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clockevents: Add generic timer broadcast function 

Currently, the timer broadcast mechanism is defined by a function
pointer on struct clock_event_device. As the fundamental mechanism for
broadcast is architecture-specific, this means that clock_event_device
drivers cannot be shared across multiple architectures.

This patch adds an (optional) architecture-specific function for timer
tick broadcast, allowing drivers which may require broadcast
functionality to be shared across multiple architectures.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: nico@linaro.org
Cc: Will.Deacon@arm.com
Cc: Marc.Zyngier@arm.com
Cc: john.stultz@linaro.org
Link: http://lkml.kernel.org/r/1358183124-28461-3-git-send-email-mark.rutland@arm.com
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
wifi-calibration
Mark Rutland 2013-01-14 17:05:22 +00:00 committed by Thomas Gleixner
parent 12572dbb53
commit 12ad100046
3 changed files with 22 additions and 0 deletions
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5
include/linux/clockchips.h
View File

@ -162,6 +162,11 @@ extern void clockevents_suspend(void);
extern void clockevents_resume(void);
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
extern void tick_broadcast(const struct cpumask *mask);
#else
#define tick_broadcast NULL
#endif
extern int tick_receive_broadcast(void);
#endif

4
kernel/time/Kconfig
View File

@ -38,6 +38,10 @@ config GENERIC_CLOCKEVENTS_BUILD
default y
depends on GENERIC_CLOCKEVENTS
# Architecture can handle broadcast in a driver-agnostic way
config ARCH_HAS_TICK_BROADCAST
bool
# Clockevents broadcasting infrastructure
config GENERIC_CLOCKEVENTS_BROADCAST
bool

13
kernel/time/tick-broadcast.c
View File

@ -18,6 +18,7 @@
#include <linux/percpu.h>
#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include "tick-internal.h"
@ -86,6 +87,11 @@ int tick_is_broadcast_device(struct clock_event_device *dev)
return (dev && tick_broadcast_device.evtdev == dev);
}
static void err_broadcast(const struct cpumask *mask)
{
pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n");
}
/*
* Check, if the device is disfunctional and a place holder, which
* needs to be handled by the broadcast device.
@ -105,6 +111,13 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
*/
if (!tick_device_is_functional(dev)) {
dev->event_handler = tick_handle_periodic;
if (!dev->broadcast)
dev->broadcast = tick_broadcast;
if (!dev->broadcast) {
pr_warn_once("%s depends on broadcast, but no broadcast function available\n",
dev->name);
dev->broadcast = err_broadcast;
}
cpumask_set_cpu(cpu, tick_get_broadcast_mask());
tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
ret = 1;