1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/pci/pci-stub.c b/drivers/pci/pci-stub.c
new file mode 100644
index 000000000..d1f4c1ce7
--- /dev/null
+++ b/drivers/pci/pci-stub.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Simple stub driver to reserve a PCI device
+ *
+ * Copyright (C) 2008 Red Hat, Inc.
+ * Author:
+ *	Chris Wright
+ *
+ * Usage is simple, allocate a new id to the stub driver and bind the
+ * device to it.  For example:
+ *
+ * # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
+ * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
+ * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
+ * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
+ * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+
+static char ids[1024] __initdata;
+
+module_param_string(ids, ids, sizeof(ids), 0);
+MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the stub driver, format is "
+		 "\"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\""
+		 " and multiple comma separated entries can be specified");
+
+static int pci_stub_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	pci_info(dev, "claimed by stub\n");
+	return 0;
+}
+
+static struct pci_driver stub_driver = {
+	.name		= "pci-stub",
+	.id_table	= NULL,	/* only dynamic id's */
+	.probe		= pci_stub_probe,
+	.driver_managed_dma = true,
+};
+
+static int __init pci_stub_init(void)
+{
+	char *p, *id;
+	int rc;
+
+	rc = pci_register_driver(&stub_driver);
+	if (rc)
+		return rc;
+
+	/* no ids passed actually */
+	if (ids[0] == '\0')
+		return 0;
+
+	/* add ids specified in the module parameter */
+	p = ids;
+	while ((id = strsep(&p, ","))) {
+		unsigned int vendor, device, subvendor = PCI_ANY_ID,
+			subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
+		int fields;
+
+		if (!strlen(id))
+			continue;
+
+		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
+				&vendor, &device, &subvendor, &subdevice,
+				&class, &class_mask);
+
+		if (fields < 2) {
+			pr_warn("pci-stub: invalid ID string \"%s\"\n", id);
+			continue;
+		}
+
+		pr_info("pci-stub: add %04X:%04X sub=%04X:%04X cls=%08X/%08X\n",
+		       vendor, device, subvendor, subdevice, class, class_mask);
+
+		rc = pci_add_dynid(&stub_driver, vendor, device,
+				   subvendor, subdevice, class, class_mask, 0);
+		if (rc)
+			pr_warn("pci-stub: failed to add dynamic ID (%d)\n",
+				rc);
+	}
+
+	return 0;
+}
+
+static void __exit pci_stub_exit(void)
+{
+	pci_unregister_driver(&stub_driver);
+}
+
+module_init(pci_stub_init);
+module_exit(pci_stub_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Chris Wright <chrisw@sous-sol.org>");