How does the probe function gets called on a PCI device driver?

[Henrique Montenegro]

Hello list,

I am reading through the e1000 driver and trying to figure out how the
probe function on it gets called.

The driver initialization function calls pci_register_driver:

----------------------------------------------------------------------------->8
static struct pci_driver e1000_driver = {
.name     = e1000_driver_name,
.id_table = e1000_pci_tbl,
.probe    = e1000_probe,
.remove   = e1000_remove,
    // ...
};

static int __init e1000_init_module(void)
{
    // ...
ret = pci_register_driver(&e1000_driver);
    // ...
}
----------------------------------------------------------------------------->8

And pci_register_driver is defined as (on linux/pci.h):

----------------------------------------------------------------------------->8
#define pci_register_driver(driver)             \
         __pci_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
----------------------------------------------------------------------------->8

Function __pci_register_driver is defined as (drivers/pci/pci-driver.c):

----------------------------------------------------------------------------->8
int __pci_register_driver(struct pci_driver *drv, struct module *owner,
                          const char *mod_name)
{
        /* initialize common driver fields */
        drv->driver.name = drv->name;
        drv->driver.bus = &pci_bus_type;
        drv->driver.owner = owner;
        drv->driver.mod_name = mod_name;

        spin_lock_init(&drv->dynids.lock);
        INIT_LIST_HEAD(&drv->dynids.list);

        /* register with core */
        return driver_register(&drv->driver);
}
EXPORT_SYMBOL(__pci_register_driver);
----------------------------------------------------------------------------->8

This is the point where I am getting lost. I can't figure out how the Kernel
will know about the functions defined in the e1000_driver struct mentioned
before, since it does not seem to pass a reference to it anywhere.

How does the kernel know where the probe function for this module is in this
case? To be honest, for any driver that calls pci_register_driver, how will
the
kernel know where the probe function is since it does not seem like it is
being passed to driver_register?

Thanks for the help!

Henrique
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