From 1995fdd6240542a89f6d0c0f274ca7ee21d06692 Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Thu, 9 Sep 2021 09:47:39 -0700 Subject: [PATCH] drm/i915/guc: Proper xarray usage for contexts_lookup Lock the xarray and take ref to the context if needed. v2: (Checkpatch) - Add new line after declaration (Daniel Vetter) - Correct put / get accounting in xa_for_loops v3: (Checkpatch) - Extra new line Reviewed-by: Daniele Ceraolo Spurio Signed-off-by: Matthew Brost Signed-off-by: John Harrison Link: https://patchwork.freedesktop.org/patch/msgid/20210909164744.31249-19-matthew.brost@intel.com --- .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 102 +++++++++++++++--- 1 file changed, 87 insertions(+), 15 deletions(-) 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 383dc10170045..4814acf1c2ace 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -608,8 +608,18 @@ static void scrub_guc_desc_for_outstanding_g2h(struct intel_guc *guc) unsigned long index, flags; bool pending_disable, pending_enable, deregister, destroyed, banned; + xa_lock_irqsave(&guc->context_lookup, flags); xa_for_each(&guc->context_lookup, index, ce) { - spin_lock_irqsave(&ce->guc_state.lock, flags); + /* + * Corner case where the ref count on the object is zero but and + * deregister G2H was lost. In this case we don't touch the ref + * count and finish the destroy of the context. + */ + bool do_put = kref_get_unless_zero(&ce->ref); + + xa_unlock(&guc->context_lookup); + + spin_lock(&ce->guc_state.lock); /* * Once we are at this point submission_disabled() is guaranteed @@ -625,7 +635,9 @@ static void scrub_guc_desc_for_outstanding_g2h(struct intel_guc *guc) banned = context_banned(ce); init_sched_state(ce); - spin_unlock_irqrestore(&ce->guc_state.lock, flags); + spin_unlock(&ce->guc_state.lock); + + GEM_BUG_ON(!do_put && !destroyed); if (pending_enable || destroyed || deregister) { decr_outstanding_submission_g2h(guc); @@ -648,13 +660,19 @@ static void scrub_guc_desc_for_outstanding_g2h(struct intel_guc *guc) } intel_context_sched_disable_unpin(ce); decr_outstanding_submission_g2h(guc); - spin_lock_irqsave(&ce->guc_state.lock, flags); + + spin_lock(&ce->guc_state.lock); guc_blocked_fence_complete(ce); - spin_unlock_irqrestore(&ce->guc_state.lock, flags); + spin_unlock(&ce->guc_state.lock); intel_context_put(ce); } + + if (do_put) + intel_context_put(ce); + xa_lock(&guc->context_lookup); } + xa_unlock_irqrestore(&guc->context_lookup, flags); } static inline bool @@ -890,16 +908,29 @@ void intel_guc_submission_reset(struct intel_guc *guc, bool stalled) { struct intel_context *ce; unsigned long index; + unsigned long flags; if (unlikely(!guc_submission_initialized(guc))) { /* Reset called during driver load? GuC not yet initialised! */ return; } - xa_for_each(&guc->context_lookup, index, ce) + xa_lock_irqsave(&guc->context_lookup, flags); + xa_for_each(&guc->context_lookup, index, ce) { + if (!kref_get_unless_zero(&ce->ref)) + continue; + + xa_unlock(&guc->context_lookup); + if (intel_context_is_pinned(ce)) __guc_reset_context(ce, stalled); + intel_context_put(ce); + + xa_lock(&guc->context_lookup); + } + xa_unlock_irqrestore(&guc->context_lookup, flags); + /* GuC is blown away, drop all references to contexts */ xa_destroy(&guc->context_lookup); } @@ -974,11 +1005,24 @@ void intel_guc_submission_cancel_requests(struct intel_guc *guc) { struct intel_context *ce; unsigned long index; + unsigned long flags; + + xa_lock_irqsave(&guc->context_lookup, flags); + xa_for_each(&guc->context_lookup, index, ce) { + if (!kref_get_unless_zero(&ce->ref)) + continue; + + xa_unlock(&guc->context_lookup); - xa_for_each(&guc->context_lookup, index, ce) if (intel_context_is_pinned(ce)) guc_cancel_context_requests(ce); + intel_context_put(ce); + + xa_lock(&guc->context_lookup); + } + xa_unlock_irqrestore(&guc->context_lookup, flags); + guc_cancel_sched_engine_requests(guc->sched_engine); /* GuC is blown away, drop all references to contexts */ @@ -2866,21 +2910,28 @@ void intel_guc_find_hung_context(struct intel_engine_cs *engine) struct intel_context *ce; struct i915_request *rq; unsigned long index; + unsigned long flags; /* Reset called during driver load? GuC not yet initialised! */ if (unlikely(!guc_submission_initialized(guc))) return; + xa_lock_irqsave(&guc->context_lookup, flags); xa_for_each(&guc->context_lookup, index, ce) { - if (!intel_context_is_pinned(ce)) + if (!kref_get_unless_zero(&ce->ref)) continue; + xa_unlock(&guc->context_lookup); + + if (!intel_context_is_pinned(ce)) + goto next; + if (intel_engine_is_virtual(ce->engine)) { if (!(ce->engine->mask & engine->mask)) - continue; + goto next; } else { if (ce->engine != engine) - continue; + goto next; } list_for_each_entry(rq, &ce->guc_active.requests, sched.link) { @@ -2890,9 +2941,16 @@ void intel_guc_find_hung_context(struct intel_engine_cs *engine) intel_engine_set_hung_context(engine, ce); /* Can only cope with one hang at a time... */ - return; + intel_context_put(ce); + xa_lock(&guc->context_lookup); + goto done; } +next: + intel_context_put(ce); + xa_lock(&guc->context_lookup); } +done: + xa_unlock_irqrestore(&guc->context_lookup, flags); } void intel_guc_dump_active_requests(struct intel_engine_cs *engine, @@ -2908,23 +2966,34 @@ void intel_guc_dump_active_requests(struct intel_engine_cs *engine, if (unlikely(!guc_submission_initialized(guc))) return; + xa_lock_irqsave(&guc->context_lookup, flags); xa_for_each(&guc->context_lookup, index, ce) { - if (!intel_context_is_pinned(ce)) + if (!kref_get_unless_zero(&ce->ref)) continue; + xa_unlock(&guc->context_lookup); + + if (!intel_context_is_pinned(ce)) + goto next; + if (intel_engine_is_virtual(ce->engine)) { if (!(ce->engine->mask & engine->mask)) - continue; + goto next; } else { if (ce->engine != engine) - continue; + goto next; } - spin_lock_irqsave(&ce->guc_active.lock, flags); + spin_lock(&ce->guc_active.lock); intel_engine_dump_active_requests(&ce->guc_active.requests, hung_rq, m); - spin_unlock_irqrestore(&ce->guc_active.lock, flags); + spin_unlock(&ce->guc_active.lock); + +next: + intel_context_put(ce); + xa_lock(&guc->context_lookup); } + xa_unlock_irqrestore(&guc->context_lookup, flags); } void intel_guc_submission_print_info(struct intel_guc *guc, @@ -2978,7 +3047,9 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc, { struct intel_context *ce; unsigned long index; + unsigned long flags; + xa_lock_irqsave(&guc->context_lookup, flags); xa_for_each(&guc->context_lookup, index, ce) { drm_printf(p, "GuC lrc descriptor %u:\n", ce->guc_id); drm_printf(p, "\tHW Context Desc: 0x%08x\n", ce->lrc.lrca); @@ -2997,6 +3068,7 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc, guc_log_context_priority(p, ce); } + xa_unlock_irqrestore(&guc->context_lookup, flags); } static struct intel_context * -- 2.39.5