drm/amdgpu: Enable SDMA utilization for Arcturus

SDMA utilization calculations are enabled/disabled by
writing to SDMAx_PUB_DUMMY_REG2 register. Currently,
enable this only for Arcturus.
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c

@@ -1063,6 +1063,15 @@ static void sdma_v4_0_ctx_switch_enable(struct amdgpu_device *adev, bool enable)
 			WREG32_SDMA(i, mmSDMA0_PHASE2_QUANTUM, phase_quantum);
 		}
 		WREG32_SDMA(i, mmSDMA0_CNTL, f32_cntl);
+
+		/*
+		 * Enable SDMA utilization. Its only supported on
+		 * Arcturus for the moment and firmware version 14
+		 * and above.
+		 */
+		if (adev->asic_type == CHIP_ARCTURUS &&
+		    adev->sdma.instance[i].fw_version >= 14)
+			WREG32_SDMA(i, mmSDMA0_PUB_DUMMY_REG2, enable);
 	}
 
 }