drm/i915: Track context current active time
Track context active (on hardware) status together with the start timestamp. This will be used to provide better granularity of context runtime reporting in conjunction with already tracked pphwsp accumulated runtime. The latter is only updated on context save so does not give us visibility to any currently executing work. As part of the patch the existing runtime tracking data is moved under the new ce->stats member and updated under the seqlock. This provides the ability to atomically read out accumulated plus active runtime. v2: * Rename and make __intel_context_get_active_time unlocked. v3: * Use GRAPHICS_VER. Signed-off-by:Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com> # v1 Reviewed-by: