struct pci_bus {
        struct list_head node;          /* node in list of buses */
        struct pci_bus  *parent;        /* parent bus this bridge is on */
        struct list_head children;      /* list of child buses */
        struct list_head devices;       /* list of devices on this bus */
        struct pci_dev  *self;          /* bridge device as seen by parent */
        struct resource *resource[4];   /* address space routed to this bus */

        struct pci_ops  *ops;           /* configuration access functions */
        void            *sysdata;       /* hook for sys-specific extension */
        struct proc_dir_entry *procdir; /* directory entry in /proc/bus/pci */

        unsigned char   number;         /* bus number */
        unsigned char   primary;        /* number of primary bridge */
        unsigned char   secondary;      /* number of secondary bridge */
        unsigned char   subordinate;    /* max number of subordinate buses */

        char            name[48];
        unsigned short  vendor;
        unsigned short  device;
        unsigned int    serial;         /* serial number */
        unsigned char   pnpver;         /* Plug & Play version */
        unsigned char   productver;     /* product version */
        unsigned char   checksum;       /* if zero - checksum passed */
        unsigned char   pad1;
};

struct pci_dev {
        struct list_head global_list;   /* node in list of all PCI devices */
        struct list_head bus_list;      /* node in per-bus list */
        struct pci_bus  *bus;           /* bus this device is on */
        struct pci_bus  *subordinate;   /* bus this device bridges to */

        void            *sysdata;       /* hook for sys-specific extension */
        struct proc_dir_entry *procent; /* device entry in /proc/bus/pci */

        unsigned int    devfn;          /* encoded device & function index */
        unsigned short  vendor;
        unsigned short  device;
        unsigned short  subsystem_vendor;
        unsigned short  subsystem_device;
        unsigned int    class;          /* 3 bytes: (base,sub,prog-if) */
        u8              hdr_type;       /* PCI header type (`multi' flag masked out) */
        u8              rom_base_reg;   /* which config register controls the ROM */

        struct pci_driver *driver;      /* which driver has allocated this device */
        void            *driver_data;   /* data private to the driver */
        u64             dma_mask;       /* Mask of the bits of bus address this
                                           device implements.  Normally this is
                                           0xffffffff.  You only need to change
                                           this if your device has broken DMA
                                           or supports 64-bit transfers.  */

        u32             current_state;  /* Current operating state. In ACPI-speak,
                                           this is D0-D3, D0 being fully functional,
                                           and D3 being off. */

        /* device is compatible with these IDs */
        unsigned short vendor_compatible[DEVICE_COUNT_COMPATIBLE];
        unsigned short device_compatible[DEVICE_COUNT_COMPATIBLE];

        /*
         * Instead of touching interrupt line and base address registers
         * directly, use the values stored here. They might be different!
         */
        unsigned int    irq;
        struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O, memory, ROMS regions*/
        struct resource dma_resource[DEVICE_COUNT_DMA];
        struct resource irq_resource[DEVICE_COUNT_IRQ];

        char            name[80];       /* device name */
        char            slot_name[8];   /* slot name */
        int             active;         /* ISAPnP: device is active */
        int             ro;             /* ISAPnP: read only */
        unsigned short  regs;           /* ISAPnP: supported registers */

        int (*prepare)(struct pci_dev *dev);    /* ISAPnP hooks */
        int (*activate)(struct pci_dev *dev);
        int (*deactivate)(struct pci_dev *dev);
};