gpu: nvgpu: Abstract get_cycles()

get_cycles is a linux specific API used in common code. This API
is being used, it seems, as a method to generate time stamps. So
add an API to generate 'high resolution' time stamps. This API
returns an opaque time stamp: that is not something one may use
directly as a time since in the Linux implementation we just use
this cycle counter.

Other implementations will, of course, be free to implement as a
real time stamp.

JIRA NVGPU-525

Change-Id: I237aac9bd6c795d000459025bdb4fce92e8aaa3d
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1673811
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@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>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/timers.h b/drivers/gpu/nvgpu/include/nvgpu/timers.h
index b0df29b6..2e260619 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/timers.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/timers.h
@@ -109,5 +109,6 @@ void nvgpu_udelay(unsigned int usecs);
  * Timekeeping.
  */
 s64 nvgpu_current_time_ms(void);
+u64 nvgpu_hr_timestamp(void);
 
 #endif