PCIE_PORT_SERVICE_DPC_SHIFT 22 drivers/pci/pcie/portdrv.h #define PCIE_PORT_SERVICE_DPC (1 << PCIE_PORT_SERVICE_DPC_SHIFT) PCIE_PORT_SERVICE_DPC_SHIFT 152 drivers/pci/pcie/portdrv_core.c irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc);