diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index 7b01f4605f217bd9740eea929be79fe11cc04194..b2f042d87be06827bac3c37c23af3425c8c1bb37 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -70,6 +70,7 @@ #include <drm/i915_drm.h> #include "gt/intel_lrc_reg.h" +#include "gt/intel_engine_heartbeat.h" #include "gt/intel_engine_user.h" #include "i915_gem_context.h" @@ -276,6 +277,135 @@ void i915_gem_context_release(struct kref *ref) schedule_work(&gc->free_work); } +static inline struct i915_gem_engines * +__context_engines_static(const struct i915_gem_context *ctx) +{ + return rcu_dereference_protected(ctx->engines, true); +} + +static bool __reset_engine(struct intel_engine_cs *engine) +{ + struct intel_gt *gt = engine->gt; + bool success = false; + + if (!intel_has_reset_engine(gt)) + return false; + + if (!test_and_set_bit(I915_RESET_ENGINE + engine->id, + >->reset.flags)) { + success = intel_engine_reset(engine, NULL) == 0; + clear_and_wake_up_bit(I915_RESET_ENGINE + engine->id, + >->reset.flags); + } + + return success; +} + +static void __reset_context(struct i915_gem_context *ctx, + struct intel_engine_cs *engine) +{ + intel_gt_handle_error(engine->gt, engine->mask, 0, + "context closure in %s", ctx->name); +} + +static bool __cancel_engine(struct intel_engine_cs *engine) +{ + /* + * Send a "high priority pulse" down the engine to cause the + * current request to be momentarily preempted. (If it fails to + * be preempted, it will be reset). As we have marked our context + * as banned, any incomplete request, including any running, will + * be skipped following the preemption. + * + * If there is no hangchecking (one of the reasons why we try to + * cancel the context) and no forced preemption, there may be no + * means by which we reset the GPU and evict the persistent hog. + * Ergo if we are unable to inject a preemptive pulse that can + * kill the banned context, we fallback to doing a local reset + * instead. + */ + if (CONFIG_DRM_I915_PREEMPT_TIMEOUT && !intel_engine_pulse(engine)) + return true; + + /* If we are unable to send a pulse, try resetting this engine. */ + return __reset_engine(engine); +} + +static struct intel_engine_cs * +active_engine(struct dma_fence *fence, struct intel_context *ce) +{ + struct i915_request *rq = to_request(fence); + struct intel_engine_cs *engine, *locked; + + /* + * Serialise with __i915_request_submit() so that it sees + * is-banned?, or we know the request is already inflight. + */ + locked = READ_ONCE(rq->engine); + spin_lock_irq(&locked->active.lock); + while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) { + spin_unlock(&locked->active.lock); + spin_lock(&engine->active.lock); + locked = engine; + } + + engine = NULL; + if (i915_request_is_active(rq) && !rq->fence.error) + engine = rq->engine; + + spin_unlock_irq(&locked->active.lock); + + return engine; +} + +static void kill_context(struct i915_gem_context *ctx) +{ + struct i915_gem_engines_iter it; + struct intel_context *ce; + + /* + * If we are already banned, it was due to a guilty request causing + * a reset and the entire context being evicted from the GPU. + */ + if (i915_gem_context_is_banned(ctx)) + return; + + i915_gem_context_set_banned(ctx); + + /* + * Map the user's engine back to the actual engines; one virtual + * engine will be mapped to multiple engines, and using ctx->engine[] + * the same engine may be have multiple instances in the user's map. + * However, we only care about pending requests, so only include + * engines on which there are incomplete requests. + */ + for_each_gem_engine(ce, __context_engines_static(ctx), it) { + struct intel_engine_cs *engine; + struct dma_fence *fence; + + if (!ce->timeline) + continue; + + fence = i915_active_fence_get(&ce->timeline->last_request); + if (!fence) + continue; + + /* Check with the backend if the request is still inflight */ + engine = active_engine(fence, ce); + + /* First attempt to gracefully cancel the context */ + if (engine && !__cancel_engine(engine)) + /* + * If we are unable to send a preemptive pulse to bump + * the context from the GPU, we have to resort to a full + * reset. We hope the collateral damage is worth it. + */ + __reset_context(ctx, engine); + + dma_fence_put(fence); + } +} + static void context_close(struct i915_gem_context *ctx) { struct i915_address_space *vm; @@ -298,6 +428,17 @@ static void context_close(struct i915_gem_context *ctx) lut_close(ctx); mutex_unlock(&ctx->mutex); + + /* + * If the user has disabled hangchecking, we can not be sure that + * the batches will ever complete after the context is closed, + * keeping the context and all resources pinned forever. So in this + * case we opt to forcibly kill off all remaining requests on + * context close. + */ + if (!i915_modparams.enable_hangcheck) + kill_context(ctx); + i915_gem_context_put(ctx); }