drm/amdgpu/gfx9: create mqd backups

And properly synchronize them with the master during
queue init.

Reviewed-by: monk liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

@@ -666,7 +666,10 @@ static int gfx_v9_0_compute_mqd_sw_init(struct amdgpu_device *adev)
 			return r;
 		}
 
-		/*TODO: prepare MQD backup */
+		/* prepare MQD backup */
+		adev->gfx.mec.mqd_backup[AMDGPU_MAX_COMPUTE_RINGS] = kmalloc(sizeof(struct v9_mqd), GFP_KERNEL);
+		if (!adev->gfx.mec.mqd_backup[AMDGPU_MAX_COMPUTE_RINGS])
+			dev_warn(adev->dev, "no memory to create MQD backup for ring %s\n", ring->name);
 	}
 
 	/* create MQD for each KCQ */
@@ -681,7 +684,10 @@ static int gfx_v9_0_compute_mqd_sw_init(struct amdgpu_device *adev)
 				return r;
 			}
 
-			/* TODO: prepare MQD backup */
+			/* prepare MQD backup */
+			adev->gfx.mec.mqd_backup[i] = kmalloc(sizeof(struct v9_mqd), GFP_KERNEL);
+			if (!adev->gfx.mec.mqd_backup[i])
+				dev_warn(adev->dev, "no memory to create MQD backup for ring %s\n", ring->name);
 		}
 	}
 
@@ -695,10 +701,12 @@ static void gfx_v9_0_compute_mqd_sw_fini(struct amdgpu_device *adev)
 
 	for (i = 0; i < adev->gfx.num_compute_rings; i++) {
 		ring = &adev->gfx.compute_ring[i];
+		kfree(adev->gfx.mec.mqd_backup[i]);
 		amdgpu_bo_free_kernel(&ring->mqd_obj, &ring->mqd_gpu_addr, (void **)&ring->mqd_ptr);
 	}
 
 	ring = &adev->gfx.kiq.ring;
+	kfree(adev->gfx.mec.mqd_backup[AMDGPU_MAX_COMPUTE_RINGS]);
 	amdgpu_bo_free_kernel(&ring->mqd_obj, &ring->mqd_gpu_addr, (void **)&ring->mqd_ptr);
 }
 
@@ -2132,8 +2140,12 @@ static int gfx_v9_0_kiq_init_queue(struct amdgpu_ring *ring)
 		soc15_grbm_select(adev, 0, 0, 0, 0);
 		mutex_unlock(&adev->srbm_mutex);
 
+		if (adev->gfx.mec.mqd_backup[mqd_idx])
+			memcpy(adev->gfx.mec.mqd_backup[mqd_idx], mqd, sizeof(*mqd));
 	} else { /* for GPU_RESET case */
 		/* reset MQD to a clean status */
+		if (adev->gfx.mec.mqd_backup[mqd_idx])
+			memcpy(mqd, adev->gfx.mec.mqd_backup[mqd_idx], sizeof(*mqd));
 
 		/* reset ring buffer */
 		ring->wptr = 0;