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1// SPDX-License-Identifier: GPL-2.02/*3 * Simple stub driver to reserve a PCI device4 *5 * Copyright (C) 2008 Red Hat, Inc.6 * Author:7 * Chris Wright8 *9 * Usage is simple, allocate a new id to the stub driver and bind the10 * device to it. For example:11 *12 * # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id13 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind14 * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind15 * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver16 * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub17 */18 19#include <linux/module.h>20#include <linux/pci.h>21 22static char ids[1024] __initdata;23 24module_param_string(ids, ids, sizeof(ids), 0);25MODULE_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 29static 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 35static 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 42static 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 87static void __exit pci_stub_exit(void)88{89 pci_unregister_driver(&stub_driver);90}91 92module_init(pci_stub_init);93module_exit(pci_stub_exit);94 95MODULE_DESCRIPTION("VM device assignment stub driver");96MODULE_LICENSE("GPL");97MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");98