1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Simple stub driver to reserve a PCI device 4 * 5 * Copyright (C) 2008 Red Hat, Inc. 6 * Author: 7 * Chris Wright 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 29 static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id) 30 { 31 pci_info(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 .driver_managed_dma = true, 40 }; 41 42 static int __init pci_stub_init(void) 43 { 44 char *p, *id; 45 int rc; 46 47 rc = pci_register_driver(&stub_driver); 48 if (rc) 49 return rc; 50 51 /* no ids passed actually */ 52 if (ids[0] == '\0') 53 return 0; 54 55 /* add ids specified in the module parameter */ 56 p = ids; 57 while ((id = strsep(&p, ","))) { 58 unsigned int vendor, device, subvendor = PCI_ANY_ID, 59 subdevice = PCI_ANY_ID, class = 0, class_mask = 0; 60 int fields; 61 62 if (!strlen(id)) 63 continue; 64 65 fields = sscanf(id, "%x:%x:%x:%x:%x:%x", 66 &vendor, &device, &subvendor, &subdevice, 67 &class, &class_mask); 68 69 if (fields < 2) { 70 pr_warn("pci-stub: invalid ID string \"%s\"\n", id); 71 continue; 72 } 73 74 pr_info("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 pr_warn("pci-stub: failed to add dynamic ID (%d)\n", 81 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