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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/*
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);