
+ int cpu = smp_processor_id();
+ ktime_t expires = { .tv64 = KTIME_MAX };
+ int64_t delta;
+ unsigned long flags;
+
+ if (devices->nextevt != evt)
+ return;
+
+ spin_lock_irqsave(&events_lock, flags);
+
+ if (broadcast) {
+ cpu_set(cpu, local_event_broadcast);
+ evt->set_mode(CLOCK_EVT_SHUTDOWN, evt);
+ } else {
+ cpu_clear(cpu, local_event_broadcast);
+ evt->set_mode(CLOCK_EVT_ONESHOT, evt);
+ }
+
+ /* Reprogram the broadcast device */
+ for (cpu = first_cpu(local_event_broadcast); cpu != NR_CPUS;
+ cpu = next_cpu(cpu, local_event_broadcast)) {
+ devices = &per_cpu(local_eventdevices, cpu);
+ if (devices->expires_next.tv64 < expires.tv64)
+ expires = devices->expires_next;
+ }
+
+ if (expires.tv64 != KTIME_MAX) {
+ delta = ktime_to_ns(ktime_sub(expires, ktime_get()));
+ do_clockevents_set_next_event(glblevt, delta);
+ }
+
+ spin_unlock_irqrestore(&events_lock, flags);
+}
+
+/**
+ * clockevents_set_global_broadcast - mark event device for global broadcast
+ *
+ * Switch an event device from / to global broadcasting. This is only relevant
+ * when the system has not switched to high resolution mode.
+ */
+void clockevents_set_global_broadcast(struct clock_event_device *evt,
+ int broadcast)
+{
+ struct local_events *devices = &__get_cpu_var(local_eventdevices);
+ int cpu = smp_processor_id();
+ unsigned long flags;
+
+ spin_lock_irqsave(&events_lock, flags);
+
+ if (broadcast) {
+ if (!cpu_isset(cpu, global_event_broadcast)) {
+ cpu_set(cpu, global_event_broadcast);
+ if (devices->nextevt != evt)
+ evt->set_mode(CLOCK_EVT_SHUTDOWN, evt);
+ }
+ } else {
+ if (cpu_isset(cpu, global_event_broadcast)) {
+ cpu_clear(cpu, global_event_broadcast);
+ if (devices->nextevt != evt)
+ evt->set_mode(CLOCK_EVT_PERIODIC, evt);
+ }
+ }
+
+ spin_unlock_irqrestore(&events_lock, flags);
+}
+
+/*
+ * Broadcast tick handler:
+ */
+static void handle_tick_broadcast(struct pt_regs *regs)
+{
+ /* Call the original handler global tick handler */
+ global_event_handler(regs);
+ broadcast_function(&global_event_broadcast);
+}
+
+/*
+ * Broadcast next event handler:
+ */
+static void handle_nextevt_broadcast(struct pt_regs *regs)
+{
+ struct local_events *devices;
+ ktime_t now = ktime_get();
+ cpumask_t mask;
+ int cpu;
+
+ spin_lock(&events_lock);
+ /* Find all expired events */
+ for (cpu = first_cpu(local_event_broadcast); cpu != NR_CPUS;
+ cpu = next_cpu(cpu, local_event_broadcast)) {
+ devices = &per_cpu(local_eventdevices, cpu);
+ if (devices->expires_next.tv64 <= now.tv64)
+ cpu_set(cpu, mask);
+ }
+ spin_unlock(&events_lock);
+ /* Wakeup the cpus which have an expired event */
+ broadcast_function(&mask);
+}
+
+/*
+ * Check, if the reconfigured event device is the global broadcast device.
+ *
+ * Called with interrupts disabled and events_lock held
+ */
+static void clockevents_check_broadcast(struct event_descr *descr)
+{
+ if (descr != &global_eventdevice)
+ return;
+
+ /* The device was disabled. switch it to oneshot mode instead */
+ if (!descr->real_caps) {
+ global_event_handler = NULL;
+ descr->event->set_mode(CLOCK_EVT_ONESHOT, descr->event);
+ descr->event->event_handler = handle_nextevt_broadcast;
+ } else {
+ global_event_handler = descr->event->event_handler;
+ descr->event->event_handler = handle_tick_broadcast;
+ }
+
+}
+
+/*
+ * Install a broadcast function
+ */
+int clockevents_register_broadcast(void (*fun)(cpumask_t *mask))
+{
+ unsigned long flags;
+
+ if (broadcast_function)
+ return -EBUSY;
+
+ spin_lock_irqsave(&events_lock, flags);
+ broadcast_function = fun;
+ clockevents_check_broadcast(&global_eventdevice);
+ spin_unlock_irqrestore(&events_lock, flags);
+
+ return 0;
+}
+
+#endif
+
/*
* Resume the cpu local clock events
*/
_
Patches currently in -mm which might be from tglx@xxxxxxxxxxxxx are
printk-timed-ratelimit.patch
schedule-removal-of-futex_fd.patch
setup_irq-better-mismatch-debugging.patch
gtod-exponential-update_wall_time.patch
gtod-persistent-clock-support-core.patch
gtod-persistent-clock-support-i386.patch
time-uninline-jiffiesh.patch
time-uninline-jiffiesh-fix.patch
time-fix-msecs_to_jiffies-bug.patch
time-fix-timeout-overflow.patch
cleanup-uninline-irq_enter-and-move-it-into-a-function.patch
dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie.patch
dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie-remove-incorrect-warning-in-kernel-timerc.patch
hrtimers-namespace-and-enum-cleanup.patch
hrtimers-clean-up-locking.patch
hrtimers-state-tracking.patch
hrtimers-clean-up-callback-tracking.patch
hrtimers-move-and-add-documentation.patch
clockevents-core.patch
clockevents-drivers-for-i386.patch
high-res-timers-core.patch
gtod-mark-tsc-unusable-for-highres-timers.patch
dynticks-core.patch
dynticks-add-nohz-stats-to-proc-stat.patch
dynticks-i386-arch-code.patch
high-res-timers-dynticks-enable-i386-support.patch
debugging-feature-timer-stats.patch
highres-timer-core-fix-status-check.patch
highres-timer-core-fix-commandline-setup.patch
clockevents-smp-on-up-features.patch
highres-depend-on-clockevents.patch
i386-apic-cleanup.patch
pm-timer-allow-early-access.patch
i386-lapic-timer-calibration.patch
clockevents-add-broadcast-support.patch
acpi-include-apic-h.patch
acpi-keep-track-of-timer-broadcast.patch
i386-apic-timer-use-clockevents-broadcast.patch
acpi-verify-lapic-timer.patch
round_jiffies-infrastructure.patch
round_jiffies-infrastructure-fix.patch
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