DMAR_FSTS_REG
fault = readl(iommu->reg + DMAR_FSTS_REG);
writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
writel(DMA_FSTS_ITE, iommu->reg + DMAR_FSTS_REG);
writel(DMA_FSTS_ICE, iommu->reg + DMAR_FSTS_REG);
fault_status = readl(iommu->reg + DMAR_FSTS_REG);
iommu->reg + DMAR_FSTS_REG);
fault_status = readl(iommu->reg + DMAR_FSTS_REG);
writel(fault_status, iommu->reg + DMAR_FSTS_REG);