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/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 const 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 /* these strings match up with the values in pci_bus_speed */ 51 static char *pci_bus_speed_strings[] = { 52 "33 MHz PCI", /* 0x00 */ 53 "66 MHz PCI", /* 0x01 */ 54 "66 MHz PCI-X", /* 0x02 */ 55 "100 MHz PCI-X", /* 0x03 */ 56 "133 MHz PCI-X", /* 0x04 */ 57 NULL, /* 0x05 */ 58 NULL, /* 0x06 */ 59 NULL, /* 0x07 */ 60 NULL, /* 0x08 */ 61 "66 MHz PCI-X 266", /* 0x09 */ 62 "100 MHz PCI-X 266", /* 0x0a */ 63 "133 MHz PCI-X 266", /* 0x0b */ 64 "Unknown AGP", /* 0x0c */ 65 "1x AGP", /* 0x0d */ 66 "2x AGP", /* 0x0e */ 67 "4x AGP", /* 0x0f */ 68 "8x AGP", /* 0x10 */ 69 "66 MHz PCI-X 533", /* 0x11 */ 70 "100 MHz PCI-X 533", /* 0x12 */ 71 "133 MHz PCI-X 533", /* 0x13 */ 72 "2.5 GT/s PCIe", /* 0x14 */ 73 "5.0 GT/s PCIe", /* 0x15 */ 74 "8.0 GT/s PCIe", /* 0x16 */ 75 }; 76 77 static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf) 78 { 79 const char *speed_string; 80 81 if (speed < ARRAY_SIZE(pci_bus_speed_strings)) 82 speed_string = pci_bus_speed_strings[speed]; 83 else 84 speed_string = "Unknown"; 85 86 return sprintf(buf, "%s\n", speed_string); 87 } 88 89 static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf) 90 { 91 return bus_speed_read(slot->bus->max_bus_speed, buf); 92 } 93 94 static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf) 95 { 96 return bus_speed_read(slot->bus->cur_bus_speed, buf); 97 } 98 99 static void pci_slot_release(struct kobject *kobj) 100 { 101 struct pci_dev *dev; 102 struct pci_slot *slot = to_pci_slot(kobj); 103 104 dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n", 105 slot->number, pci_slot_name(slot)); 106 107 list_for_each_entry(dev, &slot->bus->devices, bus_list) 108 if (PCI_SLOT(dev->devfn) == slot->number) 109 dev->slot = NULL; 110 111 list_del(&slot->list); 112 113 kfree(slot); 114 } 115 116 static struct pci_slot_attribute pci_slot_attr_address = 117 __ATTR(address, (S_IFREG | S_IRUGO), address_read_file, NULL); 118 static struct pci_slot_attribute pci_slot_attr_max_speed = 119 __ATTR(max_bus_speed, (S_IFREG | S_IRUGO), max_speed_read_file, NULL); 120 static struct pci_slot_attribute pci_slot_attr_cur_speed = 121 __ATTR(cur_bus_speed, (S_IFREG | S_IRUGO), cur_speed_read_file, NULL); 122 123 static struct attribute *pci_slot_default_attrs[] = { 124 &pci_slot_attr_address.attr, 125 &pci_slot_attr_max_speed.attr, 126 &pci_slot_attr_cur_speed.attr, 127 NULL, 128 }; 129 130 static struct kobj_type pci_slot_ktype = { 131 .sysfs_ops = &pci_slot_sysfs_ops, 132 .release = &pci_slot_release, 133 .default_attrs = pci_slot_default_attrs, 134 }; 135 136 static char *make_slot_name(const char *name) 137 { 138 char *new_name; 139 int len, max, dup; 140 141 new_name = kstrdup(name, GFP_KERNEL); 142 if (!new_name) 143 return NULL; 144 145 /* 146 * Make sure we hit the realloc case the first time through the 147 * loop. 'len' will be strlen(name) + 3 at that point which is 148 * enough space for "name-X" and the trailing NUL. 149 */ 150 len = strlen(name) + 2; 151 max = 1; 152 dup = 1; 153 154 for (;;) { 155 struct kobject *dup_slot; 156 dup_slot = kset_find_obj(pci_slots_kset, new_name); 157 if (!dup_slot) 158 break; 159 kobject_put(dup_slot); 160 if (dup == max) { 161 len++; 162 max *= 10; 163 kfree(new_name); 164 new_name = kmalloc(len, GFP_KERNEL); 165 if (!new_name) 166 break; 167 } 168 sprintf(new_name, "%s-%d", name, dup++); 169 } 170 171 return new_name; 172 } 173 174 static int rename_slot(struct pci_slot *slot, const char *name) 175 { 176 int result = 0; 177 char *slot_name; 178 179 if (strcmp(pci_slot_name(slot), name) == 0) 180 return result; 181 182 slot_name = make_slot_name(name); 183 if (!slot_name) 184 return -ENOMEM; 185 186 result = kobject_rename(&slot->kobj, slot_name); 187 kfree(slot_name); 188 189 return result; 190 } 191 192 static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr) 193 { 194 struct pci_slot *slot; 195 /* 196 * We already hold pci_bus_sem so don't worry 197 */ 198 list_for_each_entry(slot, &parent->slots, list) 199 if (slot->number == slot_nr) { 200 kobject_get(&slot->kobj); 201 return slot; 202 } 203 204 return NULL; 205 } 206 207 /** 208 * pci_create_slot - create or increment refcount for physical PCI slot 209 * @parent: struct pci_bus of parent bridge 210 * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder 211 * @name: user visible string presented in /sys/bus/pci/slots/<name> 212 * @hotplug: set if caller is hotplug driver, NULL otherwise 213 * 214 * PCI slots have first class attributes such as address, speed, width, 215 * and a &struct pci_slot is used to manage them. This interface will 216 * either return a new &struct pci_slot to the caller, or if the pci_slot 217 * already exists, its refcount will be incremented. 218 * 219 * Slots are uniquely identified by a @pci_bus, @slot_nr tuple. 220 * 221 * There are known platforms with broken firmware that assign the same 222 * name to multiple slots. Workaround these broken platforms by renaming 223 * the slots on behalf of the caller. If firmware assigns name N to 224 * multiple slots: 225 * 226 * The first slot is assigned N 227 * The second slot is assigned N-1 228 * The third slot is assigned N-2 229 * etc. 230 * 231 * Placeholder slots: 232 * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify 233 * a slot. There is one notable exception - pSeries (rpaphp), where the 234 * @slot_nr cannot be determined until a device is actually inserted into 235 * the slot. In this scenario, the caller may pass -1 for @slot_nr. 236 * 237 * The following semantics are imposed when the caller passes @slot_nr == 238 * -1. First, we no longer check for an existing %struct pci_slot, as there 239 * may be many slots with @slot_nr of -1. The other change in semantics is 240 * user-visible, which is the 'address' parameter presented in sysfs will 241 * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the 242 * %struct pci_bus and bb is the bus number. In other words, the devfn of 243 * the 'placeholder' slot will not be displayed. 244 */ 245 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr, 246 const char *name, 247 struct hotplug_slot *hotplug) 248 { 249 struct pci_dev *dev; 250 struct pci_slot *slot; 251 int err = 0; 252 char *slot_name = NULL; 253 254 down_write(&pci_bus_sem); 255 256 if (slot_nr == -1) 257 goto placeholder; 258 259 /* 260 * Hotplug drivers are allowed to rename an existing slot, 261 * but only if not already claimed. 262 */ 263 slot = get_slot(parent, slot_nr); 264 if (slot) { 265 if (hotplug) { 266 if ((err = slot->hotplug ? -EBUSY : 0) 267 || (err = rename_slot(slot, name))) { 268 kobject_put(&slot->kobj); 269 slot = NULL; 270 goto err; 271 } 272 } 273 goto out; 274 } 275 276 placeholder: 277 slot = kzalloc(sizeof(*slot), GFP_KERNEL); 278 if (!slot) { 279 err = -ENOMEM; 280 goto err; 281 } 282 283 slot->bus = parent; 284 slot->number = slot_nr; 285 286 slot->kobj.kset = pci_slots_kset; 287 288 slot_name = make_slot_name(name); 289 if (!slot_name) { 290 err = -ENOMEM; 291 goto err; 292 } 293 294 err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL, 295 "%s", slot_name); 296 if (err) 297 goto err; 298 299 INIT_LIST_HEAD(&slot->list); 300 list_add(&slot->list, &parent->slots); 301 302 list_for_each_entry(dev, &parent->devices, bus_list) 303 if (PCI_SLOT(dev->devfn) == slot_nr) 304 dev->slot = slot; 305 306 dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n", 307 slot_nr, pci_slot_name(slot)); 308 309 out: 310 kfree(slot_name); 311 up_write(&pci_bus_sem); 312 return slot; 313 err: 314 kfree(slot); 315 slot = ERR_PTR(err); 316 goto out; 317 } 318 EXPORT_SYMBOL_GPL(pci_create_slot); 319 320 /** 321 * pci_renumber_slot - update %struct pci_slot -> number 322 * @slot: &struct pci_slot to update 323 * @slot_nr: new number for slot 324 * 325 * The primary purpose of this interface is to allow callers who earlier 326 * created a placeholder slot in pci_create_slot() by passing a -1 as 327 * slot_nr, to update their %struct pci_slot with the correct @slot_nr. 328 */ 329 void pci_renumber_slot(struct pci_slot *slot, int slot_nr) 330 { 331 struct pci_slot *tmp; 332 333 down_write(&pci_bus_sem); 334 335 list_for_each_entry(tmp, &slot->bus->slots, list) { 336 WARN_ON(tmp->number == slot_nr); 337 goto out; 338 } 339 340 slot->number = slot_nr; 341 out: 342 up_write(&pci_bus_sem); 343 } 344 EXPORT_SYMBOL_GPL(pci_renumber_slot); 345 346 /** 347 * pci_destroy_slot - decrement refcount for physical PCI slot 348 * @slot: struct pci_slot to decrement 349 * 350 * %struct pci_slot is refcounted, so destroying them is really easy; we 351 * just call kobject_put on its kobj and let our release methods do the 352 * rest. 353 */ 354 void pci_destroy_slot(struct pci_slot *slot) 355 { 356 dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n", 357 slot->number, atomic_read(&slot->kobj.kref.refcount) - 1); 358 359 down_write(&pci_bus_sem); 360 kobject_put(&slot->kobj); 361 up_write(&pci_bus_sem); 362 } 363 EXPORT_SYMBOL_GPL(pci_destroy_slot); 364 365 #if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE) 366 #include <linux/pci_hotplug.h> 367 /** 368 * pci_hp_create_link - create symbolic link to the hotplug driver module. 369 * @pci_slot: struct pci_slot 370 * 371 * Helper function for pci_hotplug_core.c to create symbolic link to 372 * the hotplug driver module. 373 */ 374 void pci_hp_create_module_link(struct pci_slot *pci_slot) 375 { 376 struct hotplug_slot *slot = pci_slot->hotplug; 377 struct kobject *kobj = NULL; 378 int no_warn; 379 380 if (!slot || !slot->ops) 381 return; 382 kobj = kset_find_obj(module_kset, slot->ops->mod_name); 383 if (!kobj) 384 return; 385 no_warn = sysfs_create_link(&pci_slot->kobj, kobj, "module"); 386 kobject_put(kobj); 387 } 388 EXPORT_SYMBOL_GPL(pci_hp_create_module_link); 389 390 /** 391 * pci_hp_remove_link - remove symbolic link to the hotplug driver module. 392 * @pci_slot: struct pci_slot 393 * 394 * Helper function for pci_hotplug_core.c to remove symbolic link to 395 * the hotplug driver module. 396 */ 397 void pci_hp_remove_module_link(struct pci_slot *pci_slot) 398 { 399 sysfs_remove_link(&pci_slot->kobj, "module"); 400 } 401 EXPORT_SYMBOL_GPL(pci_hp_remove_module_link); 402 #endif 403 404 static int pci_slot_init(void) 405 { 406 struct kset *pci_bus_kset; 407 408 pci_bus_kset = bus_get_kset(&pci_bus_type); 409 pci_slots_kset = kset_create_and_add("slots", NULL, 410 &pci_bus_kset->kobj); 411 if (!pci_slots_kset) { 412 printk(KERN_ERR "PCI: Slot initialization failure\n"); 413 return -ENOMEM; 414 } 415 return 0; 416 } 417 418 subsys_initcall(pci_slot_init); 419