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f46753c5 AC |
1 | /* |
2 | * drivers/pci/slot.c | |
3 | * Copyright (C) 2006 Matthew Wilcox <matthew@wil.cx> | |
4 | * Copyright (C) 2006-2008 Hewlett-Packard Development Company, L.P. | |
5 | * Alex Chiang <achiang@hp.com> | |
6 | */ | |
7 | ||
8 | #include <linux/kobject.h> | |
9 | #include <linux/pci.h> | |
10 | #include <linux/err.h> | |
11 | #include "pci.h" | |
12 | ||
13 | struct kset *pci_slots_kset; | |
14 | EXPORT_SYMBOL_GPL(pci_slots_kset); | |
15 | ||
16 | static ssize_t pci_slot_attr_show(struct kobject *kobj, | |
17 | struct attribute *attr, char *buf) | |
18 | { | |
19 | struct pci_slot *slot = to_pci_slot(kobj); | |
20 | struct pci_slot_attribute *attribute = to_pci_slot_attr(attr); | |
21 | return attribute->show ? attribute->show(slot, buf) : -EIO; | |
22 | } | |
23 | ||
24 | static ssize_t pci_slot_attr_store(struct kobject *kobj, | |
25 | struct attribute *attr, const char *buf, size_t len) | |
26 | { | |
27 | struct pci_slot *slot = to_pci_slot(kobj); | |
28 | struct pci_slot_attribute *attribute = to_pci_slot_attr(attr); | |
29 | return attribute->store ? attribute->store(slot, buf, len) : -EIO; | |
30 | } | |
31 | ||
32 | static struct sysfs_ops pci_slot_sysfs_ops = { | |
33 | .show = pci_slot_attr_show, | |
34 | .store = pci_slot_attr_store, | |
35 | }; | |
36 | ||
37 | static ssize_t address_read_file(struct pci_slot *slot, char *buf) | |
38 | { | |
39 | if (slot->number == 0xff) | |
40 | return sprintf(buf, "%04x:%02x\n", | |
41 | pci_domain_nr(slot->bus), | |
42 | slot->bus->number); | |
43 | else | |
44 | return sprintf(buf, "%04x:%02x:%02x\n", | |
45 | pci_domain_nr(slot->bus), | |
46 | slot->bus->number, | |
47 | slot->number); | |
48 | } | |
49 | ||
50 | static void pci_slot_release(struct kobject *kobj) | |
51 | { | |
cef354db | 52 | struct pci_dev *dev; |
f46753c5 AC |
53 | struct pci_slot *slot = to_pci_slot(kobj); |
54 | ||
55 | pr_debug("%s: releasing pci_slot on %x:%d\n", __func__, | |
56 | slot->bus->number, slot->number); | |
57 | ||
cef354db AC |
58 | list_for_each_entry(dev, &slot->bus->devices, bus_list) |
59 | if (PCI_SLOT(dev->devfn) == slot->number) | |
60 | dev->slot = NULL; | |
61 | ||
f46753c5 AC |
62 | list_del(&slot->list); |
63 | ||
64 | kfree(slot); | |
65 | } | |
66 | ||
67 | static struct pci_slot_attribute pci_slot_attr_address = | |
68 | __ATTR(address, (S_IFREG | S_IRUGO), address_read_file, NULL); | |
69 | ||
70 | static struct attribute *pci_slot_default_attrs[] = { | |
71 | &pci_slot_attr_address.attr, | |
72 | NULL, | |
73 | }; | |
74 | ||
75 | static struct kobj_type pci_slot_ktype = { | |
76 | .sysfs_ops = &pci_slot_sysfs_ops, | |
77 | .release = &pci_slot_release, | |
78 | .default_attrs = pci_slot_default_attrs, | |
79 | }; | |
80 | ||
5fe6cc60 AC |
81 | static char *make_slot_name(const char *name) |
82 | { | |
83 | char *new_name; | |
84 | int len, max, dup; | |
85 | ||
86 | new_name = kstrdup(name, GFP_KERNEL); | |
87 | if (!new_name) | |
88 | return NULL; | |
89 | ||
90 | /* | |
91 | * Make sure we hit the realloc case the first time through the | |
92 | * loop. 'len' will be strlen(name) + 3 at that point which is | |
93 | * enough space for "name-X" and the trailing NUL. | |
94 | */ | |
95 | len = strlen(name) + 2; | |
96 | max = 1; | |
97 | dup = 1; | |
98 | ||
99 | for (;;) { | |
100 | struct kobject *dup_slot; | |
101 | dup_slot = kset_find_obj(pci_slots_kset, new_name); | |
102 | if (!dup_slot) | |
103 | break; | |
104 | kobject_put(dup_slot); | |
105 | if (dup == max) { | |
106 | len++; | |
107 | max *= 10; | |
108 | kfree(new_name); | |
109 | new_name = kmalloc(len, GFP_KERNEL); | |
110 | if (!new_name) | |
111 | break; | |
112 | } | |
113 | sprintf(new_name, "%s-%d", name, dup++); | |
114 | } | |
115 | ||
116 | return new_name; | |
117 | } | |
118 | ||
119 | static int rename_slot(struct pci_slot *slot, const char *name) | |
120 | { | |
121 | int result = 0; | |
122 | char *slot_name; | |
123 | ||
124 | if (strcmp(kobject_name(&slot->kobj), name) == 0) | |
125 | return result; | |
126 | ||
127 | slot_name = make_slot_name(name); | |
128 | if (!slot_name) | |
129 | return -ENOMEM; | |
130 | ||
131 | result = kobject_rename(&slot->kobj, slot_name); | |
132 | kfree(slot_name); | |
133 | ||
134 | return result; | |
135 | } | |
136 | ||
137 | static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr) | |
138 | { | |
139 | struct pci_slot *slot; | |
140 | /* | |
141 | * We already hold pci_bus_sem so don't worry | |
142 | */ | |
143 | list_for_each_entry(slot, &parent->slots, list) | |
144 | if (slot->number == slot_nr) { | |
145 | kobject_get(&slot->kobj); | |
146 | return slot; | |
147 | } | |
148 | ||
149 | return NULL; | |
150 | } | |
151 | ||
f46753c5 AC |
152 | /** |
153 | * pci_create_slot - create or increment refcount for physical PCI slot | |
154 | * @parent: struct pci_bus of parent bridge | |
155 | * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder | |
156 | * @name: user visible string presented in /sys/bus/pci/slots/<name> | |
828f3768 | 157 | * @hotplug: set if caller is hotplug driver, NULL otherwise |
f46753c5 AC |
158 | * |
159 | * PCI slots have first class attributes such as address, speed, width, | |
160 | * and a &struct pci_slot is used to manage them. This interface will | |
161 | * either return a new &struct pci_slot to the caller, or if the pci_slot | |
162 | * already exists, its refcount will be incremented. | |
163 | * | |
5fe6cc60 AC |
164 | * Slots are uniquely identified by a @pci_bus, @slot_nr tuple. |
165 | * | |
166 | * There are known platforms with broken firmware that assign the same | |
167 | * name to multiple slots. Workaround these broken platforms by renaming | |
168 | * the slots on behalf of the caller. If firmware assigns name N to | |
169 | * multiple slots: | |
170 | * | |
171 | * The first slot is assigned N | |
172 | * The second slot is assigned N-1 | |
173 | * The third slot is assigned N-2 | |
174 | * etc. | |
f46753c5 AC |
175 | * |
176 | * Placeholder slots: | |
177 | * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify | |
178 | * a slot. There is one notable exception - pSeries (rpaphp), where the | |
179 | * @slot_nr cannot be determined until a device is actually inserted into | |
180 | * the slot. In this scenario, the caller may pass -1 for @slot_nr. | |
181 | * | |
182 | * The following semantics are imposed when the caller passes @slot_nr == | |
5fe6cc60 AC |
183 | * -1. First, we no longer check for an existing %struct pci_slot, as there |
184 | * may be many slots with @slot_nr of -1. The other change in semantics is | |
f46753c5 AC |
185 | * user-visible, which is the 'address' parameter presented in sysfs will |
186 | * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the | |
187 | * %struct pci_bus and bb is the bus number. In other words, the devfn of | |
188 | * the 'placeholder' slot will not be displayed. | |
189 | */ | |
f46753c5 | 190 | struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr, |
828f3768 AC |
191 | const char *name, |
192 | struct hotplug_slot *hotplug) | |
f46753c5 | 193 | { |
cef354db | 194 | struct pci_dev *dev; |
f46753c5 | 195 | struct pci_slot *slot; |
5fe6cc60 AC |
196 | int err = 0; |
197 | char *slot_name = NULL; | |
f46753c5 AC |
198 | |
199 | down_write(&pci_bus_sem); | |
200 | ||
201 | if (slot_nr == -1) | |
202 | goto placeholder; | |
203 | ||
5fe6cc60 AC |
204 | /* |
205 | * Hotplug drivers are allowed to rename an existing slot, | |
206 | * but only if not already claimed. | |
207 | */ | |
208 | slot = get_slot(parent, slot_nr); | |
209 | if (slot) { | |
210 | if (hotplug) { | |
211 | if ((err = slot->hotplug ? -EBUSY : 0) | |
212 | || (err = rename_slot(slot, name))) { | |
213 | kobject_put(&slot->kobj); | |
214 | slot = NULL; | |
215 | goto err; | |
216 | } | |
f46753c5 | 217 | } |
5fe6cc60 | 218 | goto out; |
f46753c5 AC |
219 | } |
220 | ||
221 | placeholder: | |
222 | slot = kzalloc(sizeof(*slot), GFP_KERNEL); | |
223 | if (!slot) { | |
5fe6cc60 AC |
224 | err = -ENOMEM; |
225 | goto err; | |
f46753c5 AC |
226 | } |
227 | ||
228 | slot->bus = parent; | |
229 | slot->number = slot_nr; | |
230 | ||
231 | slot->kobj.kset = pci_slots_kset; | |
5fe6cc60 AC |
232 | |
233 | slot_name = make_slot_name(name); | |
234 | if (!slot_name) { | |
235 | err = -ENOMEM; | |
f46753c5 AC |
236 | goto err; |
237 | } | |
238 | ||
5fe6cc60 AC |
239 | err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL, |
240 | "%s", slot_name); | |
241 | if (err) | |
242 | goto err; | |
243 | ||
f46753c5 AC |
244 | INIT_LIST_HEAD(&slot->list); |
245 | list_add(&slot->list, &parent->slots); | |
246 | ||
cef354db AC |
247 | list_for_each_entry(dev, &parent->devices, bus_list) |
248 | if (PCI_SLOT(dev->devfn) == slot_nr) | |
249 | dev->slot = slot; | |
250 | ||
f46753c5 AC |
251 | /* Don't care if debug printk has a -1 for slot_nr */ |
252 | pr_debug("%s: created pci_slot on %04x:%02x:%02x\n", | |
253 | __func__, pci_domain_nr(parent), parent->number, slot_nr); | |
254 | ||
5fe6cc60 | 255 | out: |
f46753c5 AC |
256 | up_write(&pci_bus_sem); |
257 | return slot; | |
5fe6cc60 | 258 | err: |
f46753c5 AC |
259 | kfree(slot); |
260 | slot = ERR_PTR(err); | |
261 | goto out; | |
262 | } | |
263 | EXPORT_SYMBOL_GPL(pci_create_slot); | |
264 | ||
265 | /** | |
d25b7c8d | 266 | * pci_renumber_slot - update %struct pci_slot -> number |
f46753c5 AC |
267 | * @slot - %struct pci_slot to update |
268 | * @slot_nr - new number for slot | |
269 | * | |
270 | * The primary purpose of this interface is to allow callers who earlier | |
271 | * created a placeholder slot in pci_create_slot() by passing a -1 as | |
272 | * slot_nr, to update their %struct pci_slot with the correct @slot_nr. | |
273 | */ | |
d25b7c8d | 274 | void pci_renumber_slot(struct pci_slot *slot, int slot_nr) |
f46753c5 | 275 | { |
f46753c5 AC |
276 | struct pci_slot *tmp; |
277 | ||
278 | down_write(&pci_bus_sem); | |
279 | ||
280 | list_for_each_entry(tmp, &slot->bus->slots, list) { | |
281 | WARN_ON(tmp->number == slot_nr); | |
d25b7c8d | 282 | goto out; |
f46753c5 AC |
283 | } |
284 | ||
f46753c5 | 285 | slot->number = slot_nr; |
d25b7c8d | 286 | out: |
f46753c5 AC |
287 | up_write(&pci_bus_sem); |
288 | } | |
d25b7c8d | 289 | EXPORT_SYMBOL_GPL(pci_renumber_slot); |
f46753c5 AC |
290 | |
291 | /** | |
292 | * pci_destroy_slot - decrement refcount for physical PCI slot | |
293 | * @slot: struct pci_slot to decrement | |
294 | * | |
295 | * %struct pci_slot is refcounted, so destroying them is really easy; we | |
296 | * just call kobject_put on its kobj and let our release methods do the | |
297 | * rest. | |
298 | */ | |
f46753c5 AC |
299 | void pci_destroy_slot(struct pci_slot *slot) |
300 | { | |
301 | pr_debug("%s: dec refcount to %d on %04x:%02x:%02x\n", __func__, | |
302 | atomic_read(&slot->kobj.kref.refcount) - 1, | |
303 | pci_domain_nr(slot->bus), slot->bus->number, slot->number); | |
304 | ||
305 | down_write(&pci_bus_sem); | |
306 | kobject_put(&slot->kobj); | |
307 | up_write(&pci_bus_sem); | |
308 | } | |
309 | EXPORT_SYMBOL_GPL(pci_destroy_slot); | |
310 | ||
311 | static int pci_slot_init(void) | |
312 | { | |
313 | struct kset *pci_bus_kset; | |
314 | ||
315 | pci_bus_kset = bus_get_kset(&pci_bus_type); | |
316 | pci_slots_kset = kset_create_and_add("slots", NULL, | |
317 | &pci_bus_kset->kobj); | |
318 | if (!pci_slots_kset) { | |
319 | printk(KERN_ERR "PCI: Slot initialization failure\n"); | |
320 | return -ENOMEM; | |
321 | } | |
322 | return 0; | |
323 | } | |
324 | ||
325 | subsys_initcall(pci_slot_init); |