3 * Copyright (C) 2006 Matthew Wilcox <matthew@wil.cx>
4 * Copyright (C) 2006-2009 Hewlett-Packard Development Company, L.P.
5 * Alex Chiang <achiang@hp.com>
8 #include <linux/kobject.h>
9 #include <linux/slab.h>
10 #include <linux/pci.h>
11 #include <linux/err.h>
14 struct kset *pci_slots_kset;
15 EXPORT_SYMBOL_GPL(pci_slots_kset);
17 static ssize_t pci_slot_attr_show(struct kobject *kobj,
18 struct attribute *attr, char *buf)
20 struct pci_slot *slot = to_pci_slot(kobj);
21 struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
22 return attribute->show ? attribute->show(slot, buf) : -EIO;
25 static ssize_t pci_slot_attr_store(struct kobject *kobj,
26 struct attribute *attr, const char *buf, size_t len)
28 struct pci_slot *slot = to_pci_slot(kobj);
29 struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
30 return attribute->store ? attribute->store(slot, buf, len) : -EIO;
33 static const struct sysfs_ops pci_slot_sysfs_ops = {
34 .show = pci_slot_attr_show,
35 .store = pci_slot_attr_store,
38 static ssize_t address_read_file(struct pci_slot *slot, char *buf)
40 if (slot->number == 0xff)
41 return sprintf(buf, "%04x:%02x\n",
42 pci_domain_nr(slot->bus),
45 return sprintf(buf, "%04x:%02x:%02x\n",
46 pci_domain_nr(slot->bus),
51 /* these strings match up with the values in pci_bus_speed */
52 static char *pci_bus_speed_strings[] = {
53 "33 MHz PCI", /* 0x00 */
54 "66 MHz PCI", /* 0x01 */
55 "66 MHz PCI-X", /* 0x02 */
56 "100 MHz PCI-X", /* 0x03 */
57 "133 MHz PCI-X", /* 0x04 */
62 "66 MHz PCI-X 266", /* 0x09 */
63 "100 MHz PCI-X 266", /* 0x0a */
64 "133 MHz PCI-X 266", /* 0x0b */
65 "Unknown AGP", /* 0x0c */
70 "66 MHz PCI-X 533", /* 0x11 */
71 "100 MHz PCI-X 533", /* 0x12 */
72 "133 MHz PCI-X 533", /* 0x13 */
73 "2.5 GT/s PCIe", /* 0x14 */
74 "5.0 GT/s PCIe", /* 0x15 */
75 "8.0 GT/s PCIe", /* 0x16 */
78 static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
80 const char *speed_string;
82 if (speed < ARRAY_SIZE(pci_bus_speed_strings))
83 speed_string = pci_bus_speed_strings[speed];
85 speed_string = "Unknown";
87 return sprintf(buf, "%s\n", speed_string);
90 static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
92 return bus_speed_read(slot->bus->max_bus_speed, buf);
95 static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
97 return bus_speed_read(slot->bus->cur_bus_speed, buf);
100 static void remove_sysfs_files(struct pci_slot *slot)
103 struct list_head *tmp;
105 list_for_each(tmp, &slot->bus->devices) {
106 struct pci_dev *dev = pci_dev_b(tmp);
107 if (PCI_SLOT(dev->devfn) != slot->number)
109 sysfs_remove_link(&dev->dev.kobj, "slot");
111 snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
112 sysfs_remove_link(&slot->kobj, func);
116 static int create_sysfs_files(struct pci_slot *slot)
120 struct list_head *tmp;
122 list_for_each(tmp, &slot->bus->devices) {
123 struct pci_dev *dev = pci_dev_b(tmp);
124 if (PCI_SLOT(dev->devfn) != slot->number)
127 result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
131 snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
132 result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
140 remove_sysfs_files(slot);
144 static void pci_slot_release(struct kobject *kobj)
147 struct pci_slot *slot = to_pci_slot(kobj);
149 dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
150 slot->number, pci_slot_name(slot));
152 list_for_each_entry(dev, &slot->bus->devices, bus_list)
153 if (PCI_SLOT(dev->devfn) == slot->number)
156 remove_sysfs_files(slot);
158 list_del(&slot->list);
163 static struct pci_slot_attribute pci_slot_attr_address =
164 __ATTR(address, (S_IFREG | S_IRUGO), address_read_file, NULL);
165 static struct pci_slot_attribute pci_slot_attr_max_speed =
166 __ATTR(max_bus_speed, (S_IFREG | S_IRUGO), max_speed_read_file, NULL);
167 static struct pci_slot_attribute pci_slot_attr_cur_speed =
168 __ATTR(cur_bus_speed, (S_IFREG | S_IRUGO), cur_speed_read_file, NULL);
170 static struct attribute *pci_slot_default_attrs[] = {
171 &pci_slot_attr_address.attr,
172 &pci_slot_attr_max_speed.attr,
173 &pci_slot_attr_cur_speed.attr,
177 static struct kobj_type pci_slot_ktype = {
178 .sysfs_ops = &pci_slot_sysfs_ops,
179 .release = &pci_slot_release,
180 .default_attrs = pci_slot_default_attrs,
183 static char *make_slot_name(const char *name)
188 new_name = kstrdup(name, GFP_KERNEL);
193 * Make sure we hit the realloc case the first time through the
194 * loop. 'len' will be strlen(name) + 3 at that point which is
195 * enough space for "name-X" and the trailing NUL.
197 len = strlen(name) + 2;
202 struct kobject *dup_slot;
203 dup_slot = kset_find_obj(pci_slots_kset, new_name);
206 kobject_put(dup_slot);
211 new_name = kmalloc(len, GFP_KERNEL);
215 sprintf(new_name, "%s-%d", name, dup++);
221 static int rename_slot(struct pci_slot *slot, const char *name)
226 if (strcmp(pci_slot_name(slot), name) == 0)
229 slot_name = make_slot_name(name);
233 result = kobject_rename(&slot->kobj, slot_name);
239 static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
241 struct pci_slot *slot;
243 * We already hold pci_bus_sem so don't worry
245 list_for_each_entry(slot, &parent->slots, list)
246 if (slot->number == slot_nr) {
247 kobject_get(&slot->kobj);
255 * pci_create_slot - create or increment refcount for physical PCI slot
256 * @parent: struct pci_bus of parent bridge
257 * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
258 * @name: user visible string presented in /sys/bus/pci/slots/<name>
259 * @hotplug: set if caller is hotplug driver, NULL otherwise
261 * PCI slots have first class attributes such as address, speed, width,
262 * and a &struct pci_slot is used to manage them. This interface will
263 * either return a new &struct pci_slot to the caller, or if the pci_slot
264 * already exists, its refcount will be incremented.
266 * Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
268 * There are known platforms with broken firmware that assign the same
269 * name to multiple slots. Workaround these broken platforms by renaming
270 * the slots on behalf of the caller. If firmware assigns name N to
273 * The first slot is assigned N
274 * The second slot is assigned N-1
275 * The third slot is assigned N-2
279 * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
280 * a slot. There is one notable exception - pSeries (rpaphp), where the
281 * @slot_nr cannot be determined until a device is actually inserted into
282 * the slot. In this scenario, the caller may pass -1 for @slot_nr.
284 * The following semantics are imposed when the caller passes @slot_nr ==
285 * -1. First, we no longer check for an existing %struct pci_slot, as there
286 * may be many slots with @slot_nr of -1. The other change in semantics is
287 * user-visible, which is the 'address' parameter presented in sysfs will
288 * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
289 * %struct pci_bus and bb is the bus number. In other words, the devfn of
290 * the 'placeholder' slot will not be displayed.
292 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
294 struct hotplug_slot *hotplug)
297 struct pci_slot *slot;
299 char *slot_name = NULL;
301 down_write(&pci_bus_sem);
307 * Hotplug drivers are allowed to rename an existing slot,
308 * but only if not already claimed.
310 slot = get_slot(parent, slot_nr);
313 if ((err = slot->hotplug ? -EBUSY : 0)
314 || (err = rename_slot(slot, name))) {
315 kobject_put(&slot->kobj);
324 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
331 slot->number = slot_nr;
333 slot->kobj.kset = pci_slots_kset;
335 slot_name = make_slot_name(name);
341 err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
346 INIT_LIST_HEAD(&slot->list);
347 list_add(&slot->list, &parent->slots);
349 create_sysfs_files(slot);
351 list_for_each_entry(dev, &parent->devices, bus_list)
352 if (PCI_SLOT(dev->devfn) == slot_nr)
355 dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
356 slot_nr, pci_slot_name(slot));
360 up_write(&pci_bus_sem);
367 EXPORT_SYMBOL_GPL(pci_create_slot);
370 * pci_renumber_slot - update %struct pci_slot -> number
371 * @slot: &struct pci_slot to update
372 * @slot_nr: new number for slot
374 * The primary purpose of this interface is to allow callers who earlier
375 * created a placeholder slot in pci_create_slot() by passing a -1 as
376 * slot_nr, to update their %struct pci_slot with the correct @slot_nr.
378 void pci_renumber_slot(struct pci_slot *slot, int slot_nr)
380 struct pci_slot *tmp;
382 down_write(&pci_bus_sem);
384 list_for_each_entry(tmp, &slot->bus->slots, list) {
385 WARN_ON(tmp->number == slot_nr);
389 slot->number = slot_nr;
391 up_write(&pci_bus_sem);
393 EXPORT_SYMBOL_GPL(pci_renumber_slot);
396 * pci_destroy_slot - decrement refcount for physical PCI slot
397 * @slot: struct pci_slot to decrement
399 * %struct pci_slot is refcounted, so destroying them is really easy; we
400 * just call kobject_put on its kobj and let our release methods do the
403 void pci_destroy_slot(struct pci_slot *slot)
405 dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
406 slot->number, atomic_read(&slot->kobj.kref.refcount) - 1);
408 down_write(&pci_bus_sem);
409 kobject_put(&slot->kobj);
410 up_write(&pci_bus_sem);
412 EXPORT_SYMBOL_GPL(pci_destroy_slot);
414 #if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
415 #include <linux/pci_hotplug.h>
417 * pci_hp_create_link - create symbolic link to the hotplug driver module.
418 * @pci_slot: struct pci_slot
420 * Helper function for pci_hotplug_core.c to create symbolic link to
421 * the hotplug driver module.
423 void pci_hp_create_module_link(struct pci_slot *pci_slot)
425 struct hotplug_slot *slot = pci_slot->hotplug;
426 struct kobject *kobj = NULL;
429 if (!slot || !slot->ops)
431 kobj = kset_find_obj(module_kset, slot->ops->mod_name);
434 no_warn = sysfs_create_link(&pci_slot->kobj, kobj, "module");
437 EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
440 * pci_hp_remove_link - remove symbolic link to the hotplug driver module.
441 * @pci_slot: struct pci_slot
443 * Helper function for pci_hotplug_core.c to remove symbolic link to
444 * the hotplug driver module.
446 void pci_hp_remove_module_link(struct pci_slot *pci_slot)
448 sysfs_remove_link(&pci_slot->kobj, "module");
450 EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
453 static int pci_slot_init(void)
455 struct kset *pci_bus_kset;
457 pci_bus_kset = bus_get_kset(&pci_bus_type);
458 pci_slots_kset = kset_create_and_add("slots", NULL,
459 &pci_bus_kset->kobj);
460 if (!pci_slots_kset) {
461 printk(KERN_ERR "PCI: Slot initialization failure\n");
467 subsys_initcall(pci_slot_init);