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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 | 17 | /* |
45e829ea | 18 | * find the upstream PCIe-to-PCI bridge of a PCI device |
994a65e2 | 19 | * if the device is PCIE, return NULL |
45e829ea | 20 | * if the device isn't connected to a PCIe bridge (that is its parent is a |
994a65e2 KA |
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 | ||
5f4d91a1 | 29 | if (pci_is_pcie(pdev)) |
994a65e2 KA |
30 | return NULL; |
31 | while (1) { | |
6e3f36df | 32 | if (pci_is_root_bus(pdev->bus)) |
994a65e2 KA |
33 | break; |
34 | pdev = pdev->bus->self; | |
35 | /* a p2p bridge */ | |
5f4d91a1 | 36 | if (!pci_is_pcie(pdev)) { |
994a65e2 KA |
37 | tmp = pdev; |
38 | continue; | |
39 | } | |
45e829ea | 40 | /* PCI device should connect to a PCIe bridge */ |
994a65e2 KA |
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 | ||
1da177e4 LT |
116 | /** |
117 | * pci_get_slot - locate PCI device for a given PCI slot | |
118 | * @bus: PCI bus on which desired PCI device resides | |
119 | * @devfn: encodes number of PCI slot in which the desired PCI | |
120 | * device resides and the logical device number within that slot | |
121 | * in case of multi-function devices. | |
122 | * | |
123 | * Given a PCI bus and slot/function number, the desired PCI device | |
124 | * is located in the list of PCI devices. | |
125 | * If the device is found, its reference count is increased and this | |
126 | * function returns a pointer to its data structure. The caller must | |
127 | * decrement the reference count by calling pci_dev_put(). | |
128 | * If no device is found, %NULL is returned. | |
129 | */ | |
130 | struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn) | |
131 | { | |
132 | struct list_head *tmp; | |
133 | struct pci_dev *dev; | |
134 | ||
135 | WARN_ON(in_interrupt()); | |
d71374da | 136 | down_read(&pci_bus_sem); |
1da177e4 LT |
137 | |
138 | list_for_each(tmp, &bus->devices) { | |
139 | dev = pci_dev_b(tmp); | |
140 | if (dev->devfn == devfn) | |
141 | goto out; | |
142 | } | |
143 | ||
144 | dev = NULL; | |
145 | out: | |
146 | pci_dev_get(dev); | |
d71374da | 147 | up_read(&pci_bus_sem); |
1da177e4 LT |
148 | return dev; |
149 | } | |
150 | ||
29f3eb64 | 151 | /** |
3c299dc2 AP |
152 | * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot |
153 | * @domain: PCI domain/segment on which the PCI device resides. | |
154 | * @bus: PCI bus on which desired PCI device resides | |
155 | * @devfn: encodes number of PCI slot in which the desired PCI device | |
156 | * resides and the logical device number within that slot in case of | |
157 | * multi-function devices. | |
5463d9f0 | 158 | * |
3c299dc2 AP |
159 | * Given a PCI domain, bus, and slot/function number, the desired PCI |
160 | * device is located in the list of PCI devices. If the device is | |
161 | * found, its reference count is increased and this function returns a | |
162 | * pointer to its data structure. The caller must decrement the | |
163 | * reference count by calling pci_dev_put(). If no device is found, | |
164 | * %NULL is returned. | |
29f3eb64 | 165 | */ |
3c299dc2 AP |
166 | struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus, |
167 | unsigned int devfn) | |
29f3eb64 AC |
168 | { |
169 | struct pci_dev *dev = NULL; | |
170 | ||
171 | while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { | |
3c299dc2 AP |
172 | if (pci_domain_nr(dev->bus) == domain && |
173 | (dev->bus->number == bus && dev->devfn == devfn)) | |
29f3eb64 AC |
174 | return dev; |
175 | } | |
176 | return NULL; | |
177 | } | |
3c299dc2 | 178 | EXPORT_SYMBOL(pci_get_domain_bus_and_slot); |
29f3eb64 | 179 | |
95247b57 | 180 | static int match_pci_dev_by_id(struct device *dev, void *data) |
1da177e4 | 181 | { |
95247b57 GKH |
182 | struct pci_dev *pdev = to_pci_dev(dev); |
183 | struct pci_device_id *id = data; | |
1da177e4 | 184 | |
95247b57 GKH |
185 | if (pci_match_one_device(id, pdev)) |
186 | return 1; | |
187 | return 0; | |
1da177e4 LT |
188 | } |
189 | ||
95247b57 GKH |
190 | /* |
191 | * pci_get_dev_by_id - begin or continue searching for a PCI device by id | |
192 | * @id: pointer to struct pci_device_id to match for the device | |
1da177e4 LT |
193 | * @from: Previous PCI device found in search, or %NULL for new search. |
194 | * | |
d75763d2 | 195 | * Iterates through the list of known PCI devices. If a PCI device is found |
95247b57 GKH |
196 | * with a matching id a pointer to its device structure is returned, and the |
197 | * reference count to the device is incremented. Otherwise, %NULL is returned. | |
198 | * A new search is initiated by passing %NULL as the @from argument. Otherwise | |
199 | * if @from is not %NULL, searches continue from next device on the global | |
200 | * list. The reference count for @from is always decremented if it is not | |
201 | * %NULL. | |
202 | * | |
203 | * This is an internal function for use by the other search functions in | |
204 | * this file. | |
1da177e4 | 205 | */ |
95247b57 | 206 | static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id, |
b08508c4 | 207 | struct pci_dev *from) |
1da177e4 | 208 | { |
95247b57 GKH |
209 | struct device *dev; |
210 | struct device *dev_start = NULL; | |
211 | struct pci_dev *pdev = NULL; | |
212 | ||
213 | WARN_ON(in_interrupt()); | |
c4ed02fa MW |
214 | if (from) |
215 | dev_start = &from->dev; | |
95247b57 GKH |
216 | dev = bus_find_device(&pci_bus_type, dev_start, (void *)id, |
217 | match_pci_dev_by_id); | |
218 | if (dev) | |
219 | pdev = to_pci_dev(dev); | |
ebca4f1b GKH |
220 | if (from) |
221 | pci_dev_put(from); | |
95247b57 | 222 | return pdev; |
1da177e4 LT |
223 | } |
224 | ||
225 | /** | |
226 | * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id | |
227 | * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
228 | * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids | |
229 | * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
230 | * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids | |
231 | * @from: Previous PCI device found in search, or %NULL for new search. | |
232 | * | |
d75763d2 RD |
233 | * Iterates through the list of known PCI devices. If a PCI device is found |
234 | * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its | |
1da177e4 LT |
235 | * device structure is returned, and the reference count to the device is |
236 | * incremented. Otherwise, %NULL is returned. A new search is initiated by | |
d75763d2 | 237 | * passing %NULL as the @from argument. Otherwise if @from is not %NULL, |
1da177e4 LT |
238 | * searches continue from next device on the global list. |
239 | * The reference count for @from is always decremented if it is not %NULL. | |
240 | */ | |
95247b57 GKH |
241 | struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, |
242 | unsigned int ss_vendor, unsigned int ss_device, | |
b08508c4 | 243 | struct pci_dev *from) |
1da177e4 | 244 | { |
95247b57 GKH |
245 | struct pci_dev *pdev; |
246 | struct pci_device_id *id; | |
6ae4adf5 AB |
247 | |
248 | /* | |
95247b57 GKH |
249 | * pci_find_subsys() can be called on the ide_setup() path, |
250 | * super-early in boot. But the down_read() will enable local | |
251 | * interrupts, which can cause some machines to crash. So here we | |
252 | * detect and flag that situation and bail out early. | |
6ae4adf5 | 253 | */ |
35ef63f6 | 254 | if (unlikely(no_pci_devices())) |
6ae4adf5 | 255 | return NULL; |
95247b57 GKH |
256 | |
257 | id = kzalloc(sizeof(*id), GFP_KERNEL); | |
258 | if (!id) | |
259 | return NULL; | |
260 | id->vendor = vendor; | |
261 | id->device = device; | |
262 | id->subvendor = ss_vendor; | |
263 | id->subdevice = ss_device; | |
264 | ||
265 | pdev = pci_get_dev_by_id(id, from); | |
266 | kfree(id); | |
267 | ||
268 | return pdev; | |
1da177e4 LT |
269 | } |
270 | ||
271 | /** | |
272 | * pci_get_device - begin or continue searching for a PCI device by vendor/device id | |
273 | * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
274 | * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids | |
275 | * @from: Previous PCI device found in search, or %NULL for new search. | |
276 | * | |
277 | * Iterates through the list of known PCI devices. If a PCI device is | |
278 | * found with a matching @vendor and @device, the reference count to the | |
279 | * device is incremented and a pointer to its device structure is returned. | |
280 | * Otherwise, %NULL is returned. A new search is initiated by passing %NULL | |
d75763d2 | 281 | * as the @from argument. Otherwise if @from is not %NULL, searches continue |
1da177e4 LT |
282 | * from next device on the global list. The reference count for @from is |
283 | * always decremented if it is not %NULL. | |
284 | */ | |
285 | struct pci_dev * | |
286 | pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from) | |
287 | { | |
288 | return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); | |
289 | } | |
290 | ||
1da177e4 LT |
291 | /** |
292 | * pci_get_class - begin or continue searching for a PCI device by class | |
293 | * @class: search for a PCI device with this class designation | |
294 | * @from: Previous PCI device found in search, or %NULL for new search. | |
295 | * | |
296 | * Iterates through the list of known PCI devices. If a PCI device is | |
297 | * found with a matching @class, the reference count to the device is | |
298 | * incremented and a pointer to its device structure is returned. | |
299 | * Otherwise, %NULL is returned. | |
d75763d2 | 300 | * A new search is initiated by passing %NULL as the @from argument. |
1da177e4 LT |
301 | * Otherwise if @from is not %NULL, searches continue from next device |
302 | * on the global list. The reference count for @from is always decremented | |
303 | * if it is not %NULL. | |
304 | */ | |
305 | struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) | |
306 | { | |
1da177e4 | 307 | struct pci_dev *dev; |
95247b57 | 308 | struct pci_device_id *id; |
1da177e4 | 309 | |
95247b57 GKH |
310 | id = kzalloc(sizeof(*id), GFP_KERNEL); |
311 | if (!id) | |
312 | return NULL; | |
313 | id->vendor = id->device = id->subvendor = id->subdevice = PCI_ANY_ID; | |
314 | id->class_mask = PCI_ANY_ID; | |
315 | id->class = class; | |
1da177e4 | 316 | |
95247b57 GKH |
317 | dev = pci_get_dev_by_id(id, from); |
318 | kfree(id); | |
1da177e4 LT |
319 | return dev; |
320 | } | |
321 | ||
448432c4 GKH |
322 | /** |
323 | * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not. | |
324 | * @ids: A pointer to a null terminated list of struct pci_device_id structures | |
325 | * that describe the type of PCI device the caller is trying to find. | |
326 | * | |
327 | * Obvious fact: You do not have a reference to any device that might be found | |
328 | * by this function, so if that device is removed from the system right after | |
329 | * this function is finished, the value will be stale. Use this function to | |
330 | * find devices that are usually built into a system, or for a general hint as | |
331 | * to if another device happens to be present at this specific moment in time. | |
332 | */ | |
333 | int pci_dev_present(const struct pci_device_id *ids) | |
d86f90f9 | 334 | { |
95247b57 | 335 | struct pci_dev *found = NULL; |
d86f90f9 AC |
336 | |
337 | WARN_ON(in_interrupt()); | |
d86f90f9 | 338 | while (ids->vendor || ids->subvendor || ids->class_mask) { |
95247b57 GKH |
339 | found = pci_get_dev_by_id(ids, NULL); |
340 | if (found) | |
341 | goto exit; | |
d86f90f9 AC |
342 | ids++; |
343 | } | |
3c92c57a | 344 | exit: |
448432c4 GKH |
345 | if (found) |
346 | return 1; | |
347 | return 0; | |
1da177e4 LT |
348 | } |
349 | EXPORT_SYMBOL(pci_dev_present); | |
350 | ||
29f3eb64 AC |
351 | /* For boot time work */ |
352 | EXPORT_SYMBOL(pci_find_bus); | |
353 | EXPORT_SYMBOL(pci_find_next_bus); | |
354 | /* For everyone */ | |
1da177e4 LT |
355 | EXPORT_SYMBOL(pci_get_device); |
356 | EXPORT_SYMBOL(pci_get_subsys); | |
357 | EXPORT_SYMBOL(pci_get_slot); | |
358 | EXPORT_SYMBOL(pci_get_class); |