注册总线pci_bus_type，关注成员dev_attr

static int __init pci_driver_init(void)

{

return bus_register(&pci_bus_type);

}

postcore_initcall(pci_driver_init);

struct bus_type pci_bus_type = {

.name  = "pci",

.match  = pci_bus_match,

.uevent  = pci_uevent,

.probe  = pci_device_probe,

.remove  = pci_device_remove,

.shutdown = pci_device_shutdown,

.dev_attrs = pci_dev_attrs,

.bus_attrs = pci_bus_attrs,

.pm  = PCI_PM_OPS_PTR,

};

pci_dev_attrs关注成员rescan

struct device_attribute pci_dev_attrs[] = {

__ATTR_RO(resource),

__ATTR_RO(vendor),

__ATTR_RO(device),

__ATTR_RO(subsystem_vendor),

__ATTR_RO(subsystem_device),

__ATTR_RO(class),

__ATTR_RO(irq),

__ATTR_RO(local_cpus),

__ATTR_RO(local_cpulist),

__ATTR_RO(modalias),

#ifdef CONFIG_NUMA

__ATTR_RO(numa_node),

#endif

__ATTR_RO(dma_mask_bits),

__ATTR_RO(consistent_dma_mask_bits),

__ATTR(enable, 0600, is_enabled_show, is_enabled_store),

__ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),

broken_parity_status_show,broken_parity_status_store),

__ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),

#ifdef CONFIG_HOTPLUG

__ATTR(remove, (S_IWUSR|S_IWGRP), NULL, remove_store),

__ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_rescan_store),

#endif

__ATTR_NULL,

};

rescan写操作对应处理函数

static ssize_t dev_rescan_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)

{

unsigned long val;

struct pci_dev *pdev = to_pci_dev(dev);

if (strict_strtoul(buf, 0, &val) < 0)

return -EINVAL;

if (val) {

mutex_lock(&pci_remove_rescan_mutex);

pci_rescan_bus(pdev->bus);

mutex_unlock(&pci_remove_rescan_mutex);

}

return count;

}

重新扫描选定PCI总线，配置新设备和向系统添加新设备

unsigned int __ref pci_rescan_bus(struct pci_bus *bus)

{

unsigned int max;

struct pci_dev *dev;

max = pci_scan_child_bus(bus);

down_read(&pci_bus_sem);

list_for_each_entry(dev, &bus->devices, bus_list)

if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||

dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)

if (dev->subordinate)

pci_bus_size_bridges(dev->subordinate);

up_read(&pci_bus_sem);

pci_bus_assign_resources(bus);

pci_enable_bridges(bus);

pci_bus_add_devices(bus);

return max;

}

EXPORT_SYMBOL_GPL(pci_rescan_bus);

2. 应用

echo 1 > /sys/bus/pci/devices/0000:00:1e.0/rescan