From a4d1a4830e13caecf5f39f15a716f3bd63f37c34 Mon Sep 17 00:00:00 2001
From: Konsta Holtta <kholtta@nvidia.com>
Date: Thu, 17 May 2018 15:04:51 +0300
Subject: gpu: nvgpu: add nvgpu_current_time_ns()

Add an abstraction over a monotonic system clock in nanosecond units.
Use ktime_get() for the Linux implementation, similarly to
nvgpu_current_time_ms().

Jira NVGPU-708

Change-Id: I3165c20abf2652f1a1fa04e66c04cd34a8fe6dcc
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1723201
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: Sourab Gupta <sourabg@nvidia.com>
Reviewed-by: Alex Waterman <alexw@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
---
 drivers/gpu/nvgpu/common/linux/timers.c  | 12 ++++++++++++
 drivers/gpu/nvgpu/include/nvgpu/timers.h |  1 +
 2 files changed, 13 insertions(+)

(limited to 'drivers')

diff --git a/drivers/gpu/nvgpu/common/linux/timers.c b/drivers/gpu/nvgpu/common/linux/timers.c
index 41b55543..d1aa641f 100644
--- a/drivers/gpu/nvgpu/common/linux/timers.c
+++ b/drivers/gpu/nvgpu/common/linux/timers.c
@@ -242,6 +242,18 @@ s64 nvgpu_current_time_ms(void)
 	return ktime_to_ms(ktime_get());
 }
 
+/**
+ * nvgpu_current_time_ns - Time in nanoseconds from a monotonic clock.
+ *
+ * Return a clock in nanosecond units. The start time of the clock is
+ * unspecified; the time returned can be compared with older ones to measure
+ * durations. The source clock does not jump when the system clock is adjusted.
+ */
+s64 nvgpu_current_time_ns(void)
+{
+	return ktime_to_ns(ktime_get());
+}
+
 /**
  * nvgpu_hr_timestamp - Opaque 'high resolution' time stamp.
  *
diff --git a/drivers/gpu/nvgpu/include/nvgpu/timers.h b/drivers/gpu/nvgpu/include/nvgpu/timers.h
index 2e260619..83dd8d78 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/timers.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/timers.h
@@ -109,6 +109,7 @@ void nvgpu_udelay(unsigned int usecs);
  * Timekeeping.
  */
 s64 nvgpu_current_time_ms(void);
+s64 nvgpu_current_time_ns(void);
 u64 nvgpu_hr_timestamp(void);
 
 #endif
-- 
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