1 // SPDX-License-Identifier: GPL-2.0 2 /* pci-stub - simple stub driver to reserve a pci device 3 * 4 * Copyright (C) 2008 Red Hat, Inc. 5 * Author: 6 * Chris Wright 7 * 8 * Usage is simple, allocate a new id to the stub driver and bind the 9 * device to it. For example: 10 * 11 * # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id 12 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind 13 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind 14 * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver 15 * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub 16 */ 17 18 #include <linux/module.h> 19 #include <linux/pci.h> 20 21 static char ids[1024] __initdata; 22 23 module_param_string(ids, ids, sizeof(ids), 0); 24 MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the stub driver, format is " 25 "\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\"" 26 " and multiple comma separated entries can be specified"); 27 28 static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id) 29 { 30 pci_info(dev, "claimed by stub\n"); 31 return 0; 32 } 33 34 static struct pci_driver stub_driver = { 35 .name = "pci-stub", 36 .id_table = NULL, /* only dynamic id's */ 37 .probe = pci_stub_probe, 38 }; 39 40 static int __init pci_stub_init(void) 41 { 42 char *p, *id; 43 int rc; 44 45 rc = pci_register_driver(&stub_driver); 46 if (rc) 47 return rc; 48 49 /* no ids passed actually */ 50 if (ids[0] == '\0') 51 return 0; 52 53 /* add ids specified in the module parameter */ 54 p = ids; 55 while ((id = strsep(&p, ","))) { 56 unsigned int vendor, device, subvendor = PCI_ANY_ID, 57 subdevice = PCI_ANY_ID, class = 0, class_mask = 0; 58 int fields; 59 60 if (!strlen(id)) 61 continue; 62 63 fields = sscanf(id, "%x:%x:%x:%x:%x:%x", 64 &vendor, &device, &subvendor, &subdevice, 65 &class, &class_mask); 66 67 if (fields < 2) { 68 printk(KERN_WARNING 69 "pci-stub: invalid id string \"%s\"\n", id); 70 continue; 71 } 72 73 printk(KERN_INFO 74 "pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n", 75 vendor, device, subvendor, subdevice, class, class_mask); 76 77 rc = pci_add_dynid(&stub_driver, vendor, device, 78 subvendor, subdevice, class, class_mask, 0); 79 if (rc) 80 printk(KERN_WARNING 81 "pci-stub: failed to add dynamic id (%d)\n", rc); 82 } 83 84 return 0; 85 } 86 87 static void __exit pci_stub_exit(void) 88 { 89 pci_unregister_driver(&stub_driver); 90 } 91 92 module_init(pci_stub_init); 93 module_exit(pci_stub_exit); 94 95 MODULE_LICENSE("GPL"); 96 MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>"); 97