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 15 struct kset *pci_slots_kset; 16 EXPORT_SYMBOL_GPL(pci_slots_kset); 17 18 static 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 26 static 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 34 static const struct sysfs_ops pci_slot_sysfs_ops = { 35 .show = pci_slot_attr_show, 36 .store = pci_slot_attr_store, 37 }; 38 39 static 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 */ 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 */ 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 79 static 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 91 static 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 96 static 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 } 100 101 static 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 } 117 118 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); 124 125 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, 129 NULL, 130 }; 131 132 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, 136 }; 137 138 static 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 } 175 176 static 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 } 193 194 static 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 */ 247 struct 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 } 277 278 placeholder: 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)); 310 311 out: 312 kfree(slot_name); 313 up_write(&pci_bus_sem); 314 return slot; 315 err: 316 kfree(slot); 317 slot = ERR_PTR(err); 318 goto out; 319 } 320 EXPORT_SYMBOL_GPL(pci_create_slot); 321 322 /** 323 * pci_destroy_slot - decrement refcount for physical PCI slot 324 * @slot: struct pci_slot to decrement 325 * 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 328 * rest. 329 */ 330 void pci_destroy_slot(struct pci_slot *slot) 331 { 332 dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n", 333 slot->number, atomic_read(&slot->kobj.kref.refcount) - 1); 334 335 down_write(&pci_bus_sem); 336 kobject_put(&slot->kobj); 337 up_write(&pci_bus_sem); 338 } 339 EXPORT_SYMBOL_GPL(pci_destroy_slot); 340 341 #if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE) 342 #include <linux/pci_hotplug.h> 343 /** 344 * pci_hp_create_link - create symbolic link to the hotplug driver module. 345 * @pci_slot: struct pci_slot 346 * 347 * Helper function for pci_hotplug_core.c to create symbolic link to 348 * the hotplug driver module. 349 */ 350 void pci_hp_create_module_link(struct pci_slot *pci_slot) 351 { 352 struct hotplug_slot *slot = pci_slot->hotplug; 353 struct kobject *kobj = NULL; 354 int ret; 355 356 if (!slot || !slot->ops) 357 return; 358 kobj = kset_find_obj(module_kset, slot->ops->mod_name); 359 if (!kobj) 360 return; 361 ret = sysfs_create_link(&pci_slot->kobj, kobj, "module"); 362 if (ret) 363 dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n", 364 ret); 365 kobject_put(kobj); 366 } 367 EXPORT_SYMBOL_GPL(pci_hp_create_module_link); 368 369 /** 370 * pci_hp_remove_link - remove symbolic link to the hotplug driver module. 371 * @pci_slot: struct pci_slot 372 * 373 * Helper function for pci_hotplug_core.c to remove symbolic link to 374 * the hotplug driver module. 375 */ 376 void pci_hp_remove_module_link(struct pci_slot *pci_slot) 377 { 378 sysfs_remove_link(&pci_slot->kobj, "module"); 379 } 380 EXPORT_SYMBOL_GPL(pci_hp_remove_module_link); 381 #endif 382 383 static int pci_slot_init(void) 384 { 385 struct kset *pci_bus_kset; 386 387 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"); 392 return -ENOMEM; 393 } 394 return 0; 395 } 396 397 subsys_initcall(pci_slot_init); 398