drm/i915: Replace engine->timeline with a plain list

To continue the onslaught of removing the assumption of a global
execution ordering, another casualty is the engine->timeline. Without an
actual timeline to track, it is overkill and we can replace it with a
much less grand plain list. We still need a list of requests inflight,
for the simple purpose of finding inflight requests (for retiring,
resetting, preemption etc).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190614164606.15633-3-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_engine.h

@@ -565,4 +565,10 @@ static inline bool inject_preempt_hang(struct intel_engine_execlists *execlists)
 
 #endif
 
+void intel_engine_init_active(struct intel_engine_cs *engine,
+			      unsigned int subclass);
+#define ENGINE_PHYSICAL	0
+#define ENGINE_MOCK	1
+#define ENGINE_VIRTUAL	2
+
 #endif /* _INTEL_RINGBUFFER_H_ */

drivers/gpu/drm/i915/gt/intel_engine_cs.c

@@ -617,14 +617,7 @@ static int intel_engine_setup_common(struct intel_engine_cs *engine)
 	if (err)
 		return err;
 
-	err = i915_timeline_init(engine->i915,
+	intel_engine_init_active(engine, ENGINE_PHYSICAL);
-				 &engine->timeline,
-				 engine->status_page.vma);
-	if (err)
-		goto err_hwsp;
-
-	i915_timeline_set_subclass(&engine->timeline, TIMELINE_ENGINE);
-
 	intel_engine_init_breadcrumbs(engine);
 	intel_engine_init_execlists(engine);
 	intel_engine_init_hangcheck(engine);
@@ -637,10 +630,6 @@ static int intel_engine_setup_common(struct intel_engine_cs *engine)
 		intel_sseu_from_device_info(&RUNTIME_INFO(engine->i915)->sseu);
 
 	return 0;
-
-err_hwsp:
-	cleanup_status_page(engine);
-	return err;
 }
 
 /**
@@ -797,6 +786,27 @@ static int pin_context(struct i915_gem_context *ctx,
 	return 0;
 }
 
+void
+intel_engine_init_active(struct intel_engine_cs *engine, unsigned int subclass)
+{
+	INIT_LIST_HEAD(&engine->active.requests);
+
+	spin_lock_init(&engine->active.lock);
+	lockdep_set_subclass(&engine->active.lock, subclass);
+
+	/*
+	 * Due to an interesting quirk in lockdep's internal debug tracking,
+	 * after setting a subclass we must ensure the lock is used. Otherwise,
+	 * nr_unused_locks is incremented once too often.
+	 */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	local_irq_disable();
+	lock_map_acquire(&engine->active.lock.dep_map);
+	lock_map_release(&engine->active.lock.dep_map);
+	local_irq_enable();
+#endif
+}
+
 /**
  * intel_engines_init_common - initialize cengine state which might require hw access
  * @engine: Engine to initialize.
@@ -860,6 +870,8 @@ err_unpin:
  */
 void intel_engine_cleanup_common(struct intel_engine_cs *engine)
 {
+	GEM_BUG_ON(!list_empty(&engine->active.requests));
+
 	cleanup_status_page(engine);
 
 	intel_engine_fini_breadcrumbs(engine);
@@ -874,8 +886,6 @@ void intel_engine_cleanup_common(struct intel_engine_cs *engine)
 	intel_context_unpin(engine->kernel_context);
 	GEM_BUG_ON(!llist_empty(&engine->barrier_tasks));
 
-	i915_timeline_fini(&engine->timeline);
-
 	intel_wa_list_free(&engine->ctx_wa_list);
 	intel_wa_list_free(&engine->wa_list);
 	intel_wa_list_free(&engine->whitelist);
@@ -1482,16 +1492,6 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 
 	drm_printf(m, "\tRequests:\n");
 
-	rq = list_first_entry(&engine->timeline.requests,
-			      struct i915_request, link);
-	if (&rq->link != &engine->timeline.requests)
-		print_request(m, rq, "\t\tfirst  ");
-
-	rq = list_last_entry(&engine->timeline.requests,
-			     struct i915_request, link);
-	if (&rq->link != &engine->timeline.requests)
-		print_request(m, rq, "\t\tlast   ");
-
 	rq = intel_engine_find_active_request(engine);
 	if (rq) {
 		print_request(m, rq, "\t\tactive ");
@@ -1572,7 +1572,7 @@ int intel_enable_engine_stats(struct intel_engine_cs *engine)
 	if (!intel_engine_supports_stats(engine))
 		return -ENODEV;
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 	write_seqlock(&engine->stats.lock);
 
 	if (unlikely(engine->stats.enabled == ~0)) {
@@ -1598,7 +1598,7 @@ int intel_enable_engine_stats(struct intel_engine_cs *engine)
 
 unlock:
 	write_sequnlock(&engine->stats.lock);
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 
 	return err;
 }
@@ -1683,22 +1683,22 @@ intel_engine_find_active_request(struct intel_engine_cs *engine)
 	 * At all other times, we must assume the GPU is still running, but
 	 * we only care about the snapshot of this moment.
 	 */
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
-	list_for_each_entry(request, &engine->timeline.requests, link) {
+	list_for_each_entry(request, &engine->active.requests, sched.link) {
 		if (i915_request_completed(request))
 			continue;
 
 		if (!i915_request_started(request))
-			break;
+			continue;
 
 		/* More than one preemptible request may match! */
 		if (!match_ring(request))
-			break;
+			continue;
 
 		active = request;
 		break;
 	}
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 
 	return active;
 }

drivers/gpu/drm/i915/gt/intel_engine_types.h

@@ -288,7 +288,11 @@ struct intel_engine_cs {
 
 	struct intel_ring *buffer;
 
-	struct i915_timeline timeline;
+	struct {
+		spinlock_t lock;
+		struct list_head requests;
+	} active;
+
 	struct llist_head barrier_tasks;
 
 	struct intel_context *kernel_context; /* pinned */

drivers/gpu/drm/i915/gt/intel_lrc.c

@@ -298,8 +298,8 @@ static inline bool need_preempt(const struct intel_engine_cs *engine,
 	 * Check against the first request in ELSP[1], it will, thanks to the
 	 * power of PI, be the highest priority of that context.
 	 */
-	if (!list_is_last(&rq->link, &engine->timeline.requests) &&
+	if (!list_is_last(&rq->sched.link, &engine->active.requests) &&
-	    rq_prio(list_next_entry(rq, link)) > last_prio)
+	    rq_prio(list_next_entry(rq, sched.link)) > last_prio)
 		return true;
 
 	if (rb) {
@@ -434,11 +434,11 @@ __unwind_incomplete_requests(struct intel_engine_cs *engine)
 	struct list_head *uninitialized_var(pl);
 	int prio = I915_PRIORITY_INVALID;
 
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 
 	list_for_each_entry_safe_reverse(rq, rn,
-					 &engine->timeline.requests,
+					 &engine->active.requests,
-					 link) {
+					 sched.link) {
 		struct intel_engine_cs *owner;
 
 		if (i915_request_completed(rq))
@@ -465,7 +465,7 @@ __unwind_incomplete_requests(struct intel_engine_cs *engine)
 			}
 			GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
 
-			list_add(&rq->sched.link, pl);
+			list_move(&rq->sched.link, pl);
 			active = rq;
 		} else {
 			rq->engine = owner;
@@ -933,11 +933,11 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 			rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
 		struct i915_request *rq;
 
-		spin_lock(&ve->base.timeline.lock);
+		spin_lock(&ve->base.active.lock);
 
 		rq = ve->request;
 		if (unlikely(!rq)) { /* lost the race to a sibling */
-			spin_unlock(&ve->base.timeline.lock);
+			spin_unlock(&ve->base.active.lock);
 			rb_erase_cached(rb, &execlists->virtual);
 			RB_CLEAR_NODE(rb);
 			rb = rb_first_cached(&execlists->virtual);
@@ -950,13 +950,13 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 
 		if (rq_prio(rq) >= queue_prio(execlists)) {
 			if (!virtual_matches(ve, rq, engine)) {
-				spin_unlock(&ve->base.timeline.lock);
+				spin_unlock(&ve->base.active.lock);
 				rb = rb_next(rb);
 				continue;
 			}
 
 			if (last && !can_merge_rq(last, rq)) {
-				spin_unlock(&ve->base.timeline.lock);
+				spin_unlock(&ve->base.active.lock);
 				return; /* leave this rq for another engine */
 			}
 
@@ -1011,7 +1011,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 			last = rq;
 		}
 
-		spin_unlock(&ve->base.timeline.lock);
+		spin_unlock(&ve->base.active.lock);
 		break;
 	}
 
@@ -1068,8 +1068,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 				GEM_BUG_ON(port_isset(port));
 			}
 
-			list_del_init(&rq->sched.link);
-
 			__i915_request_submit(rq);
 			trace_i915_request_in(rq, port_index(port, execlists));
 
@@ -1170,7 +1168,7 @@ static void process_csb(struct intel_engine_cs *engine)
 	const u8 num_entries = execlists->csb_size;
 	u8 head, tail;
 
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 
 	/*
 	 * Note that csb_write, csb_status may be either in HWSP or mmio.
@@ -1330,7 +1328,7 @@ static void process_csb(struct intel_engine_cs *engine)
 
 static void __execlists_submission_tasklet(struct intel_engine_cs *const engine)
 {
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 
 	process_csb(engine);
 	if (!execlists_is_active(&engine->execlists, EXECLISTS_ACTIVE_PREEMPT))
@@ -1351,15 +1349,16 @@ static void execlists_submission_tasklet(unsigned long data)
 		  !!intel_wakeref_active(&engine->wakeref),
 		  engine->execlists.active);
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 	__execlists_submission_tasklet(engine);
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void queue_request(struct intel_engine_cs *engine,
 			  struct i915_sched_node *node,
 			  int prio)
 {
+	GEM_BUG_ON(!list_empty(&node->link));
 	list_add_tail(&node->link, i915_sched_lookup_priolist(engine, prio));
 }
 
@@ -1390,7 +1389,7 @@ static void execlists_submit_request(struct i915_request *request)
 	unsigned long flags;
 
 	/* Will be called from irq-context when using foreign fences. */
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	queue_request(engine, &request->sched, rq_prio(request));
 
@@ -1399,7 +1398,7 @@ static void execlists_submit_request(struct i915_request *request)
 
 	submit_queue(engine, rq_prio(request));
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void __execlists_context_fini(struct intel_context *ce)
@@ -2050,8 +2049,8 @@ static void execlists_reset_prepare(struct intel_engine_cs *engine)
 	intel_engine_stop_cs(engine);
 
 	/* And flush any current direct submission. */
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static bool lrc_regs_ok(const struct i915_request *rq)
@@ -2094,11 +2093,11 @@ static void reset_csb_pointers(struct intel_engine_execlists *execlists)
 
 static struct i915_request *active_request(struct i915_request *rq)
 {
-	const struct list_head * const list = &rq->engine->timeline.requests;
+	const struct list_head * const list = &rq->engine->active.requests;
 	const struct intel_context * const context = rq->hw_context;
 	struct i915_request *active = NULL;
 
-	list_for_each_entry_from_reverse(rq, list, link) {
+	list_for_each_entry_from_reverse(rq, list, sched.link) {
 		if (i915_request_completed(rq))
 			break;
 
@@ -2215,11 +2214,11 @@ static void execlists_reset(struct intel_engine_cs *engine, bool stalled)
 
 	GEM_TRACE("%s\n", engine->name);
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	__execlists_reset(engine, stalled);
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void nop_submission_tasklet(unsigned long data)
@@ -2250,12 +2249,12 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
 	 * submission's irq state, we also wish to remind ourselves that
 	 * it is irq state.)
 	 */
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	__execlists_reset(engine, true);
 
 	/* Mark all executing requests as skipped. */
-	list_for_each_entry(rq, &engine->timeline.requests, link) {
+	list_for_each_entry(rq, &engine->active.requests, sched.link) {
 		if (!i915_request_signaled(rq))
 			dma_fence_set_error(&rq->fence, -EIO);
 
@@ -2286,7 +2285,7 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
 		rb_erase_cached(rb, &execlists->virtual);
 		RB_CLEAR_NODE(rb);
 
-		spin_lock(&ve->base.timeline.lock);
+		spin_lock(&ve->base.active.lock);
 		if (ve->request) {
 			ve->request->engine = engine;
 			__i915_request_submit(ve->request);
@@ -2295,7 +2294,7 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
 			ve->base.execlists.queue_priority_hint = INT_MIN;
 			ve->request = NULL;
 		}
-		spin_unlock(&ve->base.timeline.lock);
+		spin_unlock(&ve->base.active.lock);
 	}
 
 	/* Remaining _unready_ requests will be nop'ed when submitted */
@@ -2307,7 +2306,7 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
 	GEM_BUG_ON(__tasklet_is_enabled(&execlists->tasklet));
 	execlists->tasklet.func = nop_submission_tasklet;
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void execlists_reset_finish(struct intel_engine_cs *engine)
@@ -3010,12 +3009,18 @@ error_deref_obj:
 	return ret;
 }
 
+static struct list_head *virtual_queue(struct virtual_engine *ve)
+{
+	return &ve->base.execlists.default_priolist.requests[0];
+}
+
 static void virtual_context_destroy(struct kref *kref)
 {
 	struct virtual_engine *ve =
 		container_of(kref, typeof(*ve), context.ref);
 	unsigned int n;
 
+	GEM_BUG_ON(!list_empty(virtual_queue(ve)));
 	GEM_BUG_ON(ve->request);
 	GEM_BUG_ON(ve->context.inflight);
 
@@ -3026,13 +3031,13 @@ static void virtual_context_destroy(struct kref *kref)
 		if (RB_EMPTY_NODE(node))
 			continue;
 
-		spin_lock_irq(&sibling->timeline.lock);
+		spin_lock_irq(&sibling->active.lock);
 
 		/* Detachment is lazily performed in the execlists tasklet */
 		if (!RB_EMPTY_NODE(node))
 			rb_erase_cached(node, &sibling->execlists.virtual);
 
-		spin_unlock_irq(&sibling->timeline.lock);
+		spin_unlock_irq(&sibling->active.lock);
 	}
 	GEM_BUG_ON(__tasklet_is_scheduled(&ve->base.execlists.tasklet));
 
@@ -3040,8 +3045,6 @@ static void virtual_context_destroy(struct kref *kref)
 		__execlists_context_fini(&ve->context);
 
 	kfree(ve->bonds);
-
-	i915_timeline_fini(&ve->base.timeline);
 	kfree(ve);
 }
 
@@ -3161,16 +3164,16 @@ static void virtual_submission_tasklet(unsigned long data)
 
 		if (unlikely(!(mask & sibling->mask))) {
 			if (!RB_EMPTY_NODE(&node->rb)) {
-				spin_lock(&sibling->timeline.lock);
+				spin_lock(&sibling->active.lock);
 				rb_erase_cached(&node->rb,
 						&sibling->execlists.virtual);
 				RB_CLEAR_NODE(&node->rb);
-				spin_unlock(&sibling->timeline.lock);
+				spin_unlock(&sibling->active.lock);
 			}
 			continue;
 		}
 
-		spin_lock(&sibling->timeline.lock);
+		spin_lock(&sibling->active.lock);
 
 		if (!RB_EMPTY_NODE(&node->rb)) {
 			/*
@@ -3214,7 +3217,7 @@ submit_engine:
 			tasklet_hi_schedule(&sibling->execlists.tasklet);
 		}
 
-		spin_unlock(&sibling->timeline.lock);
+		spin_unlock(&sibling->active.lock);
 	}
 	local_irq_enable();
 }
@@ -3231,9 +3234,13 @@ static void virtual_submit_request(struct i915_request *rq)
 	GEM_BUG_ON(ve->base.submit_request != virtual_submit_request);
 
 	GEM_BUG_ON(ve->request);
+	GEM_BUG_ON(!list_empty(virtual_queue(ve)));
+
 	ve->base.execlists.queue_priority_hint = rq_prio(rq);
 	WRITE_ONCE(ve->request, rq);
 
+	list_move_tail(&rq->sched.link, virtual_queue(ve));
+
 	tasklet_schedule(&ve->base.execlists.tasklet);
 }
 
@@ -3297,10 +3304,7 @@ intel_execlists_create_virtual(struct i915_gem_context *ctx,
 
 	snprintf(ve->base.name, sizeof(ve->base.name), "virtual");
 
-	err = i915_timeline_init(ctx->i915, &ve->base.timeline, NULL);
+	intel_engine_init_active(&ve->base, ENGINE_VIRTUAL);
-	if (err)
-		goto err_put;
-	i915_timeline_set_subclass(&ve->base.timeline, TIMELINE_VIRTUAL);
 
 	intel_engine_init_execlists(&ve->base);
 
@@ -3311,6 +3315,7 @@ intel_execlists_create_virtual(struct i915_gem_context *ctx,
 	ve->base.submit_request = virtual_submit_request;
 	ve->base.bond_execute = virtual_bond_execute;
 
+	INIT_LIST_HEAD(virtual_queue(ve));
 	ve->base.execlists.queue_priority_hint = INT_MIN;
 	tasklet_init(&ve->base.execlists.tasklet,
 		     virtual_submission_tasklet,
@@ -3465,11 +3470,11 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 	unsigned int count;
 	struct rb_node *rb;
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	last = NULL;
 	count = 0;
-	list_for_each_entry(rq, &engine->timeline.requests, link) {
+	list_for_each_entry(rq, &engine->active.requests, sched.link) {
 		if (count++ < max - 1)
 			show_request(m, rq, "\t\tE ");
 		else
@@ -3532,7 +3537,7 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 		show_request(m, last, "\t\tV ");
 	}
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 void intel_lr_context_reset(struct intel_engine_cs *engine,

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -49,12 +49,12 @@ static void engine_skip_context(struct i915_request *rq)
 	struct intel_engine_cs *engine = rq->engine;
 	struct i915_gem_context *hung_ctx = rq->gem_context;
 
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 
 	if (!i915_request_is_active(rq))
 		return;
 
-	list_for_each_entry_continue(rq, &engine->timeline.requests, link)
+	list_for_each_entry_continue(rq, &engine->active.requests, sched.link)
 		if (rq->gem_context == hung_ctx)
 			i915_request_skip(rq, -EIO);
 }
@@ -130,7 +130,7 @@ void i915_reset_request(struct i915_request *rq, bool guilty)
 		  rq->fence.seqno,
 		  yesno(guilty));
 
-	lockdep_assert_held(&rq->engine->timeline.lock);
+	lockdep_assert_held(&rq->engine->active.lock);
 	GEM_BUG_ON(i915_request_completed(rq));
 
 	if (guilty) {
@@ -785,10 +785,10 @@ static void nop_submit_request(struct i915_request *request)
 		  engine->name, request->fence.context, request->fence.seqno);
 	dma_fence_set_error(&request->fence, -EIO);
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 	__i915_request_submit(request);
 	i915_request_mark_complete(request);
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 
 	intel_engine_queue_breadcrumbs(engine);
 }

drivers/gpu/drm/i915/gt/intel_ringbuffer.c

@@ -730,14 +730,13 @@ static void reset_prepare(struct intel_engine_cs *engine)
 
 static void reset_ring(struct intel_engine_cs *engine, bool stalled)
 {
-	struct i915_timeline *tl = &engine->timeline;
 	struct i915_request *pos, *rq;
 	unsigned long flags;
 	u32 head;
 
 	rq = NULL;
-	spin_lock_irqsave(&tl->lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
-	list_for_each_entry(pos, &tl->requests, link) {
+	list_for_each_entry(pos, &engine->active.requests, sched.link) {
 		if (!i915_request_completed(pos)) {
 			rq = pos;
 			break;
@@ -791,7 +790,7 @@ static void reset_ring(struct intel_engine_cs *engine, bool stalled)
 	}
 	engine->buffer->head = intel_ring_wrap(engine->buffer, head);
 
-	spin_unlock_irqrestore(&tl->lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void reset_finish(struct intel_engine_cs *engine)
@@ -877,10 +876,10 @@ static void cancel_requests(struct intel_engine_cs *engine)
 	struct i915_request *request;
 	unsigned long flags;
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	/* Mark all submitted requests as skipped. */
-	list_for_each_entry(request, &engine->timeline.requests, link) {
+	list_for_each_entry(request, &engine->active.requests, sched.link) {
 		if (!i915_request_signaled(request))
 			dma_fence_set_error(&request->fence, -EIO);
 
@@ -889,7 +888,7 @@ static void cancel_requests(struct intel_engine_cs *engine)
 
 	/* Remaining _unready_ requests will be nop'ed when submitted */
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void i9xx_submit_request(struct i915_request *request)
@@ -1267,8 +1266,6 @@ intel_engine_create_ring(struct intel_engine_cs *engine,
 
 	GEM_BUG_ON(!is_power_of_2(size));
 	GEM_BUG_ON(RING_CTL_SIZE(size) & ~RING_NR_PAGES);
-	GEM_BUG_ON(timeline == &engine->timeline);
-	lockdep_assert_held(&engine->i915->drm.struct_mutex);
 
 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 	if (!ring)

drivers/gpu/drm/i915/gt/mock_engine.c

@@ -229,17 +229,17 @@ static void mock_cancel_requests(struct intel_engine_cs *engine)
 	struct i915_request *request;
 	unsigned long flags;
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	/* Mark all submitted requests as skipped. */
-	list_for_each_entry(request, &engine->timeline.requests, sched.link) {
+	list_for_each_entry(request, &engine->active.requests, sched.link) {
 		if (!i915_request_signaled(request))
 			dma_fence_set_error(&request->fence, -EIO);
 
 		i915_request_mark_complete(request);
 	}
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
@@ -285,28 +285,23 @@ int mock_engine_init(struct intel_engine_cs *engine)
 	struct drm_i915_private *i915 = engine->i915;
 	int err;
 
+	intel_engine_init_active(engine, ENGINE_MOCK);
 	intel_engine_init_breadcrumbs(engine);
 	intel_engine_init_execlists(engine);
 	intel_engine_init__pm(engine);
 
-	if (i915_timeline_init(i915, &engine->timeline, NULL))
-		goto err_breadcrumbs;
-	i915_timeline_set_subclass(&engine->timeline, TIMELINE_ENGINE);
-
 	engine->kernel_context =
 		i915_gem_context_get_engine(i915->kernel_context, engine->id);
 	if (IS_ERR(engine->kernel_context))
-		goto err_timeline;
+		goto err_breadcrumbs;
 
 	err = intel_context_pin(engine->kernel_context);
 	intel_context_put(engine->kernel_context);
 	if (err)
-		goto err_timeline;
+		goto err_breadcrumbs;
 
 	return 0;
 
-err_timeline:
-	i915_timeline_fini(&engine->timeline);
 err_breadcrumbs:
 	intel_engine_fini_breadcrumbs(engine);
 	return -ENOMEM;
@@ -340,7 +335,6 @@ void mock_engine_free(struct intel_engine_cs *engine)
 	intel_context_unpin(engine->kernel_context);
 
 	intel_engine_fini_breadcrumbs(engine);
-	i915_timeline_fini(&engine->timeline);
 
 	kfree(engine);
 }

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -1275,7 +1275,7 @@ static void engine_record_requests(struct intel_engine_cs *engine,
 
 	count = 0;
 	request = first;
-	list_for_each_entry_from(request, &engine->timeline.requests, link)
+	list_for_each_entry_from(request, &engine->active.requests, sched.link)
 		count++;
 	if (!count)
 		return;
@@ -1288,7 +1288,8 @@ static void engine_record_requests(struct intel_engine_cs *engine,
 
 	count = 0;
 	request = first;
-	list_for_each_entry_from(request, &engine->timeline.requests, link) {
+	list_for_each_entry_from(request,
+				 &engine->active.requests, sched.link) {
 		if (count >= ee->num_requests) {
 			/*
 			 * If the ring request list was changed in

drivers/gpu/drm/i915/i915_request.c

@@ -232,9 +232,9 @@ static bool i915_request_retire(struct i915_request *rq)
 
 	local_irq_disable();
 
-	spin_lock(&rq->engine->timeline.lock);
+	spin_lock(&rq->engine->active.lock);
-	list_del(&rq->link);
+	list_del(&rq->sched.link);
-	spin_unlock(&rq->engine->timeline.lock);
+	spin_unlock(&rq->engine->active.lock);
 
 	spin_lock(&rq->lock);
 	i915_request_mark_complete(rq);
@@ -254,6 +254,7 @@ static bool i915_request_retire(struct i915_request *rq)
 	intel_context_unpin(rq->hw_context);
 
 	i915_request_remove_from_client(rq);
+	list_del(&rq->link);
 
 	free_capture_list(rq);
 	i915_sched_node_fini(&rq->sched);
@@ -373,28 +374,17 @@ __i915_request_await_execution(struct i915_request *rq,
 	return 0;
 }
 
-static void move_to_timeline(struct i915_request *request,
-			     struct i915_timeline *timeline)
-{
-	GEM_BUG_ON(request->timeline == &request->engine->timeline);
-	lockdep_assert_held(&request->engine->timeline.lock);
-
-	spin_lock(&request->timeline->lock);
-	list_move_tail(&request->link, &timeline->requests);
-	spin_unlock(&request->timeline->lock);
-}
-
 void __i915_request_submit(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
 
-	GEM_TRACE("%s fence %llx:%lld -> current %d\n",
+	GEM_TRACE("%s fence %llx:%lld, current %d\n",
 		  engine->name,
 		  request->fence.context, request->fence.seqno,
 		  hwsp_seqno(request));
 
 	GEM_BUG_ON(!irqs_disabled());
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 
 	if (i915_gem_context_is_banned(request->gem_context))
 		i915_request_skip(request, -EIO);
@@ -422,6 +412,8 @@ void __i915_request_submit(struct i915_request *request)
 	/* We may be recursing from the signal callback of another i915 fence */
 	spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING);
 
+	list_move_tail(&request->sched.link, &engine->active.requests);
+
 	GEM_BUG_ON(test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags));
 	set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags);
 
@@ -437,9 +429,6 @@ void __i915_request_submit(struct i915_request *request)
 	engine->emit_fini_breadcrumb(request,
 				     request->ring->vaddr + request->postfix);
 
-	/* Transfer from per-context onto the global per-engine timeline */
-	move_to_timeline(request, &engine->timeline);
-
 	engine->serial++;
 
 	trace_i915_request_execute(request);
@@ -451,11 +440,11 @@ void i915_request_submit(struct i915_request *request)
 	unsigned long flags;
 
 	/* Will be called from irq-context when using foreign fences. */
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	__i915_request_submit(request);
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 void __i915_request_unsubmit(struct i915_request *request)
@@ -468,7 +457,7 @@ void __i915_request_unsubmit(struct i915_request *request)
 		  hwsp_seqno(request));
 
 	GEM_BUG_ON(!irqs_disabled());
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 
 	/*
 	 * Only unwind in reverse order, required so that the per-context list
@@ -486,9 +475,6 @@ void __i915_request_unsubmit(struct i915_request *request)
 
 	spin_unlock(&request->lock);
 
-	/* Transfer back from the global per-engine timeline to per-context */
-	move_to_timeline(request, request->timeline);
-
 	/* We've already spun, don't charge on resubmitting. */
 	if (request->sched.semaphores && i915_request_started(request)) {
 		request->sched.attr.priority |= I915_PRIORITY_NOSEMAPHORE;
@@ -510,11 +496,11 @@ void i915_request_unsubmit(struct i915_request *request)
 	unsigned long flags;
 
 	/* Will be called from irq-context when using foreign fences. */
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	__i915_request_unsubmit(request);
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static int __i915_sw_fence_call
@@ -669,7 +655,6 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
 	rq->engine = ce->engine;
 	rq->ring = ce->ring;
 	rq->timeline = tl;
-	GEM_BUG_ON(rq->timeline == &ce->engine->timeline);
 	rq->hwsp_seqno = tl->hwsp_seqno;
 	rq->hwsp_cacheline = tl->hwsp_cacheline;
 	rq->rcustate = get_state_synchronize_rcu(); /* acts as smp_mb() */
@@ -1136,9 +1121,7 @@ __i915_request_add_to_timeline(struct i915_request *rq)
 							 0);
 	}
 
-	spin_lock_irq(&timeline->lock);
 	list_add_tail(&rq->link, &timeline->requests);
-	spin_unlock_irq(&timeline->lock);
 
 	/*
 	 * Make sure that no request gazumped us - if it was allocated after

drivers/gpu/drm/i915/i915_request.h

@@ -217,7 +217,7 @@ struct i915_request {
 
 	bool waitboost;
 
-	/** engine->request_list entry for this request */
+	/** timeline->request entry for this request */
 	struct list_head link;
 
 	/** ring->request_list entry for this request */

drivers/gpu/drm/i915/i915_scheduler.c

@@ -77,7 +77,7 @@ i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio)
 	bool first = true;
 	int idx, i;
 
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 	assert_priolists(execlists);
 
 	/* buckets sorted from highest [in slot 0] to lowest priority */
@@ -162,9 +162,9 @@ sched_lock_engine(const struct i915_sched_node *node,
 	 * check that the rq still belongs to the newly locked engine.
 	 */
 	while (locked != (engine = READ_ONCE(rq->engine))) {
-		spin_unlock(&locked->timeline.lock);
+		spin_unlock(&locked->active.lock);
 		memset(cache, 0, sizeof(*cache));
-		spin_lock(&engine->timeline.lock);
+		spin_lock(&engine->active.lock);
 		locked = engine;
 	}
 
@@ -189,7 +189,7 @@ static void kick_submission(struct intel_engine_cs *engine, int prio)
 	 * tasklet, i.e. we have not change the priority queue
 	 * sufficiently to oust the running context.
 	 */
-	if (inflight && !i915_scheduler_need_preempt(prio, rq_prio(inflight)))
+	if (!inflight || !i915_scheduler_need_preempt(prio, rq_prio(inflight)))
 		return;
 
 	tasklet_hi_schedule(&engine->execlists.tasklet);
@@ -278,7 +278,7 @@ static void __i915_schedule(struct i915_sched_node *node,
 
 	memset(&cache, 0, sizeof(cache));
 	engine = node_to_request(node)->engine;
-	spin_lock(&engine->timeline.lock);
+	spin_lock(&engine->active.lock);
 
 	/* Fifo and depth-first replacement ensure our deps execute before us */
 	engine = sched_lock_engine(node, engine, &cache);
@@ -287,7 +287,7 @@ static void __i915_schedule(struct i915_sched_node *node,
 
 		node = dep->signaler;
 		engine = sched_lock_engine(node, engine, &cache);
-		lockdep_assert_held(&engine->timeline.lock);
+		lockdep_assert_held(&engine->active.lock);
 
 		/* Recheck after acquiring the engine->timeline.lock */
 		if (prio <= node->attr.priority || node_signaled(node))
@@ -296,14 +296,8 @@ static void __i915_schedule(struct i915_sched_node *node,
 		GEM_BUG_ON(node_to_request(node)->engine != engine);
 
 		node->attr.priority = prio;
-		if (!list_empty(&node->link)) {
+
-			GEM_BUG_ON(intel_engine_is_virtual(engine));
+		if (list_empty(&node->link)) {
-			if (!cache.priolist)
-				cache.priolist =
-					i915_sched_lookup_priolist(engine,
-								   prio);
-			list_move_tail(&node->link, cache.priolist);
-		} else {
 			/*
 			 * If the request is not in the priolist queue because
 			 * it is not yet runnable, then it doesn't contribute
@@ -312,10 +306,18 @@ static void __i915_schedule(struct i915_sched_node *node,
 			 * queue; but in that case we may still need to reorder
 			 * the inflight requests.
 			 */
-			if (!i915_sw_fence_done(&node_to_request(node)->submit))
 			continue;
 		}
 
+		if (!intel_engine_is_virtual(engine) &&
+		    !i915_request_is_active(node_to_request(node))) {
+			if (!cache.priolist)
+				cache.priolist =
+					i915_sched_lookup_priolist(engine,
+								   prio);
+			list_move_tail(&node->link, cache.priolist);
+		}
+
 		if (prio <= engine->execlists.queue_priority_hint)
 			continue;
 
@@ -325,7 +327,7 @@ static void __i915_schedule(struct i915_sched_node *node,
 		kick_submission(engine, prio);
 	}
 
-	spin_unlock(&engine->timeline.lock);
+	spin_unlock(&engine->active.lock);
 }
 
 void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
@@ -439,8 +441,6 @@ void i915_sched_node_fini(struct i915_sched_node *node)
 {
 	struct i915_dependency *dep, *tmp;
 
-	GEM_BUG_ON(!list_empty(&node->link));
-
 	spin_lock_irq(&schedule_lock);
 
 	/*

drivers/gpu/drm/i915/i915_timeline.c

@@ -251,7 +251,6 @@ int i915_timeline_init(struct drm_i915_private *i915,
 
 	timeline->fence_context = dma_fence_context_alloc(1);
 
-	spin_lock_init(&timeline->lock);
 	mutex_init(&timeline->mutex);
 
 	INIT_ACTIVE_REQUEST(&timeline->last_request);

drivers/gpu/drm/i915/i915_timeline.h

@@ -36,25 +36,6 @@ int i915_timeline_init(struct drm_i915_private *i915,
 		       struct i915_vma *hwsp);
 void i915_timeline_fini(struct i915_timeline *tl);
 
-static inline void
-i915_timeline_set_subclass(struct i915_timeline *timeline,
-			   unsigned int subclass)
-{
-	lockdep_set_subclass(&timeline->lock, subclass);
-
-	/*
-	 * Due to an interesting quirk in lockdep's internal debug tracking,
-	 * after setting a subclass we must ensure the lock is used. Otherwise,
-	 * nr_unused_locks is incremented once too often.
-	 */
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	local_irq_disable();
-	lock_map_acquire(&timeline->lock.dep_map);
-	lock_map_release(&timeline->lock.dep_map);
-	local_irq_enable();
-#endif
-}
-
 struct i915_timeline *
 i915_timeline_create(struct drm_i915_private *i915,
 		     struct i915_vma *global_hwsp);

drivers/gpu/drm/i915/i915_timeline_types.h

@@ -23,10 +23,6 @@ struct i915_timeline {
 	u64 fence_context;
 	u32 seqno;
 
-	spinlock_t lock;
-#define TIMELINE_CLIENT 0 /* default subclass */
-#define TIMELINE_ENGINE 1
-#define TIMELINE_VIRTUAL 2
 	struct mutex mutex; /* protects the flow of requests */
 
 	unsigned int pin_count;

drivers/gpu/drm/i915/intel_guc_submission.c

@@ -740,7 +740,7 @@ static bool __guc_dequeue(struct intel_engine_cs *engine)
 	bool submit = false;
 	struct rb_node *rb;
 
-	lockdep_assert_held(&engine->timeline.lock);
+	lockdep_assert_held(&engine->active.lock);
 
 	if (port_isset(port)) {
 		if (intel_engine_has_preemption(engine)) {
@@ -822,7 +822,7 @@ static void guc_submission_tasklet(unsigned long data)
 	struct i915_request *rq;
 	unsigned long flags;
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	rq = port_request(port);
 	while (rq && i915_request_completed(rq)) {
@@ -847,7 +847,7 @@ static void guc_submission_tasklet(unsigned long data)
 	if (!execlists_is_active(execlists, EXECLISTS_ACTIVE_PREEMPT))
 		guc_dequeue(engine);
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void guc_reset_prepare(struct intel_engine_cs *engine)
@@ -884,7 +884,7 @@ static void guc_reset(struct intel_engine_cs *engine, bool stalled)
 	struct i915_request *rq;
 	unsigned long flags;
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	execlists_cancel_port_requests(execlists);
 
@@ -900,7 +900,7 @@ static void guc_reset(struct intel_engine_cs *engine, bool stalled)
 	intel_lr_context_reset(engine, rq->hw_context, rq->head, stalled);
 
 out_unlock:
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void guc_cancel_requests(struct intel_engine_cs *engine)
@@ -926,13 +926,13 @@ static void guc_cancel_requests(struct intel_engine_cs *engine)
 	 * submission's irq state, we also wish to remind ourselves that
 	 * it is irq state.)
 	 */
-	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->active.lock, flags);
 
 	/* Cancel the requests on the HW and clear the ELSP tracker. */
 	execlists_cancel_port_requests(execlists);
 
 	/* Mark all executing requests as skipped. */
-	list_for_each_entry(rq, &engine->timeline.requests, link) {
+	list_for_each_entry(rq, &engine->active.requests, sched.link) {
 		if (!i915_request_signaled(rq))
 			dma_fence_set_error(&rq->fence, -EIO);
 
@@ -961,7 +961,7 @@ static void guc_cancel_requests(struct intel_engine_cs *engine)
 	execlists->queue = RB_ROOT_CACHED;
 	GEM_BUG_ON(port_isset(execlists->port));
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
 }
 
 static void guc_reset_finish(struct intel_engine_cs *engine)

drivers/gpu/drm/i915/selftests/mock_timeline.c

@@ -13,7 +13,6 @@ void mock_timeline_init(struct i915_timeline *timeline, u64 context)
 	timeline->i915 = NULL;
 	timeline->fence_context = context;
 
-	spin_lock_init(&timeline->lock);
 	mutex_init(&timeline->mutex);
 
 	INIT_ACTIVE_REQUEST(&timeline->last_request);