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 DEFINE_SPINLOCK(pci_bus_lock); 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 * __devinit 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 to 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 spin_lock(&pci_bus_lock); 76 n = from ? from->node.next : pci_root_buses.next; 77 if (n != &pci_root_buses) 78 b = pci_bus_b(n); 79 spin_unlock(&pci_bus_lock); 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 spin_lock(&pci_bus_lock); 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 spin_unlock(&pci_bus_lock); 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 pointer to its 152 * device structure is returned. Otherwise, %NULL is returned. 153 * A new search is initiated by passing %NULL to the @from argument. 154 * Otherwise if @from is not %NULL, searches continue from next device on the global list. 155 * 156 * NOTE: Do not use this function anymore, use pci_get_subsys() instead, as 157 * the pci device returned by this function can disappear at any moment in 158 * time. 159 */ 160 static struct pci_dev * pci_find_subsys(unsigned int vendor, 161 unsigned int device, 162 unsigned int ss_vendor, 163 unsigned int ss_device, 164 const struct pci_dev *from) 165 { 166 struct list_head *n; 167 struct pci_dev *dev; 168 169 WARN_ON(in_interrupt()); 170 spin_lock(&pci_bus_lock); 171 n = from ? from->global_list.next : pci_devices.next; 172 173 while (n && (n != &pci_devices)) { 174 dev = pci_dev_g(n); 175 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && 176 (device == PCI_ANY_ID || dev->device == device) && 177 (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) && 178 (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device)) 179 goto exit; 180 n = n->next; 181 } 182 dev = NULL; 183 exit: 184 spin_unlock(&pci_bus_lock); 185 return dev; 186 } 187 188 /** 189 * pci_find_device - begin or continue searching for a PCI device by vendor/device id 190 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 191 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 192 * @from: Previous PCI device found in search, or %NULL for new search. 193 * 194 * Iterates through the list of known PCI devices. If a PCI device is 195 * found with a matching @vendor and @device, a pointer to its device structure is 196 * returned. Otherwise, %NULL is returned. 197 * A new search is initiated by passing %NULL to the @from argument. 198 * Otherwise if @from is not %NULL, searches continue from next device on the global list. 199 * 200 * NOTE: Do not use this function anymore, use pci_get_device() instead, as 201 * the pci device returned by this function can disappear at any moment in 202 * time. 203 */ 204 struct pci_dev * 205 pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from) 206 { 207 return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); 208 } 209 210 /** 211 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id 212 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 213 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 214 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids 215 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids 216 * @from: Previous PCI device found in search, or %NULL for new search. 217 * 218 * Iterates through the list of known PCI devices. If a PCI device is 219 * found with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its 220 * device structure is returned, and the reference count to the device is 221 * incremented. Otherwise, %NULL is returned. A new search is initiated by 222 * passing %NULL to the @from argument. Otherwise if @from is not %NULL, 223 * searches continue from next device on the global list. 224 * The reference count for @from is always decremented if it is not %NULL. 225 */ 226 struct pci_dev * 227 pci_get_subsys(unsigned int vendor, unsigned int device, 228 unsigned int ss_vendor, unsigned int ss_device, 229 struct pci_dev *from) 230 { 231 struct list_head *n; 232 struct pci_dev *dev; 233 234 WARN_ON(in_interrupt()); 235 spin_lock(&pci_bus_lock); 236 n = from ? from->global_list.next : pci_devices.next; 237 238 while (n && (n != &pci_devices)) { 239 dev = pci_dev_g(n); 240 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && 241 (device == PCI_ANY_ID || dev->device == device) && 242 (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) && 243 (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device)) 244 goto exit; 245 n = n->next; 246 } 247 dev = NULL; 248 exit: 249 pci_dev_put(from); 250 dev = pci_dev_get(dev); 251 spin_unlock(&pci_bus_lock); 252 return dev; 253 } 254 255 /** 256 * pci_get_device - begin or continue searching for a PCI device by vendor/device id 257 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 258 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 259 * @from: Previous PCI device found in search, or %NULL for new search. 260 * 261 * Iterates through the list of known PCI devices. If a PCI device is 262 * found with a matching @vendor and @device, the reference count to the 263 * device is incremented and a pointer to its device structure is returned. 264 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL 265 * to the @from argument. Otherwise if @from is not %NULL, searches continue 266 * from next device on the global list. The reference count for @from is 267 * always decremented if it is not %NULL. 268 */ 269 struct pci_dev * 270 pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from) 271 { 272 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); 273 } 274 275 276 /** 277 * pci_find_device_reverse - begin or continue searching for a PCI device by vendor/device id 278 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids 279 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids 280 * @from: Previous PCI device found in search, or %NULL for new search. 281 * 282 * Iterates through the list of known PCI devices in the reverse order of pci_find_device(). 283 * If a PCI device is found with a matching @vendor and @device, a pointer to 284 * its device structure is returned. Otherwise, %NULL is returned. 285 * A new search is initiated by passing %NULL to the @from argument. 286 * Otherwise if @from is not %NULL, searches continue from previous device on the global list. 287 */ 288 struct pci_dev * 289 pci_find_device_reverse(unsigned int vendor, unsigned int device, const struct pci_dev *from) 290 { 291 struct list_head *n; 292 struct pci_dev *dev; 293 294 WARN_ON(in_interrupt()); 295 spin_lock(&pci_bus_lock); 296 n = from ? from->global_list.prev : pci_devices.prev; 297 298 while (n && (n != &pci_devices)) { 299 dev = pci_dev_g(n); 300 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && 301 (device == PCI_ANY_ID || dev->device == device)) 302 goto exit; 303 n = n->prev; 304 } 305 dev = NULL; 306 exit: 307 spin_unlock(&pci_bus_lock); 308 return dev; 309 } 310 311 /** 312 * pci_get_class - begin or continue searching for a PCI device by class 313 * @class: search for a PCI device with this class designation 314 * @from: Previous PCI device found in search, or %NULL for new search. 315 * 316 * Iterates through the list of known PCI devices. If a PCI device is 317 * found with a matching @class, the reference count to the device is 318 * incremented and a pointer to its device structure is returned. 319 * Otherwise, %NULL is returned. 320 * A new search is initiated by passing %NULL to the @from argument. 321 * Otherwise if @from is not %NULL, searches continue from next device 322 * on the global list. The reference count for @from is always decremented 323 * if it is not %NULL. 324 */ 325 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) 326 { 327 struct list_head *n; 328 struct pci_dev *dev; 329 330 WARN_ON(in_interrupt()); 331 spin_lock(&pci_bus_lock); 332 n = from ? from->global_list.next : pci_devices.next; 333 334 while (n && (n != &pci_devices)) { 335 dev = pci_dev_g(n); 336 if (dev->class == class) 337 goto exit; 338 n = n->next; 339 } 340 dev = NULL; 341 exit: 342 pci_dev_put(from); 343 dev = pci_dev_get(dev); 344 spin_unlock(&pci_bus_lock); 345 return dev; 346 } 347 348 /** 349 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not. 350 * @ids: A pointer to a null terminated list of struct pci_device_id structures 351 * that describe the type of PCI device the caller is trying to find. 352 * 353 * Obvious fact: You do not have a reference to any device that might be found 354 * by this function, so if that device is removed from the system right after 355 * this function is finished, the value will be stale. Use this function to 356 * find devices that are usually built into a system, or for a general hint as 357 * to if another device happens to be present at this specific moment in time. 358 */ 359 int pci_dev_present(const struct pci_device_id *ids) 360 { 361 struct pci_dev *dev; 362 int found = 0; 363 364 WARN_ON(in_interrupt()); 365 spin_lock(&pci_bus_lock); 366 while (ids->vendor || ids->subvendor || ids->class_mask) { 367 list_for_each_entry(dev, &pci_devices, global_list) { 368 if (pci_match_one_device(ids, dev)) { 369 found = 1; 370 goto exit; 371 } 372 } 373 ids++; 374 } 375 exit: 376 spin_unlock(&pci_bus_lock); 377 return found; 378 } 379 EXPORT_SYMBOL(pci_dev_present); 380 381 EXPORT_SYMBOL(pci_find_bus); 382 EXPORT_SYMBOL(pci_find_next_bus); 383 EXPORT_SYMBOL(pci_find_device); 384 EXPORT_SYMBOL(pci_find_device_reverse); 385 EXPORT_SYMBOL(pci_find_slot); 386 EXPORT_SYMBOL(pci_get_device); 387 EXPORT_SYMBOL(pci_get_subsys); 388 EXPORT_SYMBOL(pci_get_slot); 389 EXPORT_SYMBOL(pci_get_class); 390