drm/amdgpu/gfx10: wait for reset done before remap

There is a racing condition that cp firmware modifies
MQD in reset sequence after driver updates it for
remapping. We have to wait till CP_HQD_ACTIVE becoming
false then remap the queue.

v2: fix KIQ locking (Alex)
v3: fix KIQ locking harder (Jessie)
Acked-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Signed-off-by: Jiadong Zhu <Jiadong.Zhu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

@@ -9475,7 +9475,7 @@ static int gfx_v10_0_reset_kcq(struct amdgpu_ring *ring,
 	struct amdgpu_kiq *kiq = &adev->gfx.kiq[0];
 	struct amdgpu_ring *kiq_ring = &kiq->ring;
 	unsigned long flags;
-	int r;
+	int i, r;
 
 	if (!kiq->pmf || !kiq->pmf->kiq_unmap_queues)
 		return -EINVAL;
@@ -9483,22 +9483,42 @@ static int gfx_v10_0_reset_kcq(struct amdgpu_ring *ring,
 	spin_lock_irqsave(&kiq->ring_lock, flags);
 
 	if (amdgpu_ring_alloc(kiq_ring, kiq->pmf->unmap_queues_size)) {
-		r = -ENOMEM;
-		goto out;
+		spin_unlock_irqrestore(&kiq->ring_lock, flags);
+		return -ENOMEM;
 	}
 
 	kiq->pmf->kiq_unmap_queues(kiq_ring, ring, RESET_QUEUES,
 				   0, 0);
 	amdgpu_ring_commit(kiq_ring);
+	spin_unlock_irqrestore(&kiq->ring_lock, flags);
 
 	r = amdgpu_ring_test_ring(kiq_ring);
 	if (r)
-		goto out;
+		return r;
+
+	/* make sure dequeue is complete*/
+	gfx_v10_0_set_safe_mode(adev, 0);
+	mutex_lock(&adev->srbm_mutex);
+	nv_grbm_select(adev, ring->me, ring->pipe, ring->queue, 0);
+	for (i = 0; i < adev->usec_timeout; i++) {
+		if (!(RREG32_SOC15(GC, 0, mmCP_HQD_ACTIVE) & 1))
+			break;
+		udelay(1);
+	}
+	if (i >= adev->usec_timeout)
+		r = -ETIMEDOUT;
+	nv_grbm_select(adev, 0, 0, 0, 0);
+	mutex_unlock(&adev->srbm_mutex);
+	gfx_v10_0_unset_safe_mode(adev, 0);
+	if (r) {
+		dev_err(adev->dev, "fail to wait on hqd deactivate\n");
+		return r;
+	}
 
 	r = amdgpu_bo_reserve(ring->mqd_obj, false);
 	if (unlikely(r != 0)) {
 		dev_err(adev->dev, "fail to resv mqd_obj\n");
-		goto out;
+		return r;
 	}
 	r = amdgpu_bo_kmap(ring->mqd_obj, (void **)&ring->mqd_ptr);
 	if (!r) {
@@ -9509,20 +9529,19 @@ static int gfx_v10_0_reset_kcq(struct amdgpu_ring *ring,
 	amdgpu_bo_unreserve(ring->mqd_obj);
 	if (r) {
 		dev_err(adev->dev, "fail to unresv mqd_obj\n");
-		goto out;
+		return r;
 	}
 
+	spin_lock_irqsave(&kiq->ring_lock, flags);
 	if (amdgpu_ring_alloc(kiq_ring, kiq->pmf->map_queues_size)) {
-		r = -ENOMEM;
-		goto out;
+		spin_unlock_irqrestore(&kiq->ring_lock, flags);
+		return -ENOMEM;
 	}
 	kiq->pmf->kiq_map_queues(kiq_ring, ring);
 	amdgpu_ring_commit(kiq_ring);
+	spin_unlock_irqrestore(&kiq->ring_lock, flags);
 
 	r = amdgpu_ring_test_ring(kiq_ring);
-
-out:
-	spin_unlock_irqrestore(&kiq->ring_lock, flags);
 	if (r)
 		return r;