drm/amdgpu: toggle DF-Cstate to protect DF reg access

					   uint64_t addr)

{

	uint32_t df_inst_id;

	uint64_t dram_base_addr = 0;

	const struct amdgpu_df_funcs *df_funcs = adev->df.funcs;

	if ((!df_funcs)                 ||

	    (!df_funcs->get_df_inst_id) ||

	    (!df_funcs->get_dram_base_addr)) {

		dev_warn(adev->dev,

			 "XGMI: relative phy_addr algorithm is not supported\n");

		return addr;

	}

	if ((!adev->df.funcs)                 ||

	    (!adev->df.funcs->get_df_inst_id) ||

	    (!adev->df.funcs->get_dram_base_addr))

	if (amdgpu_dpm_set_df_cstate(adev, DF_CSTATE_DISALLOW)) {

		dev_warn(adev->dev,

			 "failed to disable DF-Cstate, DF register may not be accessible\n");

		return addr;

	}

	df_inst_id = df_funcs->get_df_inst_id(adev);

	dram_base_addr = df_funcs->get_dram_base_addr(adev, df_inst_id);

	df_inst_id = adev->df.funcs->get_df_inst_id(adev);

	if (amdgpu_dpm_set_df_cstate(adev, DF_CSTATE_ALLOW))

		dev_warn(adev->dev, "failed to enable DF-Cstate\n");

	return addr + adev->df.funcs->get_dram_base_addr(adev, df_inst_id);

	return addr + dram_base_addr;

}