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