From 12572dbb53638c6e454ef831c8fee7de3df24389 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 14 Jan 2013 17:05:21 +0000 Subject: clockevents: Add generic timer broadcast receiver Currently the broadcast mechanism used for timers is abstracted by a function pointer on struct clock_event_device. As the fundamental mechanism for broadcast is architecture-specific, this ties each clock_event_device driver to a single architecture, even where the driver is otherwise generic. This patch adds a standard path for the receipt of timer broadcasts, so drivers and/or architecture backends need not manage redundant lists of timers for the purpose of routing broadcast timer ticks. [tglx: Made the implementation depend on the config switch as well ] Signed-off-by: Mark Rutland Reviewed-by: Santosh Shilimkar 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/1358183124-28461-2-git-send-email-mark.rutland@arm.com Tested-by: Santosh Shilimkar Reviewed-by: Stephen Boyd Signed-off-by: Thomas Gleixner --- kernel/time/tick-broadcast.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'kernel/time') diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index f113755695e2..7cc81c57eb31 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -125,6 +125,23 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) return ret; } +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +int tick_receive_broadcast(void) +{ + struct tick_device *td = this_cpu_ptr(&tick_cpu_device); + struct clock_event_device *evt = td->evtdev; + + if (!evt) + return -ENODEV; + + if (!evt->event_handler) + return -EINVAL; + + evt->event_handler(evt); + return 0; +} +#endif + /* * Broadcast the event to the cpus, which are set in the mask (mangled). */ -- cgit v1.2.3 From 12ad10004645d38356b14d1fbba379c523a61916 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 14 Jan 2013 17:05:22 +0000 Subject: 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 Reviewed-by: Santosh Shilimkar 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 Reviewed-by: Stephen Boyd Signed-off-by: Thomas Gleixner --- include/linux/clockchips.h | 5 +++++ kernel/time/Kconfig | 4 ++++ kernel/time/tick-broadcast.c | 13 +++++++++++++ 3 files changed, 22 insertions(+) (limited to 'kernel/time') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index e1089aa7816d..66346521cb65 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -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 diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 8601f0db1261..b69692250af4 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -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 diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 7cc81c57eb31..f726537d24eb 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -18,6 +18,7 @@ #include #include #include +#include #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; -- cgit v1.2.3