Merge branch 'for-rmk/broadcast' of git://git.kernel.org/pub/scm/linu…

…x/kernel/git/will/linux into next/virt

* 'for-rmk/broadcast' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux:
  arm: Add generic timer broadcast support
  arm: Use generic timer broadcast receiver
  clockevents: Add generic timer broadcast function
  clockevents: Add generic timer broadcast receiver

arch/arm/Kconfig

@@ -4,6 +4,7 @@ config ARM
 	select ARCH_BINFMT_ELF_RANDOMIZE_PIE
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAVE_CUSTOM_GPIO_H
+	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select BUILDTIME_EXTABLE_SORT if MMU
 	select CPU_PM if (SUSPEND || CPU_IDLE)

arch/arm/kernel/smp.c

@@ -475,14 +475,8 @@ u64 smp_irq_stat_cpu(unsigned int cpu)
  */
 static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent);
 
-static void ipi_timer(void)
-{
-	struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);
-	evt->event_handler(evt);
-}
-
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
-static void smp_timer_broadcast(const struct cpumask *mask)
+void tick_broadcast(const struct cpumask *mask)
 {
 	smp_cross_call(mask, IPI_TIMER);
 }
@@ -530,7 +524,6 @@ static void __cpuinit percpu_timer_setup(void)
 	struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu);
 
 	evt->cpumask = cpumask_of(cpu);
-	evt->broadcast = smp_timer_broadcast;
 
 	if (!lt_ops || lt_ops->setup(evt))
 		broadcast_timer_setup(evt);
@@ -596,11 +589,13 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
 	case IPI_WAKEUP:
 		break;
 
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 	case IPI_TIMER:
 		irq_enter();
-		ipi_timer();
+		tick_receive_broadcast();
 		irq_exit();
 		break;
+#endif
 
 	case IPI_RESCHEDULE:
 		scheduler_ipi();

include/linux/clockchips.h

@@ -161,6 +161,15 @@ clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
 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
+
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 extern void clockevents_notify(unsigned long reason, void *arg);
 #else

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

kernel/time/tick-broadcast.c

@@ -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;
@@ -125,6 +138,23 @@ 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).
  */