1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Simple stub driver to reserve a PCI device
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2008 Red Hat, Inc.
6*4882a593Smuzhiyun * Author:
7*4882a593Smuzhiyun * Chris Wright
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun * Usage is simple, allocate a new id to the stub driver and bind the
10*4882a593Smuzhiyun * device to it. For example:
11*4882a593Smuzhiyun *
12*4882a593Smuzhiyun * # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
13*4882a593Smuzhiyun * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
14*4882a593Smuzhiyun * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
15*4882a593Smuzhiyun * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
16*4882a593Smuzhiyun * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub
17*4882a593Smuzhiyun */
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun #include <linux/module.h>
20*4882a593Smuzhiyun #include <linux/pci.h>
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun static char ids[1024] __initdata;
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun module_param_string(ids, ids, sizeof(ids), 0);
25*4882a593Smuzhiyun MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the stub driver, format is "
26*4882a593Smuzhiyun "\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\""
27*4882a593Smuzhiyun " and multiple comma separated entries can be specified");
28*4882a593Smuzhiyun
pci_stub_probe(struct pci_dev * dev,const struct pci_device_id * id)29*4882a593Smuzhiyun static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun pci_info(dev, "claimed by stub\n");
32*4882a593Smuzhiyun return 0;
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun static struct pci_driver stub_driver = {
36*4882a593Smuzhiyun .name = "pci-stub",
37*4882a593Smuzhiyun .id_table = NULL, /* only dynamic id's */
38*4882a593Smuzhiyun .probe = pci_stub_probe,
39*4882a593Smuzhiyun };
40*4882a593Smuzhiyun
pci_stub_init(void)41*4882a593Smuzhiyun static int __init pci_stub_init(void)
42*4882a593Smuzhiyun {
43*4882a593Smuzhiyun char *p, *id;
44*4882a593Smuzhiyun int rc;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun rc = pci_register_driver(&stub_driver);
47*4882a593Smuzhiyun if (rc)
48*4882a593Smuzhiyun return rc;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun /* no ids passed actually */
51*4882a593Smuzhiyun if (ids[0] == '\0')
52*4882a593Smuzhiyun return 0;
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun /* add ids specified in the module parameter */
55*4882a593Smuzhiyun p = ids;
56*4882a593Smuzhiyun while ((id = strsep(&p, ","))) {
57*4882a593Smuzhiyun unsigned int vendor, device, subvendor = PCI_ANY_ID,
58*4882a593Smuzhiyun subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
59*4882a593Smuzhiyun int fields;
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun if (!strlen(id))
62*4882a593Smuzhiyun continue;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
65*4882a593Smuzhiyun &vendor, &device, &subvendor, &subdevice,
66*4882a593Smuzhiyun &class, &class_mask);
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun if (fields < 2) {
69*4882a593Smuzhiyun pr_warn("pci-stub: invalid ID string \"%s\"\n", id);
70*4882a593Smuzhiyun continue;
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun pr_info("pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n",
74*4882a593Smuzhiyun vendor, device, subvendor, subdevice, class, class_mask);
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun rc = pci_add_dynid(&stub_driver, vendor, device,
77*4882a593Smuzhiyun subvendor, subdevice, class, class_mask, 0);
78*4882a593Smuzhiyun if (rc)
79*4882a593Smuzhiyun pr_warn("pci-stub: failed to add dynamic ID (%d)\n",
80*4882a593Smuzhiyun rc);
81*4882a593Smuzhiyun }
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun return 0;
84*4882a593Smuzhiyun }
85*4882a593Smuzhiyun
pci_stub_exit(void)86*4882a593Smuzhiyun static void __exit pci_stub_exit(void)
87*4882a593Smuzhiyun {
88*4882a593Smuzhiyun pci_unregister_driver(&stub_driver);
89*4882a593Smuzhiyun }
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun module_init(pci_stub_init);
92*4882a593Smuzhiyun module_exit(pci_stub_exit);
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun MODULE_LICENSE("GPL");
95*4882a593Smuzhiyun MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");
96