From 9789a88f4273089cad704a5ef219ea41882d5d55 Mon Sep 17 00:00:00 2001
From: Huang Yiwei <hyiwei@codeaurora.org>
Date: Fri, 29 Jan 2021 10:59:25 +0800
Subject: [PATCH] ANDROID: timer: Add vendor hook for timer calc index

Since we're expecting timers more precisely in short period, add
a vendor hook to calc_index when adding timers. Then we can modify
the index this timer used to make it accurate.

Bug: 178758017
Signed-off-by: Huang Yiwei <hyiwei@codeaurora.org>
Change-Id: Ie0e6493ae7ad53b0cc57eb1bbcf8a0a11f652828
---
 drivers/android/vendor_hooks.c |  2 ++
 include/trace/hooks/timer.h    | 19 +++++++++++++++++++
 kernel/time/timer.c            |  3 +++
 3 files changed, 24 insertions(+)
 create mode 100644 include/trace/hooks/timer.h

diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c
index b9f6772623a3..6a6d40bec073 100644
--- a/drivers/android/vendor_hooks.c
+++ b/drivers/android/vendor_hooks.c
@@ -31,6 +31,7 @@
 #include <trace/hooks/ftrace_dump.h>
 #include <trace/hooks/pm_domain.h>
 #include <trace/hooks/bug.h>
+#include <trace/hooks/timer.h>
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -137,3 +138,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_em_cpu_energy);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_cpu_up);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_cpu_down);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_sched_balance_rt);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_timer_calc_index);
diff --git a/include/trace/hooks/timer.h b/include/trace/hooks/timer.h
new file mode 100644
index 000000000000..174d958e4c31
--- /dev/null
+++ b/include/trace/hooks/timer.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM timer
+
+#define TRACE_INCLUDE_PATH trace/hooks
+
+#if !defined(_TRACE_HOOK_TIMER_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HOOK_TIMER_H
+
+#include <linux/tracepoint.h>
+#include <trace/hooks/vendor_hooks.h>
+
+DECLARE_HOOK(android_vh_timer_calc_index,
+	TP_PROTO(unsigned int lvl, unsigned long *expires),
+	TP_ARGS(lvl, expires));
+
+#endif /* _TRACE_HOOK_TIMER_H */
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 99d9bf8aed4c..9718e5a7bc1b 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -55,6 +55,8 @@
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/timer.h>
+#undef CREATE_TRACE_POINTS
+#include <trace/hooks/timer.h>
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(hrtimer_expire_entry);
 EXPORT_TRACEPOINT_SYMBOL_GPL(hrtimer_expire_exit);
@@ -505,6 +507,7 @@ static inline unsigned calc_index(unsigned long expires, unsigned lvl,
 	 * Round up with level granularity to prevent this.
 	 */
 	expires = (expires + LVL_GRAN(lvl)) >> LVL_SHIFT(lvl);
+	trace_android_vh_timer_calc_index(lvl, &expires);
 	*bucket_expiry = expires << LVL_SHIFT(lvl);
 	return LVL_OFFS(lvl) + (expires & LVL_MASK);
 }