Commit 1a52faed authored Oct 14, 2021 by Matthew Brost Committed by John Harrison Oct 15, 2021

drm/i915/guc: Take GT PM ref when deregistering context



Taking a PM reference to prevent intel_gt_wait_for_idle from short
circuiting while a deregister context H2G is in flight. To do this must
issue the deregister H2G from a worker as context can be destroyed from
an atomic context and taking GT PM ref blows up. Previously we took a
runtime PM from this atomic context which worked but will stop working
once runtime pm autosuspend in enabled.

So this patch is two fold, stop intel_gt_wait_for_idle from short
circuting and fix runtime pm autosuspend.

v2:
 (John Harrison)
  - Split structure changes out in different patch
 (Tvrtko)
  - Don't drop lock in deregister_destroyed_contexts
v3:
 (John Harrison)
  - Flush destroyed contexts before destroying context reg pool

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-3-matthew.brost@intel.com

parent 0ea92ace

drivers/gpu/drm/i915/gt/intel_context.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -399,6 +399,8 @@ intel_context_init(struct intel_context ce, struct intel_engine_cs engine)
		ce->guc_id.id = GUC_INVALID_LRC_ID;
		INIT_LIST_HEAD(&ce->guc_id.link);

		INIT_LIST_HEAD(&ce->destroyed_link);

		/*
		* Initialize fence to be complete as this is expected to be complete
		* unless there is a pending schedule disable outstanding.

drivers/gpu/drm/i915/gt/intel_context_types.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -213,6 +213,13 @@ struct intel_context {
		struct list_head link;
		} guc_id;

		/**
		* @destroyed_link: link in guc->submission_state.destroyed_contexts, in
		* list when context is pending to be destroyed (deregistered with the
		* GuC), protected by guc->submission_state.lock
		*/
		struct list_head destroyed_link;

		#ifdef CONFIG_DRM_I915_SELFTEST
		/**
		* @drop_schedule_enable: Force drop of schedule enable G2H for selftest

drivers/gpu/drm/i915/gt/intel_engine_pm.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,11 @@ intel_engine_pm_is_awake(const struct intel_engine_cs *engine)
		return intel_wakeref_is_active(&engine->wakeref);
		}

		static inline void __intel_engine_pm_get(struct intel_engine_cs *engine)
		{
		__intel_wakeref_get(&engine->wakeref);
		}

		static inline void intel_engine_pm_get(struct intel_engine_cs *engine)
		{
		intel_wakeref_get(&engine->wakeref);

drivers/gpu/drm/i915/gt/intel_gt_pm.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,10 @@ static inline void intel_gt_pm_put_async(struct intel_gt *gt)
		intel_wakeref_put_async(&gt->wakeref);
		}

		#define with_intel_gt_pm(gt, tmp) \
		for (tmp = 1, intel_gt_pm_get(gt); tmp; \
		intel_gt_pm_put(gt), tmp = 0)

		static inline int intel_gt_pm_wait_for_idle(struct intel_gt *gt)
		{
		return intel_wakeref_wait_for_idle(&gt->wakeref);

drivers/gpu/drm/i915/gt/uc/intel_guc.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -90,6 +90,17 @@ struct intel_guc {
		* refs
		*/
		struct list_head guc_id_list;
		/**
		* @destroyed_contexts: list of contexts waiting to be destroyed
		* (deregistered with the GuC)
		*/
		struct list_head destroyed_contexts;
		/**
		* @destroyed_worker: worker to deregister contexts, need as we
		* need to take a GT PM reference and can't from destroy
		* function as it might be in an atomic context (no sleeping)
		*/
		struct work_struct destroyed_worker;
		} submission_state;

		/**