1 /* pci-stub - simple stub driver to reserve a pci device
2 *
3 * Copyright (C) 2008 Red Hat, Inc.
4 * Author:
5 * Chris Wright
6 *
7 * This work is licensed under the terms of the GNU GPL, version 2.
8 *
9 * Usage is simple, allocate a new id to the stub driver and bind the
10 * device to it. For example:
11 *
12 * # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
13 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
14 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
15 * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
16 * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub
17 */
18
19 #include <linux/module.h>
20 #include <linux/pci.h>
21
22 static char ids[1024] __initdata;
23
24 module_param_string(ids, ids, sizeof(ids), 0);
25 MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the stub driver, format is "
26 "\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\""
27 " and multiple comma separated entries can be specified");
28
pci_stub_probe(struct pci_dev * dev,const struct pci_device_id * id)29 static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id)
30 {
31 dev_info(&dev->dev, "claimed by stub\n");
32 return 0;
33 }
34
35 static struct pci_driver stub_driver = {
36 .name = "pci-stub",
37 .id_table = NULL, /* only dynamic id's */
38 .probe = pci_stub_probe,
39 };
40
pci_stub_init(void)41 static int __init pci_stub_init(void)
42 {
43 char *p, *id;
44 int rc;
45
46 rc = pci_register_driver(&stub_driver);
47 if (rc)
48 return rc;
49
50 /* no ids passed actually */
51 if (ids[0] == '\0')
52 return 0;
53
54 /* add ids specified in the module parameter */
55 p = ids;
56 while ((id = strsep(&p, ","))) {
57 unsigned int vendor, device, subvendor = PCI_ANY_ID,
58 subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
59 int fields;
60
61 if (!strlen(id))
62 continue;
63
64 fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
65 &vendor, &device, &subvendor, &subdevice,
66 &class, &class_mask);
67
68 if (fields < 2) {
69 printk(KERN_WARNING
70 "pci-stub: invalid id string \"%s\"\n", id);
71 continue;
72 }
73
74 printk(KERN_INFO
75 "pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n",
76 vendor, device, subvendor, subdevice, class, class_mask);
77
78 rc = pci_add_dynid(&stub_driver, vendor, device,
79 subvendor, subdevice, class, class_mask, 0);
80 if (rc)
81 printk(KERN_WARNING
82 "pci-stub: failed to add dynamic id (%d)\n", rc);
83 }
84
85 return 0;
86 }
87
pci_stub_exit(void)88 static void __exit pci_stub_exit(void)
89 {
90 pci_unregister_driver(&stub_driver);
91 }
92
93 module_init(pci_stub_init);
94 module_exit(pci_stub_exit);
95
96 MODULE_LICENSE("GPL");
97 MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");
98