1 /* 2 * PCI searching functions. 3 * 4 * Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter, 5 * David Mosberger-Tang 6 * Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz> 7 * Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com> 8 */ 9 10 #include <linux/init.h> 11 #include <linux/pci.h> 12 #include <linux/module.h> 13 #include <linux/interrupt.h> 14 #include "pci.h" 15 16 DECLARE_RWSEM(pci_bus_sem); 17 18 static struct pci_bus * __devinit 19 pci_do_find_bus(struct pci_bus* bus, unsigned char busnr) 20 { 21 struct pci_bus* child; 22 struct list_head *tmp; 23 24 if(bus->number == busnr) 25 return bus; 26 27 list_for_each(tmp, &bus->children) { 28 child = pci_do_find_bus(pci_bus_b(tmp), busnr); 29 if(child) 30 return child; 31 } 32 return NULL; 33 } 34 35 /** 36 * pci_find_bus - locate PCI bus from a given domain and bus number 37 * @domain: number of PCI domain to search 38 * @busnr: number of desired PCI bus 39 * 40 * Given a PCI bus number and domain number, the desired PCI bus is located 41 * in the global list of PCI buses. If the bus is found, a pointer to its 42 * data structure is returned. If no bus is found, %NULL is returned. 43 */ 44 struct pci_bus * pci_find_bus(int domain, int busnr) 45 { 46 struct pci_bus *bus = NULL; 47 struct pci_bus *tmp_bus; 48 49 while ((bus = pci_find_next_bus(bus)) != NULL) { 50 if (pci_domain_nr(bus) != domain) 51 continue; 52 tmp_bus = pci_do_find_bus(bus, busnr); 53 if (tmp_bus) 54 return tmp_bus; 55 } 56 return NULL; 57 } 58 59 /** 60 * pci_find_next_bus - begin or continue searching for a PCI bus 61 * @from: Previous PCI bus found, or %NULL for new search. 62 * 63 * Iterates through the list of known PCI busses. A new search is 64 * initiated by passing %NULL as the @from argument. Otherwise if 65 * @from is not %NULL, searches continue from next device on the 66 * global list. 67 */ 68 struct pci_bus * 69 pci_find_next_bus(const struct pci_bus *from) 70 { 71 struct list_head *n; 72 struct pci_bus *b = NULL; 73 74 WARN_ON(in_interrupt()); 75 down_read(&pci_bus_sem); 76 n = from ? from->node.next : pci_root_buses.next; 77 if (n != &pci_root_buses) 78 b = pci_bus_b(n); 79 up_read(&pci_bus_sem); 80 return b; 81 } 82 83 /** 84 * pci_find_slot - locate PCI device from a given PCI slot 85 * @bus: number of PCI bus on which desired PCI device resides 86 * @devfn: encodes number of PCI slot in which the desired PCI 87 * device resides and the logical device number within that slot 88 * in case of multi-function devices. 89 * 90 * Given a PCI bus and slot/function number, the desired PCI device 91 * is located in system global list of PCI devices. If the device 92 * is found, a pointer to its data structure is returned. If no 93 * device is found, %NULL is returned. 94 */ 95 struct pci_dev * 96 pci_find_slot(unsigned int bus, unsigned int devfn) 97 { 98 struct pci_dev *dev = NULL; 99 100 while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { 101 if (dev->bus->number == bus && dev->devfn == devfn) 102 return dev; 103 } 104 return NULL; 105 } 106 107 /** 108 * pci_get_slot - locate PCI device for a given PCI slot 109 * @bus: PCI bus on which desired PCI device resides 110 * @devfn: encodes number of PCI slot in which the desired PCI 111 * device resides and the logical device number within that slot 112 * in case of multi-function devices. 113 * 114 * Given a PCI bus and slot/function number, the desired PCI device 115 * is located in the list of PCI devices. 116 * If the device is found, its reference count is increased and this 117 * function returns a pointer to its data structure. The caller must 118 * decrement the reference count by calling pci_dev_put(). 119 * If no device is found, %NULL is returned. 120 */ 121 struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn) 122 { 123 struct list_head *tmp; 124 struct pci_dev *dev; 125 126 WARN_ON(in_interrupt()); 127 down_read(&pci_bus_sem); 128 129 list_for_each(tmp, &bus->devices) { 130 dev = pci_dev_b(tmp); 131 if (dev->devfn == devfn) 132 goto out; 133 } 134 135 dev = NULL; 136 out: 137 pci_dev_get(dev); 138 up_read(&pci_bus_sem); 139 return dev; 140 } 141 142 /** 143 * pci_find_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id 144 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 145 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 146 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids 147 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids 148 * @from: Previous PCI device found in search, or %NULL for new search. 149 * 150 * Iterates through the list of known PCI devices. If a PCI device is 151 * found with a matching @vendor, @device, @ss_vendor and @ss_device, a 152 * pointer to its device structure is returned. Otherwise, %NULL is returned. 153 * A new search is initiated by passing %NULL as the @from argument. 154 * Otherwise if @from is not %NULL, searches continue from next device 155 * on the global list. 156 * 157 * NOTE: Do not use this function any more; use pci_get_subsys() instead, as 158 * the PCI device returned by this function can disappear at any moment in 159 * time. 160 */ 161 static struct pci_dev * pci_find_subsys(unsigned int vendor, 162 unsigned int device, 163 unsigned int ss_vendor, 164 unsigned int ss_device, 165 const struct pci_dev *from) 166 { 167 struct list_head *n; 168 struct pci_dev *dev; 169 170 WARN_ON(in_interrupt()); 171 down_read(&pci_bus_sem); 172 n = from ? from->global_list.next : pci_devices.next; 173 174 while (n && (n != &pci_devices)) { 175 dev = pci_dev_g(n); 176 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && 177 (device == PCI_ANY_ID || dev->device == device) && 178 (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) && 179 (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device)) 180 goto exit; 181 n = n->next; 182 } 183 dev = NULL; 184 exit: 185 up_read(&pci_bus_sem); 186 return dev; 187 } 188 189 /** 190 * pci_find_device - begin or continue searching for a PCI device by vendor/device id 191 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 192 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 193 * @from: Previous PCI device found in search, or %NULL for new search. 194 * 195 * Iterates through the list of known PCI devices. If a PCI device is found 196 * with a matching @vendor and @device, a pointer to its device structure is 197 * returned. Otherwise, %NULL is returned. 198 * A new search is initiated by passing %NULL as the @from argument. 199 * Otherwise if @from is not %NULL, searches continue from next device 200 * on the global list. 201 * 202 * NOTE: Do not use this function any more; use pci_get_device() instead, as 203 * the PCI device returned by this function can disappear at any moment in 204 * time. 205 */ 206 struct pci_dev * 207 pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from) 208 { 209 return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); 210 } 211 212 /** 213 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id 214 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 215 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 216 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids 217 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids 218 * @from: Previous PCI device found in search, or %NULL for new search. 219 * 220 * Iterates through the list of known PCI devices. If a PCI device is found 221 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its 222 * device structure is returned, and the reference count to the device is 223 * incremented. Otherwise, %NULL is returned. A new search is initiated by 224 * passing %NULL as the @from argument. Otherwise if @from is not %NULL, 225 * searches continue from next device on the global list. 226 * The reference count for @from is always decremented if it is not %NULL. 227 */ 228 struct pci_dev * 229 pci_get_subsys(unsigned int vendor, unsigned int device, 230 unsigned int ss_vendor, unsigned int ss_device, 231 struct pci_dev *from) 232 { 233 struct list_head *n; 234 struct pci_dev *dev; 235 236 WARN_ON(in_interrupt()); 237 down_read(&pci_bus_sem); 238 n = from ? from->global_list.next : pci_devices.next; 239 240 while (n && (n != &pci_devices)) { 241 dev = pci_dev_g(n); 242 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && 243 (device == PCI_ANY_ID || dev->device == device) && 244 (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) && 245 (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device)) 246 goto exit; 247 n = n->next; 248 } 249 dev = NULL; 250 exit: 251 dev = pci_dev_get(dev); 252 up_read(&pci_bus_sem); 253 pci_dev_put(from); 254 return dev; 255 } 256 257 /** 258 * pci_get_device - begin or continue searching for a PCI device by vendor/device id 259 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 260 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 261 * @from: Previous PCI device found in search, or %NULL for new search. 262 * 263 * Iterates through the list of known PCI devices. If a PCI device is 264 * found with a matching @vendor and @device, the reference count to the 265 * device is incremented and a pointer to its device structure is returned. 266 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL 267 * as the @from argument. Otherwise if @from is not %NULL, searches continue 268 * from next device on the global list. The reference count for @from is 269 * always decremented if it is not %NULL. 270 */ 271 struct pci_dev * 272 pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from) 273 { 274 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); 275 } 276 277 278 /** 279 * pci_find_device_reverse - begin or continue searching for a PCI device by vendor/device id 280 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 281 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 282 * @from: Previous PCI device found in search, or %NULL for new search. 283 * 284 * Iterates through the list of known PCI devices in the reverse order of 285 * pci_find_device(). 286 * If a PCI device is found with a matching @vendor and @device, a pointer to 287 * its device structure is returned. Otherwise, %NULL is returned. 288 * A new search is initiated by passing %NULL as the @from argument. 289 * Otherwise if @from is not %NULL, searches continue from previous device 290 * on the global list. 291 */ 292 struct pci_dev * 293 pci_find_device_reverse(unsigned int vendor, unsigned int device, const struct pci_dev *from) 294 { 295 struct list_head *n; 296 struct pci_dev *dev; 297 298 WARN_ON(in_interrupt()); 299 down_read(&pci_bus_sem); 300 n = from ? from->global_list.prev : pci_devices.prev; 301 302 while (n && (n != &pci_devices)) { 303 dev = pci_dev_g(n); 304 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && 305 (device == PCI_ANY_ID || dev->device == device)) 306 goto exit; 307 n = n->prev; 308 } 309 dev = NULL; 310 exit: 311 up_read(&pci_bus_sem); 312 return dev; 313 } 314 315 /** 316 * pci_get_class - begin or continue searching for a PCI device by class 317 * @class: search for a PCI device with this class designation 318 * @from: Previous PCI device found in search, or %NULL for new search. 319 * 320 * Iterates through the list of known PCI devices. If a PCI device is 321 * found with a matching @class, the reference count to the device is 322 * incremented and a pointer to its device structure is returned. 323 * Otherwise, %NULL is returned. 324 * A new search is initiated by passing %NULL as the @from argument. 325 * Otherwise if @from is not %NULL, searches continue from next device 326 * on the global list. The reference count for @from is always decremented 327 * if it is not %NULL. 328 */ 329 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) 330 { 331 struct list_head *n; 332 struct pci_dev *dev; 333 334 WARN_ON(in_interrupt()); 335 down_read(&pci_bus_sem); 336 n = from ? from->global_list.next : pci_devices.next; 337 338 while (n && (n != &pci_devices)) { 339 dev = pci_dev_g(n); 340 if (dev->class == class) 341 goto exit; 342 n = n->next; 343 } 344 dev = NULL; 345 exit: 346 dev = pci_dev_get(dev); 347 up_read(&pci_bus_sem); 348 pci_dev_put(from); 349 return dev; 350 } 351 352 /** 353 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not. 354 * @ids: A pointer to a null terminated list of struct pci_device_id structures 355 * that describe the type of PCI device the caller is trying to find. 356 * 357 * Obvious fact: You do not have a reference to any device that might be found 358 * by this function, so if that device is removed from the system right after 359 * this function is finished, the value will be stale. Use this function to 360 * find devices that are usually built into a system, or for a general hint as 361 * to if another device happens to be present at this specific moment in time. 362 */ 363 int pci_dev_present(const struct pci_device_id *ids) 364 { 365 struct pci_dev *dev; 366 int found = 0; 367 368 WARN_ON(in_interrupt()); 369 down_read(&pci_bus_sem); 370 while (ids->vendor || ids->subvendor || ids->class_mask) { 371 list_for_each_entry(dev, &pci_devices, global_list) { 372 if (pci_match_one_device(ids, dev)) { 373 found = 1; 374 goto exit; 375 } 376 } 377 ids++; 378 } 379 exit: 380 up_read(&pci_bus_sem); 381 return found; 382 } 383 EXPORT_SYMBOL(pci_dev_present); 384 385 EXPORT_SYMBOL(pci_find_bus); 386 EXPORT_SYMBOL(pci_find_next_bus); 387 EXPORT_SYMBOL(pci_find_device); 388 EXPORT_SYMBOL(pci_find_device_reverse); 389 EXPORT_SYMBOL(pci_find_slot); 390 EXPORT_SYMBOL(pci_get_device); 391 EXPORT_SYMBOL(pci_get_subsys); 392 EXPORT_SYMBOL(pci_get_slot); 393 EXPORT_SYMBOL(pci_get_class); 394