[Intel-gfx] [PATCH 04/27] drm/i915/guc: Take GT PM ref when deregistering context

[Matthew Brost <matthew.brost@intel.com>]

Taking a PM reference to prevent intel_gt_wait_for_idle from short
circuiting while a deregister context H2G is in flight.

FIXME: Move locking / structure changes into different patch

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_context.c       |   2 +
 drivers/gpu/drm/i915/gt/intel_context_types.h |  13 +-
 drivers/gpu/drm/i915/gt/intel_engine_pm.h     |   5 +
 drivers/gpu/drm/i915/gt/intel_gt_pm.h         |  13 ++
 .../gpu/drm/i915/gt/uc/abi/guc_actions_abi.h  |   1 +
 drivers/gpu/drm/i915/gt/uc/intel_guc.h        |  46 ++--
 .../gpu/drm/i915/gt/uc/intel_guc_debugfs.c    |  13 +-
 .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 212 +++++++++++-------
 8 files changed, 199 insertions(+), 106 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index adfe49b53b1b..c8595da64ad8 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -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.
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 80bbdc7810f6..fd338a30617e 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -190,22 +190,29 @@ struct intel_context {
 		/**
 		 * @id: unique handle which is used to communicate information
 		 * with the GuC about this context, protected by
-		 * guc->contexts_lock
+		 * guc->submission_state.lock
 		 */
 		u16 id;
 		/**
 		 * @ref: the number of references to the guc_id, when
 		 * transitioning in and out of zero protected by
-		 * guc->contexts_lock
+		 * guc->submission_state.lock
 		 */
 		atomic_t ref;
 		/**
 		 * @link: in guc->guc_id_list when the guc_id has no refs but is
-		 * still valid, protected by guc->contexts_lock
+		 * still valid, protected by guc->submission_state.lock
 		 */
 		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
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.h b/drivers/gpu/drm/i915/gt/intel_engine_pm.h
index 70ea46d6cfb0..17a5028ea177 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pm.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.h
@@ -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);
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.h b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
index d0588d8aaa44..a17bf0d4592b 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_pm.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
@@ -41,6 +41,19 @@ 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)
+#define with_intel_gt_pm_async(gt, tmp) \
+	for (tmp = 1, intel_gt_pm_get(gt); tmp; \
+	     intel_gt_pm_put_async(gt), tmp = 0)
+#define with_intel_gt_pm_if_awake(gt, tmp) \
+	for (tmp = intel_gt_pm_get_if_awake(gt); tmp; \
+	     intel_gt_pm_put(gt), tmp = 0)
+#define with_intel_gt_pm_if_awake_async(gt, tmp) \
+	for (tmp = intel_gt_pm_get_if_awake(gt); tmp; \
+	     intel_gt_pm_put_async(gt), tmp = 0)
+
 static inline int intel_gt_pm_wait_for_idle(struct intel_gt *gt)
 {
 	return intel_wakeref_wait_for_idle(&gt->wakeref);
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
index 8ff582222aff..ba10bd374cee 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
@@ -142,6 +142,7 @@ enum intel_guc_action {
 	INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER = 0x4505,
 	INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER = 0x4506,
 	INTEL_GUC_ACTION_DEREGISTER_CONTEXT_DONE = 0x4600,
+	INTEL_GUC_ACTION_REGISTER_CONTEXT_MULTI_LRC = 0x4601,
 	INTEL_GUC_ACTION_RESET_CLIENT = 0x5507,
 	INTEL_GUC_ACTION_LIMIT
 };
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
index 6fd2719d1b75..7358883f1540 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
@@ -53,21 +53,37 @@ struct intel_guc {
 		void (*disable)(struct intel_guc *guc);
 	} interrupts;
 
-	/**
-	 * @contexts_lock: protects guc_ids, guc_id_list, ce->guc_id.id, and
-	 * ce->guc_id.ref when transitioning in and out of zero
-	 */
-	spinlock_t contexts_lock;
-	/** @guc_ids: used to allocate new guc_ids */
-	struct ida guc_ids;
-	/** @num_guc_ids: number of guc_ids that can be used */
-	u32 num_guc_ids;
-	/** @max_guc_ids: max number of guc_ids that can be used */
-	u32 max_guc_ids;
-	/**
-	 * @guc_id_list: list of intel_context with valid guc_ids but no refs
-	 */
-	struct list_head guc_id_list;
+	struct {
+		/**
+		 * @lock: protects everything in submission_state, ce->guc_id,
+		 * and ce->destroyed_link
+		 */
+		spinlock_t lock;
+		/**
+		 * @guc_ids: used to allocate new guc_ids
+		 */
+		struct ida guc_ids;
+		/** @num_guc_ids: number of guc_ids that can be used */
+		u32 num_guc_ids;
+		/** @max_guc_ids: max number of guc_ids that can be used */
+		u32 max_guc_ids;
+		/**
+		 * @guc_id_list: list of intel_context with valid guc_ids but no
+		 * 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;
 
 	bool submission_supported;
 	bool submission_selected;
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c
index b88d343ee432..27655460ee84 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c
@@ -78,7 +78,7 @@ static int guc_num_id_get(void *data, u64 *val)
 	if (!intel_guc_submission_is_used(guc))
 		return -ENODEV;
 
-	*val = guc->num_guc_ids;
+	*val = guc->submission_state.num_guc_ids;
 
 	return 0;
 }
@@ -86,16 +86,21 @@ static int guc_num_id_get(void *data, u64 *val)
 static int guc_num_id_set(void *data, u64 val)
 {
 	struct intel_guc *guc = data;
+	unsigned long flags;
 
 	if (!intel_guc_submission_is_used(guc))
 		return -ENODEV;
 
-	if (val > guc->max_guc_ids)
-		val = guc->max_guc_ids;
+	spin_lock_irqsave(&guc->submission_state.lock, flags);
+
+	if (val > guc->submission_state.max_guc_ids)
+		val = guc->submission_state.max_guc_ids;
 	else if (val < 256)
 		val = 256;
 
-	guc->num_guc_ids = val;
+	guc->submission_state.num_guc_ids = val;
+
+	spin_unlock_irqrestore(&guc->submission_state.lock, flags);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 68742b612692..f835e06e5f9f 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -86,9 +86,9 @@
  * submitting at a time. Currently only 1 sched_engine used for all of GuC
  * submission but that could change in the future.
  *
- * guc->contexts_lock
- * Protects guc_id allocation. Global lock i.e. Only 1 context that uses GuC
- * submission can hold this at a time.
+ * guc->submission_state.lock
+ * Global lock for GuC submission state. Protects guc_ids and destroyed contexts
+ * list.
  *
  * ce->guc_state.lock
  * Protects everything under ce->guc_state. Ensures that a context is in the
@@ -100,7 +100,7 @@
  *
  * Lock ordering rules:
  * sched_engine->lock -> ce->guc_state.lock
- * guc->contexts_lock -> ce->guc_state.lock
+ * guc->submission_state.lock -> ce->guc_state.lock
  *
  * Reset races:
  * When a GPU full reset is triggered it is assumed that some G2H responses to
@@ -344,7 +344,7 @@ static struct guc_lrc_desc *__get_lrc_desc(struct intel_guc *guc, u32 index)
 {
 	struct guc_lrc_desc *base = guc->lrc_desc_pool_vaddr;
 
-	GEM_BUG_ON(index >= guc->max_guc_ids);
+	GEM_BUG_ON(index >= guc->submission_state.max_guc_ids);
 
 	return &base[index];
 }
@@ -353,7 +353,7 @@ static struct intel_context *__get_context(struct intel_guc *guc, u32 id)
 {
 	struct intel_context *ce = xa_load(&guc->context_lookup, id);
 
-	GEM_BUG_ON(id >= guc->max_guc_ids);
+	GEM_BUG_ON(id >= guc->submission_state.max_guc_ids);
 
 	return ce;
 }
@@ -363,7 +363,8 @@ static int guc_lrc_desc_pool_create(struct intel_guc *guc)
 	u32 size;
 	int ret;
 
-	size = PAGE_ALIGN(sizeof(struct guc_lrc_desc) * guc->max_guc_ids);
+	size = PAGE_ALIGN(sizeof(struct guc_lrc_desc) *
+			  guc->submission_state.max_guc_ids);
 	ret = intel_guc_allocate_and_map_vma(guc, size, &guc->lrc_desc_pool,
 					     (void **)&guc->lrc_desc_pool_vaddr);
 	if (ret)
@@ -711,6 +712,7 @@ static void scrub_guc_desc_for_outstanding_g2h(struct intel_guc *guc)
 			if (deregister)
 				guc_signal_context_fence(ce);
 			if (destroyed) {
+				intel_gt_pm_put_async(guc_to_gt(guc));
 				release_guc_id(guc, ce);
 				__guc_context_destroy(ce);
 			}
@@ -789,6 +791,8 @@ static void guc_flush_submissions(struct intel_guc *guc)
 	spin_unlock_irqrestore(&sched_engine->lock, flags);
 }
 
+static void guc_flush_destroyed_contexts(struct intel_guc *guc);
+
 void intel_guc_submission_reset_prepare(struct intel_guc *guc)
 {
 	if (unlikely(!guc_submission_initialized(guc))) {
@@ -805,6 +809,7 @@ void intel_guc_submission_reset_prepare(struct intel_guc *guc)
 	spin_unlock_irq(&guc_to_gt(guc)->irq_lock);
 
 	flush_work(&guc->ct.requests.worker);
+	guc_flush_destroyed_contexts(guc);
 
 	scrub_guc_desc_for_outstanding_g2h(guc);
 }
@@ -1102,6 +1107,8 @@ void intel_guc_submission_reset_finish(struct intel_guc *guc)
 	intel_gt_unpark_heartbeats(guc_to_gt(guc));
 }
 
+static void destroyed_worker_func(struct work_struct *w);
+
 /*
  * Set up the memory resources to be shared with the GuC (via the GGTT)
  * at firmware loading time.
@@ -1124,9 +1131,11 @@ int intel_guc_submission_init(struct intel_guc *guc)
 
 	xa_init_flags(&guc->context_lookup, XA_FLAGS_LOCK_IRQ);
 
-	spin_lock_init(&guc->contexts_lock);
-	INIT_LIST_HEAD(&guc->guc_id_list);
-	ida_init(&guc->guc_ids);
+	spin_lock_init(&guc->submission_state.lock);
+	INIT_LIST_HEAD(&guc->submission_state.guc_id_list);
+	ida_init(&guc->submission_state.guc_ids);
+	INIT_LIST_HEAD(&guc->submission_state.destroyed_contexts);
+	INIT_WORK(&guc->submission_state.destroyed_worker, destroyed_worker_func);
 
 	return 0;
 }
@@ -1137,6 +1146,7 @@ void intel_guc_submission_fini(struct intel_guc *guc)
 		return;
 
 	guc_lrc_desc_pool_destroy(guc);
+	guc_flush_destroyed_contexts(guc);
 	i915_sched_engine_put(guc->sched_engine);
 }
 
@@ -1191,15 +1201,16 @@ static void guc_submit_request(struct i915_request *rq)
 
 static int new_guc_id(struct intel_guc *guc)
 {
-	return ida_simple_get(&guc->guc_ids, 0,
-			      guc->num_guc_ids, GFP_KERNEL |
+	return ida_simple_get(&guc->submission_state.guc_ids, 0,
+			      guc->submission_state.num_guc_ids, GFP_KERNEL |
 			      __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
 }
 
 static void __release_guc_id(struct intel_guc *guc, struct intel_context *ce)
 {
 	if (!context_guc_id_invalid(ce)) {
-		ida_simple_remove(&guc->guc_ids, ce->guc_id.id);
+		ida_simple_remove(&guc->submission_state.guc_ids,
+				  ce->guc_id.id);
 		reset_lrc_desc(guc, ce->guc_id.id);
 		set_context_guc_id_invalid(ce);
 	}
@@ -1211,9 +1222,9 @@ static void release_guc_id(struct intel_guc *guc, struct intel_context *ce)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&guc->contexts_lock, flags);
+	spin_lock_irqsave(&guc->submission_state.lock, flags);
 	__release_guc_id(guc, ce);
-	spin_unlock_irqrestore(&guc->contexts_lock, flags);
+	spin_unlock_irqrestore(&guc->submission_state.lock, flags);
 }
 
 static int steal_guc_id(struct intel_guc *guc)
@@ -1221,10 +1232,10 @@ static int steal_guc_id(struct intel_guc *guc)
 	struct intel_context *ce;
 	int guc_id;
 
-	lockdep_assert_held(&guc->contexts_lock);
+	lockdep_assert_held(&guc->submission_state.lock);
 
-	if (!list_empty(&guc->guc_id_list)) {
-		ce = list_first_entry(&guc->guc_id_list,
+	if (!list_empty(&guc->submission_state.guc_id_list)) {
+		ce = list_first_entry(&guc->submission_state.guc_id_list,
 				      struct intel_context,
 				      guc_id.link);
 
@@ -1249,7 +1260,7 @@ static int assign_guc_id(struct intel_guc *guc, u16 *out)
 {
 	int ret;
 
-	lockdep_assert_held(&guc->contexts_lock);
+	lockdep_assert_held(&guc->submission_state.lock);
 
 	ret = new_guc_id(guc);
 	if (unlikely(ret < 0)) {
@@ -1271,7 +1282,7 @@ static int pin_guc_id(struct intel_guc *guc, struct intel_context *ce)
 	GEM_BUG_ON(atomic_read(&ce->guc_id.ref));
 
 try_again:
-	spin_lock_irqsave(&guc->contexts_lock, flags);
+	spin_lock_irqsave(&guc->submission_state.lock, flags);
 
 	might_lock(&ce->guc_state.lock);
 
@@ -1286,7 +1297,7 @@ static int pin_guc_id(struct intel_guc *guc, struct intel_context *ce)
 	atomic_inc(&ce->guc_id.ref);
 
 out_unlock:
-	spin_unlock_irqrestore(&guc->contexts_lock, flags);
+	spin_unlock_irqrestore(&guc->submission_state.lock, flags);
 
 	/*
 	 * -EAGAIN indicates no guc_id are available, let's retire any
@@ -1322,11 +1333,12 @@ static void unpin_guc_id(struct intel_guc *guc, struct intel_context *ce)
 	if (unlikely(context_guc_id_invalid(ce)))
 		return;
 
-	spin_lock_irqsave(&guc->contexts_lock, flags);
+	spin_lock_irqsave(&guc->submission_state.lock, flags);
 	if (!context_guc_id_invalid(ce) && list_empty(&ce->guc_id.link) &&
 	    !atomic_read(&ce->guc_id.ref))
-		list_add_tail(&ce->guc_id.link, &guc->guc_id_list);
-	spin_unlock_irqrestore(&guc->contexts_lock, flags);
+		list_add_tail(&ce->guc_id.link,
+			      &guc->submission_state.guc_id_list);
+	spin_unlock_irqrestore(&guc->submission_state.lock, flags);
 }
 
 static int __guc_action_register_context(struct intel_guc *guc,
@@ -1841,11 +1853,30 @@ static void guc_context_sched_disable(struct intel_context *ce)
 static void guc_lrc_desc_unpin(struct intel_context *ce)
 {
 	struct intel_guc *guc = ce_to_guc(ce);
+	struct intel_gt *gt = guc_to_gt(guc);
+	unsigned long flags;
+	bool disabled;
 
+	GEM_BUG_ON(!intel_gt_pm_is_awake(gt));
 	GEM_BUG_ON(!lrc_desc_registered(guc, ce->guc_id.id));
 	GEM_BUG_ON(ce != __get_context(guc, ce->guc_id.id));
 	GEM_BUG_ON(context_enabled(ce));
 
+	/* Seal race with Reset */
+	spin_lock_irqsave(&ce->guc_state.lock, flags);
+	disabled = submission_disabled(guc);
+	if (likely(!disabled)) {
+		__intel_gt_pm_get(gt);
+		set_context_destroyed(ce);
+		clr_context_registered(ce);
+	}
+	spin_unlock_irqrestore(&ce->guc_state.lock, flags);
+	if (unlikely(disabled)) {
+		release_guc_id(guc, ce);
+		__guc_context_destroy(ce);
+		return;
+	}
+
 	deregister_context(ce, ce->guc_id.id, true);
 }
 
@@ -1873,78 +1904,88 @@ static void __guc_context_destroy(struct intel_context *ce)
 	}
 }
 
+static void guc_flush_destroyed_contexts(struct intel_guc *guc)
+{
+	struct intel_context *ce, *cn;
+	unsigned long flags;
+
+	GEM_BUG_ON(!submission_disabled(guc) &&
+		   guc_submission_initialized(guc));
+
+	spin_lock_irqsave(&guc->submission_state.lock, flags);
+	list_for_each_entry_safe(ce, cn,
+				 &guc->submission_state.destroyed_contexts,
+				 destroyed_link) {
+		list_del_init(&ce->destroyed_link);
+		__release_guc_id(guc, ce);
+		__guc_context_destroy(ce);
+	}
+	spin_unlock_irqrestore(&guc->submission_state.lock, flags);
+}
+
+static void deregister_destroyed_contexts(struct intel_guc *guc)
+{
+	struct intel_context *ce, *cn;
+	unsigned long flags;
+
+	spin_lock_irqsave(&guc->submission_state.lock, flags);
+	list_for_each_entry_safe(ce, cn,
+				 &guc->submission_state.destroyed_contexts,
+				 destroyed_link) {
+		list_del_init(&ce->destroyed_link);
+		spin_unlock_irqrestore(&guc->submission_state.lock, flags);
+		guc_lrc_desc_unpin(ce);
+		spin_lock_irqsave(&guc->submission_state.lock, flags);
+	}
+	spin_unlock_irqrestore(&guc->submission_state.lock, flags);
+}
+
+static void destroyed_worker_func(struct work_struct *w)
+{
+	struct intel_guc *guc = container_of(w, struct intel_guc,
+					     submission_state.destroyed_worker);
+	struct intel_gt *gt = guc_to_gt(guc);
+	int tmp;
+
+	with_intel_gt_pm(gt, tmp)
+		deregister_destroyed_contexts(guc);
+}
+
 static void guc_context_destroy(struct kref *kref)
 {
 	struct intel_context *ce = container_of(kref, typeof(*ce), ref);
-	struct intel_runtime_pm *runtime_pm = ce->engine->uncore->rpm;
 	struct intel_guc *guc = ce_to_guc(ce);
-	intel_wakeref_t wakeref;
 	unsigned long flags;
-	bool disabled;
+	bool destroy;
 
 	/*
 	 * If the guc_id is invalid this context has been stolen and we can free
 	 * it immediately. Also can be freed immediately if the context is not
 	 * registered with the GuC or the GuC is in the middle of a reset.
 	 */
-	if (context_guc_id_invalid(ce)) {
-		__guc_context_destroy(ce);
-		return;
-	} else if (submission_disabled(guc) ||
-		   !lrc_desc_registered(guc, ce->guc_id.id)) {
-		release_guc_id(guc, ce);
-		__guc_context_destroy(ce);
-		return;
-	}
-
-	/*
-	 * We have to acquire the context spinlock and check guc_id again, if it
-	 * is valid it hasn't been stolen and needs to be deregistered. We
-	 * delete this context from the list of unpinned guc_id available to
-	 * steal to seal a race with guc_lrc_desc_pin(). When the G2H CTB
-	 * returns indicating this context has been deregistered the guc_id is
-	 * returned to the pool of available guc_id.
-	 */
-	spin_lock_irqsave(&guc->contexts_lock, flags);
-	if (context_guc_id_invalid(ce)) {
-		spin_unlock_irqrestore(&guc->contexts_lock, flags);
-		__guc_context_destroy(ce);
-		return;
-	}
-
-	if (!list_empty(&ce->guc_id.link))
-		list_del_init(&ce->guc_id.link);
-	spin_unlock_irqrestore(&guc->contexts_lock, flags);
-
-	/* Seal race with Reset */
-	spin_lock_irqsave(&ce->guc_state.lock, flags);
-	disabled = submission_disabled(guc);
-	if (likely(!disabled)) {
-		set_context_destroyed(ce);
-		clr_context_registered(ce);
+	spin_lock_irqsave(&guc->submission_state.lock, flags);
+	destroy = submission_disabled(guc) || context_guc_id_invalid(ce) ||
+		!lrc_desc_registered(guc, ce->guc_id.id);
+	if (likely(!destroy)) {
+		if (!list_empty(&ce->guc_id.link))
+			list_del_init(&ce->guc_id.link);
+		list_add_tail(&ce->destroyed_link,
+			      &guc->submission_state.destroyed_contexts);
+	} else {
+		__release_guc_id(guc, ce);
 	}
-	spin_unlock_irqrestore(&ce->guc_state.lock, flags);
-	if (unlikely(disabled)) {
-		release_guc_id(guc, ce);
+	spin_unlock_irqrestore(&guc->submission_state.lock, flags);
+	if (unlikely(destroy)) {
 		__guc_context_destroy(ce);
 		return;
 	}
 
 	/*
-	 * We defer GuC context deregistration until the context is destroyed
-	 * in order to save on CTBs. With this optimization ideally we only need
-	 * 1 CTB to register the context during the first pin and 1 CTB to
-	 * deregister the context when the context is destroyed. Without this
-	 * optimization, a CTB would be needed every pin & unpin.
-	 *
-	 * XXX: Need to acqiure the runtime wakeref as this can be triggered
-	 * from context_free_worker when runtime wakeref is not held.
-	 * guc_lrc_desc_unpin requires the runtime as a GuC register is written
-	 * in H2G CTB to deregister the context. A future patch may defer this
-	 * H2G CTB if the runtime wakeref is zero.
+	 * We use a worker to issue the H2G to deregister the context as we can
+	 * take the GT PM for the first time which isn't allowed from an atomic
+	 * context.
 	 */
-	with_intel_runtime_pm(runtime_pm, wakeref)
-		guc_lrc_desc_unpin(ce);
+	queue_work(system_unbound_wq, &guc->submission_state.destroyed_worker);
 }
 
 static int guc_context_alloc(struct intel_context *ce)
@@ -2703,8 +2744,8 @@ static bool __guc_submission_selected(struct intel_guc *guc)
 
 void intel_guc_submission_init_early(struct intel_guc *guc)
 {
-	guc->max_guc_ids = GUC_MAX_LRC_DESCRIPTORS;
-	guc->num_guc_ids = GUC_MAX_LRC_DESCRIPTORS;
+	guc->submission_state.max_guc_ids = GUC_MAX_LRC_DESCRIPTORS;
+	guc->submission_state.num_guc_ids = GUC_MAX_LRC_DESCRIPTORS;
 	guc->submission_supported = __guc_submission_supported(guc);
 	guc->submission_selected = __guc_submission_selected(guc);
 }
@@ -2714,10 +2755,10 @@ g2h_context_lookup(struct intel_guc *guc, u32 desc_idx)
 {
 	struct intel_context *ce;
 
-	if (unlikely(desc_idx >= guc->max_guc_ids)) {
+	if (unlikely(desc_idx >= guc->submission_state.max_guc_ids)) {
 		drm_err(&guc_to_gt(guc)->i915->drm,
 			"Invalid desc_idx %u, max %u",
-			desc_idx, guc->max_guc_ids);
+			desc_idx, guc->submission_state.max_guc_ids);
 		return NULL;
 	}
 
@@ -2771,6 +2812,7 @@ int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
 		intel_context_put(ce);
 	} else if (context_destroyed(ce)) {
 		/* Context has been destroyed */
+		intel_gt_pm_put_async(guc_to_gt(guc));
 		release_guc_id(guc, ce);
 		__guc_context_destroy(ce);
 	}
@@ -3065,8 +3107,10 @@ void intel_guc_submission_print_info(struct intel_guc *guc,
 
 	drm_printf(p, "GuC Number Outstanding Submission G2H: %u\n",
 		   atomic_read(&guc->outstanding_submission_g2h));
-	drm_printf(p, "GuC Number GuC IDs: %u\n", guc->num_guc_ids);
-	drm_printf(p, "GuC Max GuC IDs: %u\n", guc->max_guc_ids);
+	drm_printf(p, "GuC Number GuC IDs: %u\n",
+		   guc->submission_state.num_guc_ids);
+	drm_printf(p, "GuC Max GuC IDs: %u\n",
+		   guc->submission_state.max_guc_ids);
 	drm_printf(p, "GuC tasklet count: %u\n\n",
 		   atomic_read(&sched_engine->tasklet.count));
 
-- 
2.32.0