i915/guc: Accumulate active runtime on gt reset

On gt reset, if a context is running, then accumulate it's active time
into the busyness counter since there will be no chance for the context
to switch out and update it's run time.

v2: Move comment right above the if (John)

Fixes: 77cdd05 ("drm/i915/pmu: Connect engine busyness stats from GuC to pmu")
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241127174006.190128-4-umesh.nerlige.ramappa@intel.com

Author: unerlige

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -1449,8 +1449,21 @@ static void __reset_guc_busyness_stats(struct intel_guc *guc)
 
 	guc_update_pm_timestamp(guc, &unused);
 	for_each_engine(engine, gt, id) {
+		struct intel_engine_guc_stats *stats = &engine->stats.guc;
+
 		guc_update_engine_gt_clks(engine);
-		engine->stats.guc.prev_total = 0;
+
+		/*
+		 * If resetting a running context, accumulate the active
+		 * time as well since there will be no context switch.
+		 */
+		if (stats->running) {
+			u64 clk = guc->timestamp.gt_stamp - stats->start_gt_clk;
+
+			stats->total_gt_clks += clk;
+		}
+		stats->prev_total = 0;
+		stats->running = 0;
 	}
 
 	spin_unlock_irqrestore(&guc->timestamp.lock, flags);