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Message-ID: <1457439972-20285-4-git-send-email-vgupta@synopsys.com>
Date: Tue, 8 Mar 2016 17:56:06 +0530
From: Vineet Gupta <Vineet.Gupta1@...opsys.com>
To: <linux-snps-arc@...ts.infradead.org>
CC: lkml <linux-kernel@...r.kernel.org>, Noam Camus <noamc@...hip.com>,
Alexey Brodkin <Alexey.Brodkin@...opsys.com>,
Rob Herring <robh@...nel.org>,
Daniel Lezcano <daniel.lezcano@...aro.org>,
Vineet Gupta <Vineet.Gupta1@...opsys.com>
Subject: [PATCH v2 3/9] ARC: clockevent: switch to cpu notifier for clockevent setup
From: Noam Camus <noamc@...hip.com>
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)
Cc: Daniel Lezcano <daniel.lezcano@...aro.org>
Signed-off-by: Noam Camus <noamc@...hip.com>
[vgupta: broken off from a bigger patch]
Signed-off-by: Vineet Gupta <vgupta@...opsys.com>
---
Changes v1 -> v2
- Rebased on 4.5-rc6 (some changes due to interim changes)
- Reduced the extraneous header includes
- Fixed @ret handling in arc_clockevent_setup()
- Fix snafu in a adapting patch from EZChip tree:
nps_timer_cpu_nb -> arc_timer_cpu_nb
v1:
- http://lists.infradead.org/pipermail/linux-snps-arc/2016-February/000454.html
Signed-off-by: Vineet Gupta <vgupta@...opsys.com>
---
arch/arc/include/asm/irq.h | 1 -
arch/arc/kernel/smp.c | 2 --
arch/arc/kernel/time.c | 62 ++++++++++++++++++++++++++++++----------------
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 96cb0d8887e5..74e7ce4c1508 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_ONLINE);
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();
}
--
2.5.0
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