drm/i915/gt: Extract busy-stats for ring-scheduler

Lift the busy-stats context-in/out implementation out of intel_lrc, so
that we can reuse it for other scheduler implementations.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115142331.24458-2-chris@chris-wilson.co.uk

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_stats.h b/drivers/gpu/drm/i915/gt/intel_engine_stats.h
new file mode 100644
index 000000000000..58491eae3482
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_engine_stats.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#ifndef __INTEL_ENGINE_STATS_H__
+#define __INTEL_ENGINE_STATS_H__
+
+#include <linux/atomic.h>
+#include <linux/ktime.h>
+#include <linux/seqlock.h>
+
+#include "i915_gem.h" /* GEM_BUG_ON */
+#include "intel_engine.h"
+
+static inline void intel_engine_context_in(struct intel_engine_cs *engine)
+{
+	unsigned long flags;
+
+	if (atomic_add_unless(&engine->stats.active, 1, 0))
+		return;
+
+	write_seqlock_irqsave(&engine->stats.lock, flags);
+	if (!atomic_add_unless(&engine->stats.active, 1, 0)) {
+		engine->stats.start = ktime_get();
+		atomic_inc(&engine->stats.active);
+	}
+	write_sequnlock_irqrestore(&engine->stats.lock, flags);
+}
+
+static inline void intel_engine_context_out(struct intel_engine_cs *engine)
+{
+	unsigned long flags;
+
+	GEM_BUG_ON(!atomic_read(&engine->stats.active));
+
+	if (atomic_add_unless(&engine->stats.active, -1, 1))
+		return;
+
+	write_seqlock_irqsave(&engine->stats.lock, flags);
+	if (atomic_dec_and_test(&engine->stats.active)) {
+		engine->stats.total =
+			ktime_add(engine->stats.total,
+				  ktime_sub(ktime_get(), engine->stats.start));
+	}
+	write_sequnlock_irqrestore(&engine->stats.lock, flags);
+}
+
+#endif /* __INTEL_ENGINE_STATS_H__ */