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1/*
2 * drivers/pci/slot.c
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>
6 */
7
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>
13#include "pci.h"
14
15struct kset *pci_slots_kset;
16EXPORT_SYMBOL_GPL(pci_slots_kset);
17
18static ssize_t pci_slot_attr_show(struct kobject *kobj,
19 struct attribute *attr, char *buf)
20{
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;
24}
25
26static ssize_t pci_slot_attr_store(struct kobject *kobj,
27 struct attribute *attr, const char *buf, size_t len)
28{
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;
32}
33
34static const struct sysfs_ops pci_slot_sysfs_ops = {
35 .show = pci_slot_attr_show,
36 .store = pci_slot_attr_store,
37};
38
39static ssize_t address_read_file(struct pci_slot *slot, char *buf)
40{
41 if (slot->number == 0xff)
42 return sprintf(buf, "%04x:%02x\n",
43 pci_domain_nr(slot->bus),
44 slot->bus->number);
45 else
46 return sprintf(buf, "%04x:%02x:%02x\n",
47 pci_domain_nr(slot->bus),
48 slot->bus->number,
49 slot->number);
50}
51
52/* these strings match up with the values in pci_bus_speed */
53static 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 */
59 NULL, /* 0x05 */
60 NULL, /* 0x06 */
61 NULL, /* 0x07 */
62 NULL, /* 0x08 */
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 */
67 "1x AGP", /* 0x0d */
68 "2x AGP", /* 0x0e */
69 "4x AGP", /* 0x0f */
70 "8x AGP", /* 0x10 */
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 */
77};
78
79static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
80{
81 const char *speed_string;
82
83 if (speed < ARRAY_SIZE(pci_bus_speed_strings))
84 speed_string = pci_bus_speed_strings[speed];
85 else
86 speed_string = "Unknown";
87
88 return sprintf(buf, "%s\n", speed_string);
89}
90
91static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
92{
93 return bus_speed_read(slot->bus->max_bus_speed, buf);
94}
95
96static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
97{
98 return bus_speed_read(slot->bus->cur_bus_speed, buf);
99}
100
101static void pci_slot_release(struct kobject *kobj)
102{
103 struct pci_dev *dev;
104 struct pci_slot *slot = to_pci_slot(kobj);
105
106 dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
107 slot->number, pci_slot_name(slot));
108
109 list_for_each_entry(dev, &slot->bus->devices, bus_list)
110 if (PCI_SLOT(dev->devfn) == slot->number)
111 dev->slot = NULL;
112
113 list_del(&slot->list);
114
115 kfree(slot);
116}
117
118static struct pci_slot_attribute pci_slot_attr_address =
119 __ATTR(address, (S_IFREG | S_IRUGO), address_read_file, NULL);
120static struct pci_slot_attribute pci_slot_attr_max_speed =
121 __ATTR(max_bus_speed, (S_IFREG | S_IRUGO), max_speed_read_file, NULL);
122static struct pci_slot_attribute pci_slot_attr_cur_speed =
123 __ATTR(cur_bus_speed, (S_IFREG | S_IRUGO), cur_speed_read_file, NULL);
124
125static 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,
129 NULL,
130};
131
132static 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,
136};
137
138static char *make_slot_name(const char *name)
139{
140 char *new_name;
141 int len, max, dup;
142
143 new_name = kstrdup(name, GFP_KERNEL);
144 if (!new_name)
145 return NULL;
146
147 /*
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.
151 */
152 len = strlen(name) + 2;
153 max = 1;
154 dup = 1;
155
156 for (;;) {
157 struct kobject *dup_slot;
158 dup_slot = kset_find_obj(pci_slots_kset, new_name);
159 if (!dup_slot)
160 break;
161 kobject_put(dup_slot);
162 if (dup == max) {
163 len++;
164 max *= 10;
165 kfree(new_name);
166 new_name = kmalloc(len, GFP_KERNEL);
167 if (!new_name)
168 break;
169 }
170 sprintf(new_name, "%s-%d", name, dup++);
171 }
172
173 return new_name;
174}
175
176static int rename_slot(struct pci_slot *slot, const char *name)
177{
178 int result = 0;
179 char *slot_name;
180
181 if (strcmp(pci_slot_name(slot), name) == 0)
182 return result;
183
184 slot_name = make_slot_name(name);
185 if (!slot_name)
186 return -ENOMEM;
187
188 result = kobject_rename(&slot->kobj, slot_name);
189 kfree(slot_name);
190
191 return result;
192}
193
194static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
195{
196 struct pci_slot *slot;
197 /*
198 * We already hold pci_bus_sem so don't worry
199 */
200 list_for_each_entry(slot, &parent->slots, list)
201 if (slot->number == slot_nr) {
202 kobject_get(&slot->kobj);
203 return slot;
204 }
205
206 return NULL;
207}
208
209/**
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
215 *
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.
220 *
221 * Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
222 *
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
226 * multiple slots:
227 *
228 * The first slot is assigned N
229 * The second slot is assigned N-1
230 * The third slot is assigned N-2
231 * etc.
232 *
233 * Placeholder slots:
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.
238 *
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.
246 */
247struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
248 const char *name,
249 struct hotplug_slot *hotplug)
250{
251 struct pci_dev *dev;
252 struct pci_slot *slot;
253 int err = 0;
254 char *slot_name = NULL;
255
256 down_write(&pci_bus_sem);
257
258 if (slot_nr == -1)
259 goto placeholder;
260
261 /*
262 * Hotplug drivers are allowed to rename an existing slot,
263 * but only if not already claimed.
264 */
265 slot = get_slot(parent, slot_nr);
266 if (slot) {
267 if (hotplug) {
268 if ((err = slot->hotplug ? -EBUSY : 0)
269 || (err = rename_slot(slot, name))) {
270 kobject_put(&slot->kobj);
271 slot = NULL;
272 goto err;
273 }
274 }
275 goto out;
276 }
277
278placeholder:
279 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
280 if (!slot) {
281 err = -ENOMEM;
282 goto err;
283 }
284
285 slot->bus = parent;
286 slot->number = slot_nr;
287
288 slot->kobj.kset = pci_slots_kset;
289
290 slot_name = make_slot_name(name);
291 if (!slot_name) {
292 err = -ENOMEM;
293 goto err;
294 }
295
296 err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
297 "%s", slot_name);
298 if (err)
299 goto err;
300
301 INIT_LIST_HEAD(&slot->list);
302 list_add(&slot->list, &parent->slots);
303
304 list_for_each_entry(dev, &parent->devices, bus_list)
305 if (PCI_SLOT(dev->devfn) == slot_nr)
306 dev->slot = slot;
307
308 dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
309 slot_nr, pci_slot_name(slot));
310
311out:
312 kfree(slot_name);
313 up_write(&pci_bus_sem);
314 return slot;
315err:
316 kfree(slot);
317 slot = ERR_PTR(err);
318 goto out;
319}
320EXPORT_SYMBOL_GPL(pci_create_slot);
321
322/**
323 * pci_renumber_slot - update %struct pci_slot -> number
324 * @slot: &struct pci_slot to update
325 * @slot_nr: new number for slot
326 *
327 * The primary purpose of this interface is to allow callers who earlier
328 * created a placeholder slot in pci_create_slot() by passing a -1 as
329 * slot_nr, to update their %struct pci_slot with the correct @slot_nr.
330 */
331void pci_renumber_slot(struct pci_slot *slot, int slot_nr)
332{
333 struct pci_slot *tmp;
334
335 down_write(&pci_bus_sem);
336
337 list_for_each_entry(tmp, &slot->bus->slots, list) {
338 WARN_ON(tmp->number == slot_nr);
339 goto out;
340 }
341
342 slot->number = slot_nr;
343out:
344 up_write(&pci_bus_sem);
345}
346EXPORT_SYMBOL_GPL(pci_renumber_slot);
347
348/**
349 * pci_destroy_slot - decrement refcount for physical PCI slot
350 * @slot: struct pci_slot to decrement
351 *
352 * %struct pci_slot is refcounted, so destroying them is really easy; we
353 * just call kobject_put on its kobj and let our release methods do the
354 * rest.
355 */
356void pci_destroy_slot(struct pci_slot *slot)
357{
358 dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
359 slot->number, atomic_read(&slot->kobj.kref.refcount) - 1);
360
361 down_write(&pci_bus_sem);
362 kobject_put(&slot->kobj);
363 up_write(&pci_bus_sem);
364}
365EXPORT_SYMBOL_GPL(pci_destroy_slot);
366
367#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
368#include <linux/pci_hotplug.h>
369/**
370 * pci_hp_create_link - create symbolic link to the hotplug driver module.
371 * @pci_slot: struct pci_slot
372 *
373 * Helper function for pci_hotplug_core.c to create symbolic link to
374 * the hotplug driver module.
375 */
376void pci_hp_create_module_link(struct pci_slot *pci_slot)
377{
378 struct hotplug_slot *slot = pci_slot->hotplug;
379 struct kobject *kobj = NULL;
380 int no_warn;
381
382 if (!slot || !slot->ops)
383 return;
384 kobj = kset_find_obj(module_kset, slot->ops->mod_name);
385 if (!kobj)
386 return;
387 no_warn = sysfs_create_link(&pci_slot->kobj, kobj, "module");
388 kobject_put(kobj);
389}
390EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
391
392/**
393 * pci_hp_remove_link - remove symbolic link to the hotplug driver module.
394 * @pci_slot: struct pci_slot
395 *
396 * Helper function for pci_hotplug_core.c to remove symbolic link to
397 * the hotplug driver module.
398 */
399void pci_hp_remove_module_link(struct pci_slot *pci_slot)
400{
401 sysfs_remove_link(&pci_slot->kobj, "module");
402}
403EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
404#endif
405
406static int pci_slot_init(void)
407{
408 struct kset *pci_bus_kset;
409
410 pci_bus_kset = bus_get_kset(&pci_bus_type);
411 pci_slots_kset = kset_create_and_add("slots", NULL,
412 &pci_bus_kset->kobj);
413 if (!pci_slots_kset) {
414 printk(KERN_ERR "PCI: Slot initialization failure\n");
415 return -ENOMEM;
416 }
417 return 0;
418}
419
420subsys_initcall(pci_slot_init);