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/module.h>
11 #include <linux/pci.h>
12 #include <linux/err.h>
15 struct kset *pci_slots_kset;
16 EXPORT_SYMBOL_GPL(pci_slots_kset);
18 static ssize_t pci_slot_attr_show(struct kobject *kobj,
19 struct attribute *attr, char *buf)
21 struct pci_slot *slot = to_pci_slot(kobj);
22 struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
23 return attribute->show ? attribute->show(slot, buf) : -EIO;
26 static ssize_t pci_slot_attr_store(struct kobject *kobj,
27 struct attribute *attr, const char *buf, size_t len)
29 struct pci_slot *slot = to_pci_slot(kobj);
30 struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
31 return attribute->store ? attribute->store(slot, buf, len) : -EIO;
34 static const struct sysfs_ops pci_slot_sysfs_ops = {
35 .show = pci_slot_attr_show,
36 .store = pci_slot_attr_store,
39 static ssize_t address_read_file(struct pci_slot *slot, char *buf)
41 if (slot->number == 0xff)
42 return sprintf(buf, "%04x:%02x\n",
43 pci_domain_nr(slot->bus),
46 return sprintf(buf, "%04x:%02x:%02x\n",
47 pci_domain_nr(slot->bus),
52 /* these strings match up with the values in pci_bus_speed */
53 static const char *pci_bus_speed_strings[] = {
54 "33 MHz PCI", /* 0x00 */
55 "66 MHz PCI", /* 0x01 */
56 "66 MHz PCI-X", /* 0x02 */
57 "100 MHz PCI-X", /* 0x03 */
58 "133 MHz PCI-X", /* 0x04 */
63 "66 MHz PCI-X 266", /* 0x09 */
64 "100 MHz PCI-X 266", /* 0x0a */
65 "133 MHz PCI-X 266", /* 0x0b */
66 "Unknown AGP", /* 0x0c */
71 "66 MHz PCI-X 533", /* 0x11 */
72 "100 MHz PCI-X 533", /* 0x12 */
73 "133 MHz PCI-X 533", /* 0x13 */
74 "2.5 GT/s PCIe", /* 0x14 */
75 "5.0 GT/s PCIe", /* 0x15 */
76 "8.0 GT/s PCIe", /* 0x16 */
79 static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
81 const char *speed_string;
83 if (speed < ARRAY_SIZE(pci_bus_speed_strings))
84 speed_string = pci_bus_speed_strings[speed];
86 speed_string = "Unknown";
88 return sprintf(buf, "%s\n", speed_string);
91 static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
93 return bus_speed_read(slot->bus->max_bus_speed, buf);
96 static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
98 return bus_speed_read(slot->bus->cur_bus_speed, buf);
101 static void pci_slot_release(struct kobject *kobj)
104 struct pci_slot *slot = to_pci_slot(kobj);
106 dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
107 slot->number, pci_slot_name(slot));
109 list_for_each_entry(dev, &slot->bus->devices, bus_list)
110 if (PCI_SLOT(dev->devfn) == slot->number)
113 list_del(&slot->list);
118 static struct pci_slot_attribute pci_slot_attr_address =
119 __ATTR(address, S_IRUGO, address_read_file, NULL);
120 static struct pci_slot_attribute pci_slot_attr_max_speed =
121 __ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL);
122 static struct pci_slot_attribute pci_slot_attr_cur_speed =
123 __ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL);
125 static struct attribute *pci_slot_default_attrs[] = {
126 &pci_slot_attr_address.attr,
127 &pci_slot_attr_max_speed.attr,
128 &pci_slot_attr_cur_speed.attr,
132 static struct kobj_type pci_slot_ktype = {
133 .sysfs_ops = &pci_slot_sysfs_ops,
134 .release = &pci_slot_release,
135 .default_attrs = pci_slot_default_attrs,
138 static char *make_slot_name(const char *name)
143 new_name = kstrdup(name, GFP_KERNEL);
148 * Make sure we hit the realloc case the first time through the
149 * loop. 'len' will be strlen(name) + 3 at that point which is
150 * enough space for "name-X" and the trailing NUL.
152 len = strlen(name) + 2;
157 struct kobject *dup_slot;
158 dup_slot = kset_find_obj(pci_slots_kset, new_name);
161 kobject_put(dup_slot);
166 new_name = kmalloc(len, GFP_KERNEL);
170 sprintf(new_name, "%s-%d", name, dup++);
176 static int rename_slot(struct pci_slot *slot, const char *name)
181 if (strcmp(pci_slot_name(slot), name) == 0)
184 slot_name = make_slot_name(name);
188 result = kobject_rename(&slot->kobj, slot_name);
194 static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
196 struct pci_slot *slot;
198 * We already hold pci_bus_sem so don't worry
200 list_for_each_entry(slot, &parent->slots, list)
201 if (slot->number == slot_nr) {
202 kobject_get(&slot->kobj);
210 * pci_create_slot - create or increment refcount for physical PCI slot
211 * @parent: struct pci_bus of parent bridge
212 * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
213 * @name: user visible string presented in /sys/bus/pci/slots/<name>
214 * @hotplug: set if caller is hotplug driver, NULL otherwise
216 * PCI slots have first class attributes such as address, speed, width,
217 * and a &struct pci_slot is used to manage them. This interface will
218 * either return a new &struct pci_slot to the caller, or if the pci_slot
219 * already exists, its refcount will be incremented.
221 * Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
223 * There are known platforms with broken firmware that assign the same
224 * name to multiple slots. Workaround these broken platforms by renaming
225 * the slots on behalf of the caller. If firmware assigns name N to
228 * The first slot is assigned N
229 * The second slot is assigned N-1
230 * The third slot is assigned N-2
234 * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
235 * a slot. There is one notable exception - pSeries (rpaphp), where the
236 * @slot_nr cannot be determined until a device is actually inserted into
237 * the slot. In this scenario, the caller may pass -1 for @slot_nr.
239 * The following semantics are imposed when the caller passes @slot_nr ==
240 * -1. First, we no longer check for an existing %struct pci_slot, as there
241 * may be many slots with @slot_nr of -1. The other change in semantics is
242 * user-visible, which is the 'address' parameter presented in sysfs will
243 * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
244 * %struct pci_bus and bb is the bus number. In other words, the devfn of
245 * the 'placeholder' slot will not be displayed.
247 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
249 struct hotplug_slot *hotplug)
252 struct pci_slot *slot;
254 char *slot_name = NULL;
256 down_write(&pci_bus_sem);
262 * Hotplug drivers are allowed to rename an existing slot,
263 * but only if not already claimed.
265 slot = get_slot(parent, slot_nr);
268 if ((err = slot->hotplug ? -EBUSY : 0)
269 || (err = rename_slot(slot, name))) {
270 kobject_put(&slot->kobj);
279 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
286 slot->number = slot_nr;
288 slot->kobj.kset = pci_slots_kset;
290 slot_name = make_slot_name(name);
296 err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
301 INIT_LIST_HEAD(&slot->list);
302 list_add(&slot->list, &parent->slots);
304 list_for_each_entry(dev, &parent->devices, bus_list)
305 if (PCI_SLOT(dev->devfn) == slot_nr)
308 dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
309 slot_nr, pci_slot_name(slot));
313 up_write(&pci_bus_sem);
320 EXPORT_SYMBOL_GPL(pci_create_slot);
323 * pci_destroy_slot - decrement refcount for physical PCI slot
324 * @slot: struct pci_slot to decrement
326 * %struct pci_slot is refcounted, so destroying them is really easy; we
327 * just call kobject_put on its kobj and let our release methods do the
330 void pci_destroy_slot(struct pci_slot *slot)
332 dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
333 slot->number, atomic_read(&slot->kobj.kref.refcount) - 1);
335 down_write(&pci_bus_sem);
336 kobject_put(&slot->kobj);
337 up_write(&pci_bus_sem);
339 EXPORT_SYMBOL_GPL(pci_destroy_slot);
341 #if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
342 #include <linux/pci_hotplug.h>
344 * pci_hp_create_link - create symbolic link to the hotplug driver module.
345 * @pci_slot: struct pci_slot
347 * Helper function for pci_hotplug_core.c to create symbolic link to
348 * the hotplug driver module.
350 void pci_hp_create_module_link(struct pci_slot *pci_slot)
352 struct hotplug_slot *slot = pci_slot->hotplug;
353 struct kobject *kobj = NULL;
356 if (!slot || !slot->ops)
358 kobj = kset_find_obj(module_kset, slot->ops->mod_name);
361 ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
363 dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
367 EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
370 * pci_hp_remove_link - remove symbolic link to the hotplug driver module.
371 * @pci_slot: struct pci_slot
373 * Helper function for pci_hotplug_core.c to remove symbolic link to
374 * the hotplug driver module.
376 void pci_hp_remove_module_link(struct pci_slot *pci_slot)
378 sysfs_remove_link(&pci_slot->kobj, "module");
380 EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
383 static int pci_slot_init(void)
385 struct kset *pci_bus_kset;
387 pci_bus_kset = bus_get_kset(&pci_bus_type);
388 pci_slots_kset = kset_create_and_add("slots", NULL,
389 &pci_bus_kset->kobj);
390 if (!pci_slots_kset) {
391 printk(KERN_ERR "PCI: Slot initialization failure\n");
397 subsys_initcall(pci_slot_init);