1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/gator/gator_hrtimer_perf.c b/drivers/gator/gator_hrtimer_perf.c
new file mode 100644
index 00000000000..7b95399478e
--- /dev/null
+++ b/drivers/gator/gator_hrtimer_perf.c
@@ -0,0 +1,113 @@
+/**
+ * Copyright (C) ARM Limited 2011-2013. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+// gator_hrtimer_gator.c is used if perf is not supported
+//   update, gator_hrtimer_gator.c always used until issues resolved with perf hrtimers
+#if 0
+
+// Note: perf Cortex support added in 2.6.35 and PERF_COUNT_SW_CPU_CLOCK/hrtimer broken on 2.6.35 and 2.6.36
+//       not relevant as this code is not active until 3.0.0, but wanted to document the issue
+
+void (*callback)(void);
+static int profiling_interval;
+static DEFINE_PER_CPU(struct perf_event *, perf_hrtimer);
+static DEFINE_PER_CPU(struct perf_event_attr *, perf_hrtimer_attr);
+
+static void gator_hrtimer_shutdown(void);
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0)
+static void hrtimer_overflow_handler(struct perf_event *event, int unused, struct perf_sample_data *data, struct pt_regs *regs)
+#else
+static void hrtimer_overflow_handler(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs)
+#endif
+{
+	(*callback)();
+}
+
+static int gator_online_single_hrtimer(int cpu)
+{
+	if (per_cpu(perf_hrtimer, cpu) != 0 || per_cpu(perf_hrtimer_attr, cpu) == 0)
+		return 0;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0)
+	per_cpu(perf_hrtimer, cpu) = perf_event_create_kernel_counter(per_cpu(perf_hrtimer_attr, cpu), cpu, 0, hrtimer_overflow_handler);
+#else
+	per_cpu(perf_hrtimer, cpu) = perf_event_create_kernel_counter(per_cpu(perf_hrtimer_attr, cpu), cpu, 0, hrtimer_overflow_handler, 0);
+#endif
+	if (IS_ERR(per_cpu(perf_hrtimer, cpu))) {
+		per_cpu(perf_hrtimer, cpu) = NULL;
+		return -1;
+	}
+
+	if (per_cpu(perf_hrtimer, cpu)->state != PERF_EVENT_STATE_ACTIVE) {
+		perf_event_release_kernel(per_cpu(perf_hrtimer, cpu));
+		per_cpu(perf_hrtimer, cpu) = NULL;
+		return -1;
+	}
+
+	return 0;
+}
+
+static void gator_hrtimer_online(int cpu)
+{
+	if (gator_online_single_hrtimer(cpu) < 0) {
+		pr_debug("gator: unable to online the hrtimer on cpu%d\n", cpu);
+	}
+}
+
+static void gator_hrtimer_offline(int cpu)
+{
+	if (per_cpu(perf_hrtimer, cpu)) {
+		perf_event_release_kernel(per_cpu(perf_hrtimer, cpu));
+		per_cpu(perf_hrtimer, cpu) = NULL;
+	}
+}
+
+static int gator_hrtimer_init(int interval, void (*func)(void))
+{
+	u32 size = sizeof(struct perf_event_attr);
+	int cpu;
+
+	callback = func;
+
+	// calculate profiling interval
+	profiling_interval = 1000000000 / interval;
+
+	for_each_present_cpu(cpu) {
+		per_cpu(perf_hrtimer, cpu) = 0;
+		per_cpu(perf_hrtimer_attr, cpu) = kmalloc(size, GFP_KERNEL);
+		if (per_cpu(perf_hrtimer_attr, cpu) == 0) {
+			gator_hrtimer_shutdown();
+			return -1;
+		}
+
+		memset(per_cpu(perf_hrtimer_attr, cpu), 0, size);
+		per_cpu(perf_hrtimer_attr, cpu)->type = PERF_TYPE_SOFTWARE;
+		per_cpu(perf_hrtimer_attr, cpu)->size = size;
+		per_cpu(perf_hrtimer_attr, cpu)->config = PERF_COUNT_SW_CPU_CLOCK;
+		per_cpu(perf_hrtimer_attr, cpu)->sample_period = profiling_interval;
+		per_cpu(perf_hrtimer_attr, cpu)->pinned = 1;
+	}
+
+	return 0;
+}
+
+static void gator_hrtimer_shutdown(void)
+{
+	int cpu;
+
+	for_each_present_cpu(cpu) {
+		if (per_cpu(perf_hrtimer_attr, cpu)) {
+			kfree(per_cpu(perf_hrtimer_attr, cpu));
+			per_cpu(perf_hrtimer_attr, cpu) = NULL;
+		}
+	}
+}
+
+#endif