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7328c8f4 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
df62ab5e | 3 | * PCI searching functions |
1da177e4 | 4 | * |
df62ab5e | 5 | * Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter, |
1da177e4 | 6 | * David Mosberger-Tang |
df62ab5e BH |
7 | * Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz> |
8 | * Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com> | |
1da177e4 LT |
9 | */ |
10 | ||
1da177e4 | 11 | #include <linux/pci.h> |
5a0e3ad6 | 12 | #include <linux/slab.h> |
1da177e4 LT |
13 | #include <linux/module.h> |
14 | #include <linux/interrupt.h> | |
15 | #include "pci.h" | |
16 | ||
d71374da | 17 | DECLARE_RWSEM(pci_bus_sem); |
ce29ca3e AK |
18 | EXPORT_SYMBOL_GPL(pci_bus_sem); |
19 | ||
c25dc828 AW |
20 | /* |
21 | * pci_for_each_dma_alias - Iterate over DMA aliases for a device | |
22 | * @pdev: starting downstream device | |
23 | * @fn: function to call for each alias | |
24 | * @data: opaque data to pass to @fn | |
25 | * | |
26 | * Starting @pdev, walk up the bus calling @fn for each possible alias | |
27 | * of @pdev at the root bus. | |
28 | */ | |
29 | int pci_for_each_dma_alias(struct pci_dev *pdev, | |
30 | int (*fn)(struct pci_dev *pdev, | |
31 | u16 alias, void *data), void *data) | |
32 | { | |
33 | struct pci_bus *bus; | |
34 | int ret; | |
35 | ||
36 | ret = fn(pdev, PCI_DEVID(pdev->bus->number, pdev->devfn), data); | |
37 | if (ret) | |
38 | return ret; | |
39 | ||
31c2b815 AW |
40 | /* |
41 | * If the device is broken and uses an alias requester ID for | |
42 | * DMA, iterate over that too. | |
43 | */ | |
338c3149 JL |
44 | if (unlikely(pdev->dma_alias_mask)) { |
45 | u8 devfn; | |
46 | ||
47 | for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX) { | |
48 | ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn), | |
49 | data); | |
50 | if (ret) | |
51 | return ret; | |
52 | } | |
31c2b815 AW |
53 | } |
54 | ||
c25dc828 AW |
55 | for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) { |
56 | struct pci_dev *tmp; | |
57 | ||
58 | /* Skip virtual buses */ | |
59 | if (!bus->self) | |
60 | continue; | |
61 | ||
62 | tmp = bus->self; | |
63 | ||
ffff8858 J |
64 | /* stop at bridge where translation unit is associated */ |
65 | if (tmp->dev_flags & PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT) | |
66 | return ret; | |
67 | ||
c25dc828 AW |
68 | /* |
69 | * PCIe-to-PCI/X bridges alias transactions from downstream | |
70 | * devices using the subordinate bus number (PCI Express to | |
71 | * PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases | |
72 | * where the upstream bus is PCI/X we alias to the bridge | |
73 | * (there are various conditions in the previous reference | |
74 | * where the bridge may take ownership of transactions, even | |
75 | * when the secondary interface is PCI-X). | |
76 | */ | |
77 | if (pci_is_pcie(tmp)) { | |
78 | switch (pci_pcie_type(tmp)) { | |
79 | case PCI_EXP_TYPE_ROOT_PORT: | |
80 | case PCI_EXP_TYPE_UPSTREAM: | |
81 | case PCI_EXP_TYPE_DOWNSTREAM: | |
82 | continue; | |
83 | case PCI_EXP_TYPE_PCI_BRIDGE: | |
84 | ret = fn(tmp, | |
85 | PCI_DEVID(tmp->subordinate->number, | |
86 | PCI_DEVFN(0, 0)), data); | |
87 | if (ret) | |
88 | return ret; | |
89 | continue; | |
90 | case PCI_EXP_TYPE_PCIE_BRIDGE: | |
91 | ret = fn(tmp, | |
92 | PCI_DEVID(tmp->bus->number, | |
93 | tmp->devfn), data); | |
94 | if (ret) | |
95 | return ret; | |
96 | continue; | |
97 | } | |
98 | } else { | |
c8fe16e3 AW |
99 | if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS) |
100 | ret = fn(tmp, | |
101 | PCI_DEVID(tmp->subordinate->number, | |
102 | PCI_DEVFN(0, 0)), data); | |
103 | else | |
104 | ret = fn(tmp, | |
105 | PCI_DEVID(tmp->bus->number, | |
106 | tmp->devfn), data); | |
c25dc828 AW |
107 | if (ret) |
108 | return ret; | |
109 | } | |
110 | } | |
111 | ||
112 | return ret; | |
113 | } | |
114 | ||
96bde06a | 115 | static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr) |
1da177e4 | 116 | { |
94e6a9b9 YW |
117 | struct pci_bus *child; |
118 | struct pci_bus *tmp; | |
1da177e4 | 119 | |
3c78bc61 | 120 | if (bus->number == busnr) |
1da177e4 LT |
121 | return bus; |
122 | ||
94e6a9b9 YW |
123 | list_for_each_entry(tmp, &bus->children, node) { |
124 | child = pci_do_find_bus(tmp, busnr); | |
3c78bc61 | 125 | if (child) |
1da177e4 LT |
126 | return child; |
127 | } | |
128 | return NULL; | |
129 | } | |
130 | ||
131 | /** | |
132 | * pci_find_bus - locate PCI bus from a given domain and bus number | |
133 | * @domain: number of PCI domain to search | |
134 | * @busnr: number of desired PCI bus | |
135 | * | |
136 | * Given a PCI bus number and domain number, the desired PCI bus is located | |
137 | * in the global list of PCI buses. If the bus is found, a pointer to its | |
138 | * data structure is returned. If no bus is found, %NULL is returned. | |
139 | */ | |
3c78bc61 | 140 | struct pci_bus *pci_find_bus(int domain, int busnr) |
1da177e4 LT |
141 | { |
142 | struct pci_bus *bus = NULL; | |
143 | struct pci_bus *tmp_bus; | |
144 | ||
145 | while ((bus = pci_find_next_bus(bus)) != NULL) { | |
146 | if (pci_domain_nr(bus) != domain) | |
147 | continue; | |
148 | tmp_bus = pci_do_find_bus(bus, busnr); | |
149 | if (tmp_bus) | |
150 | return tmp_bus; | |
151 | } | |
152 | return NULL; | |
153 | } | |
b7fe9434 | 154 | EXPORT_SYMBOL(pci_find_bus); |
1da177e4 LT |
155 | |
156 | /** | |
157 | * pci_find_next_bus - begin or continue searching for a PCI bus | |
158 | * @from: Previous PCI bus found, or %NULL for new search. | |
159 | * | |
f7625980 | 160 | * Iterates through the list of known PCI buses. A new search is |
d75763d2 | 161 | * initiated by passing %NULL as the @from argument. Otherwise if |
1da177e4 LT |
162 | * @from is not %NULL, searches continue from next device on the |
163 | * global list. | |
164 | */ | |
3c78bc61 | 165 | struct pci_bus *pci_find_next_bus(const struct pci_bus *from) |
1da177e4 LT |
166 | { |
167 | struct list_head *n; | |
168 | struct pci_bus *b = NULL; | |
169 | ||
170 | WARN_ON(in_interrupt()); | |
d71374da | 171 | down_read(&pci_bus_sem); |
1da177e4 LT |
172 | n = from ? from->node.next : pci_root_buses.next; |
173 | if (n != &pci_root_buses) | |
94e6a9b9 | 174 | b = list_entry(n, struct pci_bus, node); |
d71374da | 175 | up_read(&pci_bus_sem); |
1da177e4 LT |
176 | return b; |
177 | } | |
b7fe9434 | 178 | EXPORT_SYMBOL(pci_find_next_bus); |
1da177e4 | 179 | |
1da177e4 LT |
180 | /** |
181 | * pci_get_slot - locate PCI device for a given PCI slot | |
182 | * @bus: PCI bus on which desired PCI device resides | |
f7625980 BH |
183 | * @devfn: encodes number of PCI slot in which the desired PCI |
184 | * device resides and the logical device number within that slot | |
1da177e4 LT |
185 | * in case of multi-function devices. |
186 | * | |
f7625980 | 187 | * Given a PCI bus and slot/function number, the desired PCI device |
1da177e4 LT |
188 | * is located in the list of PCI devices. |
189 | * If the device is found, its reference count is increased and this | |
190 | * function returns a pointer to its data structure. The caller must | |
191 | * decrement the reference count by calling pci_dev_put(). | |
192 | * If no device is found, %NULL is returned. | |
193 | */ | |
66455f54 | 194 | struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn) |
1da177e4 | 195 | { |
1da177e4 LT |
196 | struct pci_dev *dev; |
197 | ||
198 | WARN_ON(in_interrupt()); | |
d71374da | 199 | down_read(&pci_bus_sem); |
1da177e4 | 200 | |
66455f54 | 201 | list_for_each_entry(dev, &bus->devices, bus_list) { |
1da177e4 LT |
202 | if (dev->devfn == devfn) |
203 | goto out; | |
204 | } | |
205 | ||
206 | dev = NULL; | |
207 | out: | |
208 | pci_dev_get(dev); | |
d71374da | 209 | up_read(&pci_bus_sem); |
1da177e4 LT |
210 | return dev; |
211 | } | |
b7fe9434 | 212 | EXPORT_SYMBOL(pci_get_slot); |
1da177e4 | 213 | |
29f3eb64 | 214 | /** |
3c299dc2 AP |
215 | * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot |
216 | * @domain: PCI domain/segment on which the PCI device resides. | |
217 | * @bus: PCI bus on which desired PCI device resides | |
218 | * @devfn: encodes number of PCI slot in which the desired PCI device | |
219 | * resides and the logical device number within that slot in case of | |
220 | * multi-function devices. | |
5463d9f0 | 221 | * |
3c299dc2 AP |
222 | * Given a PCI domain, bus, and slot/function number, the desired PCI |
223 | * device is located in the list of PCI devices. If the device is | |
224 | * found, its reference count is increased and this function returns a | |
225 | * pointer to its data structure. The caller must decrement the | |
226 | * reference count by calling pci_dev_put(). If no device is found, | |
227 | * %NULL is returned. | |
29f3eb64 | 228 | */ |
3c299dc2 AP |
229 | struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus, |
230 | unsigned int devfn) | |
29f3eb64 AC |
231 | { |
232 | struct pci_dev *dev = NULL; | |
233 | ||
4e344b1c | 234 | for_each_pci_dev(dev) { |
3c299dc2 AP |
235 | if (pci_domain_nr(dev->bus) == domain && |
236 | (dev->bus->number == bus && dev->devfn == devfn)) | |
29f3eb64 AC |
237 | return dev; |
238 | } | |
239 | return NULL; | |
240 | } | |
3c299dc2 | 241 | EXPORT_SYMBOL(pci_get_domain_bus_and_slot); |
29f3eb64 | 242 | |
95247b57 | 243 | static int match_pci_dev_by_id(struct device *dev, void *data) |
1da177e4 | 244 | { |
95247b57 GKH |
245 | struct pci_dev *pdev = to_pci_dev(dev); |
246 | struct pci_device_id *id = data; | |
1da177e4 | 247 | |
95247b57 GKH |
248 | if (pci_match_one_device(id, pdev)) |
249 | return 1; | |
250 | return 0; | |
1da177e4 LT |
251 | } |
252 | ||
95247b57 GKH |
253 | /* |
254 | * pci_get_dev_by_id - begin or continue searching for a PCI device by id | |
255 | * @id: pointer to struct pci_device_id to match for the device | |
1da177e4 LT |
256 | * @from: Previous PCI device found in search, or %NULL for new search. |
257 | * | |
d75763d2 | 258 | * Iterates through the list of known PCI devices. If a PCI device is found |
95247b57 GKH |
259 | * with a matching id a pointer to its device structure is returned, and the |
260 | * reference count to the device is incremented. Otherwise, %NULL is returned. | |
261 | * A new search is initiated by passing %NULL as the @from argument. Otherwise | |
262 | * if @from is not %NULL, searches continue from next device on the global | |
263 | * list. The reference count for @from is always decremented if it is not | |
264 | * %NULL. | |
265 | * | |
266 | * This is an internal function for use by the other search functions in | |
267 | * this file. | |
1da177e4 | 268 | */ |
95247b57 | 269 | static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id, |
b08508c4 | 270 | struct pci_dev *from) |
1da177e4 | 271 | { |
95247b57 GKH |
272 | struct device *dev; |
273 | struct device *dev_start = NULL; | |
274 | struct pci_dev *pdev = NULL; | |
275 | ||
276 | WARN_ON(in_interrupt()); | |
c4ed02fa MW |
277 | if (from) |
278 | dev_start = &from->dev; | |
95247b57 GKH |
279 | dev = bus_find_device(&pci_bus_type, dev_start, (void *)id, |
280 | match_pci_dev_by_id); | |
281 | if (dev) | |
282 | pdev = to_pci_dev(dev); | |
ff0387c3 | 283 | pci_dev_put(from); |
95247b57 | 284 | return pdev; |
1da177e4 LT |
285 | } |
286 | ||
287 | /** | |
288 | * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id | |
289 | * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
290 | * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids | |
291 | * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
292 | * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids | |
293 | * @from: Previous PCI device found in search, or %NULL for new search. | |
294 | * | |
d75763d2 RD |
295 | * Iterates through the list of known PCI devices. If a PCI device is found |
296 | * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its | |
1da177e4 LT |
297 | * device structure is returned, and the reference count to the device is |
298 | * incremented. Otherwise, %NULL is returned. A new search is initiated by | |
d75763d2 | 299 | * passing %NULL as the @from argument. Otherwise if @from is not %NULL, |
1da177e4 LT |
300 | * searches continue from next device on the global list. |
301 | * The reference count for @from is always decremented if it is not %NULL. | |
302 | */ | |
95247b57 GKH |
303 | struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, |
304 | unsigned int ss_vendor, unsigned int ss_device, | |
b08508c4 | 305 | struct pci_dev *from) |
1da177e4 | 306 | { |
b9443f40 FT |
307 | struct pci_device_id id = { |
308 | .vendor = vendor, | |
309 | .device = device, | |
310 | .subvendor = ss_vendor, | |
311 | .subdevice = ss_device, | |
312 | }; | |
6ae4adf5 | 313 | |
b9443f40 | 314 | return pci_get_dev_by_id(&id, from); |
1da177e4 | 315 | } |
b7fe9434 | 316 | EXPORT_SYMBOL(pci_get_subsys); |
1da177e4 LT |
317 | |
318 | /** | |
319 | * pci_get_device - begin or continue searching for a PCI device by vendor/device id | |
320 | * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids | |
321 | * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids | |
322 | * @from: Previous PCI device found in search, or %NULL for new search. | |
323 | * | |
324 | * Iterates through the list of known PCI devices. If a PCI device is | |
325 | * found with a matching @vendor and @device, the reference count to the | |
326 | * device is incremented and a pointer to its device structure is returned. | |
327 | * Otherwise, %NULL is returned. A new search is initiated by passing %NULL | |
d75763d2 | 328 | * as the @from argument. Otherwise if @from is not %NULL, searches continue |
1da177e4 LT |
329 | * from next device on the global list. The reference count for @from is |
330 | * always decremented if it is not %NULL. | |
331 | */ | |
3c78bc61 RD |
332 | struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device, |
333 | struct pci_dev *from) | |
1da177e4 LT |
334 | { |
335 | return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); | |
336 | } | |
b7fe9434 | 337 | EXPORT_SYMBOL(pci_get_device); |
1da177e4 | 338 | |
1da177e4 LT |
339 | /** |
340 | * pci_get_class - begin or continue searching for a PCI device by class | |
341 | * @class: search for a PCI device with this class designation | |
342 | * @from: Previous PCI device found in search, or %NULL for new search. | |
343 | * | |
344 | * Iterates through the list of known PCI devices. If a PCI device is | |
345 | * found with a matching @class, the reference count to the device is | |
346 | * incremented and a pointer to its device structure is returned. | |
347 | * Otherwise, %NULL is returned. | |
d75763d2 | 348 | * A new search is initiated by passing %NULL as the @from argument. |
1da177e4 LT |
349 | * Otherwise if @from is not %NULL, searches continue from next device |
350 | * on the global list. The reference count for @from is always decremented | |
351 | * if it is not %NULL. | |
352 | */ | |
353 | struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) | |
354 | { | |
b9443f40 FT |
355 | struct pci_device_id id = { |
356 | .vendor = PCI_ANY_ID, | |
357 | .device = PCI_ANY_ID, | |
358 | .subvendor = PCI_ANY_ID, | |
359 | .subdevice = PCI_ANY_ID, | |
360 | .class_mask = PCI_ANY_ID, | |
361 | .class = class, | |
362 | }; | |
363 | ||
364 | return pci_get_dev_by_id(&id, from); | |
1da177e4 | 365 | } |
b7fe9434 | 366 | EXPORT_SYMBOL(pci_get_class); |
1da177e4 | 367 | |
448432c4 GKH |
368 | /** |
369 | * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not. | |
370 | * @ids: A pointer to a null terminated list of struct pci_device_id structures | |
371 | * that describe the type of PCI device the caller is trying to find. | |
372 | * | |
373 | * Obvious fact: You do not have a reference to any device that might be found | |
374 | * by this function, so if that device is removed from the system right after | |
375 | * this function is finished, the value will be stale. Use this function to | |
376 | * find devices that are usually built into a system, or for a general hint as | |
377 | * to if another device happens to be present at this specific moment in time. | |
378 | */ | |
379 | int pci_dev_present(const struct pci_device_id *ids) | |
d86f90f9 | 380 | { |
95247b57 | 381 | struct pci_dev *found = NULL; |
d86f90f9 AC |
382 | |
383 | WARN_ON(in_interrupt()); | |
d86f90f9 | 384 | while (ids->vendor || ids->subvendor || ids->class_mask) { |
95247b57 | 385 | found = pci_get_dev_by_id(ids, NULL); |
d5af7d98 JL |
386 | if (found) { |
387 | pci_dev_put(found); | |
388 | return 1; | |
389 | } | |
d86f90f9 AC |
390 | ids++; |
391 | } | |
d5af7d98 | 392 | |
448432c4 | 393 | return 0; |
1da177e4 LT |
394 | } |
395 | EXPORT_SYMBOL(pci_dev_present); |