Merge tag 'drm-for-v4.17' of git://people.freedesktop.org/~airlied/linux

Pull drm updates from Dave Airlie:
 "Cannonlake and Vega12 support are probably the two major things. This
  pull lacks nouveau, Ben had some unforseen leave and a few other
  blockers so we'll see how things look or maybe leave it for this merge
  window.

  core:
   - Device links to handle sound/gpu pm dependency
   - Color encoding/range properties
   - Plane clipping into plane check helper
   - Backlight helpers
   - DP TP4 + HBR3 helper support

  amdgpu:
   - Vega12 support
   - Enable DC by default on all supported GPUs
   - Powerplay restructuring and cleanup
   - DC bandwidth calc updates
   - DC backlight on pre-DCE11
   - TTM backing store dropping support
   - SR-IOV fixes
   - Adding "wattman" like functionality
   - DC crc support
   - Improved DC dual-link handling

  amdkfd:
   - GPUVM support for dGPU
   - KFD events for dGPU
   - Enable PCIe atomics for dGPUs
   - HSA process eviction support
   - Live-lock fixes for process eviction
   - VM page table allocation fix for large-bar systems

  panel:
   - Raydium RM68200
   - AUO G104SN02 V2
   - KEO TX31D200VM0BAA
   - ARM Versatile panels

  i915:
   - Cannonlake support enabled
   - AUX-F port support added
   - Icelake base enabling until internal milestone of forcewake support
   - Query uAPI interface (used for GPU topology information currently)
   - Compressed framebuffer support for sprites
   - kmem cache shrinking when GPU is idle
   - Avoid boosting GPU when waited item is being processed already
   - Avoid retraining LSPCON link unnecessarily
   - Decrease request signaling latency
   - Deprecation of I915_SET_COLORKEY_NONE
   - Kerneldoc and compiler warning cleanup for upcoming CI enforcements
   - Full range ycbcr toggling
   - HDCP support

  i915/gvt:
   - Big refactor for shadow ppgtt
   - KBL context save/restore via LRI cmd (Weinan)
   - Properly unmap dma for guest page (Changbin)

  vmwgfx:
   - Lots of various improvements

  etnaviv:
   - Use the drm gpu scheduler
   - prep work for GC7000L support

  vc4:
   - fix alpha blending
   - Expose perf counters to userspace

  pl111:
   - Bandwidth checking/limiting
   - Versatile panel support

  sun4i:
   - A83T HDMI support
   - A80 support
   - YUV plane support
   - H3/H5 HDMI support

  omapdrm:
   - HPD support for DVI connector
   - remove lots of static variables

  msm:
   - DSI updates from 10nm / SDM845
   - fix for race condition with a3xx/a4xx fence completion irq
   - some refactoring/prep work for eventual a6xx support (ie. when we
     have a userspace)
   - a5xx debugfs enhancements
   - some mdp5 fixes/cleanups to prepare for eventually merging
     writeback
   - support (ie. when we have a userspace)

  tegra:
   - mmap() fixes for fbdev devices
   - Overlay plane for hw cursor fix
   - dma-buf cache maintenance support

  mali-dp:
   - YUV->RGB conversion support

  rockchip:
   - rk3399/chromebook fixes and improvements

  rcar-du:
   - LVDS support move to drm bridge
   - DT bindings for R8A77995
   - Driver/DT support for R8A77970

  tilcdc:
   - DRM panel support"

* tag 'drm-for-v4.17' of git://people.freedesktop.org/~airlied/linux: (1646 commits)
  drm/i915: Fix hibernation with ACPI S0 target state
  drm/i915/execlists: Use a locked clear_bit() for synchronisation with interrupt
  drm/i915: Specify which engines to reset following semaphore/event lockups
  drm/i915/dp: Write to SET_POWER dpcd to enable MST hub.
  drm/amdkfd: Use ordered workqueue to restore processes
  drm/amdgpu: Fix acquiring VM on large-BAR systems
  drm/amd/pp: clean header file hwmgr.h
  drm/amd/pp: use mlck_table.count for array loop index limit
  drm: Fix uabi regression by allowing garbage mode->type from userspace
  drm/amdgpu: Add an ATPX quirk for hybrid laptop
  drm/amdgpu: fix spelling mistake: "asssert" -> "assert"
  drm/amd/pp: Add new asic support in pp_psm.c
  drm/amd/pp: Clean up powerplay code on Vega12
  drm/amd/pp: Add smu irq handlers for legacy asics
  drm/amd/pp: Fix set wrong temperature range on smu7
  drm/amdgpu: Don't change preferred domian when fallback GTT v5
  drm/vmwgfx: Bump version patchlevel and date
  drm/vmwgfx: use monotonic event timestamps
  drm/vmwgfx: Unpin the screen object backup buffer when not used
  drm/vmwgfx: Stricter count of legacy surface device resources
  ...

1 files changed, 1413 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
new file mode 100644
index 000000000000..282f57630cc1
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -0,0 +1,1413 @@
+/*
+ * Copyright © 2008-2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/prefetch.h>
+#include <linux/dma-fence-array.h>
+#include <linux/sched.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/signal.h>
+
+#include "i915_drv.h"
+
+static const char *i915_fence_get_driver_name(struct dma_fence *fence)
+{
+	return "i915";
+}
+
+static const char *i915_fence_get_timeline_name(struct dma_fence *fence)
+{
+	/*
+	 * The timeline struct (as part of the ppgtt underneath a context)
+	 * may be freed when the request is no longer in use by the GPU.
+	 * We could extend the life of a context to beyond that of all
+	 * fences, possibly keeping the hw resource around indefinitely,
+	 * or we just give them a false name. Since
+	 * dma_fence_ops.get_timeline_name is a debug feature, the occasional
+	 * lie seems justifiable.
+	 */
+	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+		return "signaled";
+
+	return to_request(fence)->timeline->common->name;
+}
+
+static bool i915_fence_signaled(struct dma_fence *fence)
+{
+	return i915_request_completed(to_request(fence));
+}
+
+static bool i915_fence_enable_signaling(struct dma_fence *fence)
+{
+	if (i915_fence_signaled(fence))
+		return false;
+
+	intel_engine_enable_signaling(to_request(fence), true);
+	return !i915_fence_signaled(fence);
+}
+
+static signed long i915_fence_wait(struct dma_fence *fence,
+				   bool interruptible,
+				   signed long timeout)
+{
+	return i915_request_wait(to_request(fence), interruptible, timeout);
+}
+
+static void i915_fence_release(struct dma_fence *fence)
+{
+	struct i915_request *rq = to_request(fence);
+
+	/*
+	 * The request is put onto a RCU freelist (i.e. the address
+	 * is immediately reused), mark the fences as being freed now.
+	 * Otherwise the debugobjects for the fences are only marked as
+	 * freed when the slab cache itself is freed, and so we would get
+	 * caught trying to reuse dead objects.
+	 */
+	i915_sw_fence_fini(&rq->submit);
+
+	kmem_cache_free(rq->i915->requests, rq);
+}
+
+const struct dma_fence_ops i915_fence_ops = {
+	.get_driver_name = i915_fence_get_driver_name,
+	.get_timeline_name = i915_fence_get_timeline_name,
+	.enable_signaling = i915_fence_enable_signaling,
+	.signaled = i915_fence_signaled,
+	.wait = i915_fence_wait,
+	.release = i915_fence_release,
+};
+
+static inline void
+i915_request_remove_from_client(struct i915_request *request)
+{
+	struct drm_i915_file_private *file_priv;
+
+	file_priv = request->file_priv;
+	if (!file_priv)
+		return;
+
+	spin_lock(&file_priv->mm.lock);
+	if (request->file_priv) {
+		list_del(&request->client_link);
+		request->file_priv = NULL;
+	}
+	spin_unlock(&file_priv->mm.lock);
+}
+
+static struct i915_dependency *
+i915_dependency_alloc(struct drm_i915_private *i915)
+{
+	return kmem_cache_alloc(i915->dependencies, GFP_KERNEL);
+}
+
+static void
+i915_dependency_free(struct drm_i915_private *i915,
+		     struct i915_dependency *dep)
+{
+	kmem_cache_free(i915->dependencies, dep);
+}
+
+static void
+__i915_priotree_add_dependency(struct i915_priotree *pt,
+			       struct i915_priotree *signal,
+			       struct i915_dependency *dep,
+			       unsigned long flags)
+{
+	INIT_LIST_HEAD(&dep->dfs_link);
+	list_add(&dep->wait_link, &signal->waiters_list);
+	list_add(&dep->signal_link, &pt->signalers_list);
+	dep->signaler = signal;
+	dep->flags = flags;
+}
+
+static int
+i915_priotree_add_dependency(struct drm_i915_private *i915,
+			     struct i915_priotree *pt,
+			     struct i915_priotree *signal)
+{
+	struct i915_dependency *dep;
+
+	dep = i915_dependency_alloc(i915);
+	if (!dep)
+		return -ENOMEM;
+
+	__i915_priotree_add_dependency(pt, signal, dep, I915_DEPENDENCY_ALLOC);
+	return 0;
+}
+
+static void
+i915_priotree_fini(struct drm_i915_private *i915, struct i915_priotree *pt)
+{
+	struct i915_dependency *dep, *next;
+
+	GEM_BUG_ON(!list_empty(&pt->link));
+
+	/*
+	 * Everyone we depended upon (the fences we wait to be signaled)
+	 * should retire before us and remove themselves from our list.
+	 * However, retirement is run independently on each timeline and
+	 * so we may be called out-of-order.
+	 */
+	list_for_each_entry_safe(dep, next, &pt->signalers_list, signal_link) {
+		GEM_BUG_ON(!i915_priotree_signaled(dep->signaler));
+		GEM_BUG_ON(!list_empty(&dep->dfs_link));
+
+		list_del(&dep->wait_link);
+		if (dep->flags & I915_DEPENDENCY_ALLOC)
+			i915_dependency_free(i915, dep);
+	}
+
+	/* Remove ourselves from everyone who depends upon us */
+	list_for_each_entry_safe(dep, next, &pt->waiters_list, wait_link) {
+		GEM_BUG_ON(dep->signaler != pt);
+		GEM_BUG_ON(!list_empty(&dep->dfs_link));
+
+		list_del(&dep->signal_link);
+		if (dep->flags & I915_DEPENDENCY_ALLOC)
+			i915_dependency_free(i915, dep);
+	}
+}
+
+static void
+i915_priotree_init(struct i915_priotree *pt)
+{
+	INIT_LIST_HEAD(&pt->signalers_list);
+	INIT_LIST_HEAD(&pt->waiters_list);
+	INIT_LIST_HEAD(&pt->link);
+	pt->priority = I915_PRIORITY_INVALID;
+}
+
+static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int ret;
+
+	/* Carefully retire all requests without writing to the rings */
+	ret = i915_gem_wait_for_idle(i915,
+				     I915_WAIT_INTERRUPTIBLE |
+				     I915_WAIT_LOCKED);
+	if (ret)
+		return ret;
+
+	/* If the seqno wraps around, we need to clear the breadcrumb rbtree */
+	for_each_engine(engine, i915, id) {
+		struct i915_gem_timeline *timeline;
+		struct intel_timeline *tl = engine->timeline;
+
+		if (!i915_seqno_passed(seqno, tl->seqno)) {
+			/* Flush any waiters before we reuse the seqno */
+			intel_engine_disarm_breadcrumbs(engine);
+			GEM_BUG_ON(!list_empty(&engine->breadcrumbs.signals));
+		}
+
+		/* Check we are idle before we fiddle with hw state! */
+		GEM_BUG_ON(!intel_engine_is_idle(engine));
+		GEM_BUG_ON(i915_gem_active_isset(&engine->timeline->last_request));
+
+		/* Finally reset hw state */
+		intel_engine_init_global_seqno(engine, seqno);
+		tl->seqno = seqno;
+
+		list_for_each_entry(timeline, &i915->gt.timelines, link)
+			memset(timeline->engine[id].global_sync, 0,
+			       sizeof(timeline->engine[id].global_sync));
+	}
+
+	return 0;
+}
+
+int i915_gem_set_global_seqno(struct drm_device *dev, u32 seqno)
+{
+	struct drm_i915_private *i915 = to_i915(dev);
+
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	if (seqno == 0)
+		return -EINVAL;
+
+	/* HWS page needs to be set less than what we will inject to ring */
+	return reset_all_global_seqno(i915, seqno - 1);
+}
+
+static void mark_busy(struct drm_i915_private *i915)
+{
+	if (i915->gt.awake)
+		return;
+
+	GEM_BUG_ON(!i915->gt.active_requests);
+
+	intel_runtime_pm_get_noresume(i915);
+
+	/*
+	 * It seems that the DMC likes to transition between the DC states a lot
+	 * when there are no connected displays (no active power domains) during
+	 * command submission.
+	 *
+	 * This activity has negative impact on the performance of the chip with
+	 * huge latencies observed in the interrupt handler and elsewhere.
+	 *
+	 * Work around it by grabbing a GT IRQ power domain whilst there is any
+	 * GT activity, preventing any DC state transitions.
+	 */
+	intel_display_power_get(i915, POWER_DOMAIN_GT_IRQ);
+
+	i915->gt.awake = true;
+	if (unlikely(++i915->gt.epoch == 0)) /* keep 0 as invalid */
+		i915->gt.epoch = 1;
+
+	intel_enable_gt_powersave(i915);
+	i915_update_gfx_val(i915);
+	if (INTEL_GEN(i915) >= 6)
+		gen6_rps_busy(i915);
+	i915_pmu_gt_unparked(i915);
+
+	intel_engines_unpark(i915);
+
+	i915_queue_hangcheck(i915);
+
+	queue_delayed_work(i915->wq,
+			   &i915->gt.retire_work,
+			   round_jiffies_up_relative(HZ));
+}
+
+static int reserve_engine(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *i915 = engine->i915;
+	u32 active = ++engine->timeline->inflight_seqnos;
+	u32 seqno = engine->timeline->seqno;
+	int ret;
+
+	/* Reservation is fine until we need to wrap around */
+	if (unlikely(add_overflows(seqno, active))) {
+		ret = reset_all_global_seqno(i915, 0);
+		if (ret) {
+			engine->timeline->inflight_seqnos--;
+			return ret;
+		}
+	}
+
+	if (!i915->gt.active_requests++)
+		mark_busy(i915);
+
+	return 0;
+}
+
+static void unreserve_engine(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *i915 = engine->i915;
+
+	if (!--i915->gt.active_requests) {
+		/* Cancel the mark_busy() from our reserve_engine() */
+		GEM_BUG_ON(!i915->gt.awake);
+		mod_delayed_work(i915->wq,
+				 &i915->gt.idle_work,
+				 msecs_to_jiffies(100));
+	}
+
+	GEM_BUG_ON(!engine->timeline->inflight_seqnos);
+	engine->timeline->inflight_seqnos--;
+}
+
+void i915_gem_retire_noop(struct i915_gem_active *active,
+			  struct i915_request *request)
+{
+	/* Space left intentionally blank */
+}
+
+static void advance_ring(struct i915_request *request)
+{
+	unsigned int tail;
+
+	/*
+	 * We know the GPU must have read the request to have
+	 * sent us the seqno + interrupt, so use the position
+	 * of tail of the request to update the last known position
+	 * of the GPU head.
+	 *
+	 * Note this requires that we are always called in request
+	 * completion order.
+	 */
+	if (list_is_last(&request->ring_link, &request->ring->request_list)) {
+		/*
+		 * We may race here with execlists resubmitting this request
+		 * as we retire it. The resubmission will move the ring->tail
+		 * forwards (to request->wa_tail). We either read the
+		 * current value that was written to hw, or the value that
+		 * is just about to be. Either works, if we miss the last two
+		 * noops - they are safe to be replayed on a reset.
+		 */
+		tail = READ_ONCE(request->ring->tail);
+	} else {
+		tail = request->postfix;
+	}
+	list_del(&request->ring_link);
+
+	request->ring->head = tail;
+}
+
+static void free_capture_list(struct i915_request *request)
+{
+	struct i915_capture_list *capture;
+
+	capture = request->capture_list;
+	while (capture) {
+		struct i915_capture_list *next = capture->next;
+
+		kfree(capture);
+		capture = next;
+	}
+}
+
+static void i915_request_retire(struct i915_request *request)
+{
+	struct intel_engine_cs *engine = request->engine;
+	struct i915_gem_active *active, *next;
+
+	lockdep_assert_held(&request->i915->drm.struct_mutex);
+	GEM_BUG_ON(!i915_sw_fence_signaled(&request->submit));
+	GEM_BUG_ON(!i915_request_completed(request));
+	GEM_BUG_ON(!request->i915->gt.active_requests);
+
+	trace_i915_request_retire(request);
+
+	spin_lock_irq(&engine->timeline->lock);
+	list_del_init(&request->link);
+	spin_unlock_irq(&engine->timeline->lock);
+
+	unreserve_engine(request->engine);
+	advance_ring(request);
+
+	free_capture_list(request);
+
+	/*
+	 * Walk through the active list, calling retire on each. This allows
+	 * objects to track their GPU activity and mark themselves as idle
+	 * when their *last* active request is completed (updating state
+	 * tracking lists for eviction, active references for GEM, etc).
+	 *
+	 * As the ->retire() may free the node, we decouple it first and
+	 * pass along the auxiliary information (to avoid dereferencing
+	 * the node after the callback).
+	 */
+	list_for_each_entry_safe(active, next, &request->active_list, link) {
+		/*
+		 * In microbenchmarks or focusing upon time inside the kernel,
+		 * we may spend an inordinate amount of time simply handling
+		 * the retirement of requests and processing their callbacks.
+		 * Of which, this loop itself is particularly hot due to the
+		 * cache misses when jumping around the list of i915_gem_active.
+		 * So we try to keep this loop as streamlined as possible and
+		 * also prefetch the next i915_gem_active to try and hide
+		 * the likely cache miss.
+		 */
+		prefetchw(next);
+
+		INIT_LIST_HEAD(&active->link);
+		RCU_INIT_POINTER(active->request, NULL);
+
+		active->retire(active, request);
+	}
+
+	i915_request_remove_from_client(request);
+
+	/* Retirement decays the ban score as it is a sign of ctx progress */
+	atomic_dec_if_positive(&request->ctx->ban_score);
+
+	/*
+	 * The backing object for the context is done after switching to the
+	 * *next* context. Therefore we cannot retire the previous context until
+	 * the next context has already started running. However, since we
+	 * cannot take the required locks at i915_request_submit() we
+	 * defer the unpinning of the active context to now, retirement of
+	 * the subsequent request.
+	 */
+	if (engine->last_retired_context)
+		engine->context_unpin(engine, engine->last_retired_context);
+	engine->last_retired_context = request->ctx;
+
+	spin_lock_irq(&request->lock);
+	if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &request->fence.flags))
+		dma_fence_signal_locked(&request->fence);
+	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))
+		intel_engine_cancel_signaling(request);
+	if (request->waitboost) {
+		GEM_BUG_ON(!atomic_read(&request->i915->gt_pm.rps.num_waiters));
+		atomic_dec(&request->i915->gt_pm.rps.num_waiters);
+	}
+	spin_unlock_irq(&request->lock);
+
+	i915_priotree_fini(request->i915, &request->priotree);
+	i915_request_put(request);
+}
+
+void i915_request_retire_upto(struct i915_request *rq)
+{
+	struct intel_engine_cs *engine = rq->engine;
+	struct i915_request *tmp;
+
+	lockdep_assert_held(&rq->i915->drm.struct_mutex);
+	GEM_BUG_ON(!i915_request_completed(rq));
+
+	if (list_empty(&rq->link))
+		return;
+
+	do {
+		tmp = list_first_entry(&engine->timeline->requests,
+				       typeof(*tmp), link);
+
+		i915_request_retire(tmp);
+	} while (tmp != rq);
+}
+
+static u32 timeline_get_seqno(struct intel_timeline *tl)
+{
+	return ++tl->seqno;
+}
+
+void __i915_request_submit(struct i915_request *request)
+{
+	struct intel_engine_cs *engine = request->engine;
+	struct intel_timeline *timeline;
+	u32 seqno;
+
+	GEM_BUG_ON(!irqs_disabled());
+	lockdep_assert_held(&engine->timeline->lock);
+
+	/* Transfer from per-context onto the global per-engine timeline */
+	timeline = engine->timeline;
+	GEM_BUG_ON(timeline == request->timeline);
+	GEM_BUG_ON(request->global_seqno);
+
+	seqno = timeline_get_seqno(timeline);
+	GEM_BUG_ON(!seqno);
+	GEM_BUG_ON(i915_seqno_passed(intel_engine_get_seqno(engine), seqno));
+
+	/* We may be recursing from the signal callback of another i915 fence */
+	spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING);
+	request->global_seqno = seqno;
+	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))
+		intel_engine_enable_signaling(request, false);
+	spin_unlock(&request->lock);
+
+	engine->emit_breadcrumb(request,
+				request->ring->vaddr + request->postfix);
+
+	spin_lock(&request->timeline->lock);
+	list_move_tail(&request->link, &timeline->requests);
+	spin_unlock(&request->timeline->lock);
+
+	trace_i915_request_execute(request);
+
+	wake_up_all(&request->execute);
+}
+
+void i915_request_submit(struct i915_request *request)
+{
+	struct intel_engine_cs *engine = request->engine;
+	unsigned long flags;
+
+	/* Will be called from irq-context when using foreign fences. */
+	spin_lock_irqsave(&engine->timeline->lock, flags);
+
+	__i915_request_submit(request);
+
+	spin_unlock_irqrestore(&engine->timeline->lock, flags);
+}
+
+void __i915_request_unsubmit(struct i915_request *request)
+{
+	struct intel_engine_cs *engine = request->engine;
+	struct intel_timeline *timeline;
+
+	GEM_BUG_ON(!irqs_disabled());
+	lockdep_assert_held(&engine->timeline->lock);
+
+	/*
+	 * Only unwind in reverse order, required so that the per-context list
+	 * is kept in seqno/ring order.
+	 */
+	GEM_BUG_ON(!request->global_seqno);
+	GEM_BUG_ON(request->global_seqno != engine->timeline->seqno);
+	GEM_BUG_ON(i915_seqno_passed(intel_engine_get_seqno(engine),
+				     request->global_seqno));
+	engine->timeline->seqno--;
+
+	/* We may be recursing from the signal callback of another i915 fence */
+	spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING);
+	request->global_seqno = 0;
+	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))
+		intel_engine_cancel_signaling(request);
+	spin_unlock(&request->lock);
+
+	/* Transfer back from the global per-engine timeline to per-context */
+	timeline = request->timeline;
+	GEM_BUG_ON(timeline == engine->timeline);
+
+	spin_lock(&timeline->lock);
+	list_move(&request->link, &timeline->requests);
+	spin_unlock(&timeline->lock);
+
+	/*
+	 * We don't need to wake_up any waiters on request->execute, they
+	 * will get woken by any other event or us re-adding this request
+	 * to the engine timeline (__i915_request_submit()). The waiters
+	 * should be quite adapt at finding that the request now has a new
+	 * global_seqno to the one they went to sleep on.
+	 */
+}
+
+void i915_request_unsubmit(struct i915_request *request)
+{
+	struct intel_engine_cs *engine = request->engine;
+	unsigned long flags;
+
+	/* Will be called from irq-context when using foreign fences. */
+	spin_lock_irqsave(&engine->timeline->lock, flags);
+
+	__i915_request_unsubmit(request);
+
+	spin_unlock_irqrestore(&engine->timeline->lock, flags);
+}
+
+static int __i915_sw_fence_call
+submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
+{
+	struct i915_request *request =
+		container_of(fence, typeof(*request), submit);
+
+	switch (state) {
+	case FENCE_COMPLETE:
+		trace_i915_request_submit(request);
+		/*
+		 * We need to serialize use of the submit_request() callback
+		 * with its hotplugging performed during an emergency
+		 * i915_gem_set_wedged().  We use the RCU mechanism to mark the
+		 * critical section in order to force i915_gem_set_wedged() to
+		 * wait until the submit_request() is completed before
+		 * proceeding.
+		 */
+		rcu_read_lock();
+		request->engine->submit_request(request);
+		rcu_read_unlock();
+		break;
+
+	case FENCE_FREE:
+		i915_request_put(request);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+/**
+ * i915_request_alloc - allocate a request structure
+ *
+ * @engine: engine that we wish to issue the request on.
+ * @ctx: context that the request will be associated with.
+ *
+ * Returns a pointer to the allocated request if successful,
+ * or an error code if not.
+ */
+struct i915_request *
+i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
+{
+	struct drm_i915_private *i915 = engine->i915;
+	struct i915_request *rq;
+	struct intel_ring *ring;
+	int ret;
+
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	/*
+	 * Preempt contexts are reserved for exclusive use to inject a
+	 * preemption context switch. They are never to be used for any trivial
+	 * request!
+	 */
+	GEM_BUG_ON(ctx == i915->preempt_context);
+
+	/*
+	 * ABI: Before userspace accesses the GPU (e.g. execbuffer), report
+	 * EIO if the GPU is already wedged.
+	 */
+	if (i915_terminally_wedged(&i915->gpu_error))
+		return ERR_PTR(-EIO);
+
+	/*
+	 * Pinning the contexts may generate requests in order to acquire
+	 * GGTT space, so do this first before we reserve a seqno for
+	 * ourselves.
+	 */
+	ring = engine->context_pin(engine, ctx);
+	if (IS_ERR(ring))
+		return ERR_CAST(ring);
+	GEM_BUG_ON(!ring);
+
+	ret = reserve_engine(engine);
+	if (ret)
+		goto err_unpin;
+
+	ret = intel_ring_wait_for_space(ring, MIN_SPACE_FOR_ADD_REQUEST);
+	if (ret)
+		goto err_unreserve;
+
+	/* Move the oldest request to the slab-cache (if not in use!) */
+	rq = list_first_entry_or_null(&engine->timeline->requests,
+				      typeof(*rq), link);
+	if (rq && i915_request_completed(rq))
+		i915_request_retire(rq);
+
+	/*
+	 * Beware: Dragons be flying overhead.
+	 *
+	 * We use RCU to look up requests in flight. The lookups may
+	 * race with the request being allocated from the slab freelist.
+	 * That is the request we are writing to here, may be in the process
+	 * of being read by __i915_gem_active_get_rcu(). As such,
+	 * we have to be very careful when overwriting the contents. During
+	 * the RCU lookup, we change chase the request->engine pointer,
+	 * read the request->global_seqno and increment the reference count.
+	 *
+	 * The reference count is incremented atomically. If it is zero,
+	 * the lookup knows the request is unallocated and complete. Otherwise,
+	 * it is either still in use, or has been reallocated and reset
+	 * with dma_fence_init(). This increment is safe for release as we
+	 * check that the request we have a reference to and matches the active
+	 * request.
+	 *
+	 * Before we increment the refcount, we chase the request->engine
+	 * pointer. We must not call kmem_cache_zalloc() or else we set
+	 * that pointer to NULL and cause a crash during the lookup. If
+	 * we see the request is completed (based on the value of the
+	 * old engine and seqno), the lookup is complete and reports NULL.
+	 * If we decide the request is not completed (new engine or seqno),
+	 * then we grab a reference and double check that it is still the
+	 * active request - which it won't be and restart the lookup.
+	 *
+	 * Do not use kmem_cache_zalloc() here!
+	 */
+	rq = kmem_cache_alloc(i915->requests,
+			      GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+	if (unlikely(!rq)) {
+		/* Ratelimit ourselves to prevent oom from malicious clients */
+		ret = i915_gem_wait_for_idle(i915,
+					     I915_WAIT_LOCKED |
+					     I915_WAIT_INTERRUPTIBLE);
+		if (ret)
+			goto err_unreserve;
+
+		/*
+		 * We've forced the client to stall and catch up with whatever
+		 * backlog there might have been. As we are assuming that we
+		 * caused the mempressure, now is an opportune time to
+		 * recover as much memory from the request pool as is possible.
+		 * Having already penalized the client to stall, we spend
+		 * a little extra time to re-optimise page allocation.
+		 */
+		kmem_cache_shrink(i915->requests);
+		rcu_barrier(); /* Recover the TYPESAFE_BY_RCU pages */
+
+		rq = kmem_cache_alloc(i915->requests, GFP_KERNEL);
+		if (!rq) {
+			ret = -ENOMEM;
+			goto err_unreserve;
+		}
+	}
+
+	rq->timeline = i915_gem_context_lookup_timeline(ctx, engine);
+	GEM_BUG_ON(rq->timeline == engine->timeline);
+
+	spin_lock_init(&rq->lock);
+	dma_fence_init(&rq->fence,
+		       &i915_fence_ops,
+		       &rq->lock,
+		       rq->timeline->fence_context,
+		       timeline_get_seqno(rq->timeline));
+
+	/* We bump the ref for the fence chain */
+	i915_sw_fence_init(&i915_request_get(rq)->submit, submit_notify);
+	init_waitqueue_head(&rq->execute);
+
+	i915_priotree_init(&rq->priotree);
+
+	INIT_LIST_HEAD(&rq->active_list);
+	rq->i915 = i915;
+	rq->engine = engine;
+	rq->ctx = ctx;
+	rq->ring = ring;
+
+	/* No zalloc, must clear what we need by hand */
+	rq->global_seqno = 0;
+	rq->signaling.wait.seqno = 0;
+	rq->file_priv = NULL;
+	rq->batch = NULL;
+	rq->capture_list = NULL;
+	rq->waitboost = false;
+
+	/*
+	 * Reserve space in the ring buffer for all the commands required to
+	 * eventually emit this request. This is to guarantee that the
+	 * i915_request_add() call can't fail. Note that the reserve may need
+	 * to be redone if the request is not actually submitted straight
+	 * away, e.g. because a GPU scheduler has deferred it.
+	 */
+	rq->reserved_space = MIN_SPACE_FOR_ADD_REQUEST;
+	GEM_BUG_ON(rq->reserved_space < engine->emit_breadcrumb_sz);
+
+	/*
+	 * Record the position of the start of the request so that
+	 * should we detect the updated seqno part-way through the
+	 * GPU processing the request, we never over-estimate the
+	 * position of the head.
+	 */
+	rq->head = rq->ring->emit;
+
+	/* Unconditionally invalidate GPU caches and TLBs. */
+	ret = engine->emit_flush(rq, EMIT_INVALIDATE);
+	if (ret)
+		goto err_unwind;
+
+	ret = engine->request_alloc(rq);
+	if (ret)
+		goto err_unwind;
+
+	/* Check that we didn't interrupt ourselves with a new request */
+	GEM_BUG_ON(rq->timeline->seqno != rq->fence.seqno);
+	return rq;
+
+err_unwind:
+	rq->ring->emit = rq->head;
+
+	/* Make sure we didn't add ourselves to external state before freeing */
+	GEM_BUG_ON(!list_empty(&rq->active_list));
+	GEM_BUG_ON(!list_empty(&rq->priotree.signalers_list));
+	GEM_BUG_ON(!list_empty(&rq->priotree.waiters_list));
+
+	kmem_cache_free(i915->requests, rq);
+err_unreserve:
+	unreserve_engine(engine);
+err_unpin:
+	engine->context_unpin(engine, ctx);
+	return ERR_PTR(ret);
+}
+
+static int
+i915_request_await_request(struct i915_request *to, struct i915_request *from)
+{
+	int ret;
+
+	GEM_BUG_ON(to == from);
+	GEM_BUG_ON(to->timeline == from->timeline);
+
+	if (i915_request_completed(from))
+		return 0;
+
+	if (to->engine->schedule) {
+		ret = i915_priotree_add_dependency(to->i915,
+						   &to->priotree,
+						   &from->priotree);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (to->engine == from->engine) {
+		ret = i915_sw_fence_await_sw_fence_gfp(&to->submit,
+						       &from->submit,
+						       I915_FENCE_GFP);
+		return ret < 0 ? ret : 0;
+	}
+
+	if (to->engine->semaphore.sync_to) {
+		u32 seqno;
+
+		GEM_BUG_ON(!from->engine->semaphore.signal);
+
+		seqno = i915_request_global_seqno(from);
+		if (!seqno)
+			goto await_dma_fence;
+
+		if (seqno <= to->timeline->global_sync[from->engine->id])
+			return 0;
+
+		trace_i915_gem_ring_sync_to(to, from);
+		ret = to->engine->semaphore.sync_to(to, from);
+		if (ret)
+			return ret;
+
+		to->timeline->global_sync[from->engine->id] = seqno;
+		return 0;
+	}
+
+await_dma_fence:
+	ret = i915_sw_fence_await_dma_fence(&to->submit,
+					    &from->fence, 0,
+					    I915_FENCE_GFP);
+	return ret < 0 ? ret : 0;
+}
+
+int
+i915_request_await_dma_fence(struct i915_request *rq, struct dma_fence *fence)
+{
+	struct dma_fence **child = &fence;
+	unsigned int nchild = 1;
+	int ret;
+
+	/*
+	 * Note that if the fence-array was created in signal-on-any mode,
+	 * we should *not* decompose it into its individual fences. However,
+	 * we don't currently store which mode the fence-array is operating
+	 * in. Fortunately, the only user of signal-on-any is private to
+	 * amdgpu and we should not see any incoming fence-array from
+	 * sync-file being in signal-on-any mode.
+	 */
+	if (dma_fence_is_array(fence)) {
+		struct dma_fence_array *array = to_dma_fence_array(fence);
+
+		child = array->fences;
+		nchild = array->num_fences;
+		GEM_BUG_ON(!nchild);
+	}
+
+	do {
+		fence = *child++;
+		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+			continue;
+
+		/*
+		 * Requests on the same timeline are explicitly ordered, along
+		 * with their dependencies, by i915_request_add() which ensures
+		 * that requests are submitted in-order through each ring.
+		 */
+		if (fence->context == rq->fence.context)
+			continue;
+
+		/* Squash repeated waits to the same timelines */
+		if (fence->context != rq->i915->mm.unordered_timeline &&
+		    intel_timeline_sync_is_later(rq->timeline, fence))
+			continue;
+
+		if (dma_fence_is_i915(fence))
+			ret = i915_request_await_request(rq, to_request(fence));
+		else
+			ret = i915_sw_fence_await_dma_fence(&rq->submit, fence,
+							    I915_FENCE_TIMEOUT,
+							    I915_FENCE_GFP);
+		if (ret < 0)
+			return ret;
+
+		/* Record the latest fence used against each timeline */
+		if (fence->context != rq->i915->mm.unordered_timeline)
+			intel_timeline_sync_set(rq->timeline, fence);
+	} while (--nchild);
+
+	return 0;
+}
+
+/**
+ * i915_request_await_object - set this request to (async) wait upon a bo
+ * @to: request we are wishing to use
+ * @obj: object which may be in use on another ring.
+ * @write: whether the wait is on behalf of a writer
+ *
+ * This code is meant to abstract object synchronization with the GPU.
+ * Conceptually we serialise writes between engines inside the GPU.
+ * We only allow one engine to write into a buffer at any time, but
+ * multiple readers. To ensure each has a coherent view of memory, we must:
+ *
+ * - If there is an outstanding write request to the object, the new
+ *   request must wait for it to complete (either CPU or in hw, requests
+ *   on the same ring will be naturally ordered).
+ *
+ * - If we are a write request (pending_write_domain is set), the new
+ *   request must wait for outstanding read requests to complete.
+ *
+ * Returns 0 if successful, else propagates up the lower layer error.
+ */
+int
+i915_request_await_object(struct i915_request *to,
+			  struct drm_i915_gem_object *obj,
+			  bool write)
+{
+	struct dma_fence *excl;
+	int ret = 0;
+
+	if (write) {
+		struct dma_fence **shared;
+		unsigned int count, i;
+
+		ret = reservation_object_get_fences_rcu(obj->resv,
+							&excl, &count, &shared);
+		if (ret)
+			return ret;
+
+		for (i = 0; i < count; i++) {
+			ret = i915_request_await_dma_fence(to, shared[i]);
+			if (ret)
+				break;
+
+			dma_fence_put(shared[i]);
+		}
+
+		for (; i < count; i++)
+			dma_fence_put(shared[i]);
+		kfree(shared);
+	} else {
+		excl = reservation_object_get_excl_rcu(obj->resv);
+	}
+
+	if (excl) {
+		if (ret == 0)
+			ret = i915_request_await_dma_fence(to, excl);
+
+		dma_fence_put(excl);
+	}
+
+	return ret;
+}
+
+/*
+ * NB: This function is not allowed to fail. Doing so would mean the the
+ * request is not being tracked for completion but the work itself is
+ * going to happen on the hardware. This would be a Bad Thing(tm).
+ */
+void __i915_request_add(struct i915_request *request, bool flush_caches)
+{
+	struct intel_engine_cs *engine = request->engine;
+	struct intel_ring *ring = request->ring;
+	struct intel_timeline *timeline = request->timeline;
+	struct i915_request *prev;
+	u32 *cs;
+	int err;
+
+	lockdep_assert_held(&request->i915->drm.struct_mutex);
+	trace_i915_request_add(request);
+
+	/*
+	 * Make sure that no request gazumped us - if it was allocated after
+	 * our i915_request_alloc() and called __i915_request_add() before
+	 * us, the timeline will hold its seqno which is later than ours.
+	 */
+	GEM_BUG_ON(timeline->seqno != request->fence.seqno);
+
+	/*
+	 * To ensure that this call will not fail, space for its emissions
+	 * should already have been reserved in the ring buffer. Let the ring
+	 * know that it is time to use that space up.
+	 */
+	request->reserved_space = 0;
+
+	/*
+	 * Emit any outstanding flushes - execbuf can fail to emit the flush
+	 * after having emitted the batchbuffer command. Hence we need to fix
+	 * things up similar to emitting the lazy request. The difference here
+	 * is that the flush _must_ happen before the next request, no matter
+	 * what.
+	 */
+	if (flush_caches) {
+		err = engine->emit_flush(request, EMIT_FLUSH);
+
+		/* Not allowed to fail! */
+		WARN(err, "engine->emit_flush() failed: %d!\n", err);
+	}
+
+	/*
+	 * Record the position of the start of the breadcrumb so that
+	 * should we detect the updated seqno part-way through the
+	 * GPU processing the request, we never over-estimate the
+	 * position of the ring's HEAD.
+	 */
+	cs = intel_ring_begin(request, engine->emit_breadcrumb_sz);
+	GEM_BUG_ON(IS_ERR(cs));
+	request->postfix = intel_ring_offset(request, cs);
+
+	/*
+	 * Seal the request and mark it as pending execution. Note that
+	 * we may inspect this state, without holding any locks, during
+	 * hangcheck. Hence we apply the barrier to ensure that we do not
+	 * see a more recent value in the hws than we are tracking.
+	 */
+
+	prev = i915_gem_active_raw(&timeline->last_request,
+				   &request->i915->drm.struct_mutex);
+	if (prev && !i915_request_completed(prev)) {
+		i915_sw_fence_await_sw_fence(&request->submit, &prev->submit,
+					     &request->submitq);
+		if (engine->schedule)
+			__i915_priotree_add_dependency(&request->priotree,
+						       &prev->priotree,
+						       &request->dep,
+						       0);
+	}
+
+	spin_lock_irq(&timeline->lock);
+	list_add_tail(&request->link, &timeline->requests);
+	spin_unlock_irq(&timeline->lock);
+
+	GEM_BUG_ON(timeline->seqno != request->fence.seqno);
+	i915_gem_active_set(&timeline->last_request, request);
+
+	list_add_tail(&request->ring_link, &ring->request_list);
+	request->emitted_jiffies = jiffies;
+
+	/*
+	 * Let the backend know a new request has arrived that may need
+	 * to adjust the existing execution schedule due to a high priority
+	 * request - i.e. we may want to preempt the current request in order
+	 * to run a high priority dependency chain *before* we can execute this
+	 * request.
+	 *
+	 * This is called before the request is ready to run so that we can
+	 * decide whether to preempt the entire chain so that it is ready to
+	 * run at the earliest possible convenience.
+	 */
+	rcu_read_lock();
+	if (engine->schedule)
+		engine->schedule(request, request->ctx->priority);
+	rcu_read_unlock();
+
+	local_bh_disable();
+	i915_sw_fence_commit(&request->submit);
+	local_bh_enable(); /* Kick the execlists tasklet if just scheduled */
+
+	/*
+	 * In typical scenarios, we do not expect the previous request on
+	 * the timeline to be still tracked by timeline->last_request if it
+	 * has been completed. If the completed request is still here, that
+	 * implies that request retirement is a long way behind submission,
+	 * suggesting that we haven't been retiring frequently enough from
+	 * the combination of retire-before-alloc, waiters and the background
+	 * retirement worker. So if the last request on this timeline was
+	 * already completed, do a catch up pass, flushing the retirement queue
+	 * up to this client. Since we have now moved the heaviest operations
+	 * during retirement onto secondary workers, such as freeing objects
+	 * or contexts, retiring a bunch of requests is mostly list management
+	 * (and cache misses), and so we should not be overly penalizing this
+	 * client by performing excess work, though we may still performing
+	 * work on behalf of others -- but instead we should benefit from
+	 * improved resource management. (Well, that's the theory at least.)
+	 */
+	if (prev && i915_request_completed(prev))
+		i915_request_retire_upto(prev);
+}
+
+static unsigned long local_clock_us(unsigned int *cpu)
+{
+	unsigned long t;
+
+	/*
+	 * Cheaply and approximately convert from nanoseconds to microseconds.
+	 * The result and subsequent calculations are also defined in the same
+	 * approximate microseconds units. The principal source of timing
+	 * error here is from the simple truncation.
+	 *
+	 * Note that local_clock() is only defined wrt to the current CPU;
+	 * the comparisons are no longer valid if we switch CPUs. Instead of
+	 * blocking preemption for the entire busywait, we can detect the CPU
+	 * switch and use that as indicator of system load and a reason to
+	 * stop busywaiting, see busywait_stop().
+	 */
+	*cpu = get_cpu();
+	t = local_clock() >> 10;
+	put_cpu();
+
+	return t;
+}
+
+static bool busywait_stop(unsigned long timeout, unsigned int cpu)
+{
+	unsigned int this_cpu;
+
+	if (time_after(local_clock_us(&this_cpu), timeout))
+		return true;
+
+	return this_cpu != cpu;
+}
+
+static bool __i915_spin_request(const struct i915_request *rq,
+				u32 seqno, int state, unsigned long timeout_us)
+{
+	struct intel_engine_cs *engine = rq->engine;
+	unsigned int irq, cpu;
+
+	GEM_BUG_ON(!seqno);
+
+	/*
+	 * Only wait for the request if we know it is likely to complete.
+	 *
+	 * We don't track the timestamps around requests, nor the average
+	 * request length, so we do not have a good indicator that this
+	 * request will complete within the timeout. What we do know is the
+	 * order in which requests are executed by the engine and so we can
+	 * tell if the request has started. If the request hasn't started yet,
+	 * it is a fair assumption that it will not complete within our
+	 * relatively short timeout.
+	 */
+	if (!i915_seqno_passed(intel_engine_get_seqno(engine), seqno - 1))
+		return false;
+
+	/*
+	 * When waiting for high frequency requests, e.g. during synchronous
+	 * rendering split between the CPU and GPU, the finite amount of time
+	 * required to set up the irq and wait upon it limits the response
+	 * rate. By busywaiting on the request completion for a short while we
+	 * can service the high frequency waits as quick as possible. However,
+	 * if it is a slow request, we want to sleep as quickly as possible.
+	 * The tradeoff between waiting and sleeping is roughly the time it
+	 * takes to sleep on a request, on the order of a microsecond.
+	 */
+
+	irq = atomic_read(&engine->irq_count);
+	timeout_us += local_clock_us(&cpu);
+	do {
+		if (i915_seqno_passed(intel_engine_get_seqno(engine), seqno))
+			return seqno == i915_request_global_seqno(rq);
+
+		/*
+		 * Seqno are meant to be ordered *before* the interrupt. If
+		 * we see an interrupt without a corresponding seqno advance,
+		 * assume we won't see one in the near future but require
+		 * the engine->seqno_barrier() to fixup coherency.
+		 */
+		if (atomic_read(&engine->irq_count) != irq)
+			break;
+
+		if (signal_pending_state(state, current))
+			break;
+
+		if (busywait_stop(timeout_us, cpu))
+			break;
+
+		cpu_relax();
+	} while (!need_resched());
+
+	return false;
+}
+
+static bool __i915_wait_request_check_and_reset(struct i915_request *request)
+{
+	if (likely(!i915_reset_handoff(&request->i915->gpu_error)))
+		return false;
+
+	__set_current_state(TASK_RUNNING);
+	i915_reset(request->i915, 0);
+	return true;
+}
+
+/**
+ * i915_request_wait - wait until execution of request has finished
+ * @rq: the request to wait upon
+ * @flags: how to wait
+ * @timeout: how long to wait in jiffies
+ *
+ * i915_request_wait() waits for the request to be completed, for a
+ * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an
+ * unbounded wait).
+ *
+ * If the caller holds the struct_mutex, the caller must pass I915_WAIT_LOCKED
+ * in via the flags, and vice versa if the struct_mutex is not held, the caller
+ * must not specify that the wait is locked.
+ *
+ * Returns the remaining time (in jiffies) if the request completed, which may
+ * be zero or -ETIME if the request is unfinished after the timeout expires.
+ * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is
+ * pending before the request completes.
+ */
+long i915_request_wait(struct i915_request *rq,
+		       unsigned int flags,
+		       long timeout)
+{
+	const int state = flags & I915_WAIT_INTERRUPTIBLE ?
+		TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
+	wait_queue_head_t *errq = &rq->i915->gpu_error.wait_queue;
+	DEFINE_WAIT_FUNC(reset, default_wake_function);
+	DEFINE_WAIT_FUNC(exec, default_wake_function);
+	struct intel_wait wait;
+
+	might_sleep();
+#if IS_ENABLED(CONFIG_LOCKDEP)
+	GEM_BUG_ON(debug_locks &&
+		   !!lockdep_is_held(&rq->i915->drm.struct_mutex) !=
+		   !!(flags & I915_WAIT_LOCKED));
+#endif
+	GEM_BUG_ON(timeout < 0);
+
+	if (i915_request_completed(rq))
+		return timeout;
+
+	if (!timeout)
+		return -ETIME;
+
+	trace_i915_request_wait_begin(rq, flags);
+
+	add_wait_queue(&rq->execute, &exec);
+	if (flags & I915_WAIT_LOCKED)
+		add_wait_queue(errq, &reset);
+
+	intel_wait_init(&wait, rq);
+
+restart:
+	do {
+		set_current_state(state);
+		if (intel_wait_update_request(&wait, rq))
+			break;
+
+		if (flags & I915_WAIT_LOCKED &&
+		    __i915_wait_request_check_and_reset(rq))
+			continue;
+
+		if (signal_pending_state(state, current)) {
+			timeout = -ERESTARTSYS;
+			goto complete;
+		}
+
+		if (!timeout) {
+			timeout = -ETIME;
+			goto complete;
+		}
+
+		timeout = io_schedule_timeout(timeout);
+	} while (1);
+
+	GEM_BUG_ON(!intel_wait_has_seqno(&wait));
+	GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit));
+
+	/* Optimistic short spin before touching IRQs */
+	if (__i915_spin_request(rq, wait.seqno, state, 5))
+		goto complete;
+
+	set_current_state(state);
+	if (intel_engine_add_wait(rq->engine, &wait))
+		/*
+		 * In order to check that we haven't missed the interrupt
+		 * as we enabled it, we need to kick ourselves to do a
+		 * coherent check on the seqno before we sleep.
+		 */
+		goto wakeup;
+
+	if (flags & I915_WAIT_LOCKED)
+		__i915_wait_request_check_and_reset(rq);
+
+	for (;;) {
+		if (signal_pending_state(state, current)) {
+			timeout = -ERESTARTSYS;
+			break;
+		}
+
+		if (!timeout) {
+			timeout = -ETIME;
+			break;
+		}
+
+		timeout = io_schedule_timeout(timeout);
+
+		if (intel_wait_complete(&wait) &&
+		    intel_wait_check_request(&wait, rq))
+			break;
+
+		set_current_state(state);
+
+wakeup:
+		/*
+		 * Carefully check if the request is complete, giving time
+		 * for the seqno to be visible following the interrupt.
+		 * We also have to check in case we are kicked by the GPU
+		 * reset in order to drop the struct_mutex.
+		 */
+		if (__i915_request_irq_complete(rq))
+			break;
+
+		/*
+		 * If the GPU is hung, and we hold the lock, reset the GPU
+		 * and then check for completion. On a full reset, the engine's
+		 * HW seqno will be advanced passed us and we are complete.
+		 * If we do a partial reset, we have to wait for the GPU to
+		 * resume and update the breadcrumb.
+		 *
+		 * If we don't hold the mutex, we can just wait for the worker
+		 * to come along and update the breadcrumb (either directly
+		 * itself, or indirectly by recovering the GPU).
+		 */
+		if (flags & I915_WAIT_LOCKED &&
+		    __i915_wait_request_check_and_reset(rq))
+			continue;
+
+		/* Only spin if we know the GPU is processing this request */
+		if (__i915_spin_request(rq, wait.seqno, state, 2))
+			break;
+
+		if (!intel_wait_check_request(&wait, rq)) {
+			intel_engine_remove_wait(rq->engine, &wait);
+			goto restart;
+		}
+	}
+
+	intel_engine_remove_wait(rq->engine, &wait);
+complete:
+	__set_current_state(TASK_RUNNING);
+	if (flags & I915_WAIT_LOCKED)
+		remove_wait_queue(errq, &reset);
+	remove_wait_queue(&rq->execute, &exec);
+	trace_i915_request_wait_end(rq);
+
+	return timeout;
+}
+
+static void engine_retire_requests(struct intel_engine_cs *engine)
+{
+	struct i915_request *request, *next;
+	u32 seqno = intel_engine_get_seqno(engine);
+	LIST_HEAD(retire);
+
+	spin_lock_irq(&engine->timeline->lock);
+	list_for_each_entry_safe(request, next,
+				 &engine->timeline->requests, link) {
+		if (!i915_seqno_passed(seqno, request->global_seqno))
+			break;
+
+		list_move_tail(&request->link, &retire);
+	}
+	spin_unlock_irq(&engine->timeline->lock);
+
+	list_for_each_entry_safe(request, next, &retire, link)
+		i915_request_retire(request);
+}
+
+void i915_retire_requests(struct drm_i915_private *i915)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	if (!i915->gt.active_requests)
+		return;
+
+	for_each_engine(engine, i915, id)
+		engine_retire_requests(engine);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/mock_request.c"
+#include "selftests/i915_request.c"
+#endif