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1// SPDX-License-Identifier: GPL-2.0
2/*
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 "16.0 GT/s PCIe", /* 0x17 */
78 "32.0 GT/s PCIe", /* 0x18 */
79};
80
81static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
82{
83 const char *speed_string;
84
85 if (speed < ARRAY_SIZE(pci_bus_speed_strings))
86 speed_string = pci_bus_speed_strings[speed];
87 else
88 speed_string = "Unknown";
89
90 return sprintf(buf, "%s\n", speed_string);
91}
92
93static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
94{
95 return bus_speed_read(slot->bus->max_bus_speed, buf);
96}
97
98static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
99{
100 return bus_speed_read(slot->bus->cur_bus_speed, buf);
101}
102
103static void pci_slot_release(struct kobject *kobj)
104{
105 struct pci_dev *dev;
106 struct pci_slot *slot = to_pci_slot(kobj);
107
108 dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
109 slot->number, pci_slot_name(slot));
110
111 down_read(&pci_bus_sem);
112 list_for_each_entry(dev, &slot->bus->devices, bus_list)
113 if (PCI_SLOT(dev->devfn) == slot->number)
114 dev->slot = NULL;
115 up_read(&pci_bus_sem);
116
117 list_del(&slot->list);
118
119 kfree(slot);
120}
121
122static struct pci_slot_attribute pci_slot_attr_address =
123 __ATTR(address, S_IRUGO, address_read_file, NULL);
124static struct pci_slot_attribute pci_slot_attr_max_speed =
125 __ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL);
126static struct pci_slot_attribute pci_slot_attr_cur_speed =
127 __ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL);
128
129static struct attribute *pci_slot_default_attrs[] = {
130 &pci_slot_attr_address.attr,
131 &pci_slot_attr_max_speed.attr,
132 &pci_slot_attr_cur_speed.attr,
133 NULL,
134};
135
136static struct kobj_type pci_slot_ktype = {
137 .sysfs_ops = &pci_slot_sysfs_ops,
138 .release = &pci_slot_release,
139 .default_attrs = pci_slot_default_attrs,
140};
141
142static char *make_slot_name(const char *name)
143{
144 char *new_name;
145 int len, max, dup;
146
147 new_name = kstrdup(name, GFP_KERNEL);
148 if (!new_name)
149 return NULL;
150
151 /*
152 * Make sure we hit the realloc case the first time through the
153 * loop. 'len' will be strlen(name) + 3 at that point which is
154 * enough space for "name-X" and the trailing NUL.
155 */
156 len = strlen(name) + 2;
157 max = 1;
158 dup = 1;
159
160 for (;;) {
161 struct kobject *dup_slot;
162 dup_slot = kset_find_obj(pci_slots_kset, new_name);
163 if (!dup_slot)
164 break;
165 kobject_put(dup_slot);
166 if (dup == max) {
167 len++;
168 max *= 10;
169 kfree(new_name);
170 new_name = kmalloc(len, GFP_KERNEL);
171 if (!new_name)
172 break;
173 }
174 sprintf(new_name, "%s-%d", name, dup++);
175 }
176
177 return new_name;
178}
179
180static int rename_slot(struct pci_slot *slot, const char *name)
181{
182 int result = 0;
183 char *slot_name;
184
185 if (strcmp(pci_slot_name(slot), name) == 0)
186 return result;
187
188 slot_name = make_slot_name(name);
189 if (!slot_name)
190 return -ENOMEM;
191
192 result = kobject_rename(&slot->kobj, slot_name);
193 kfree(slot_name);
194
195 return result;
196}
197
198void pci_dev_assign_slot(struct pci_dev *dev)
199{
200 struct pci_slot *slot;
201
202 mutex_lock(&pci_slot_mutex);
203 list_for_each_entry(slot, &dev->bus->slots, list)
204 if (PCI_SLOT(dev->devfn) == slot->number)
205 dev->slot = slot;
206 mutex_unlock(&pci_slot_mutex);
207}
208
209static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
210{
211 struct pci_slot *slot;
212
213 /* We already hold pci_slot_mutex */
214 list_for_each_entry(slot, &parent->slots, list)
215 if (slot->number == slot_nr) {
216 kobject_get(&slot->kobj);
217 return slot;
218 }
219
220 return NULL;
221}
222
223/**
224 * pci_create_slot - create or increment refcount for physical PCI slot
225 * @parent: struct pci_bus of parent bridge
226 * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
227 * @name: user visible string presented in /sys/bus/pci/slots/<name>
228 * @hotplug: set if caller is hotplug driver, NULL otherwise
229 *
230 * PCI slots have first class attributes such as address, speed, width,
231 * and a &struct pci_slot is used to manage them. This interface will
232 * either return a new &struct pci_slot to the caller, or if the pci_slot
233 * already exists, its refcount will be incremented.
234 *
235 * Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
236 *
237 * There are known platforms with broken firmware that assign the same
238 * name to multiple slots. Workaround these broken platforms by renaming
239 * the slots on behalf of the caller. If firmware assigns name N to
240 * multiple slots:
241 *
242 * The first slot is assigned N
243 * The second slot is assigned N-1
244 * The third slot is assigned N-2
245 * etc.
246 *
247 * Placeholder slots:
248 * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
249 * a slot. There is one notable exception - pSeries (rpaphp), where the
250 * @slot_nr cannot be determined until a device is actually inserted into
251 * the slot. In this scenario, the caller may pass -1 for @slot_nr.
252 *
253 * The following semantics are imposed when the caller passes @slot_nr ==
254 * -1. First, we no longer check for an existing %struct pci_slot, as there
255 * may be many slots with @slot_nr of -1. The other change in semantics is
256 * user-visible, which is the 'address' parameter presented in sysfs will
257 * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
258 * %struct pci_bus and bb is the bus number. In other words, the devfn of
259 * the 'placeholder' slot will not be displayed.
260 */
261struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
262 const char *name,
263 struct hotplug_slot *hotplug)
264{
265 struct pci_dev *dev;
266 struct pci_slot *slot;
267 int err = 0;
268 char *slot_name = NULL;
269
270 mutex_lock(&pci_slot_mutex);
271
272 if (slot_nr == -1)
273 goto placeholder;
274
275 /*
276 * Hotplug drivers are allowed to rename an existing slot,
277 * but only if not already claimed.
278 */
279 slot = get_slot(parent, slot_nr);
280 if (slot) {
281 if (hotplug) {
282 if ((err = slot->hotplug ? -EBUSY : 0)
283 || (err = rename_slot(slot, name))) {
284 kobject_put(&slot->kobj);
285 slot = NULL;
286 goto err;
287 }
288 }
289 goto out;
290 }
291
292placeholder:
293 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
294 if (!slot) {
295 err = -ENOMEM;
296 goto err;
297 }
298
299 slot->bus = parent;
300 slot->number = slot_nr;
301
302 slot->kobj.kset = pci_slots_kset;
303
304 slot_name = make_slot_name(name);
305 if (!slot_name) {
306 err = -ENOMEM;
307 goto err;
308 }
309
310 err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
311 "%s", slot_name);
312 if (err)
313 goto err;
314
315 INIT_LIST_HEAD(&slot->list);
316 list_add(&slot->list, &parent->slots);
317
318 down_read(&pci_bus_sem);
319 list_for_each_entry(dev, &parent->devices, bus_list)
320 if (PCI_SLOT(dev->devfn) == slot_nr)
321 dev->slot = slot;
322 up_read(&pci_bus_sem);
323
324 dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
325 slot_nr, pci_slot_name(slot));
326
327out:
328 kfree(slot_name);
329 mutex_unlock(&pci_slot_mutex);
330 return slot;
331err:
332 kfree(slot);
333 slot = ERR_PTR(err);
334 goto out;
335}
336EXPORT_SYMBOL_GPL(pci_create_slot);
337
338/**
339 * pci_destroy_slot - decrement refcount for physical PCI slot
340 * @slot: struct pci_slot to decrement
341 *
342 * %struct pci_slot is refcounted, so destroying them is really easy; we
343 * just call kobject_put on its kobj and let our release methods do the
344 * rest.
345 */
346void pci_destroy_slot(struct pci_slot *slot)
347{
348 dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
349 slot->number, kref_read(&slot->kobj.kref) - 1);
350
351 mutex_lock(&pci_slot_mutex);
352 kobject_put(&slot->kobj);
353 mutex_unlock(&pci_slot_mutex);
354}
355EXPORT_SYMBOL_GPL(pci_destroy_slot);
356
357#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
358#include <linux/pci_hotplug.h>
359/**
360 * pci_hp_create_link - create symbolic link to the hotplug driver module.
361 * @pci_slot: struct pci_slot
362 *
363 * Helper function for pci_hotplug_core.c to create symbolic link to
364 * the hotplug driver module.
365 */
366void pci_hp_create_module_link(struct pci_slot *pci_slot)
367{
368 struct hotplug_slot *slot = pci_slot->hotplug;
369 struct kobject *kobj = NULL;
370 int ret;
371
372 if (!slot || !slot->ops)
373 return;
374 kobj = kset_find_obj(module_kset, slot->mod_name);
375 if (!kobj)
376 return;
377 ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
378 if (ret)
379 dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
380 ret);
381 kobject_put(kobj);
382}
383EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
384
385/**
386 * pci_hp_remove_link - remove symbolic link to the hotplug driver module.
387 * @pci_slot: struct pci_slot
388 *
389 * Helper function for pci_hotplug_core.c to remove symbolic link to
390 * the hotplug driver module.
391 */
392void pci_hp_remove_module_link(struct pci_slot *pci_slot)
393{
394 sysfs_remove_link(&pci_slot->kobj, "module");
395}
396EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
397#endif
398
399static int pci_slot_init(void)
400{
401 struct kset *pci_bus_kset;
402
403 pci_bus_kset = bus_get_kset(&pci_bus_type);
404 pci_slots_kset = kset_create_and_add("slots", NULL,
405 &pci_bus_kset->kobj);
406 if (!pci_slots_kset) {
407 pr_err("PCI: Slot initialization failure\n");
408 return -ENOMEM;
409 }
410 return 0;
411}
412
413subsys_initcall(pci_slot_init);
1// SPDX-License-Identifier: GPL-2.0
2/*
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 sysfs_emit(buf, "%04x:%02x\n",
43 pci_domain_nr(slot->bus),
44 slot->bus->number);
45
46 return sysfs_emit(buf, "%04x:%02x:%02x\n",
47 pci_domain_nr(slot->bus),
48 slot->bus->number,
49 slot->number);
50}
51
52static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
53{
54 return sysfs_emit(buf, "%s\n", pci_speed_string(speed));
55}
56
57static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
58{
59 return bus_speed_read(slot->bus->max_bus_speed, buf);
60}
61
62static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
63{
64 return bus_speed_read(slot->bus->cur_bus_speed, buf);
65}
66
67static void pci_slot_release(struct kobject *kobj)
68{
69 struct pci_dev *dev;
70 struct pci_slot *slot = to_pci_slot(kobj);
71
72 dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
73 slot->number, pci_slot_name(slot));
74
75 down_read(&pci_bus_sem);
76 list_for_each_entry(dev, &slot->bus->devices, bus_list)
77 if (PCI_SLOT(dev->devfn) == slot->number)
78 dev->slot = NULL;
79 up_read(&pci_bus_sem);
80
81 list_del(&slot->list);
82
83 kfree(slot);
84}
85
86static struct pci_slot_attribute pci_slot_attr_address =
87 __ATTR(address, S_IRUGO, address_read_file, NULL);
88static struct pci_slot_attribute pci_slot_attr_max_speed =
89 __ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL);
90static struct pci_slot_attribute pci_slot_attr_cur_speed =
91 __ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL);
92
93static struct attribute *pci_slot_default_attrs[] = {
94 &pci_slot_attr_address.attr,
95 &pci_slot_attr_max_speed.attr,
96 &pci_slot_attr_cur_speed.attr,
97 NULL,
98};
99ATTRIBUTE_GROUPS(pci_slot_default);
100
101static const struct kobj_type pci_slot_ktype = {
102 .sysfs_ops = &pci_slot_sysfs_ops,
103 .release = &pci_slot_release,
104 .default_groups = pci_slot_default_groups,
105};
106
107static char *make_slot_name(const char *name)
108{
109 char *new_name;
110 int len, max, dup;
111
112 new_name = kstrdup(name, GFP_KERNEL);
113 if (!new_name)
114 return NULL;
115
116 /*
117 * Make sure we hit the realloc case the first time through the
118 * loop. 'len' will be strlen(name) + 3 at that point which is
119 * enough space for "name-X" and the trailing NUL.
120 */
121 len = strlen(name) + 2;
122 max = 1;
123 dup = 1;
124
125 for (;;) {
126 struct kobject *dup_slot;
127 dup_slot = kset_find_obj(pci_slots_kset, new_name);
128 if (!dup_slot)
129 break;
130 kobject_put(dup_slot);
131 if (dup == max) {
132 len++;
133 max *= 10;
134 kfree(new_name);
135 new_name = kmalloc(len, GFP_KERNEL);
136 if (!new_name)
137 break;
138 }
139 sprintf(new_name, "%s-%d", name, dup++);
140 }
141
142 return new_name;
143}
144
145static int rename_slot(struct pci_slot *slot, const char *name)
146{
147 int result = 0;
148 char *slot_name;
149
150 if (strcmp(pci_slot_name(slot), name) == 0)
151 return result;
152
153 slot_name = make_slot_name(name);
154 if (!slot_name)
155 return -ENOMEM;
156
157 result = kobject_rename(&slot->kobj, slot_name);
158 kfree(slot_name);
159
160 return result;
161}
162
163void pci_dev_assign_slot(struct pci_dev *dev)
164{
165 struct pci_slot *slot;
166
167 mutex_lock(&pci_slot_mutex);
168 list_for_each_entry(slot, &dev->bus->slots, list)
169 if (PCI_SLOT(dev->devfn) == slot->number)
170 dev->slot = slot;
171 mutex_unlock(&pci_slot_mutex);
172}
173
174static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
175{
176 struct pci_slot *slot;
177
178 /* We already hold pci_slot_mutex */
179 list_for_each_entry(slot, &parent->slots, list)
180 if (slot->number == slot_nr) {
181 kobject_get(&slot->kobj);
182 return slot;
183 }
184
185 return NULL;
186}
187
188/**
189 * pci_create_slot - create or increment refcount for physical PCI slot
190 * @parent: struct pci_bus of parent bridge
191 * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
192 * @name: user visible string presented in /sys/bus/pci/slots/<name>
193 * @hotplug: set if caller is hotplug driver, NULL otherwise
194 *
195 * PCI slots have first class attributes such as address, speed, width,
196 * and a &struct pci_slot is used to manage them. This interface will
197 * either return a new &struct pci_slot to the caller, or if the pci_slot
198 * already exists, its refcount will be incremented.
199 *
200 * Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
201 *
202 * There are known platforms with broken firmware that assign the same
203 * name to multiple slots. Workaround these broken platforms by renaming
204 * the slots on behalf of the caller. If firmware assigns name N to
205 * multiple slots:
206 *
207 * The first slot is assigned N
208 * The second slot is assigned N-1
209 * The third slot is assigned N-2
210 * etc.
211 *
212 * Placeholder slots:
213 * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
214 * a slot. There is one notable exception - pSeries (rpaphp), where the
215 * @slot_nr cannot be determined until a device is actually inserted into
216 * the slot. In this scenario, the caller may pass -1 for @slot_nr.
217 *
218 * The following semantics are imposed when the caller passes @slot_nr ==
219 * -1. First, we no longer check for an existing %struct pci_slot, as there
220 * may be many slots with @slot_nr of -1. The other change in semantics is
221 * user-visible, which is the 'address' parameter presented in sysfs will
222 * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
223 * %struct pci_bus and bb is the bus number. In other words, the devfn of
224 * the 'placeholder' slot will not be displayed.
225 */
226struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
227 const char *name,
228 struct hotplug_slot *hotplug)
229{
230 struct pci_dev *dev;
231 struct pci_slot *slot;
232 int err = 0;
233 char *slot_name = NULL;
234
235 mutex_lock(&pci_slot_mutex);
236
237 if (slot_nr == -1)
238 goto placeholder;
239
240 /*
241 * Hotplug drivers are allowed to rename an existing slot,
242 * but only if not already claimed.
243 */
244 slot = get_slot(parent, slot_nr);
245 if (slot) {
246 if (hotplug) {
247 if ((err = slot->hotplug ? -EBUSY : 0)
248 || (err = rename_slot(slot, name))) {
249 kobject_put(&slot->kobj);
250 slot = NULL;
251 goto err;
252 }
253 }
254 goto out;
255 }
256
257placeholder:
258 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
259 if (!slot) {
260 err = -ENOMEM;
261 goto err;
262 }
263
264 slot->bus = parent;
265 slot->number = slot_nr;
266
267 slot->kobj.kset = pci_slots_kset;
268
269 slot_name = make_slot_name(name);
270 if (!slot_name) {
271 err = -ENOMEM;
272 kfree(slot);
273 goto err;
274 }
275
276 INIT_LIST_HEAD(&slot->list);
277 list_add(&slot->list, &parent->slots);
278
279 err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
280 "%s", slot_name);
281 if (err) {
282 kobject_put(&slot->kobj);
283 goto err;
284 }
285
286 down_read(&pci_bus_sem);
287 list_for_each_entry(dev, &parent->devices, bus_list)
288 if (PCI_SLOT(dev->devfn) == slot_nr)
289 dev->slot = slot;
290 up_read(&pci_bus_sem);
291
292 dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
293 slot_nr, pci_slot_name(slot));
294
295out:
296 kfree(slot_name);
297 mutex_unlock(&pci_slot_mutex);
298 return slot;
299err:
300 slot = ERR_PTR(err);
301 goto out;
302}
303EXPORT_SYMBOL_GPL(pci_create_slot);
304
305/**
306 * pci_destroy_slot - decrement refcount for physical PCI slot
307 * @slot: struct pci_slot to decrement
308 *
309 * %struct pci_slot is refcounted, so destroying them is really easy; we
310 * just call kobject_put on its kobj and let our release methods do the
311 * rest.
312 */
313void pci_destroy_slot(struct pci_slot *slot)
314{
315 dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
316 slot->number, kref_read(&slot->kobj.kref) - 1);
317
318 mutex_lock(&pci_slot_mutex);
319 kobject_put(&slot->kobj);
320 mutex_unlock(&pci_slot_mutex);
321}
322EXPORT_SYMBOL_GPL(pci_destroy_slot);
323
324#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
325#include <linux/pci_hotplug.h>
326/**
327 * pci_hp_create_module_link - create symbolic link to hotplug driver module
328 * @pci_slot: struct pci_slot
329 *
330 * Helper function for pci_hotplug_core.c to create symbolic link to
331 * the hotplug driver module.
332 */
333void pci_hp_create_module_link(struct pci_slot *pci_slot)
334{
335 struct hotplug_slot *slot = pci_slot->hotplug;
336 struct kobject *kobj = NULL;
337 int ret;
338
339 if (!slot || !slot->ops)
340 return;
341 kobj = kset_find_obj(module_kset, slot->mod_name);
342 if (!kobj)
343 return;
344 ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
345 if (ret)
346 dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
347 ret);
348 kobject_put(kobj);
349}
350EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
351
352/**
353 * pci_hp_remove_module_link - remove symbolic link to the hotplug driver
354 * module.
355 * @pci_slot: struct pci_slot
356 *
357 * Helper function for pci_hotplug_core.c to remove symbolic link to
358 * the hotplug driver module.
359 */
360void pci_hp_remove_module_link(struct pci_slot *pci_slot)
361{
362 sysfs_remove_link(&pci_slot->kobj, "module");
363}
364EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
365#endif
366
367static int pci_slot_init(void)
368{
369 struct kset *pci_bus_kset;
370
371 pci_bus_kset = bus_get_kset(&pci_bus_type);
372 pci_slots_kset = kset_create_and_add("slots", NULL,
373 &pci_bus_kset->kobj);
374 if (!pci_slots_kset) {
375 pr_err("PCI: Slot initialization failure\n");
376 return -ENOMEM;
377 }
378 return 0;
379}
380
381subsys_initcall(pci_slot_init);