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
 197         /*
 198          * pci_find_subsys() can be called on the ide_setup() path, super-early
 199          * in boot.  But the down_read() will enable local interrupts, which
 200          * can cause some machines to crash.  So here we detect and flag that
 201          * situation and bail out early.
 202          */
 203         if (unlikely(list_empty(&pci_devices))) {
 204                 printk(KERN_INFO "pci_find_subsys() called while pci_devices "
 205                                 "is still empty\n");
 206                 return NULL;
 207         }
 208         down_read(&pci_bus_sem);
 209         n = from ? from->global_list.next : pci_devices.next;
 210
 211         while (n && (n != &pci_devices)) {
 212                 dev = pci_dev_g(n);
 213                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 214                     (device == PCI_ANY_ID || dev->device == device) &&
 215                     (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
 216                     (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
 217                         goto exit;
 218                 n = n->next;
 219         }
 220         dev = NULL;
 221 exit:
 222         up_read(&pci_bus_sem);
 223         return dev;
 224 }
 225
 226 /**
 227  * pci_find_device - begin or continue searching for a PCI device by vendor/device id
 228  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 229  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 230  * @from: Previous PCI device found in search, or %NULL for new search.
 231  *
 232  * Iterates through the list of known PCI devices.  If a PCI device is found
 233  * with a matching @vendor and @device, a pointer to its device structure is
 234  * returned.  Otherwise, %NULL is returned.
 235  * A new search is initiated by passing %NULL as the @from argument.
 236  * Otherwise if @from is not %NULL, searches continue from next device
 237  * on the global list.
 238  *
 239  * NOTE: Do not use this function any more; use pci_get_device() instead, as
 240  * the PCI device returned by this function can disappear at any moment in
 241  * time.
 242  */
 243 struct pci_dev *
 244 pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from)
 245 {
 246         return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
 247 }
 248
 249 /**
 250  * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
 251  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 252  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 253  * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
 254  * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
 255  * @from: Previous PCI device found in search, or %NULL for new search.
 256  *
 257  * Iterates through the list of known PCI devices.  If a PCI device is found
 258  * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
 259  * device structure is returned, and the reference count to the device is
 260  * incremented.  Otherwise, %NULL is returned.  A new search is initiated by
 261  * passing %NULL as the @from argument.  Otherwise if @from is not %NULL,
 262  * searches continue from next device on the global list.
 263  * The reference count for @from is always decremented if it is not %NULL.
 264  */
 265 struct pci_dev *
 266 pci_get_subsys(unsigned int vendor, unsigned int device,
 267                unsigned int ss_vendor, unsigned int ss_device,
 268                struct pci_dev *from)
 269 {
 270         struct list_head *n;
 271         struct pci_dev *dev;
 272
 273         WARN_ON(in_interrupt());
 274
 275         /*
 276          * pci_get_subsys() can potentially be called by drivers super-early
 277          * in boot.  But the down_read() will enable local interrupts, which
 278          * can cause some machines to crash.  So here we detect and flag that
 279          * situation and bail out early.
 280          */
 281         if (unlikely(list_empty(&pci_devices))) {
 282                 printk(KERN_NOTICE "pci_get_subsys() called while pci_devices "
 283                                 "is still empty\n");
 284                 return NULL;
 285         }
 286         down_read(&pci_bus_sem);
 287         n = from ? from->global_list.next : pci_devices.next;
 288
 289         while (n && (n != &pci_devices)) {
 290                 dev = pci_dev_g(n);
 291                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 292                     (device == PCI_ANY_ID || dev->device == device) &&
 293                     (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
 294                     (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
 295                         goto exit;
 296                 n = n->next;
 297         }
 298         dev = NULL;
 299 exit:
 300         dev = pci_dev_get(dev);
 301         up_read(&pci_bus_sem);
 302         pci_dev_put(from);
 303         return dev;
 304 }
 305
 306 /**
 307  * pci_get_device - begin or continue searching for a PCI device by vendor/device id
 308  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 309  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 310  * @from: Previous PCI device found in search, or %NULL for new search.
 311  *
 312  * Iterates through the list of known PCI devices.  If a PCI device is
 313  * found with a matching @vendor and @device, the reference count to the
 314  * device is incremented and a pointer to its device structure is returned.
 315  * Otherwise, %NULL is returned.  A new search is initiated by passing %NULL
 316  * as the @from argument.  Otherwise if @from is not %NULL, searches continue
 317  * from next device on the global list.  The reference count for @from is
 318  * always decremented if it is not %NULL.
 319  */
 320 struct pci_dev *
 321 pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
 322 {
 323         return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
 324 }
 325
 326 /**
 327  * pci_get_device_reverse - begin or continue searching for a PCI device by vendor/device id
 328  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 329  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 330  * @from: Previous PCI device found in search, or %NULL for new search.
 331  *
 332  * Iterates through the list of known PCI devices in the reverse order of
 333  * pci_get_device.
 334  * If a PCI device is found with a matching @vendor and @device, the reference
 335  * count to the  device is incremented and a pointer to its device structure
 336  * is returned Otherwise, %NULL is returned.  A new search is initiated by
 337  * passing %NULL as the @from argument.  Otherwise if @from is not %NULL,
 338  * searches continue from next device on the global list.  The reference
 339  * count for @from is always decremented if it is not %NULL.
 340  */
 341 struct pci_dev *
 342 pci_get_device_reverse(unsigned int vendor, unsigned int device, struct pci_dev *from)
 343 {
 344         struct list_head *n;
 345         struct pci_dev *dev;
 346
 347         WARN_ON(in_interrupt());
 348         down_read(&pci_bus_sem);
 349         n = from ? from->global_list.prev : pci_devices.prev;
 350
 351         while (n && (n != &pci_devices)) {
 352                 dev = pci_dev_g(n);
 353                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 354                     (device == PCI_ANY_ID || dev->device == device))
 355                         goto exit;
 356                 n = n->prev;
 357         }
 358         dev = NULL;
 359 exit:
 360         dev = pci_dev_get(dev);
 361         up_read(&pci_bus_sem);
 362         pci_dev_put(from);
 363         return dev;
 364 }
 365
 366 /**
 367  * pci_find_device_reverse - begin or continue searching for a PCI device by vendor/device id
 368  * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 369  * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 370  * @from: Previous PCI device found in search, or %NULL for new search.
 371  *
 372  * Iterates through the list of known PCI devices in the reverse order of
 373  * pci_find_device().
 374  * If a PCI device is found with a matching @vendor and @device, a pointer to
 375  * its device structure is returned.  Otherwise, %NULL is returned.
 376  * A new search is initiated by passing %NULL as the @from argument.
 377  * Otherwise if @from is not %NULL, searches continue from previous device
 378  * on the global list.
 379  */
 380 struct pci_dev *
 381 pci_find_device_reverse(unsigned int vendor, unsigned int device, const struct pci_dev *from)
 382 {
 383         struct list_head *n;
 384         struct pci_dev *dev;
 385
 386         WARN_ON(in_interrupt());
 387         down_read(&pci_bus_sem);
 388         n = from ? from->global_list.prev : pci_devices.prev;
 389
 390         while (n && (n != &pci_devices)) {
 391                 dev = pci_dev_g(n);
 392                 if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
 393                     (device == PCI_ANY_ID || dev->device == device))
 394                         goto exit;
 395                 n = n->prev;
 396         }
 397         dev = NULL;
 398 exit:
 399         up_read(&pci_bus_sem);
 400         return dev;
 401 }
 402
 403 /**
 404  * pci_get_class - begin or continue searching for a PCI device by class
 405  * @class: search for a PCI device with this class designation
 406  * @from: Previous PCI device found in search, or %NULL for new search.
 407  *
 408  * Iterates through the list of known PCI devices.  If a PCI device is
 409  * found with a matching @class, the reference count to the device is
 410  * incremented and a pointer to its device structure is returned.
 411  * Otherwise, %NULL is returned.
 412  * A new search is initiated by passing %NULL as the @from argument.
 413  * Otherwise if @from is not %NULL, searches continue from next device
 414  * on the global list.  The reference count for @from is always decremented
 415  * if it is not %NULL.
 416  */
 417 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
 418 {
 419         struct list_head *n;
 420         struct pci_dev *dev;
 421
 422         WARN_ON(in_interrupt());
 423         down_read(&pci_bus_sem);
 424         n = from ? from->global_list.next : pci_devices.next;
 425
 426         while (n && (n != &pci_devices)) {
 427                 dev = pci_dev_g(n);
 428                 if (dev->class == class)
 429                         goto exit;
 430                 n = n->next;
 431         }
 432         dev = NULL;
 433 exit:
 434         dev = pci_dev_get(dev);
 435         up_read(&pci_bus_sem);
 436         pci_dev_put(from);
 437         return dev;
 438 }
 439
 440 const struct pci_device_id *pci_find_present(const struct pci_device_id *ids)
 441 {
 442         struct pci_dev *dev;
 443         const struct pci_device_id *found = NULL;
 444
 445         WARN_ON(in_interrupt());
 446         down_read(&pci_bus_sem);
 447         while (ids->vendor || ids->subvendor || ids->class_mask) {
 448                 list_for_each_entry(dev, &pci_devices, global_list) {
 449                         if ((found = pci_match_one_device(ids, dev)) != NULL)
 450                                 break;
 451                 }
 452                 ids++;
 453         }
 454         up_read(&pci_bus_sem);
 455         return found;
 456 }
 457
 458 /**
 459  * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
 460  * @ids: A pointer to a null terminated list of struct pci_device_id structures
 461  * that describe the type of PCI device the caller is trying to find.
 462  *
 463  * Obvious fact: You do not have a reference to any device that might be found
 464  * by this function, so if that device is removed from the system right after
 465  * this function is finished, the value will be stale.  Use this function to
 466  * find devices that are usually built into a system, or for a general hint as
 467  * to if another device happens to be present at this specific moment in time.
 468  */
 469 int pci_dev_present(const struct pci_device_id *ids)
 470 {
 471         return pci_find_present(ids) == NULL ? 0 : 1;
 472 }
 473
 474 EXPORT_SYMBOL(pci_dev_present);
 475 EXPORT_SYMBOL(pci_find_present);
 476
 477 EXPORT_SYMBOL(pci_find_device);
 478 EXPORT_SYMBOL(pci_find_device_reverse);
 479 EXPORT_SYMBOL(pci_find_slot);
 480 /* For boot time work */
 481 EXPORT_SYMBOL(pci_find_bus);
 482 EXPORT_SYMBOL(pci_find_next_bus);
 483 /* For everyone */
 484 EXPORT_SYMBOL(pci_get_device);
 485 EXPORT_SYMBOL(pci_get_device_reverse);
 486 EXPORT_SYMBOL(pci_get_subsys);
 487 EXPORT_SYMBOL(pci_get_slot);
 488 EXPORT_SYMBOL(pci_get_bus_and_slot);
 489 EXPORT_SYMBOL(pci_get_class);