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.br...@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

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