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authorMark Brown <broonie@kernel.org>2015-01-22 11:00:04 +0000
committerMark Brown <broonie@kernel.org>2015-01-22 11:00:04 +0000
commit17d1e25c88c8fb108faddf3276aa74331f17aabe (patch)
treea0a613afa4fab27373f3543b0560193a9d3bdbbc
parent22ad963d66fa029662b459d2066017f9c4a99ee9 (diff)
parent709d22822886bfb105a1c498c14ab6647d0f1284 (diff)
downloadlinux-linaro-stable-17d1e25c88c8fb108faddf3276aa74331f17aabe.tar.gz
Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-android
-rw-r--r--include/linux/clockchips.h16
-rw-r--r--kernel/time/Makefile5
-rw-r--r--kernel/time/clockevents.c34
-rw-r--r--kernel/time/tick-broadcast-hrtimer.c106
-rw-r--r--kernel/time/tick-broadcast.c60
-rw-r--r--kernel/time/tick-common.c47
-rw-r--r--kernel/time/tick-internal.h13
7 files changed, 222 insertions, 59 deletions
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index ae1193bcf074..3abe1e9a1bde 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -61,6 +61,11 @@ enum clock_event_mode {
*/
#define CLOCK_EVT_FEAT_DYNIRQ 0x000020
+/*
+ * Clockevent device is based on a hrtimer for broadcast
+ */
+#define CLOCK_EVT_FEAT_HRTIMER 0x000080
+
/**
* struct clock_event_device - clock event device descriptor
* @event_handler: Assigned by the framework to be called by the low
@@ -82,6 +87,7 @@ enum clock_event_mode {
* @name: ptr to clock event name
* @rating: variable to rate clock event devices
* @irq: IRQ number (only for non CPU local devices)
+ * @bound_on: Bound on CPU
* @cpumask: cpumask to indicate for which CPUs this device works
* @list: list head for the management code
* @owner: module reference
@@ -112,6 +118,7 @@ struct clock_event_device {
const char *name;
int rating;
int irq;
+ int bound_on;
const struct cpumask *cpumask;
struct list_head list;
struct module *owner;
@@ -178,15 +185,17 @@ extern int tick_receive_broadcast(void);
#endif
#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
+extern void tick_setup_hrtimer_broadcast(void);
extern int tick_check_broadcast_expired(void);
#else
static inline int tick_check_broadcast_expired(void) { return 0; }
+static inline void tick_setup_hrtimer_broadcast(void) {};
#endif
#ifdef CONFIG_GENERIC_CLOCKEVENTS
-extern void clockevents_notify(unsigned long reason, void *arg);
+extern int clockevents_notify(unsigned long reason, void *arg);
#else
-static inline void clockevents_notify(unsigned long reason, void *arg) {}
+static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
#endif
#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
@@ -194,8 +203,9 @@ static inline void clockevents_notify(unsigned long reason, void *arg) {}
static inline void clockevents_suspend(void) {}
static inline void clockevents_resume(void) {}
-static inline void clockevents_notify(unsigned long reason, void *arg) {}
+static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
static inline int tick_check_broadcast_expired(void) { return 0; }
+static inline void tick_setup_hrtimer_broadcast(void) {};
#endif
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index ff7d9d2ab504..a64e0de74c0d 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -3,7 +3,10 @@ obj-y += timeconv.o posix-clock.o alarmtimer.o
obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD) += clockevents.o
obj-$(CONFIG_GENERIC_CLOCKEVENTS) += tick-common.o
-obj-$(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) += tick-broadcast.o
+ifeq ($(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST),y)
+ obj-y += tick-broadcast.o
+ obj-$(CONFIG_TICK_ONESHOT) += tick-broadcast-hrtimer.o
+endif
obj-$(CONFIG_TICK_ONESHOT) += tick-oneshot.o
obj-$(CONFIG_TICK_ONESHOT) += tick-sched.o
obj-$(CONFIG_TIMER_STATS) += timer_stats.o
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 58e8430165b5..378613bebb13 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -434,18 +434,45 @@ void clockevents_resume(void)
#ifdef CONFIG_GENERIC_CLOCKEVENTS
/**
* clockevents_notify - notification about relevant events
+ * Returns 0 on success, any other value on error
*/
-void clockevents_notify(unsigned long reason, void *arg)
+int clockevents_notify(unsigned long reason, void *arg)
{
struct clock_event_device *dev, *tmp;
unsigned long flags;
- int cpu;
+ int cpu, ret = 0;
raw_spin_lock_irqsave(&clockevents_lock, flags);
- tick_notify(reason, arg);
switch (reason) {
+ case CLOCK_EVT_NOTIFY_BROADCAST_ON:
+ case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
+ case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
+ tick_broadcast_on_off(reason, arg);
+ break;
+
+ case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
+ case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
+ ret = tick_broadcast_oneshot_control(reason);
+ break;
+
+ case CLOCK_EVT_NOTIFY_CPU_DYING:
+ 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);
+ tick_shutdown(arg);
/*
* Unregister the clock event devices which were
* released from the users in the notify chain.
@@ -469,6 +496,7 @@ void clockevents_notify(unsigned long reason, void *arg)
break;
}
raw_spin_unlock_irqrestore(&clockevents_lock, flags);
+ return ret;
}
EXPORT_SYMBOL_GPL(clockevents_notify);
#endif
diff --git a/kernel/time/tick-broadcast-hrtimer.c b/kernel/time/tick-broadcast-hrtimer.c
new file mode 100644
index 000000000000..eb682d5c697c
--- /dev/null
+++ b/kernel/time/tick-broadcast-hrtimer.c
@@ -0,0 +1,106 @@
+/*
+ * linux/kernel/time/tick-broadcast-hrtimer.c
+ * This file emulates a local clock event device
+ * via a pseudo clock device.
+ */
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/interrupt.h>
+#include <linux/percpu.h>
+#include <linux/profile.h>
+#include <linux/clockchips.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/module.h>
+
+#include "tick-internal.h"
+
+static struct hrtimer bctimer;
+
+static void bc_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *bc)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ /*
+ * Note, we cannot cancel the timer here as we might
+ * run into the following live lock scenario:
+ *
+ * cpu 0 cpu1
+ * lock(broadcast_lock);
+ * hrtimer_interrupt()
+ * bc_handler()
+ * tick_handle_oneshot_broadcast();
+ * lock(broadcast_lock);
+ * hrtimer_cancel()
+ * wait_for_callback()
+ */
+ hrtimer_try_to_cancel(&bctimer);
+ break;
+ default:
+ break;
+ }
+}
+
+/*
+ * This is called from the guts of the broadcast code when the cpu
+ * which is about to enter idle has the earliest broadcast timer event.
+ */
+static int bc_set_next(ktime_t expires, struct clock_event_device *bc)
+{
+ /*
+ * We try to cancel the timer first. If the callback is on
+ * flight on some other cpu then we let it handle it. If we
+ * were able to cancel the timer nothing can rearm it as we
+ * own broadcast_lock.
+ *
+ * However we can also be called from the event handler of
+ * ce_broadcast_hrtimer itself when it expires. We cannot
+ * restart the timer because we are in the callback, but we
+ * can set the expiry time and let the callback return
+ * HRTIMER_RESTART.
+ */
+ if (hrtimer_try_to_cancel(&bctimer) >= 0) {
+ hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED);
+ /* Bind the "device" to the cpu */
+ bc->bound_on = smp_processor_id();
+ } else if (bc->bound_on == smp_processor_id()) {
+ hrtimer_set_expires(&bctimer, expires);
+ }
+ return 0;
+}
+
+static struct clock_event_device ce_broadcast_hrtimer = {
+ .set_mode = bc_set_mode,
+ .set_next_ktime = bc_set_next,
+ .features = CLOCK_EVT_FEAT_ONESHOT |
+ CLOCK_EVT_FEAT_KTIME |
+ CLOCK_EVT_FEAT_HRTIMER,
+ .rating = 0,
+ .bound_on = -1,
+ .min_delta_ns = 1,
+ .max_delta_ns = KTIME_MAX,
+ .min_delta_ticks = 1,
+ .max_delta_ticks = ULONG_MAX,
+ .mult = 1,
+ .shift = 0,
+ .cpumask = cpu_all_mask,
+};
+
+static enum hrtimer_restart bc_handler(struct hrtimer *t)
+{
+ ce_broadcast_hrtimer.event_handler(&ce_broadcast_hrtimer);
+
+ if (ce_broadcast_hrtimer.next_event.tv64 == KTIME_MAX)
+ return HRTIMER_NORESTART;
+
+ return HRTIMER_RESTART;
+}
+
+void tick_setup_hrtimer_broadcast(void)
+{
+ hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ bctimer.function = bc_handler;
+ clockevents_register_device(&ce_broadcast_hrtimer);
+}
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 19ee339a1d0d..16f4830a5498 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -626,24 +626,61 @@ again:
raw_spin_unlock(&tick_broadcast_lock);
}
+static int broadcast_needs_cpu(struct clock_event_device *bc, int cpu)
+{
+ if (!(bc->features & CLOCK_EVT_FEAT_HRTIMER))
+ return 0;
+ if (bc->next_event.tv64 == KTIME_MAX)
+ return 0;
+ return bc->bound_on == cpu ? -EBUSY : 0;
+}
+
+static void broadcast_shutdown_local(struct clock_event_device *bc,
+ struct clock_event_device *dev)
+{
+ /*
+ * For hrtimer based broadcasting we cannot shutdown the cpu
+ * local device if our own event is the first one to expire or
+ * if we own the broadcast timer.
+ */
+ if (bc->features & CLOCK_EVT_FEAT_HRTIMER) {
+ if (broadcast_needs_cpu(bc, smp_processor_id()))
+ return;
+ if (dev->next_event.tv64 < bc->next_event.tv64)
+ return;
+ }
+ clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
+}
+
+static void broadcast_move_bc(int deadcpu)
+{
+ struct clock_event_device *bc = tick_broadcast_device.evtdev;
+
+ if (!bc || !broadcast_needs_cpu(bc, deadcpu))
+ return;
+ /* This moves the broadcast assignment to this cpu */
+ clockevents_program_event(bc, bc->next_event, 1);
+}
+
/*
* Powerstate information: The system enters/leaves a state, where
* affected devices might stop
+ * Returns 0 on success, -EBUSY if the cpu is used to broadcast wakeups.
*/
-void tick_broadcast_oneshot_control(unsigned long reason)
+int tick_broadcast_oneshot_control(unsigned long reason)
{
struct clock_event_device *bc, *dev;
struct tick_device *td;
unsigned long flags;
ktime_t now;
- int cpu;
+ int cpu, ret = 0;
/*
* Periodic mode does not care about the enter/exit of power
* states
*/
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
- return;
+ return 0;
/*
* We are called with preemtion disabled from the depth of the
@@ -654,7 +691,7 @@ void tick_broadcast_oneshot_control(unsigned long reason)
dev = td->evtdev;
if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
- return;
+ return 0;
bc = tick_broadcast_device.evtdev;
@@ -662,7 +699,7 @@ void tick_broadcast_oneshot_control(unsigned long reason)
if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) {
if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_oneshot_mask)) {
WARN_ON_ONCE(cpumask_test_cpu(cpu, tick_broadcast_pending_mask));
- clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
+ broadcast_shutdown_local(bc, dev);
/*
* We only reprogram the broadcast timer if we
* did not mark ourself in the force mask and
@@ -675,6 +712,16 @@ void tick_broadcast_oneshot_control(unsigned long reason)
dev->next_event.tv64 < bc->next_event.tv64)
tick_broadcast_set_event(bc, cpu, dev->next_event, 1);
}
+ /*
+ * If the current CPU owns the hrtimer broadcast
+ * mechanism, it cannot go deep idle and we remove the
+ * CPU from the broadcast mask. We don't have to go
+ * through the EXIT path as the local timer is not
+ * shutdown.
+ */
+ ret = broadcast_needs_cpu(bc, cpu);
+ if (ret)
+ cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask);
} else {
if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_oneshot_mask)) {
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
@@ -742,6 +789,7 @@ void tick_broadcast_oneshot_control(unsigned long reason)
}
out:
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+ return ret;
}
/*
@@ -848,6 +896,8 @@ void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
cpumask_clear_cpu(cpu, tick_broadcast_pending_mask);
cpumask_clear_cpu(cpu, tick_broadcast_force_mask);
+ broadcast_move_bc(cpu);
+
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 086216c433fa..21711bc2bc25 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -303,7 +303,7 @@ out_bc:
*
* Called with interrupts disabled.
*/
-static void tick_handover_do_timer(int *cpup)
+void tick_handover_do_timer(int *cpup)
{
if (*cpup == tick_do_timer_cpu) {
int cpu = cpumask_first(cpu_online_mask);
@@ -320,7 +320,7 @@ static void tick_handover_do_timer(int *cpup)
* access the hardware device itself.
* We just set the mode and remove it from the lists.
*/
-static void tick_shutdown(unsigned int *cpup)
+void tick_shutdown(unsigned int *cpup)
{
struct tick_device *td = &per_cpu(tick_cpu_device, *cpup);
struct clock_event_device *dev = td->evtdev;
@@ -341,7 +341,7 @@ static void tick_shutdown(unsigned int *cpup)
raw_spin_unlock_irqrestore(&tick_device_lock, flags);
}
-static void tick_suspend(void)
+void tick_suspend(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
@@ -351,7 +351,7 @@ static void tick_suspend(void)
raw_spin_unlock_irqrestore(&tick_device_lock, flags);
}
-static void tick_resume(void)
+void tick_resume(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
@@ -369,45 +369,6 @@ static void tick_resume(void)
raw_spin_unlock_irqrestore(&tick_device_lock, flags);
}
-void tick_notify(unsigned long reason, void *dev)
-{
- switch (reason) {
-
- case CLOCK_EVT_NOTIFY_BROADCAST_ON:
- case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
- case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
- tick_broadcast_on_off(reason, dev);
- break;
-
- case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
- case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
- tick_broadcast_oneshot_control(reason);
- break;
-
- case CLOCK_EVT_NOTIFY_CPU_DYING:
- tick_handover_do_timer(dev);
- break;
-
- case CLOCK_EVT_NOTIFY_CPU_DEAD:
- tick_shutdown_broadcast_oneshot(dev);
- tick_shutdown_broadcast(dev);
- tick_shutdown(dev);
- break;
-
- case CLOCK_EVT_NOTIFY_SUSPEND:
- tick_suspend();
- tick_suspend_broadcast();
- break;
-
- case CLOCK_EVT_NOTIFY_RESUME:
- tick_resume();
- break;
-
- default:
- break;
- }
-}
-
/**
* tick_init - initialize the tick control
*/
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 60742fe6f63d..c85edb18d68e 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -18,8 +18,11 @@ extern int tick_do_timer_cpu __read_mostly;
extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
extern void tick_handle_periodic(struct clock_event_device *dev);
-extern void tick_notify(unsigned long reason, void *dev);
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 void clockevents_shutdown(struct clock_event_device *dev);
@@ -36,7 +39,7 @@ extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
extern void tick_resume_oneshot(void);
# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
-extern void tick_broadcast_oneshot_control(unsigned long reason);
+extern int tick_broadcast_oneshot_control(unsigned long reason);
extern void tick_broadcast_switch_to_oneshot(void);
extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
@@ -48,7 +51,7 @@ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
BUG();
}
-static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
+static inline int tick_broadcast_oneshot_control(unsigned long reason) { return 0; }
static inline void tick_broadcast_switch_to_oneshot(void) { }
static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
static inline int tick_broadcast_oneshot_active(void) { return 0; }
@@ -77,7 +80,7 @@ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
BUG();
}
-static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
+static inline int tick_broadcast_oneshot_control(unsigned long reason) { return 0; }
static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
{
@@ -142,6 +145,8 @@ static inline int tick_device_is_functional(struct clock_event_device *dev)
return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
}
+int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);
+
#endif
extern void do_timer(unsigned long ticks);