From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 drivers/oprofile/timer_int.c | 120 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 drivers/oprofile/timer_int.c

(limited to 'drivers/oprofile/timer_int.c')

diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c
new file mode 100644
index 000000000..bdef916e5
--- /dev/null
+++ b/drivers/oprofile/timer_int.c
@@ -0,0 +1,120 @@
+/**
+ * @file timer_int.c
+ *
+ * @remark Copyright 2002 OProfile authors
+ * @remark Read the file COPYING
+ *
+ * @author John Levon <levon@movementarian.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+#include <linux/oprofile.h>
+#include <linux/profile.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/hrtimer.h>
+#include <asm/irq_regs.h>
+#include <asm/ptrace.h>
+
+#include "oprof.h"
+
+static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
+static int ctr_running;
+
+static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
+{
+	oprofile_add_sample(get_irq_regs(), 0);
+	hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
+	return HRTIMER_RESTART;
+}
+
+static void __oprofile_hrtimer_start(void *unused)
+{
+	struct hrtimer *hrtimer = this_cpu_ptr(&oprofile_hrtimer);
+
+	if (!ctr_running)
+		return;
+
+	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer->function = oprofile_hrtimer_notify;
+
+	hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
+		      HRTIMER_MODE_REL_PINNED);
+}
+
+static int oprofile_hrtimer_start(void)
+{
+	get_online_cpus();
+	ctr_running = 1;
+	on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
+	put_online_cpus();
+	return 0;
+}
+
+static void __oprofile_hrtimer_stop(int cpu)
+{
+	struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
+
+	if (!ctr_running)
+		return;
+
+	hrtimer_cancel(hrtimer);
+}
+
+static void oprofile_hrtimer_stop(void)
+{
+	int cpu;
+
+	get_online_cpus();
+	for_each_online_cpu(cpu)
+		__oprofile_hrtimer_stop(cpu);
+	ctr_running = 0;
+	put_online_cpus();
+}
+
+static int oprofile_cpu_notify(struct notifier_block *self,
+			       unsigned long action, void *hcpu)
+{
+	long cpu = (long) hcpu;
+
+	switch (action) {
+	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
+		smp_call_function_single(cpu, __oprofile_hrtimer_start,
+					 NULL, 1);
+		break;
+	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
+		__oprofile_hrtimer_stop(cpu);
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __refdata oprofile_cpu_notifier = {
+	.notifier_call = oprofile_cpu_notify,
+};
+
+static int oprofile_hrtimer_setup(void)
+{
+	return register_hotcpu_notifier(&oprofile_cpu_notifier);
+}
+
+static void oprofile_hrtimer_shutdown(void)
+{
+	unregister_hotcpu_notifier(&oprofile_cpu_notifier);
+}
+
+int oprofile_timer_init(struct oprofile_operations *ops)
+{
+	ops->create_files	= NULL;
+	ops->setup		= oprofile_hrtimer_setup;
+	ops->shutdown		= oprofile_hrtimer_shutdown;
+	ops->start		= oprofile_hrtimer_start;
+	ops->stop		= oprofile_hrtimer_stop;
+	ops->cpu_type		= "timer";
+	printk(KERN_INFO "oprofile: using timer interrupt.\n");
+	return 0;
+}
-- 
cgit v1.2.3-54-g00ecf