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authorNoam Camus <noamc@ezchip.com>2016-01-01 15:48:49 +0530
committerVineet Gupta <vgupta@synopsys.com>2016-05-09 09:32:28 +0530
commiteec3c58efa271d7dfa30c978dda2c88280212634 (patch)
tree028246d1987a60246134ebdee95da4d634445b4e /arch/arc
parent0eeb3dfe4b85aa7367e5e4efc365abbe4e50bbfa (diff)
ARC: clockevent: switch to cpu notifier for clockevent setup
ARC Timers so far have been handled as "legacy" w/o explicit description in DT. This poses challenge for newer platforms wanting to use them. This series will eventually help move timers over to DT. This patch does a small change of using a CPU notifier to set clockevent on non-boot CPUs. So explicit setup is done only on boot CPU (which will later be done by DT) Signed-off-by: Noam Camus <noamc@ezchip.com> [vgupta: broken off from a bigger patch] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/include/asm/irq.h1
-rw-r--r--arch/arc/kernel/smp.c2
-rw-r--r--arch/arc/kernel/time.c62
3 files changed, 41 insertions, 24 deletions
diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
index f9c735ede4fc..5c0b5abda67a 100644
--- a/arch/arc/include/asm/irq.h
+++ b/arch/arc/include/asm/irq.h
@@ -25,6 +25,5 @@
#include <asm-generic/irq.h>
extern void arc_init_IRQ(void);
-void arc_local_timer_setup(void);
#endif
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index ca83ebe15a64..6b1813456336 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -138,8 +138,6 @@ void start_kernel_secondary(void)
if (machine_desc->init_per_cpu)
machine_desc->init_per_cpu(cpu);
- arc_local_timer_setup();
-
local_irq_enable();
preempt_disable();
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 146da3cbcc99..e97be743d47b 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -29,17 +29,14 @@
* which however is currently broken
*/
-#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/module.h>
-#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/profile.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
+#include <linux/cpu.h>
#include <asm/irq.h>
#include <asm/arcregs.h>
#include <asm/clk.h>
@@ -183,6 +180,8 @@ static struct clocksource arc_counter = {
/********** Clock Event Device *********/
+static int arc_timer_irq = TIMER0_IRQ;
+
/*
* Arm the timer to interrupt after @cycles
* The distinction for oneshot/periodic is done in arc_event_timer_ack() below
@@ -218,7 +217,6 @@ static DEFINE_PER_CPU(struct clock_event_device, arc_clockevent_device) = {
.features = CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_PERIODIC,
.rating = 300,
- .irq = TIMER0_IRQ, /* hardwired, no need for resources */
.set_next_event = arc_clkevent_set_next_event,
.set_state_periodic = arc_clkevent_set_periodic,
};
@@ -244,29 +242,52 @@ static irqreturn_t timer_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}
+static int arc_timer_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
+
+ evt->cpumask = cpumask_of(smp_processor_id());
+
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ clockevents_config_and_register(evt, arc_get_core_freq(),
+ 0, ULONG_MAX);
+ enable_percpu_irq(arc_timer_irq, 0);
+ break;
+ case CPU_DYING:
+ disable_percpu_irq(arc_timer_irq);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block arc_timer_cpu_nb = {
+ .notifier_call = arc_timer_cpu_notify,
+};
+
/*
- * Setup the local event timer for @cpu
+ * clockevent setup for boot CPU
*/
-void arc_local_timer_setup()
+static void __init arc_clockevent_setup(void)
{
struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
- int cpu = smp_processor_id();
- int irq = TIMER0_IRQ;
+ int ret;
- evt->cpumask = cpumask_of(cpu);
+ register_cpu_notifier(&arc_timer_cpu_nb);
+
+ evt->cpumask = cpumask_of(smp_processor_id());
clockevents_config_and_register(evt, arc_get_core_freq(),
0, ARC_TIMER_MAX);
- if (!cpu) {
- int rc;
-
- rc = request_percpu_irq(irq, timer_irq_handler,
- "Timer0 (per-cpu-tick)", evt);
- if (rc)
- panic("Percpu IRQ request failed for TIMER\n");
- }
+ /* Needs apriori irq_set_percpu_devid() done in intc map function */
+ ret = request_percpu_irq(arc_timer_irq, timer_irq_handler,
+ "Timer0 (per-cpu-tick)", evt);
+ if (ret)
+ pr_err("Unable to register interrupt\n");
- enable_percpu_irq(irq, 0);
+ enable_percpu_irq(arc_timer_irq, 0);
}
/*
@@ -291,6 +312,5 @@ void __init time_init(void)
*/
clocksource_register_hz(&arc_counter, arc_get_core_freq());
- /* sets up the periodic event timer */
- arc_local_timer_setup();
+ arc_clockevent_setup();
}