From 76b58ff07b29541231a8e0781ef0e3865495a4f6 Mon Sep 17 00:00:00 2001
From: Murali Nalajala <mnalajal@codeaurora.org>
Date: Tue, 10 Nov 2020 14:21:37 -0800
Subject: [PATCH] ANDROID: sched_clock: Add vendor hook to print epoch values

Add vendor hook to print epoch values when system enter and exit
out of suspend and resume. These epoch values are useful to know
how long the device is in suspend state. These values can be used
to synchronize various subsystem timestamps and have an unique
timestamp to correlate between various subsystems.

Bug: 172945021
Change-Id: I82a01e348d05a46c9c3921869cc9d2fc0fd28867
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
---
 drivers/android/vendor_hooks.c |  3 +++
 include/trace/hooks/epoch.h    | 31 +++++++++++++++++++++++++++++++
 kernel/time/sched_clock.c      |  3 +++
 3 files changed, 37 insertions(+)
 create mode 100644 include/trace/hooks/epoch.h

diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c
index 418bbb6e3ab9..7b8cd82fed19 100644
--- a/drivers/android/vendor_hooks.c
+++ b/drivers/android/vendor_hooks.c
@@ -23,6 +23,7 @@
 #include <trace/hooks/sysrqcrash.h>
 #include <trace/hooks/printk.h>
 #include <trace/hooks/gic_v3.h>
+#include <trace/hooks/epoch.h>
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -70,3 +71,5 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_printk_hotplug);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_jiffies_update);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_gic_v3_set_affinity);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_gic_v3_affinity_init);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_show_suspend_epoch_val);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_show_resume_epoch_val);
diff --git a/include/trace/hooks/epoch.h b/include/trace/hooks/epoch.h
new file mode 100644
index 000000000000..7da3139dfeb0
--- /dev/null
+++ b/include/trace/hooks/epoch.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM epoch
+
+#define TRACE_INCLUDE_PATH trace/hooks
+
+#if !defined(_TRACE_HOOK_EPOCH_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HOOK_EPOCH_H
+
+#include <linux/tracepoint.h>
+#include <trace/hooks/vendor_hooks.h>
+
+#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_ANDROID_VENDOR_HOOKS)
+
+DECLARE_HOOK(android_vh_show_suspend_epoch_val,
+	TP_PROTO(u64 suspend_ns, u64 suspend_cycles),
+	TP_ARGS(suspend_ns, suspend_cycles));
+
+DECLARE_HOOK(android_vh_show_resume_epoch_val,
+	TP_PROTO(u64 resume_cycles),
+	TP_ARGS(resume_cycles));
+#else
+
+#define trace_android_vh_show_suspend_epoch_val(suspend_ns, suspend_cycles)
+#define trace_android_vh_show_resume_epoch_val(resume_cycles)
+
+#endif
+
+#endif /* _TRACE_HOOK_EPOCH_H */
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index b1b9b12899f5..d5ab3fbc191c 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -16,6 +16,7 @@
 #include <linux/sched_clock.h>
 #include <linux/seqlock.h>
 #include <linux/bitops.h>
+#include <trace/hooks/epoch.h>
 
 #include "timekeeping.h"
 
@@ -270,6 +271,7 @@ int sched_clock_suspend(void)
 	update_sched_clock();
 	hrtimer_cancel(&sched_clock_timer);
 	rd->read_sched_clock = suspended_sched_clock_read;
+	trace_android_vh_show_suspend_epoch_val(rd->epoch_ns, rd->epoch_cyc);
 
 	return 0;
 }
@@ -281,6 +283,7 @@ void sched_clock_resume(void)
 	rd->epoch_cyc = cd.actual_read_sched_clock();
 	hrtimer_start(&sched_clock_timer, cd.wrap_kt, HRTIMER_MODE_REL_HARD);
 	rd->read_sched_clock = cd.actual_read_sched_clock;
+	trace_android_vh_show_resume_epoch_val(rd->epoch_cyc);
 }
 
 static struct syscore_ops sched_clock_ops = {