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1da177e4 LT |
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 | ||
d71374da | 16 | DECLARE_RWSEM(pci_bus_sem); |
994a65e2 KA |
17 | /* |
18 | * find the upstream PCIE-to-PCI bridge of a PCI device | |
19 | * if the device is PCIE, return NULL | |
20 | * if the device isn't connected to a PCIE bridge (that is its parent is a | |
21 | * legacy PCI bridge and the bridge is directly connected to bus 0), return its | |
22 | * parent | |
23 | */ | |
24 | struct pci_dev * | |
25 | pci_find_upstream_pcie_bridge(struct pci_dev *pdev) | |
26 | { | |
27 | struct pci_dev *tmp = NULL; | |
28 | ||
29 | if (pdev->is_pcie) | |
30 | return NULL; | |
31 | while (1) { | |
32 | if (!pdev->bus->self) | |
33 | break; | |
34 | pdev = pdev->bus->self; | |
35 | /* a p2p bridge */ | |
36 | if (!pdev->is_pcie) { | |
37 | tmp = pdev; | |
38 | continue; | |
39 | } | |
40 | /* PCI device should connect to a PCIE bridge */ | |
41 | if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) { | |
42 | /* Busted hardware? */ | |
43 | WARN_ON_ONCE(1); | |
44 | return NULL; | |
45 | } | |
46 | return pdev; | |
47 | } | |
48 | ||
49 | return tmp; | |
50 | } | |
1da177e4 | 51 | |
96bde06a | 52 | static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr) |
1da177e4 LT |
53 | { |
54 | struct pci_bus* child; | |
55 | struct list_head *tmp; | |
56 | ||
57 | if(bus->number == busnr) | |
58 | return bus; | |
59 | ||
60 | list_for_each(tmp, &bus->children) { | |
61 | child = pci_do_find_bus(pci_bus_b(tmp), busnr); | |
62 | if(child) | |
63 | return child; | |
64 | } | |
65 | return NULL; | |
66 | } | |
67 | ||
68 | /** | |
69 | * pci_find_bus - locate PCI bus from a given domain and bus number | |
70 | * @domain: number of PCI domain to search | |
71 | * @busnr: number of desired PCI bus | |
72 | * | |
73 | * Given a PCI bus number and domain number, the desired PCI bus is located | |
74 | * in the global list of PCI buses. If the bus is found, a pointer to its | |
75 | * data structure is returned. If no bus is found, %NULL is returned. | |
76 | */ | |
c8439cfc | 77 | struct pci_bus * pci_find_bus(int domain, int busnr) |
1da177e4 LT |
78 | { |
79 | struct pci_bus *bus = NULL; | |
80 | struct pci_bus *tmp_bus; | |
81 | ||
82 | while ((bus = pci_find_next_bus(bus)) != NULL) { | |
83 | if (pci_domain_nr(bus) != domain) | |
84 | continue; | |
85 | tmp_bus = pci_do_find_bus(bus, busnr); | |
86 | if (tmp_bus) | |
87 | return tmp_bus; | |
88 | } | |
89 | return NULL; | |
90 | } | |
91 | ||
92 | /** | |
93 | * pci_find_next_bus - begin or continue searching for a PCI bus | |
94 | * @from: Previous PCI bus found, or %NULL for new search. | |
95 | * | |
96 | * Iterates through the list of known PCI busses. A new search is | |
d75763d2 | 97 | * initiated by passing %NULL as the @from argument. Otherwise if |
1da177e4 LT |
98 | * @from is not %NULL, searches continue from next device on the |
99 | * global list. | |
100 | */ | |
101 | struct pci_bus * | |
102 | pci_find_next_bus(const struct pci_bus *from) | |
103 | { | |
104 | struct list_head *n; | |
105 | struct pci_bus *b = NULL; | |
106 | ||
107 | WARN_ON(in_interrupt()); | |
d71374da | 108 | down_read(&pci_bus_sem); |
1da177e4 LT |
109 | n = from ? from->node.next : pci_root_buses.next; |
110 | if (n != &pci_root_buses) | |
111 | b = pci_bus_b(n); | |
d71374da | 112 | up_read(&pci_bus_sem); |
1da177e4 LT |
113 | return b; |
114 | } | |
115 | ||
bd3989e0 JG |
116 | #ifdef CONFIG_PCI_LEGACY |
117 | ||
1da177e4 LT |
118 | /** |
119 | * pci_find_slot - locate PCI device from a given PCI slot | |
120 | * @bus: number of PCI bus on which desired PCI device resides | |
121 | * @devfn: encodes number of PCI slot in which the desired PCI | |
122 | * device resides and the logical device number within that slot | |
123 | * in case of multi-function devices. | |
124 | * | |
125 | * Given a PCI bus and slot/function number, the desired PCI device | |
126 | * is located in system global list of PCI devices. If the device | |
127 | * is found, a pointer to its data structure is returned. If no | |
128 | * device is found, %NULL is returned. | |
129 | */ | |
130 | struct pci_dev * | |
131 | pci_find_slot(unsigned int bus, unsigned int devfn) | |
132 | { | |
133 | struct pci_dev *dev = NULL; | |
134 | ||
135 | while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { | |
136 | if (dev->bus->number == bus && dev->devfn == devfn) | |
137 | return dev; | |
138 | } | |
139 | return NULL; | |
140 | } | |
141 | ||
bd3989e0 JG |
142 | #endif /* CONFIG_PCI_LEGACY */ |
143 | ||
1da177e4 LT |
144 | /** |
145 | * pci_get_slot - locate PCI device for a given PCI slot | |
146 | * @bus: PCI bus on which desired PCI device resides | |
147 | * @devfn: encodes number of PCI slot in which the desired PCI | |
148 | * device resides and the logical device number within that slot | |
149 | * in case of multi-function devices. | |
150 | * | |
151 | * Given a PCI bus and slot/function number, the desired PCI device | |
152 | * is located in the list of PCI devices. | |
153 | * If the device is found, its reference count is increased and this | |
154 | * function returns a pointer to its data structure. The caller must | |
155 | * decrement the reference count by calling pci_dev_put(). | |
156 | * If no device is found, %NULL is returned. | |
157 | */ | |
158 | struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn) | |
159 | { | |
160 | struct list_head *tmp; | |
161 | struct pci_dev *dev; | |
162 | ||
163 | WARN_ON(in_interrupt()); | |
d71374da | 164 | down_read(&pci_bus_sem); |
1da177e4 LT |
165 | |
166 | list_for_each(tmp, &bus->devices) { | |
167 | dev = pci_dev_b(tmp); | |
168 | if (dev->devfn == devfn) | |
169 | goto out; | |
170 | } | |
171 | ||
172 | dev = NULL; | |
173 | out: | |
174 | pci_dev_get(dev); | |
d71374da | 175 | up_read(&pci_bus_sem); |
1da177e4 LT |
176 | return dev; |
177 | } | |
178 | ||
29f3eb64 | 179 | /** |
5463d9f0 | 180 | * pci_get_bus_and_slot - locate PCI device from a given PCI bus & slot |
29f3eb64 AC |
181 | * @bus: number of PCI bus on which desired PCI device resides |
182 | * @devfn: encodes number of PCI slot in which the desired PCI | |
183 | * device resides and the logical device number within that slot | |
184 | * in case of multi-function devices. | |
185 | * | |
5463d9f0 RD |
186 | * Note: the bus/slot search is limited to PCI domain (segment) 0. |
187 | * | |
29f3eb64 AC |
188 | * Given a PCI bus and slot/function number, the desired PCI device |
189 | * is located in system global list of PCI devices. If the device | |
190 | * is found, a pointer to its data structure is returned. If no | |
191 | * device is found, %NULL is returned. The returned device has its | |
192 | * reference count bumped by one. | |
193 | */ | |
194 | ||
195 | struct pci_dev * pci_get_bus_and_slot(unsigned int bus, unsigned int devfn) | |
196 | { | |
197 | struct pci_dev *dev = NULL; | |
198 | ||
199 | while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { | |
5463d9f0 RD |
200 | if (pci_domain_nr(dev->bus) == 0 && |
201 | (dev->bus->number == bus && dev->devfn == devfn)) | |
29f3eb64 AC |
202 | return dev; |
203 | } | |
204 | return NULL; | |
205 | } | |
206 | ||
bd3989e0 | 207 | #ifdef CONFIG_PCI_LEGACY |
1da177e4 LT |
208 | /** |
209 | * pci_find_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id | |
210 | * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
211 | * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids | |
212 | * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
213 | * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids | |
214 | * @from: Previous PCI device found in search, or %NULL for new search. | |
215 | * | |
216 | * Iterates through the list of known PCI devices. If a PCI device is | |
d75763d2 RD |
217 | * found with a matching @vendor, @device, @ss_vendor and @ss_device, a |
218 | * pointer to its device structure is returned. Otherwise, %NULL is returned. | |
219 | * A new search is initiated by passing %NULL as the @from argument. | |
220 | * Otherwise if @from is not %NULL, searches continue from next device | |
221 | * on the global list. | |
1da177e4 | 222 | * |
d75763d2 RD |
223 | * NOTE: Do not use this function any more; use pci_get_subsys() instead, as |
224 | * the PCI device returned by this function can disappear at any moment in | |
1da177e4 LT |
225 | * time. |
226 | */ | |
227 | static struct pci_dev * pci_find_subsys(unsigned int vendor, | |
228 | unsigned int device, | |
229 | unsigned int ss_vendor, | |
230 | unsigned int ss_device, | |
231 | const struct pci_dev *from) | |
232 | { | |
233 | struct list_head *n; | |
234 | struct pci_dev *dev; | |
235 | ||
236 | WARN_ON(in_interrupt()); | |
6ae4adf5 AB |
237 | |
238 | /* | |
239 | * pci_find_subsys() can be called on the ide_setup() path, super-early | |
240 | * in boot. But the down_read() will enable local interrupts, which | |
241 | * can cause some machines to crash. So here we detect and flag that | |
242 | * situation and bail out early. | |
243 | */ | |
35ef63f6 | 244 | if (unlikely(no_pci_devices())) |
6ae4adf5 | 245 | return NULL; |
d71374da | 246 | down_read(&pci_bus_sem); |
1da177e4 LT |
247 | n = from ? from->global_list.next : pci_devices.next; |
248 | ||
249 | while (n && (n != &pci_devices)) { | |
250 | dev = pci_dev_g(n); | |
251 | if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && | |
252 | (device == PCI_ANY_ID || dev->device == device) && | |
253 | (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) && | |
254 | (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device)) | |
255 | goto exit; | |
256 | n = n->next; | |
257 | } | |
258 | dev = NULL; | |
259 | exit: | |
d71374da | 260 | up_read(&pci_bus_sem); |
1da177e4 LT |
261 | return dev; |
262 | } | |
263 | ||
264 | /** | |
265 | * pci_find_device - begin or continue searching for a PCI device by vendor/device id | |
266 | * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
267 | * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids | |
268 | * @from: Previous PCI device found in search, or %NULL for new search. | |
269 | * | |
d75763d2 RD |
270 | * Iterates through the list of known PCI devices. If a PCI device is found |
271 | * with a matching @vendor and @device, a pointer to its device structure is | |
1da177e4 | 272 | * returned. Otherwise, %NULL is returned. |
d75763d2 RD |
273 | * A new search is initiated by passing %NULL as the @from argument. |
274 | * Otherwise if @from is not %NULL, searches continue from next device | |
275 | * on the global list. | |
1da177e4 | 276 | * |
d75763d2 RD |
277 | * NOTE: Do not use this function any more; use pci_get_device() instead, as |
278 | * the PCI device returned by this function can disappear at any moment in | |
1da177e4 LT |
279 | * time. |
280 | */ | |
281 | struct pci_dev * | |
282 | pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from) | |
283 | { | |
284 | return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); | |
285 | } | |
bd3989e0 | 286 | #endif /* CONFIG_PCI_LEGACY */ |
1da177e4 LT |
287 | |
288 | /** | |
289 | * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id | |
290 | * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
291 | * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids | |
292 | * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
293 | * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids | |
294 | * @from: Previous PCI device found in search, or %NULL for new search. | |
295 | * | |
d75763d2 RD |
296 | * Iterates through the list of known PCI devices. If a PCI device is found |
297 | * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its | |
1da177e4 LT |
298 | * device structure is returned, and the reference count to the device is |
299 | * incremented. Otherwise, %NULL is returned. A new search is initiated by | |
d75763d2 | 300 | * passing %NULL as the @from argument. Otherwise if @from is not %NULL, |
1da177e4 LT |
301 | * searches continue from next device on the global list. |
302 | * The reference count for @from is always decremented if it is not %NULL. | |
303 | */ | |
304 | struct pci_dev * | |
305 | pci_get_subsys(unsigned int vendor, unsigned int device, | |
306 | unsigned int ss_vendor, unsigned int ss_device, | |
307 | struct pci_dev *from) | |
308 | { | |
309 | struct list_head *n; | |
310 | struct pci_dev *dev; | |
311 | ||
312 | WARN_ON(in_interrupt()); | |
6ae4adf5 AB |
313 | |
314 | /* | |
315 | * pci_get_subsys() can potentially be called by drivers super-early | |
316 | * in boot. But the down_read() will enable local interrupts, which | |
317 | * can cause some machines to crash. So here we detect and flag that | |
318 | * situation and bail out early. | |
319 | */ | |
35ef63f6 | 320 | if (unlikely(no_pci_devices())) |
6ae4adf5 | 321 | return NULL; |
d71374da | 322 | down_read(&pci_bus_sem); |
1da177e4 LT |
323 | n = from ? from->global_list.next : pci_devices.next; |
324 | ||
325 | while (n && (n != &pci_devices)) { | |
326 | dev = pci_dev_g(n); | |
327 | if ((vendor == PCI_ANY_ID || dev->vendor == vendor) && | |
328 | (device == PCI_ANY_ID || dev->device == device) && | |
329 | (ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) && | |
330 | (ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device)) | |
331 | goto exit; | |
332 | n = n->next; | |
333 | } | |
334 | dev = NULL; | |
335 | exit: | |
1da177e4 | 336 | dev = pci_dev_get(dev); |
d71374da | 337 | up_read(&pci_bus_sem); |
b89b7ea0 | 338 | pci_dev_put(from); |
1da177e4 LT |
339 | return dev; |
340 | } | |
341 | ||
342 | /** | |
343 | * pci_get_device - 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. If a PCI device is | |
349 | * found with a matching @vendor and @device, the reference count to the | |
350 | * device is incremented and a pointer to its device structure is returned. | |
351 | * Otherwise, %NULL is returned. A new search is initiated by passing %NULL | |
d75763d2 | 352 | * as the @from argument. Otherwise if @from is not %NULL, searches continue |
1da177e4 LT |
353 | * from next device on the global list. The reference count for @from is |
354 | * always decremented if it is not %NULL. | |
355 | */ | |
356 | struct pci_dev * | |
357 | pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from) | |
358 | { | |
359 | return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); | |
360 | } | |
361 | ||
1da177e4 LT |
362 | /** |
363 | * pci_get_class - begin or continue searching for a PCI device by class | |
364 | * @class: search for a PCI device with this class designation | |
365 | * @from: Previous PCI device found in search, or %NULL for new search. | |
366 | * | |
367 | * Iterates through the list of known PCI devices. If a PCI device is | |
368 | * found with a matching @class, the reference count to the device is | |
369 | * incremented and a pointer to its device structure is returned. | |
370 | * Otherwise, %NULL is returned. | |
d75763d2 | 371 | * A new search is initiated by passing %NULL as the @from argument. |
1da177e4 LT |
372 | * Otherwise if @from is not %NULL, searches continue from next device |
373 | * on the global list. The reference count for @from is always decremented | |
374 | * if it is not %NULL. | |
375 | */ | |
376 | struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) | |
377 | { | |
378 | struct list_head *n; | |
379 | struct pci_dev *dev; | |
380 | ||
381 | WARN_ON(in_interrupt()); | |
d71374da | 382 | down_read(&pci_bus_sem); |
1da177e4 LT |
383 | n = from ? from->global_list.next : pci_devices.next; |
384 | ||
385 | while (n && (n != &pci_devices)) { | |
386 | dev = pci_dev_g(n); | |
387 | if (dev->class == class) | |
388 | goto exit; | |
389 | n = n->next; | |
390 | } | |
391 | dev = NULL; | |
392 | exit: | |
1da177e4 | 393 | dev = pci_dev_get(dev); |
d71374da | 394 | up_read(&pci_bus_sem); |
b89b7ea0 | 395 | pci_dev_put(from); |
1da177e4 LT |
396 | return dev; |
397 | } | |
398 | ||
448432c4 GKH |
399 | /** |
400 | * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not. | |
401 | * @ids: A pointer to a null terminated list of struct pci_device_id structures | |
402 | * that describe the type of PCI device the caller is trying to find. | |
403 | * | |
404 | * Obvious fact: You do not have a reference to any device that might be found | |
405 | * by this function, so if that device is removed from the system right after | |
406 | * this function is finished, the value will be stale. Use this function to | |
407 | * find devices that are usually built into a system, or for a general hint as | |
408 | * to if another device happens to be present at this specific moment in time. | |
409 | */ | |
410 | int pci_dev_present(const struct pci_device_id *ids) | |
d86f90f9 AC |
411 | { |
412 | struct pci_dev *dev; | |
1597cacb | 413 | const struct pci_device_id *found = NULL; |
d86f90f9 AC |
414 | |
415 | WARN_ON(in_interrupt()); | |
416 | down_read(&pci_bus_sem); | |
417 | while (ids->vendor || ids->subvendor || ids->class_mask) { | |
418 | list_for_each_entry(dev, &pci_devices, global_list) { | |
419 | if ((found = pci_match_one_device(ids, dev)) != NULL) | |
3c92c57a | 420 | goto exit; |
d86f90f9 AC |
421 | } |
422 | ids++; | |
423 | } | |
3c92c57a | 424 | exit: |
d86f90f9 | 425 | up_read(&pci_bus_sem); |
448432c4 GKH |
426 | if (found) |
427 | return 1; | |
428 | return 0; | |
1da177e4 LT |
429 | } |
430 | EXPORT_SYMBOL(pci_dev_present); | |
431 | ||
bd3989e0 | 432 | #ifdef CONFIG_PCI_LEGACY |
1da177e4 | 433 | EXPORT_SYMBOL(pci_find_device); |
1da177e4 | 434 | EXPORT_SYMBOL(pci_find_slot); |
bd3989e0 JG |
435 | #endif /* CONFIG_PCI_LEGACY */ |
436 | ||
29f3eb64 AC |
437 | /* For boot time work */ |
438 | EXPORT_SYMBOL(pci_find_bus); | |
439 | EXPORT_SYMBOL(pci_find_next_bus); | |
440 | /* For everyone */ | |
1da177e4 LT |
441 | EXPORT_SYMBOL(pci_get_device); |
442 | EXPORT_SYMBOL(pci_get_subsys); | |
443 | EXPORT_SYMBOL(pci_get_slot); | |
29f3eb64 | 444 | EXPORT_SYMBOL(pci_get_bus_and_slot); |
1da177e4 | 445 | EXPORT_SYMBOL(pci_get_class); |