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

John Harrison
2021-09-09T22:29:12Z

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
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?

John.

>
> 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));
>