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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI searching functions
4 *
5 * Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
6 * David Mosberger-Tang
7 * Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
8 * Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
9 */
10
11#include <linux/pci.h>
12#include <linux/slab.h>
13#include <linux/module.h>
14#include <linux/interrupt.h>
15#include "pci.h"
16
17DECLARE_RWSEM(pci_bus_sem);
18
19/*
20 * pci_for_each_dma_alias - Iterate over DMA aliases for a device
21 * @pdev: starting downstream device
22 * @fn: function to call for each alias
23 * @data: opaque data to pass to @fn
24 *
25 * Starting @pdev, walk up the bus calling @fn for each possible alias
26 * of @pdev at the root bus.
27 */
28int pci_for_each_dma_alias(struct pci_dev *pdev,
29 int (*fn)(struct pci_dev *pdev,
30 u16 alias, void *data), void *data)
31{
32 struct pci_bus *bus;
33 int ret;
34
35 ret = fn(pdev, pci_dev_id(pdev), data);
36 if (ret)
37 return ret;
38
39 /*
40 * If the device is broken and uses an alias requester ID for
41 * DMA, iterate over that too.
42 */
43 if (unlikely(pdev->dma_alias_mask)) {
44 u8 devfn;
45
46 for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX) {
47 ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn),
48 data);
49 if (ret)
50 return ret;
51 }
52 }
53
54 for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
55 struct pci_dev *tmp;
56
57 /* Skip virtual buses */
58 if (!bus->self)
59 continue;
60
61 tmp = bus->self;
62
63 /* stop at bridge where translation unit is associated */
64 if (tmp->dev_flags & PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT)
65 return ret;
66
67 /*
68 * PCIe-to-PCI/X bridges alias transactions from downstream
69 * devices using the subordinate bus number (PCI Express to
70 * PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases
71 * where the upstream bus is PCI/X we alias to the bridge
72 * (there are various conditions in the previous reference
73 * where the bridge may take ownership of transactions, even
74 * when the secondary interface is PCI-X).
75 */
76 if (pci_is_pcie(tmp)) {
77 switch (pci_pcie_type(tmp)) {
78 case PCI_EXP_TYPE_ROOT_PORT:
79 case PCI_EXP_TYPE_UPSTREAM:
80 case PCI_EXP_TYPE_DOWNSTREAM:
81 continue;
82 case PCI_EXP_TYPE_PCI_BRIDGE:
83 ret = fn(tmp,
84 PCI_DEVID(tmp->subordinate->number,
85 PCI_DEVFN(0, 0)), data);
86 if (ret)
87 return ret;
88 continue;
89 case PCI_EXP_TYPE_PCIE_BRIDGE:
90 ret = fn(tmp, pci_dev_id(tmp), data);
91 if (ret)
92 return ret;
93 continue;
94 }
95 } else {
96 if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS)
97 ret = fn(tmp,
98 PCI_DEVID(tmp->subordinate->number,
99 PCI_DEVFN(0, 0)), data);
100 else
101 ret = fn(tmp, pci_dev_id(tmp), data);
102 if (ret)
103 return ret;
104 }
105 }
106
107 return ret;
108}
109
110static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
111{
112 struct pci_bus *child;
113 struct pci_bus *tmp;
114
115 if (bus->number == busnr)
116 return bus;
117
118 list_for_each_entry(tmp, &bus->children, node) {
119 child = pci_do_find_bus(tmp, busnr);
120 if (child)
121 return child;
122 }
123 return NULL;
124}
125
126/**
127 * pci_find_bus - locate PCI bus from a given domain and bus number
128 * @domain: number of PCI domain to search
129 * @busnr: number of desired PCI bus
130 *
131 * Given a PCI bus number and domain number, the desired PCI bus is located
132 * in the global list of PCI buses. If the bus is found, a pointer to its
133 * data structure is returned. If no bus is found, %NULL is returned.
134 */
135struct pci_bus *pci_find_bus(int domain, int busnr)
136{
137 struct pci_bus *bus = NULL;
138 struct pci_bus *tmp_bus;
139
140 while ((bus = pci_find_next_bus(bus)) != NULL) {
141 if (pci_domain_nr(bus) != domain)
142 continue;
143 tmp_bus = pci_do_find_bus(bus, busnr);
144 if (tmp_bus)
145 return tmp_bus;
146 }
147 return NULL;
148}
149EXPORT_SYMBOL(pci_find_bus);
150
151/**
152 * pci_find_next_bus - begin or continue searching for a PCI bus
153 * @from: Previous PCI bus found, or %NULL for new search.
154 *
155 * Iterates through the list of known PCI buses. A new search is
156 * initiated by passing %NULL as the @from argument. Otherwise if
157 * @from is not %NULL, searches continue from next device on the
158 * global list.
159 */
160struct pci_bus *pci_find_next_bus(const struct pci_bus *from)
161{
162 struct list_head *n;
163 struct pci_bus *b = NULL;
164
165 WARN_ON(in_interrupt());
166 down_read(&pci_bus_sem);
167 n = from ? from->node.next : pci_root_buses.next;
168 if (n != &pci_root_buses)
169 b = list_entry(n, struct pci_bus, node);
170 up_read(&pci_bus_sem);
171 return b;
172}
173EXPORT_SYMBOL(pci_find_next_bus);
174
175/**
176 * pci_get_slot - locate PCI device for a given PCI slot
177 * @bus: PCI bus on which desired PCI device resides
178 * @devfn: encodes number of PCI slot in which the desired PCI
179 * device resides and the logical device number within that slot
180 * in case of multi-function devices.
181 *
182 * Given a PCI bus and slot/function number, the desired PCI device
183 * is located in the list of PCI devices.
184 * If the device is found, its reference count is increased and this
185 * function returns a pointer to its data structure. The caller must
186 * decrement the reference count by calling pci_dev_put().
187 * If no device is found, %NULL is returned.
188 */
189struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
190{
191 struct pci_dev *dev;
192
193 WARN_ON(in_interrupt());
194 down_read(&pci_bus_sem);
195
196 list_for_each_entry(dev, &bus->devices, bus_list) {
197 if (dev->devfn == devfn)
198 goto out;
199 }
200
201 dev = NULL;
202 out:
203 pci_dev_get(dev);
204 up_read(&pci_bus_sem);
205 return dev;
206}
207EXPORT_SYMBOL(pci_get_slot);
208
209/**
210 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
211 * @domain: PCI domain/segment on which the PCI device resides.
212 * @bus: PCI bus on which desired PCI device resides
213 * @devfn: encodes number of PCI slot in which the desired PCI device
214 * resides and the logical device number within that slot in case of
215 * multi-function devices.
216 *
217 * Given a PCI domain, bus, and slot/function number, the desired PCI
218 * device is located in the list of PCI devices. If the device is
219 * found, its reference count is increased and this function returns a
220 * pointer to its data structure. The caller must decrement the
221 * reference count by calling pci_dev_put(). If no device is found,
222 * %NULL is returned.
223 */
224struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
225 unsigned int devfn)
226{
227 struct pci_dev *dev = NULL;
228
229 for_each_pci_dev(dev) {
230 if (pci_domain_nr(dev->bus) == domain &&
231 (dev->bus->number == bus && dev->devfn == devfn))
232 return dev;
233 }
234 return NULL;
235}
236EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
237
238static int match_pci_dev_by_id(struct device *dev, const void *data)
239{
240 struct pci_dev *pdev = to_pci_dev(dev);
241 const struct pci_device_id *id = data;
242
243 if (pci_match_one_device(id, pdev))
244 return 1;
245 return 0;
246}
247
248/*
249 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
250 * @id: pointer to struct pci_device_id to match for the device
251 * @from: Previous PCI device found in search, or %NULL for new search.
252 *
253 * Iterates through the list of known PCI devices. If a PCI device is found
254 * with a matching id a pointer to its device structure is returned, and the
255 * reference count to the device is incremented. Otherwise, %NULL is returned.
256 * A new search is initiated by passing %NULL as the @from argument. Otherwise
257 * if @from is not %NULL, searches continue from next device on the global
258 * list. The reference count for @from is always decremented if it is not
259 * %NULL.
260 *
261 * This is an internal function for use by the other search functions in
262 * this file.
263 */
264static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
265 struct pci_dev *from)
266{
267 struct device *dev;
268 struct device *dev_start = NULL;
269 struct pci_dev *pdev = NULL;
270
271 WARN_ON(in_interrupt());
272 if (from)
273 dev_start = &from->dev;
274 dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
275 match_pci_dev_by_id);
276 if (dev)
277 pdev = to_pci_dev(dev);
278 pci_dev_put(from);
279 return pdev;
280}
281
282/**
283 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
284 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
285 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
286 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
287 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
288 * @from: Previous PCI device found in search, or %NULL for new search.
289 *
290 * Iterates through the list of known PCI devices. If a PCI device is found
291 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
292 * device structure is returned, and the reference count to the device is
293 * incremented. Otherwise, %NULL is returned. A new search is initiated by
294 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
295 * searches continue from next device on the global list.
296 * The reference count for @from is always decremented if it is not %NULL.
297 */
298struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
299 unsigned int ss_vendor, unsigned int ss_device,
300 struct pci_dev *from)
301{
302 struct pci_device_id id = {
303 .vendor = vendor,
304 .device = device,
305 .subvendor = ss_vendor,
306 .subdevice = ss_device,
307 };
308
309 return pci_get_dev_by_id(&id, from);
310}
311EXPORT_SYMBOL(pci_get_subsys);
312
313/**
314 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
315 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
316 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
317 * @from: Previous PCI device found in search, or %NULL for new search.
318 *
319 * Iterates through the list of known PCI devices. If a PCI device is
320 * found with a matching @vendor and @device, the reference count to the
321 * device is incremented and a pointer to its device structure is returned.
322 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
323 * as the @from argument. Otherwise if @from is not %NULL, searches continue
324 * from next device on the global list. The reference count for @from is
325 * always decremented if it is not %NULL.
326 */
327struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
328 struct pci_dev *from)
329{
330 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
331}
332EXPORT_SYMBOL(pci_get_device);
333
334/**
335 * pci_get_class - begin or continue searching for a PCI device by class
336 * @class: search for a PCI device with this class designation
337 * @from: Previous PCI device found in search, or %NULL for new search.
338 *
339 * Iterates through the list of known PCI devices. If a PCI device is
340 * found with a matching @class, the reference count to the device is
341 * incremented and a pointer to its device structure is returned.
342 * Otherwise, %NULL is returned.
343 * A new search is initiated by passing %NULL as the @from argument.
344 * Otherwise if @from is not %NULL, searches continue from next device
345 * on the global list. The reference count for @from is always decremented
346 * if it is not %NULL.
347 */
348struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
349{
350 struct pci_device_id id = {
351 .vendor = PCI_ANY_ID,
352 .device = PCI_ANY_ID,
353 .subvendor = PCI_ANY_ID,
354 .subdevice = PCI_ANY_ID,
355 .class_mask = PCI_ANY_ID,
356 .class = class,
357 };
358
359 return pci_get_dev_by_id(&id, from);
360}
361EXPORT_SYMBOL(pci_get_class);
362
363/**
364 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
365 * @ids: A pointer to a null terminated list of struct pci_device_id structures
366 * that describe the type of PCI device the caller is trying to find.
367 *
368 * Obvious fact: You do not have a reference to any device that might be found
369 * by this function, so if that device is removed from the system right after
370 * this function is finished, the value will be stale. Use this function to
371 * find devices that are usually built into a system, or for a general hint as
372 * to if another device happens to be present at this specific moment in time.
373 */
374int pci_dev_present(const struct pci_device_id *ids)
375{
376 struct pci_dev *found = NULL;
377
378 WARN_ON(in_interrupt());
379 while (ids->vendor || ids->subvendor || ids->class_mask) {
380 found = pci_get_dev_by_id(ids, NULL);
381 if (found) {
382 pci_dev_put(found);
383 return 1;
384 }
385 ids++;
386 }
387
388 return 0;
389}
390EXPORT_SYMBOL(pci_dev_present);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI searching functions
4 *
5 * Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
6 * David Mosberger-Tang
7 * Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
8 * Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
9 */
10
11#include <linux/pci.h>
12#include <linux/slab.h>
13#include <linux/module.h>
14#include <linux/interrupt.h>
15#include "pci.h"
16
17DECLARE_RWSEM(pci_bus_sem);
18
19/*
20 * pci_for_each_dma_alias - Iterate over DMA aliases for a device
21 * @pdev: starting downstream device
22 * @fn: function to call for each alias
23 * @data: opaque data to pass to @fn
24 *
25 * Starting @pdev, walk up the bus calling @fn for each possible alias
26 * of @pdev at the root bus.
27 */
28int pci_for_each_dma_alias(struct pci_dev *pdev,
29 int (*fn)(struct pci_dev *pdev,
30 u16 alias, void *data), void *data)
31{
32 struct pci_bus *bus;
33 int ret;
34
35 /*
36 * The device may have an explicit alias requester ID for DMA where the
37 * requester is on another PCI bus.
38 */
39 pdev = pci_real_dma_dev(pdev);
40
41 ret = fn(pdev, pci_dev_id(pdev), data);
42 if (ret)
43 return ret;
44
45 /*
46 * If the device is broken and uses an alias requester ID for
47 * DMA, iterate over that too.
48 */
49 if (unlikely(pdev->dma_alias_mask)) {
50 unsigned int devfn;
51
52 for_each_set_bit(devfn, pdev->dma_alias_mask, MAX_NR_DEVFNS) {
53 ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn),
54 data);
55 if (ret)
56 return ret;
57 }
58 }
59
60 for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
61 struct pci_dev *tmp;
62
63 /* Skip virtual buses */
64 if (!bus->self)
65 continue;
66
67 tmp = bus->self;
68
69 /* stop at bridge where translation unit is associated */
70 if (tmp->dev_flags & PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT)
71 return ret;
72
73 /*
74 * PCIe-to-PCI/X bridges alias transactions from downstream
75 * devices using the subordinate bus number (PCI Express to
76 * PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases
77 * where the upstream bus is PCI/X we alias to the bridge
78 * (there are various conditions in the previous reference
79 * where the bridge may take ownership of transactions, even
80 * when the secondary interface is PCI-X).
81 */
82 if (pci_is_pcie(tmp)) {
83 switch (pci_pcie_type(tmp)) {
84 case PCI_EXP_TYPE_ROOT_PORT:
85 case PCI_EXP_TYPE_UPSTREAM:
86 case PCI_EXP_TYPE_DOWNSTREAM:
87 continue;
88 case PCI_EXP_TYPE_PCI_BRIDGE:
89 ret = fn(tmp,
90 PCI_DEVID(tmp->subordinate->number,
91 PCI_DEVFN(0, 0)), data);
92 if (ret)
93 return ret;
94 continue;
95 case PCI_EXP_TYPE_PCIE_BRIDGE:
96 ret = fn(tmp, pci_dev_id(tmp), data);
97 if (ret)
98 return ret;
99 continue;
100 }
101 } else {
102 if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS)
103 ret = fn(tmp,
104 PCI_DEVID(tmp->subordinate->number,
105 PCI_DEVFN(0, 0)), data);
106 else
107 ret = fn(tmp, pci_dev_id(tmp), data);
108 if (ret)
109 return ret;
110 }
111 }
112
113 return ret;
114}
115
116static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
117{
118 struct pci_bus *child;
119 struct pci_bus *tmp;
120
121 if (bus->number == busnr)
122 return bus;
123
124 list_for_each_entry(tmp, &bus->children, node) {
125 child = pci_do_find_bus(tmp, busnr);
126 if (child)
127 return child;
128 }
129 return NULL;
130}
131
132/**
133 * pci_find_bus - locate PCI bus from a given domain and bus number
134 * @domain: number of PCI domain to search
135 * @busnr: number of desired PCI bus
136 *
137 * Given a PCI bus number and domain number, the desired PCI bus is located
138 * in the global list of PCI buses. If the bus is found, a pointer to its
139 * data structure is returned. If no bus is found, %NULL is returned.
140 */
141struct pci_bus *pci_find_bus(int domain, int busnr)
142{
143 struct pci_bus *bus = NULL;
144 struct pci_bus *tmp_bus;
145
146 while ((bus = pci_find_next_bus(bus)) != NULL) {
147 if (pci_domain_nr(bus) != domain)
148 continue;
149 tmp_bus = pci_do_find_bus(bus, busnr);
150 if (tmp_bus)
151 return tmp_bus;
152 }
153 return NULL;
154}
155EXPORT_SYMBOL(pci_find_bus);
156
157/**
158 * pci_find_next_bus - begin or continue searching for a PCI bus
159 * @from: Previous PCI bus found, or %NULL for new search.
160 *
161 * Iterates through the list of known PCI buses. A new search is
162 * initiated by passing %NULL as the @from argument. Otherwise if
163 * @from is not %NULL, searches continue from next device on the
164 * global list.
165 */
166struct pci_bus *pci_find_next_bus(const struct pci_bus *from)
167{
168 struct list_head *n;
169 struct pci_bus *b = NULL;
170
171 WARN_ON(in_interrupt());
172 down_read(&pci_bus_sem);
173 n = from ? from->node.next : pci_root_buses.next;
174 if (n != &pci_root_buses)
175 b = list_entry(n, struct pci_bus, node);
176 up_read(&pci_bus_sem);
177 return b;
178}
179EXPORT_SYMBOL(pci_find_next_bus);
180
181/**
182 * pci_get_slot - locate PCI device for a given PCI slot
183 * @bus: PCI bus on which desired PCI device resides
184 * @devfn: encodes number of PCI slot in which the desired PCI
185 * device resides and the logical device number within that slot
186 * in case of multi-function devices.
187 *
188 * Given a PCI bus and slot/function number, the desired PCI device
189 * is located in the list of PCI devices.
190 * If the device is found, its reference count is increased and this
191 * function returns a pointer to its data structure. The caller must
192 * decrement the reference count by calling pci_dev_put().
193 * If no device is found, %NULL is returned.
194 */
195struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
196{
197 struct pci_dev *dev;
198
199 WARN_ON(in_interrupt());
200 down_read(&pci_bus_sem);
201
202 list_for_each_entry(dev, &bus->devices, bus_list) {
203 if (dev->devfn == devfn)
204 goto out;
205 }
206
207 dev = NULL;
208 out:
209 pci_dev_get(dev);
210 up_read(&pci_bus_sem);
211 return dev;
212}
213EXPORT_SYMBOL(pci_get_slot);
214
215/**
216 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
217 * @domain: PCI domain/segment on which the PCI device resides.
218 * @bus: PCI bus on which desired PCI device resides
219 * @devfn: encodes number of PCI slot in which the desired PCI device
220 * resides and the logical device number within that slot in case of
221 * multi-function devices.
222 *
223 * Given a PCI domain, bus, and slot/function number, the desired PCI
224 * device is located in the list of PCI devices. If the device is
225 * found, its reference count is increased and this function returns a
226 * pointer to its data structure. The caller must decrement the
227 * reference count by calling pci_dev_put(). If no device is found,
228 * %NULL is returned.
229 */
230struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
231 unsigned int devfn)
232{
233 struct pci_dev *dev = NULL;
234
235 for_each_pci_dev(dev) {
236 if (pci_domain_nr(dev->bus) == domain &&
237 (dev->bus->number == bus && dev->devfn == devfn))
238 return dev;
239 }
240 return NULL;
241}
242EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
243
244static int match_pci_dev_by_id(struct device *dev, const void *data)
245{
246 struct pci_dev *pdev = to_pci_dev(dev);
247 const struct pci_device_id *id = data;
248
249 if (pci_match_one_device(id, pdev))
250 return 1;
251 return 0;
252}
253
254/*
255 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
256 * @id: pointer to struct pci_device_id to match for the device
257 * @from: Previous PCI device found in search, or %NULL for new search.
258 *
259 * Iterates through the list of known PCI devices. If a PCI device is found
260 * with a matching id a pointer to its device structure is returned, and the
261 * reference count to the device is incremented. Otherwise, %NULL is returned.
262 * A new search is initiated by passing %NULL as the @from argument. Otherwise
263 * if @from is not %NULL, searches continue from next device on the global
264 * list. The reference count for @from is always decremented if it is not
265 * %NULL.
266 *
267 * This is an internal function for use by the other search functions in
268 * this file.
269 */
270static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
271 struct pci_dev *from)
272{
273 struct device *dev;
274 struct device *dev_start = NULL;
275 struct pci_dev *pdev = NULL;
276
277 WARN_ON(in_interrupt());
278 if (from)
279 dev_start = &from->dev;
280 dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
281 match_pci_dev_by_id);
282 if (dev)
283 pdev = to_pci_dev(dev);
284 pci_dev_put(from);
285 return pdev;
286}
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 *
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
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
300 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
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 */
304struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
305 unsigned int ss_vendor, unsigned int ss_device,
306 struct pci_dev *from)
307{
308 struct pci_device_id id = {
309 .vendor = vendor,
310 .device = device,
311 .subvendor = ss_vendor,
312 .subdevice = ss_device,
313 };
314
315 return pci_get_dev_by_id(&id, from);
316}
317EXPORT_SYMBOL(pci_get_subsys);
318
319/**
320 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
321 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
322 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
323 * @from: Previous PCI device found in search, or %NULL for new search.
324 *
325 * Iterates through the list of known PCI devices. If a PCI device is
326 * found with a matching @vendor and @device, the reference count to the
327 * device is incremented and a pointer to its device structure is returned.
328 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
329 * as the @from argument. Otherwise if @from is not %NULL, searches continue
330 * from next device on the global list. The reference count for @from is
331 * always decremented if it is not %NULL.
332 */
333struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
334 struct pci_dev *from)
335{
336 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
337}
338EXPORT_SYMBOL(pci_get_device);
339
340/**
341 * pci_get_class - begin or continue searching for a PCI device by class
342 * @class: search for a PCI device with this class designation
343 * @from: Previous PCI device found in search, or %NULL for new search.
344 *
345 * Iterates through the list of known PCI devices. If a PCI device is
346 * found with a matching @class, the reference count to the device is
347 * incremented and a pointer to its device structure is returned.
348 * Otherwise, %NULL is returned.
349 * A new search is initiated by passing %NULL as the @from argument.
350 * Otherwise if @from is not %NULL, searches continue from next device
351 * on the global list. The reference count for @from is always decremented
352 * if it is not %NULL.
353 */
354struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
355{
356 struct pci_device_id id = {
357 .vendor = PCI_ANY_ID,
358 .device = PCI_ANY_ID,
359 .subvendor = PCI_ANY_ID,
360 .subdevice = PCI_ANY_ID,
361 .class_mask = PCI_ANY_ID,
362 .class = class,
363 };
364
365 return pci_get_dev_by_id(&id, from);
366}
367EXPORT_SYMBOL(pci_get_class);
368
369/**
370 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
371 * @ids: A pointer to a null terminated list of struct pci_device_id structures
372 * that describe the type of PCI device the caller is trying to find.
373 *
374 * Obvious fact: You do not have a reference to any device that might be found
375 * by this function, so if that device is removed from the system right after
376 * this function is finished, the value will be stale. Use this function to
377 * find devices that are usually built into a system, or for a general hint as
378 * to if another device happens to be present at this specific moment in time.
379 */
380int pci_dev_present(const struct pci_device_id *ids)
381{
382 struct pci_dev *found = NULL;
383
384 WARN_ON(in_interrupt());
385 while (ids->vendor || ids->subvendor || ids->class_mask) {
386 found = pci_get_dev_by_id(ids, NULL);
387 if (found) {
388 pci_dev_put(found);
389 return 1;
390 }
391 ids++;
392 }
393
394 return 0;
395}
396EXPORT_SYMBOL(pci_dev_present);