[PATCH 11/14] drm/i915/gt: Track if an engine requires forcewake w/a

[Chris Wilson]

Sometimes an engine might need to keep forcewake active while it is busy
submitting requests for a particular workaround. Track such nuisance
with engine->fw_domain.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_engine_types.h   | 8 ++++++++
 drivers/gpu/drm/i915/gt/intel_ring_scheduler.c | 4 ++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
index 3782e27c2945..61f23cc23c6a 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -313,6 +313,14 @@ struct intel_engine_cs {
 	u32 context_size;
 	u32 mmio_base;
 
+	/*
+	 * Some w/a require forcewake to be held (which prevents RC6) while
+	 * a particular engine is active. If so, we set fw_domain to which
+	 * domains need to be held for the duration of request activity,
+	 * and 0 if none.
+	 */
+	unsigned int fw_domain;
+
 	unsigned long context_tag;
 
 	struct rb_node uabi_node;
diff --git a/drivers/gpu/drm/i915/gt/intel_ring_scheduler.c b/drivers/gpu/drm/i915/gt/intel_ring_scheduler.c
index a27ceb85938c..f37ab2269817 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring_scheduler.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring_scheduler.c
@@ -442,10 +442,14 @@ static void submission_park(struct intel_engine_cs *engine)
 	GEM_BUG_ON(engine->execlists.queue_priority_hint != INT_MIN);
 	intel_engine_unpin_breadcrumbs_irq(engine);
 	submission_tasklet((unsigned long)engine); /* drain the submit queue */
+	if (engine->fw_domain)
+		intel_uncore_forcewake_put(engine->uncore, engine->fw_domain);
 }
 
 static void submission_unpark(struct intel_engine_cs *engine)
 {
+	if (engine->fw_domain)
+		intel_uncore_forcewake_get(engine->uncore, engine->fw_domain);
 	intel_engine_pin_breadcrumbs_irq(engine);
 }
 
-- 
2.20.1