From 9a6b51976ea3a326b6de534beec3fd87275f4ef6 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 16 Jul 2014 21:04:22 +0000
Subject: [PATCH] timekeeping: Provide ktime_mono_to_any()
ktime based conversion function to map a monotonic time stamp to a
different CLOCK.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
include/linux/timekeeping.h | 9 +++++++++
kernel/time/timekeeping.c | 20 ++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 3050a7d0a5a9..910a98ef2154 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -109,6 +109,7 @@ enum tk_offsets {
extern ktime_t ktime_get(void);
extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
extern ktime_t ktime_get_monotonic_offset(void);
+extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
/**
* ktime_get_real - get the real (wall-) time in ktime_t format
@@ -137,6 +138,14 @@ static inline ktime_t ktime_get_clocktai(void)
return ktime_get_with_offset(TK_OFFS_TAI);
}
+/**
+ * ktime_mono_to_real - Convert monotonic time to clock realtime
+ */
+static inline ktime_t ktime_mono_to_real(ktime_t mono)
+{
+ return ktime_mono_to_any(mono, TK_OFFS_REAL);
+}
+
/*
* RTC specific
*/
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e99350319eec..032e77a54a79 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -450,6 +450,26 @@ ktime_t ktime_get_with_offset(enum tk_offsets offs)
}
EXPORT_SYMBOL_GPL(ktime_get_with_offset);
+/**
+ * ktime_mono_to_any() - convert mononotic time to any other time
+ * @tmono: time to convert.
+ * @offs: which offset to use
+ */
+ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs)
+{
+ ktime_t *offset = offsets[offs];
+ unsigned long seq;
+ ktime_t tconv;
+
+ do {
+ seq = read_seqcount_begin(&tk_core.seq);
+ tconv = ktime_add(tmono, *offset);
+ } while (read_seqcount_retry(&tk_core.seq, seq));
+
+ return tconv;
+}
+EXPORT_SYMBOL_GPL(ktime_mono_to_any);
+
/**
* ktime_get_ts64 - get the monotonic clock in timespec64 format
* @ts: pointer to timespec variable
--
2.34.1