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 * __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 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);