ARM: SMP: Always enable clock event broadcast support
The TWD local timers are unable to wake up the CPU when it is placed
into a low power mode, eg. C3. Therefore, we need to adapt things
such that the TWD code can cope with this.
We do this by always providing a broadcast tick function, and marking
the fact that the TWD local timer will stop in low power modes. This
means that when the CPU is placed into a low power mode, the core
timer code marks this fact, and allows an IPI to be given to the core.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 88b4f38..157b08a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -56,7 +56,7 @@
config GENERIC_CLOCKEVENTS_BROADCAST
bool
depends on GENERIC_CLOCKEVENTS
- default y if SMP && !LOCAL_TIMERS
+ default y if SMP
config HAVE_TCM
bool
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index b8c3d0f..0170e24 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -429,7 +429,11 @@
{
send_ipi_message(mask, IPI_TIMER);
}
+#else
+#define smp_timer_broadcast NULL
+#endif
+#ifndef CONFIG_LOCAL_TIMERS
static void broadcast_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
@@ -444,7 +448,6 @@
evt->rating = 400;
evt->mult = 1;
evt->set_mode = broadcast_timer_set_mode;
- evt->broadcast = smp_timer_broadcast;
clockevents_register_device(evt);
}
@@ -456,6 +459,7 @@
struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu);
evt->cpumask = cpumask_of(cpu);
+ evt->broadcast = smp_timer_broadcast;
local_timer_setup(evt);
}
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index 7c5f0c0..35882fb 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -132,7 +132,8 @@
twd_calibrate_rate();
clk->name = "local_timer";
- clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+ clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
+ CLOCK_EVT_FEAT_C3STOP;
clk->rating = 350;
clk->set_mode = twd_set_mode;
clk->set_next_event = twd_set_next_event;