clear-pkgs-linux-iot-lts2018/1235-Revert-drm-i915-gvt-removed-save-store-registers.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Liu Xinyun <xinyun.liu@intel.com>
Date: Thu, 19 Sep 2019 00:31:20 +0800
Subject: [PATCH] Revert "drm/i915/gvt: removed save/store registers"

bring back this feature to improve stability for WaaG

This reverts commit 7b25f1946a757a5c67ed45a773ff1f98e0889a97.

Tracked-On: projectacrn/acrn-hypervisor#3830
Signed-off-by: Liu Xinyun <xinyun.liu@intel.com>
Reviewed-by: Zhao Yakui <yakui.zhao@intel.com>
---
 drivers/gpu/drm/i915/gvt/sched_policy.c | 12 ++++++++
 drivers/gpu/drm/i915/gvt/scheduler.c    | 40 +++++++++++++++++--------
 2 files changed, 40 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/sched_policy.c b/drivers/gpu/drm/i915/gvt/sched_policy.c
index 4fac40d26549..c32e7d5e8629 100644
--- a/drivers/gpu/drm/i915/gvt/sched_policy.c
+++ b/drivers/gpu/drm/i915/gvt/sched_policy.c
@@ -444,7 +444,9 @@ void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
 {
 	struct intel_gvt_workload_scheduler *scheduler =
 		&vgpu->gvt->scheduler;
+	int ring_id;
 	struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
 
 	if (!vgpu_data->active)
 		return;
@@ -463,5 +465,15 @@ void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
 		scheduler->current_vgpu = NULL;
 	}
 
+	intel_runtime_pm_get(dev_priv);
+	spin_lock_bh(&scheduler->mmio_context_lock);
+	for (ring_id = 0; ring_id < I915_NUM_ENGINES; ring_id++) {
+		if (scheduler->engine_owner[ring_id] == vgpu) {
+			intel_gvt_switch_mmio(vgpu, NULL, ring_id);
+			scheduler->engine_owner[ring_id] = NULL;
+		}
+	}
+	spin_unlock_bh(&scheduler->mmio_context_lock);
+	intel_runtime_pm_put(dev_priv);
 	mutex_unlock(&vgpu->gvt->sched_lock);
 }
diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index 7ebbcd22c024..37207c12e196 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -249,7 +249,6 @@ static inline bool is_gvt_request(struct i915_request *req)
 	return i915_gem_context_force_single_submission(req->gem_context);
 }
 
-/*
 static void save_ring_hw_state(struct intel_vgpu *vgpu, int ring_id)
 {
 	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
@@ -263,7 +262,6 @@ static void save_ring_hw_state(struct intel_vgpu *vgpu, int ring_id)
 	reg = RING_ACTHD_UDW(ring_base);
 	vgpu_vreg(vgpu, i915_mmio_reg_offset(reg)) = I915_READ_FW(reg);
 }
-*/
 
 static void active_hp_work(struct work_struct *work)
 {
@@ -291,9 +289,21 @@ static int shadow_context_status_change(struct notifier_block *nb,
 	struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
 	enum intel_engine_id ring_id = req->engine->id;
 	struct intel_vgpu_workload *workload;
+	unsigned long flags;
+
+	if (!is_gvt_request(req)) {
+		spin_lock_irqsave(&scheduler->mmio_context_lock, flags);
+		if (action == INTEL_CONTEXT_SCHEDULE_IN &&
+		    scheduler->engine_owner[ring_id]) {
+			/* Switch ring from vGPU to host. */
+			intel_gvt_switch_mmio(scheduler->engine_owner[ring_id],
+					      NULL, ring_id);
+			scheduler->engine_owner[ring_id] = NULL;
+		}
+		spin_unlock_irqrestore(&scheduler->mmio_context_lock, flags);
 
-	if (!is_gvt_request(req))
 		return NOTIFY_OK;
+	}
 
 	workload = scheduler->current_workload[ring_id];
 	if (unlikely(!workload))
@@ -301,14 +311,27 @@ static int shadow_context_status_change(struct notifier_block *nb,
 
 	switch (action) {
 	case INTEL_CONTEXT_SCHEDULE_IN:
+		spin_lock_irqsave(&scheduler->mmio_context_lock, flags);
+		if (workload->vgpu != scheduler->engine_owner[ring_id]) {
+			/* Switch ring from host to vGPU or vGPU to vGPU. */
+			intel_gvt_switch_mmio(scheduler->engine_owner[ring_id],
+					      workload->vgpu, ring_id);
+			scheduler->engine_owner[ring_id] = workload->vgpu;
+		} else
+			gvt_dbg_sched("skip ring %d mmio switch for vgpu%d\n",
+				      ring_id, workload->vgpu->id);
+		spin_unlock_irqrestore(&scheduler->mmio_context_lock, flags);
+
 		schedule_work(&gvt->active_hp_work);
 		atomic_set(&workload->shadow_ctx_active, 1);
 		break;
 	case INTEL_CONTEXT_SCHEDULE_OUT:
+		save_ring_hw_state(workload->vgpu, ring_id);
 		atomic_set(&workload->shadow_ctx_active, 0);
 		break;
 	case INTEL_CONTEXT_SCHEDULE_PREEMPTED:
-		return NOTIFY_OK;
+		save_ring_hw_state(workload->vgpu, ring_id);
+		break;
 	default:
 		WARN_ON(1);
 		return NOTIFY_OK;
@@ -1031,7 +1054,6 @@ static int workload_thread(void *priv)
 	struct intel_vgpu_workload *workload = NULL;
 	struct intel_vgpu *vgpu = NULL;
 	int ret;
-	long lret;
 	bool need_force_wake = IS_SKYLAKE(gvt->dev_priv)
 			|| IS_KABYLAKE(gvt->dev_priv);
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
@@ -1077,13 +1099,7 @@ static int workload_thread(void *priv)
 
 		gvt_dbg_sched("ring id %d wait workload %p\n",
 				workload->ring_id, workload);
-		lret = i915_request_wait(workload->req, 0,
-				MAX_SCHEDULE_TIMEOUT);
-
-		gvt_dbg_sched("i915_wait_request %p returns %ld\n",
-				workload, lret);
-		if (lret >= 0 && workload->status == -EINPROGRESS)
-			workload->status = 0;
+		i915_request_wait(workload->req, 0, MAX_SCHEDULE_TIMEOUT);
 
 		/*
 		 * increased guilty_count means that this request triggerred
-- 
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