DMAR_IQH_REG
dmar_readq(iommu->reg + DMAR_IQH_REG) >> shift,
unsigned int head = dmar_readl(iommu->reg + DMAR_IQH_REG);
head = readl(iommu->reg + DMAR_IQH_REG);
head = readl(iommu->reg + DMAR_IQH_REG);
readl(iommu->reg + DMAR_IQH_REG)) &&