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Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-android

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This commit is contained in:
Mark Brown 2015-01-22 11:00:04 +00:00
commit 17d1e25c88
7 changed files with 222 additions and 59 deletions
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16
include/linux/clockchips.h
View file

@ -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

5
kernel/time/Makefile
View file

@ -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

34
kernel/time/clockevents.c
View file

@ -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

106
kernel/time/tick-broadcast-hrtimer.c Normal file
View file

@ -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);
}

60
kernel/time/tick-broadcast.c
View file

@ -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);
}

47
kernel/time/tick-common.c
View file

@ -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
*/

13
kernel/time/tick-internal.h
View file

@ -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);