1 /**
2 * Copyright (C) ARM Limited 2011-2014. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 */
10 void (*callback)(void);
11 DEFINE_PER_CPU(struct hrtimer, percpu_hrtimer);
12 DEFINE_PER_CPU(ktime_t, hrtimer_expire);
13 DEFINE_PER_CPU(int, hrtimer_is_active);
14 static ktime_t profiling_interval;
15 static void gator_hrtimer_online(void);
16 static void gator_hrtimer_offline(void);
18 static enum hrtimer_restart gator_hrtimer_notify(struct hrtimer *hrtimer)
19 {
20 int cpu = get_logical_cpu();
21 hrtimer_forward(hrtimer, per_cpu(hrtimer_expire, cpu), profiling_interval);
22 per_cpu(hrtimer_expire, cpu) = ktime_add(per_cpu(hrtimer_expire, cpu), profiling_interval);
23 (*callback)();
24 return HRTIMER_RESTART;
25 }
27 static void gator_hrtimer_online(void)
28 {
29 int cpu = get_logical_cpu();
30 struct hrtimer *hrtimer = &per_cpu(percpu_hrtimer, cpu);
32 if (per_cpu(hrtimer_is_active, cpu) || profiling_interval.tv64 == 0)
33 return;
35 per_cpu(hrtimer_is_active, cpu) = 1;
36 hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
37 hrtimer->function = gator_hrtimer_notify;
38 #ifdef CONFIG_PREEMPT_RT_BASE
39 hrtimer->irqsafe = 1;
40 #endif
41 per_cpu(hrtimer_expire, cpu) = ktime_add(hrtimer->base->get_time(), profiling_interval);
42 hrtimer_start(hrtimer, per_cpu(hrtimer_expire, cpu), HRTIMER_MODE_ABS_PINNED);
43 }
45 static void gator_hrtimer_offline(void)
46 {
47 int cpu = get_logical_cpu();
48 struct hrtimer *hrtimer = &per_cpu(percpu_hrtimer, cpu);
50 if (!per_cpu(hrtimer_is_active, cpu))
51 return;
53 per_cpu(hrtimer_is_active, cpu) = 0;
54 hrtimer_cancel(hrtimer);
55 }
57 static int gator_hrtimer_init(int interval, void (*func)(void))
58 {
59 int cpu;
61 (callback) = (func);
63 for_each_present_cpu(cpu) {
64 per_cpu(hrtimer_is_active, cpu) = 0;
65 }
67 // calculate profiling interval
68 if (interval > 0) {
69 profiling_interval = ns_to_ktime(1000000000UL / interval);
70 } else {
71 profiling_interval.tv64 = 0;
72 }
74 return 0;
75 }
77 static void gator_hrtimer_shutdown(void)
78 {
79 /* empty */
80 }