On Thu, Sep 09, 2021 at 03:28:51PM -0700, John Harrison wrote:
> On 8/20/2021 15:44, Matthew Brost wrote:
> > 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
> This split needs to be done. It would also be helpful to have a more

Can do the split in the next rev.

> detailed explanation of what is going on and why the change is necessary. Is
> this a generic problem and the code currently in the tree is broken? Or is
> it something specific to parallel submission and isn't actually a problem
> until later in the series?
>

This a generic problem - we should always have PM reference when a user
context has submission enable (a follow on patch) or any G2H is in
flight to avoid reporting the GPU falsely idle.

Matt 

> John.
> 
> > 
> > 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));
> 

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