drivers/pci/search.c

   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_get_bus_and_slot - locate PCI device from a given PCI slot
 144  * @bus: number of PCI bus on which desired PCI device resides
 145  * @devfn: encodes number of PCI slot in which the desired PCI
 146  * device resides and the logical device number within that slot
 147  * in case of multi-function devices.
 148  *
 149  * Given a PCI bus and slot/function number, the desired PCI device
 150  * is located in system global list of PCI devices.  If the device
 151  * is found, a pointer to its data structure is returned.  If no
 152  * device is found, %NULL is returned. The returned device has its
 153  * reference count bumped by one.
 154  */
 155
 156 struct pci_dev * pci_get_bus_and_slot(unsigned int bus, unsigned int devfn)
 157 {
 158         struct pci_dev *dev = NULL;
 159
 160         while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
 161                 if (dev->bus->number == bus && dev->devfn == devfn)
 162                         return dev;
 163         }
 164         return NULL;
 165 }
 166
 167 /**
 168  * pci_find_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
 169  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 170  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 171  * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
 172  * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
 173  * @from: Previous PCI device found in search, or %NULL for new search.
 174  *
 175  * Iterates through the list of known PCI devices.  If a PCI device is
 176  * found with a matching @vendor, @device, @ss_vendor and @ss_device, a
 177  * pointer to its device structure is returned.  Otherwise, %NULL is returned.
 178  * A new search is initiated by passing %NULL as the @from argument.
 179  * Otherwise if @from is not %NULL, searches continue from next device
 180  * on the global list.
 181  *
 182  * NOTE: Do not use this function any more; use pci_get_subsys() instead, as
 183  * the PCI device returned by this function can disappear at any moment in
 184  * time.
 185  */
 186 static struct pci_dev * pci_find_subsys(unsigned int vendor,
 187                                         unsigned int device,
 188                                         unsigned int ss_vendor,
 189                                         unsigned int ss_device,
 190                                         const struct pci_dev *from)
 191 {
 192         struct list_head *n;
 193         struct pci_dev *dev;
 194
 195         WARN_ON(in_interrupt());
 196         down_read(&pci_bus_sem);
 197         n = from ? from->global_list.next : pci_devices.next;
 198
 199         while (n && (n != &pci_devices)) {
 200                 dev = pci_dev_g(n);
 201                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 202                     (device == PCI_ANY_ID || dev->device == device) &&
 203                     (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
 204                     (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
 205                         goto exit;
 206                 n = n->next;
 207         }
 208         dev = NULL;
 209 exit:
 210         up_read(&pci_bus_sem);
 211         return dev;
 212 }
 213
 214 /**
 215  * pci_find_device - begin or continue searching for a PCI device by vendor/device id
 216  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 217  * @device: PCI 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 and @device, a pointer to its device structure is
 222  * returned.  Otherwise, %NULL is returned.
 223  * A new search is initiated by passing %NULL as the @from argument.
 224  * Otherwise if @from is not %NULL, searches continue from next device
 225  * on the global list.
 226  *
 227  * NOTE: Do not use this function any more; use pci_get_device() instead, as
 228  * the PCI device returned by this function can disappear at any moment in
 229  * time.
 230  */
 231 struct pci_dev *
 232 pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from)
 233 {
 234         return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
 235 }
 236
 237 /**
 238  * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
 239  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 240  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 241  * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
 242  * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
 243  * @from: Previous PCI device found in search, or %NULL for new search.
 244  *
 245  * Iterates through the list of known PCI devices.  If a PCI device is found
 246  * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
 247  * device structure is returned, and the reference count to the device is
 248  * incremented.  Otherwise, %NULL is returned.  A new search is initiated by
 249  * passing %NULL as the @from argument.  Otherwise if @from is not %NULL,
 250  * searches continue from next device on the global list.
 251  * The reference count for @from is always decremented if it is not %NULL.
 252  */
 253 struct pci_dev *
 254 pci_get_subsys(unsigned int vendor, unsigned int device,
 255                unsigned int ss_vendor, unsigned int ss_device,
 256                struct pci_dev *from)
 257 {
 258         struct list_head *n;
 259         struct pci_dev *dev;
 260
 261         WARN_ON(in_interrupt());
 262         down_read(&pci_bus_sem);
 263         n = from ? from->global_list.next : pci_devices.next;
 264
 265         while (n && (n != &pci_devices)) {
 266                 dev = pci_dev_g(n);
 267                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 268                     (device == PCI_ANY_ID || dev->device == device) &&
 269                     (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
 270                     (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
 271                         goto exit;
 272                 n = n->next;
 273         }
 274         dev = NULL;
 275 exit:
 276         dev = pci_dev_get(dev);
 277         up_read(&pci_bus_sem);
 278         pci_dev_put(from);
 279         return dev;
 280 }
 281
 282 /**
 283  * pci_get_device - begin or continue searching for a PCI device by vendor/device id
 284  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 285  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 286  * @from: Previous PCI device found in search, or %NULL for new search.
 287  *
 288  * Iterates through the list of known PCI devices.  If a PCI device is
 289  * found with a matching @vendor and @device, the reference count to the
 290  * device is incremented and a pointer to its device structure is returned.
 291  * Otherwise, %NULL is returned.  A new search is initiated by passing %NULL
 292  * as the @from argument.  Otherwise if @from is not %NULL, searches continue
 293  * from next device on the global list.  The reference count for @from is
 294  * always decremented if it is not %NULL.
 295  */
 296 struct pci_dev *
 297 pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
 298 {
 299         return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
 300 }
 301
 302 /**
 303  * pci_get_device_reverse - begin or continue searching for a PCI device by vendor/device id
 304  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 305  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 306  * @from: Previous PCI device found in search, or %NULL for new search.
 307  *
 308  * Iterates through the list of known PCI devices in the reverse order of
 309  * pci_get_device.
 310  * If a PCI device is found with a matching @vendor and @device, the reference
 311  * count to the  device is incremented and a pointer to its device structure
 312  * is returned Otherwise, %NULL is returned.  A new search is initiated by
 313  * passing %NULL as the @from argument.  Otherwise if @from is not %NULL,
 314  * searches continue from next device on the global list.  The reference
 315  * count for @from is always decremented if it is not %NULL.
 316  */
 317 struct pci_dev *
 318 pci_get_device_reverse(unsigned int vendor, unsigned int device, struct pci_dev *from)
 319 {
 320         struct list_head *n;
 321         struct pci_dev *dev;
 322
 323         WARN_ON(in_interrupt());
 324         down_read(&pci_bus_sem);
 325         n = from ? from->global_list.prev : pci_devices.prev;
 326
 327         while (n && (n != &pci_devices)) {
 328                 dev = pci_dev_g(n);
 329                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 330                     (device == PCI_ANY_ID || dev->device == device))
 331                         goto exit;
 332                 n = n->prev;
 333         }
 334         dev = NULL;
 335 exit:
 336         dev = pci_dev_get(dev);
 337         up_read(&pci_bus_sem);
 338         pci_dev_put(from);
 339         return dev;
 340 }
 341
 342 /**
 343  * pci_find_device_reverse - begin or continue searching for a PCI device by vendor/device id
 344  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 345  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 346  * @from: Previous PCI device found in search, or %NULL for new search.
 347  *
 348  * Iterates through the list of known PCI devices in the reverse order of
 349  * pci_find_device().
 350  * If a PCI device is found with a matching @vendor and @device, a pointer to
 351  * its device structure is returned.  Otherwise, %NULL is returned.
 352  * A new search is initiated by passing %NULL as the @from argument.
 353  * Otherwise if @from is not %NULL, searches continue from previous device
 354  * on the global list.
 355  */
 356 struct pci_dev *
 357 pci_find_device_reverse(unsigned int vendor, unsigned int device, const struct pci_dev *from)
 358 {
 359         struct list_head *n;
 360         struct pci_dev *dev;
 361
 362         WARN_ON(in_interrupt());
 363         down_read(&pci_bus_sem);
 364         n = from ? from->global_list.prev : pci_devices.prev;
 365
 366         while (n && (n != &pci_devices)) {
 367                 dev = pci_dev_g(n);
 368                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 369                     (device == PCI_ANY_ID || dev->device == device))
 370                         goto exit;
 371                 n = n->prev;
 372         }
 373         dev = NULL;
 374 exit:
 375         up_read(&pci_bus_sem);
 376         return dev;
 377 }
 378
 379 /**
 380  * pci_get_class - begin or continue searching for a PCI device by class
 381  * @class: search for a PCI device with this class designation
 382  * @from: Previous PCI device found in search, or %NULL for new search.
 383  *
 384  * Iterates through the list of known PCI devices.  If a PCI device is
 385  * found with a matching @class, the reference count to the device is
 386  * incremented and a pointer to its device structure is returned.
 387  * Otherwise, %NULL is returned.
 388  * A new search is initiated by passing %NULL as the @from argument.
 389  * Otherwise if @from is not %NULL, searches continue from next device
 390  * on the global list.  The reference count for @from is always decremented
 391  * if it is not %NULL.
 392  */
 393 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
 394 {
 395         struct list_head *n;
 396         struct pci_dev *dev;
 397
 398         WARN_ON(in_interrupt());
 399         down_read(&pci_bus_sem);
 400         n = from ? from->global_list.next : pci_devices.next;
 401
 402         while (n && (n != &pci_devices)) {
 403                 dev = pci_dev_g(n);
 404                 if (dev->class == class)
 405                         goto exit;
 406                 n = n->next;
 407         }
 408         dev = NULL;
 409 exit:
 410         dev = pci_dev_get(dev);
 411         up_read(&pci_bus_sem);
 412         pci_dev_put(from);
 413         return dev;
 414 }
 415
 416 const struct pci_device_id *pci_find_present(const struct pci_device_id *ids)
 417 {
 418         struct pci_dev *dev;
 419         struct pci_device_id * found = NULL;
 420
 421         WARN_ON(in_interrupt());
 422         down_read(&pci_bus_sem);
 423         while (ids->vendor || ids->subvendor || ids->class_mask) {
 424                 list_for_each_entry(dev, &pci_devices, global_list) {
 425                         if ((found = pci_match_one_device(ids, dev)) != NULL)
 426                                 break;
 427                 }
 428                 ids++;
 429         }
 430         up_read(&pci_bus_sem);
 431         return found;
 432 }
 433
 434 /**
 435  * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
 436  * @ids: A pointer to a null terminated list of struct pci_device_id structures
 437  * that describe the type of PCI device the caller is trying to find.
 438  *
 439  * Obvious fact: You do not have a reference to any device that might be found
 440  * by this function, so if that device is removed from the system right after
 441  * this function is finished, the value will be stale.  Use this function to
 442  * find devices that are usually built into a system, or for a general hint as
 443  * to if another device happens to be present at this specific moment in time.
 444  */
 445
 446 int pci_dev_present(const struct pci_device_id *ids)
 447 {
 448         return pci_find_present(ids) == NULL ? 0 : 1;
 449 }
 450
 451 EXPORT_SYMBOL(pci_dev_present);
 452 EXPORT_SYMBOL(pci_find_present);
 453
 454 EXPORT_SYMBOL(pci_find_device);
 455 EXPORT_SYMBOL(pci_find_device_reverse);
 456 EXPORT_SYMBOL(pci_find_slot);
 457 /* For boot time work */
 458 EXPORT_SYMBOL(pci_find_bus);
 459 EXPORT_SYMBOL(pci_find_next_bus);
 460 /* For everyone */
 461 EXPORT_SYMBOL(pci_get_device);
 462 EXPORT_SYMBOL(pci_get_device_reverse);
 463 EXPORT_SYMBOL(pci_get_subsys);
 464 EXPORT_SYMBOL(pci_get_slot);
 465 EXPORT_SYMBOL(pci_get_bus_and_slot);
 466 EXPORT_SYMBOL(pci_get_class);