// SPDX-License-Identifier: GPL-2.0
/*
* Simple stub driver to reserve a PCI device
*
* Copyright (C) 2008 Red Hat, Inc.
* Author:
* Chris Wright
*
* Usage is simple, allocate a new id to the stub driver and bind the
* device to it. For example:
*
* # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
* # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
* # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
* .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub
*/
#include <linux/module.h>
#include <linux/pci.h>
static char ids[1024] __initdata;
module_param_string(ids, ids, sizeof(ids), 0);
MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the stub driver, format is "
"\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\""
" and multiple comma separated entries can be specified");
static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
pci_info(dev, "claimed by stub\n");
return 0;
}
static struct pci_driver stub_driver = {
.name = "pci-stub",
.id_table = NULL, /* only dynamic id's */
.probe = pci_stub_probe,
};
static int __init pci_stub_init(void)
{
char *p, *id;
int rc;
rc = pci_register_driver(&stub_driver);
if (rc)
return rc;
/* no ids passed actually */
if (ids[0] == '\0')
return 0;
/* add ids specified in the module parameter */
p = ids;
while ((id = strsep(&p, ","))) {
unsigned int vendor, device, subvendor = PCI_ANY_ID,
subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
int fields;
if (!strlen(id))
continue;
fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
&vendor, &device, &subvendor, &subdevice,
&class, &class_mask);
if (fields < 2) {
pr_warn("pci-stub: invalid ID string \"%s\"\n", id);
continue;
}
pr_info("pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n",
vendor, device, subvendor, subdevice, class, class_mask);
rc = pci_add_dynid(&stub_driver, vendor, device,
subvendor, subdevice, class, class_mask, 0);
if (rc)
pr_warn("pci-stub: failed to add dynamic ID (%d)\n",
rc);
}
return 0;
}
static void __exit pci_stub_exit(void)
{
pci_unregister_driver(&stub_driver);
}
module_init(pci_stub_init);
module_exit(pci_stub_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");
