2 * Fake PCI Hot Plug Controller Driver
4 * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2003 IBM Corp.
6 * Copyright (C) 2003 Rolf Eike Beer <eike-kernel@sf-tec.de>
8 * Based on ideas and code from:
9 * Vladimir Kondratiev <vladimir.kondratiev@intel.com>
10 * Rolf Eike Beer <eike-kernel@sf-tec.de>
12 * All rights reserved.
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation, version 2 of the License.
18 * Send feedback to <greg@kroah.com>
23 * This driver will "emulate" removing PCI devices from the system. If
24 * the "power" file is written to with "0" then the specified PCI device
25 * will be completely removed from the kernel.
27 * WARNING, this does NOT turn off the power to the PCI device. This is
28 * a "logical" removal, not a physical or electrical removal.
30 * Use this module at your own risk, you have been warned!
32 * Enabling PCI devices is left as an exercise for the reader...
35 #include <linux/kernel.h>
36 #include <linux/module.h>
37 #include <linux/pci.h>
38 #include <linux/init.h>
39 #include <linux/string.h>
40 #include <linux/slab.h>
41 #include "pci_hotplug.h"
45 #define MY_NAME "fakephp"
47 #define MY_NAME THIS_MODULE->name
50 #define dbg(format, arg...) \
53 printk(KERN_DEBUG "%s: " format, \
56 #define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME , ## arg)
57 #define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME , ## arg)
59 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>"
60 #define DRIVER_DESC "Fake PCI Hot Plug Controller Driver"
63 struct list_head node;
64 struct hotplug_slot *slot;
69 static LIST_HEAD(slot_list);
71 static int enable_slot (struct hotplug_slot *slot);
72 static int disable_slot (struct hotplug_slot *slot);
74 static struct hotplug_slot_ops dummy_hotplug_slot_ops = {
76 .enable_slot = enable_slot,
77 .disable_slot = disable_slot,
80 static void dummy_release(struct hotplug_slot *slot)
82 struct dummy_slot *dslot = slot->private;
84 list_del(&dslot->node);
85 kfree(dslot->slot->info);
87 pci_dev_put(dslot->dev);
91 static int add_slot(struct pci_dev *dev)
93 struct dummy_slot *dslot;
94 struct hotplug_slot *slot;
97 slot = kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
101 slot->info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
105 slot->info->power_status = 1;
106 slot->info->max_bus_speed = PCI_SPEED_UNKNOWN;
107 slot->info->cur_bus_speed = PCI_SPEED_UNKNOWN;
109 slot->name = &dev->dev.bus_id[0];
110 dbg("slot->name = %s\n", slot->name);
112 dslot = kmalloc(sizeof(struct dummy_slot), GFP_KERNEL);
116 slot->ops = &dummy_hotplug_slot_ops;
117 slot->release = &dummy_release;
118 slot->private = dslot;
120 retval = pci_hp_register(slot);
122 err("pci_hp_register failed with error %d\n", retval);
127 dslot->dev = pci_dev_get(dev);
128 list_add (&dslot->node, &slot_list);
141 static int __init pci_scan_buses(void)
143 struct pci_dev *dev = NULL;
146 while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
147 retval = add_slot(dev);
157 static void remove_slot(struct dummy_slot *dslot)
161 dbg("removing slot %s\n", dslot->slot->name);
162 retval = pci_hp_deregister(dslot->slot);
164 err("Problem unregistering a slot %s\n", dslot->slot->name);
169 * Tries hard not to re-enable already existing devices
170 * also handles scanning of subfunctions
172 * @param temp Device template. Should be set: bus and devfn.
174 static void pci_rescan_slot(struct pci_dev *temp)
176 struct pci_bus *bus = temp->bus;
180 if (!pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type)) {
181 temp->hdr_type = hdr_type & 0x7f;
182 if (!pci_find_slot(bus->number, temp->devfn)) {
183 dev = pci_scan_single_device(bus, temp->devfn);
185 dbg("New device on %s function %x:%x\n",
186 bus->name, temp->devfn >> 3,
188 pci_bus_add_device(dev);
192 /* multifunction device? */
193 if (!(hdr_type & 0x80))
196 /* continue scanning for other functions */
197 for (func = 1, temp->devfn++; func < 8; func++, temp->devfn++) {
198 if (pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type))
200 temp->hdr_type = hdr_type & 0x7f;
202 if (!pci_find_slot(bus->number, temp->devfn)) {
203 dev = pci_scan_single_device(bus, temp->devfn);
205 dbg("New device on %s function %x:%x\n",
206 bus->name, temp->devfn >> 3,
208 pci_bus_add_device(dev);
219 * call pci_rescan_slot for each possible function of the bus
223 static void pci_rescan_bus(const struct pci_bus *bus)
227 dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
231 dev->bus = (struct pci_bus*)bus;
232 dev->sysdata = bus->sysdata;
233 for (devfn = 0; devfn < 0x100; devfn += 8) {
235 pci_rescan_slot(dev);
240 /* recursively scan all buses */
241 static void pci_rescan_buses(const struct list_head *list)
243 const struct list_head *l;
244 list_for_each(l,list) {
245 const struct pci_bus *b = pci_bus_b(l);
247 pci_rescan_buses(&b->children);
251 /* initiate rescan of all pci buses */
252 static inline void pci_rescan(void) {
253 pci_rescan_buses(&pci_root_buses);
257 static int enable_slot(struct hotplug_slot *hotplug_slot)
259 /* mis-use enable_slot for rescanning of the pci bus */
264 /* find the hotplug_slot for the pci_dev */
265 static struct hotplug_slot *get_slot_from_dev(struct pci_dev *dev)
267 struct dummy_slot *dslot;
269 list_for_each_entry(dslot, &slot_list, node) {
270 if (dslot->dev == dev)
277 static int disable_slot(struct hotplug_slot *slot)
279 struct dummy_slot *dslot;
280 struct hotplug_slot *hslot;
286 dslot = slot->private;
288 dbg("%s - physical_slot = %s\n", __FUNCTION__, slot->name);
290 /* don't disable bridged devices just yet, we can't handle them easily... */
291 if (dslot->dev->subordinate) {
292 err("Can't remove PCI devices with other PCI devices behind it yet.\n");
295 /* search for subfunctions and disable them first */
296 if (!(dslot->dev->devfn & 7)) {
297 for (func = 1; func < 8; func++) {
298 dev = pci_find_slot(dslot->dev->bus->number,
299 dslot->dev->devfn + func);
301 hslot = get_slot_from_dev(dev);
305 err("Hotplug slot not found for subfunction of PCI device\n");
309 dbg("No device in slot found\n");
313 /* remove the device from the pci core */
314 pci_remove_bus_device(dslot->dev);
316 /* blow away this sysfs entry and other parts. */
322 static void cleanup_slots (void)
324 struct list_head *tmp;
325 struct list_head *next;
326 struct dummy_slot *dslot;
328 list_for_each_safe (tmp, next, &slot_list) {
329 dslot = list_entry (tmp, struct dummy_slot, node);
335 static int __init dummyphp_init(void)
337 info(DRIVER_DESC "\n");
339 return pci_scan_buses();
343 static void __exit dummyphp_exit(void)
348 module_init(dummyphp_init);
349 module_exit(dummyphp_exit);
351 MODULE_AUTHOR(DRIVER_AUTHOR);
352 MODULE_DESCRIPTION(DRIVER_DESC);
353 MODULE_LICENSE("GPL");
354 module_param(debug, bool, S_IRUGO | S_IWUSR);
355 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");