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 <ch...@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gt/intel_engine_types.h | 9 +++++++++
drivers/gpu/drm/i915/gt/intel_ring_scheduler.c | 4 ++++
2 files changed, 13 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..ccdd69923793 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -313,6 +313,15 @@ 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 int fw_active;
+
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 aaff554865b1..777cab6d9540 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring_scheduler.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring_scheduler.c
@@ -60,6 +60,8 @@ static struct i915_request *
schedule_in(struct intel_engine_cs *engine, struct i915_request *rq)
{
__intel_gt_pm_get(engine->gt);
+ if (!engine->fw_active++ && engine->fw_domain)
+ intel_uncore_forcewake_get(engine->uncore, engine->fw_domain);
intel_engine_context_in(engine);
return i915_request_get(rq);
}
@@ -74,6 +76,8 @@ schedule_out(struct intel_engine_cs *engine, struct
i915_request *rq)
i915_request_put(rq);
intel_engine_context_out(engine);
+ if (!--engine->fw_active && engine->fw_domain)
+ intel_uncore_forcewake_put(engine->uncore, engine->fw_domain);
intel_gt_pm_put_async(engine->gt);
}
--
2.20.1
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