[ARM] 4814/1: RealView: Add broadcasting clockevents support for ARM11MPCore
This patch adds dummy local timers for each CPU so that the board clock
device is used to broadcast events to the other CPUs. The patch also
adds the declaration for the dummy_timer_setup function (the equivalent
of local_timer_setup when CONFIG_LOCAL_TIMERS is not set).
Due to the way clockevents work, the dummy timer on the first CPU has to
be registered before the board timer.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b82828e..a0aeecc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -33,6 +33,11 @@
bool
default n
+config GENERIC_CLOCKEVENTS_BROADCAST
+ bool
+ depends on GENERIC_CLOCKEVENTS
+ default y if SMP && !LOCAL_TIMERS
+
config MMU
bool
default y
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index aef6f9a..e9dfbab 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -290,6 +290,11 @@
local_irq_enable();
local_fiq_enable();
+ /*
+ * Setup local timer for this CPU.
+ */
+ local_timer_setup(cpu);
+
calibrate_delay();
smp_store_cpu_info(cpu);
@@ -300,11 +305,6 @@
cpu_set(cpu, cpu_online_map);
/*
- * Setup local timer for this CPU.
- */
- local_timer_setup(cpu);
-
- /*
* OK, it's off to the idle thread for us
*/
cpu_idle();
diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile
index 36e76ba..ca1e390 100644
--- a/arch/arm/mach-realview/Makefile
+++ b/arch/arm/mach-realview/Makefile
@@ -4,6 +4,5 @@
obj-y := core.o clock.o
obj-$(CONFIG_MACH_REALVIEW_EB) += realview_eb.o
-obj-$(CONFIG_SMP) += platsmp.o headsmp.o
+obj-$(CONFIG_SMP) += platsmp.o headsmp.o localtimer.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
-obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
diff --git a/arch/arm/mach-realview/core.c b/arch/arm/mach-realview/core.c
index 6c68dee..8cabfec 100644
--- a/arch/arm/mach-realview/core.c
+++ b/arch/arm/mach-realview/core.c
@@ -596,12 +596,20 @@
}
/*
- * Set up timer interrupt, and return the current time in seconds.
+ * Set up the clock source and clock events devices
*/
static void __init realview_timer_init(void)
{
u32 val;
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+ /*
+ * The dummy clock device has to be registered before the main device
+ * so that the latter will broadcast the clock events
+ */
+ local_timer_setup(smp_processor_id());
+#endif
+
/*
* set clock frequency:
* REALVIEW_REFCLK is 32KHz
diff --git a/arch/arm/mach-realview/localtimer.c b/arch/arm/mach-realview/localtimer.c
index c7bdf04..529eb69 100644
--- a/arch/arm/mach-realview/localtimer.c
+++ b/arch/arm/mach-realview/localtimer.c
@@ -14,6 +14,8 @@
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/jiffies.h>
+#include <linux/percpu.h>
+#include <linux/clockchips.h>
#include <asm/mach/time.h>
#include <asm/hardware/arm_twd.h>
@@ -25,6 +27,20 @@
#define TWD_BASE(cpu) (__io_address(REALVIEW_TWD_BASE) + \
((cpu) * REALVIEW_TWD_SIZE))
+static DEFINE_PER_CPU(struct clock_event_device, local_clockevent);
+
+/*
+ * Used on SMP for either the local timer or IPI_TIMER
+ */
+void local_timer_interrupt(void)
+{
+ struct clock_event_device *clk = &__get_cpu_var(local_clockevent);
+
+ clk->event_handler(clk);
+}
+
+#ifdef CONFIG_LOCAL_TIMERS
+
static unsigned long mpcore_timer_rate;
/*
@@ -127,3 +143,26 @@
{
__raw_writel(0, TWD_BASE(cpu) + TWD_TIMER_CONTROL);
}
+
+#else /* CONFIG_LOCAL_TIMERS */
+
+static void dummy_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *clk)
+{
+}
+
+void __cpuinit local_timer_setup(unsigned int cpu)
+{
+ struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
+
+ clk->name = "dummy_timer";
+ clk->features = CLOCK_EVT_FEAT_DUMMY;
+ clk->rating = 200;
+ clk->set_mode = dummy_timer_set_mode;
+ clk->broadcast = smp_timer_broadcast;
+ clk->cpumask = cpumask_of_cpu(cpu);
+
+ clockevents_register_device(clk);
+}
+
+#endif /* !CONFIG_LOCAL_TIMERS */
diff --git a/arch/arm/mach-realview/platsmp.c b/arch/arm/mach-realview/platsmp.c
index fce3596..bb5eaa4 100644
--- a/arch/arm/mach-realview/platsmp.c
+++ b/arch/arm/mach-realview/platsmp.c
@@ -187,10 +187,14 @@
if (max_cpus > ncores)
max_cpus = ncores;
+#ifdef CONFIG_LOCAL_TIMERS
/*
- * Enable the local timer for primary CPU
+ * Enable the local timer for primary CPU. If the device is
+ * dummy (!CONFIG_LOCAL_TIMERS), it was already registers in
+ * realview_timer_init
*/
local_timer_setup(cpu);
+#endif
/*
* Initialise the present map, which describes the set of CPUs
diff --git a/include/asm-arm/smp.h b/include/asm-arm/smp.h
index 1f7c51a..af99636 100644
--- a/include/asm-arm/smp.h
+++ b/include/asm-arm/smp.h
@@ -107,10 +107,6 @@
extern void local_timer_interrupt(void);
#ifdef CONFIG_LOCAL_TIMERS
-/*
- * Setup a local timer interrupt for a CPU.
- */
-extern void local_timer_setup(unsigned int cpu);
/*
* Stop a local timer interrupt.
@@ -124,10 +120,6 @@
#else
-static inline void local_timer_setup(unsigned int cpu)
-{
-}
-
static inline void local_timer_stop(unsigned int cpu)
{
}
@@ -135,6 +127,11 @@
#endif
/*
+ * Setup a local timer interrupt for a CPU.
+ */
+extern void local_timer_setup(unsigned int cpu);
+
+/*
* show local interrupt info
*/
extern void show_local_irqs(struct seq_file *);