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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/init.h>
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);
18EXPORT_SYMBOL_GPL(pci_bus_sem);
19
20/*
21 * find the upstream PCIe-to-PCI bridge of a PCI device
22 * if the device is PCIE, return NULL
23 * if the device isn't connected to a PCIe bridge (that is its parent is a
24 * legacy PCI bridge and the bridge is directly connected to bus 0), return its
25 * parent
26 */
27struct pci_dev *
28pci_find_upstream_pcie_bridge(struct pci_dev *pdev)
29{
30 struct pci_dev *tmp = NULL;
31
32 if (pci_is_pcie(pdev))
33 return NULL;
34 while (1) {
35 if (pci_is_root_bus(pdev->bus))
36 break;
37 pdev = pdev->bus->self;
38 /* a p2p bridge */
39 if (!pci_is_pcie(pdev)) {
40 tmp = pdev;
41 continue;
42 }
43 /* PCI device should connect to a PCIe bridge */
44 if (pci_pcie_type(pdev) != PCI_EXP_TYPE_PCI_BRIDGE) {
45 /* Busted hardware? */
46 WARN_ON_ONCE(1);
47 return NULL;
48 }
49 return pdev;
50 }
51
52 return tmp;
53}
54
55static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
56{
57 struct pci_bus *child;
58 struct pci_bus *tmp;
59
60 if(bus->number == busnr)
61 return bus;
62
63 list_for_each_entry(tmp, &bus->children, node) {
64 child = pci_do_find_bus(tmp, busnr);
65 if(child)
66 return child;
67 }
68 return NULL;
69}
70
71/**
72 * pci_find_bus - locate PCI bus from a given domain and bus number
73 * @domain: number of PCI domain to search
74 * @busnr: number of desired PCI bus
75 *
76 * Given a PCI bus number and domain number, the desired PCI bus is located
77 * in the global list of PCI buses. If the bus is found, a pointer to its
78 * data structure is returned. If no bus is found, %NULL is returned.
79 */
80struct pci_bus * pci_find_bus(int domain, int busnr)
81{
82 struct pci_bus *bus = NULL;
83 struct pci_bus *tmp_bus;
84
85 while ((bus = pci_find_next_bus(bus)) != NULL) {
86 if (pci_domain_nr(bus) != domain)
87 continue;
88 tmp_bus = pci_do_find_bus(bus, busnr);
89 if (tmp_bus)
90 return tmp_bus;
91 }
92 return NULL;
93}
94
95/**
96 * pci_find_next_bus - begin or continue searching for a PCI bus
97 * @from: Previous PCI bus found, or %NULL for new search.
98 *
99 * Iterates through the list of known PCI buses. A new search is
100 * initiated by passing %NULL as the @from argument. Otherwise if
101 * @from is not %NULL, searches continue from next device on the
102 * global list.
103 */
104struct pci_bus *
105pci_find_next_bus(const struct pci_bus *from)
106{
107 struct list_head *n;
108 struct pci_bus *b = NULL;
109
110 WARN_ON(in_interrupt());
111 down_read(&pci_bus_sem);
112 n = from ? from->node.next : pci_root_buses.next;
113 if (n != &pci_root_buses)
114 b = list_entry(n, struct pci_bus, node);
115 up_read(&pci_bus_sem);
116 return b;
117}
118
119/**
120 * pci_get_slot - locate PCI device for a given PCI slot
121 * @bus: PCI bus on which desired PCI device resides
122 * @devfn: encodes number of PCI slot in which the desired PCI
123 * device resides and the logical device number within that slot
124 * in case of multi-function devices.
125 *
126 * Given a PCI bus and slot/function number, the desired PCI device
127 * is located in the list of PCI devices.
128 * If the device is found, its reference count is increased and this
129 * function returns a pointer to its data structure. The caller must
130 * decrement the reference count by calling pci_dev_put().
131 * If no device is found, %NULL is returned.
132 */
133struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
134{
135 struct pci_dev *dev;
136
137 WARN_ON(in_interrupt());
138 down_read(&pci_bus_sem);
139
140 list_for_each_entry(dev, &bus->devices, bus_list) {
141 if (dev->devfn == devfn)
142 goto out;
143 }
144
145 dev = NULL;
146 out:
147 pci_dev_get(dev);
148 up_read(&pci_bus_sem);
149 return dev;
150}
151
152/**
153 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
154 * @domain: PCI domain/segment on which the PCI device resides.
155 * @bus: PCI bus on which desired PCI device resides
156 * @devfn: encodes number of PCI slot in which the desired PCI device
157 * resides and the logical device number within that slot in case of
158 * multi-function devices.
159 *
160 * Given a PCI domain, bus, and slot/function number, the desired PCI
161 * device is located in the list of PCI devices. If the device is
162 * found, its reference count is increased and this function returns a
163 * pointer to its data structure. The caller must decrement the
164 * reference count by calling pci_dev_put(). If no device is found,
165 * %NULL is returned.
166 */
167struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
168 unsigned int devfn)
169{
170 struct pci_dev *dev = NULL;
171
172 for_each_pci_dev(dev) {
173 if (pci_domain_nr(dev->bus) == domain &&
174 (dev->bus->number == bus && dev->devfn == devfn))
175 return dev;
176 }
177 return NULL;
178}
179EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
180
181static int match_pci_dev_by_id(struct device *dev, void *data)
182{
183 struct pci_dev *pdev = to_pci_dev(dev);
184 struct pci_device_id *id = data;
185
186 if (pci_match_one_device(id, pdev))
187 return 1;
188 return 0;
189}
190
191/*
192 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
193 * @id: pointer to struct pci_device_id to match for the device
194 * @from: Previous PCI device found in search, or %NULL for new search.
195 *
196 * Iterates through the list of known PCI devices. If a PCI device is found
197 * with a matching id a pointer to its device structure is returned, and the
198 * reference count to the device is incremented. Otherwise, %NULL is returned.
199 * A new search is initiated by passing %NULL as the @from argument. Otherwise
200 * if @from is not %NULL, searches continue from next device on the global
201 * list. The reference count for @from is always decremented if it is not
202 * %NULL.
203 *
204 * This is an internal function for use by the other search functions in
205 * this file.
206 */
207static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
208 struct pci_dev *from)
209{
210 struct device *dev;
211 struct device *dev_start = NULL;
212 struct pci_dev *pdev = NULL;
213
214 WARN_ON(in_interrupt());
215 if (from)
216 dev_start = &from->dev;
217 dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
218 match_pci_dev_by_id);
219 if (dev)
220 pdev = to_pci_dev(dev);
221 if (from)
222 pci_dev_put(from);
223 return pdev;
224}
225
226/**
227 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
228 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
229 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
230 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
231 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
232 * @from: Previous PCI device found in search, or %NULL for new search.
233 *
234 * Iterates through the list of known PCI devices. If a PCI device is found
235 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
236 * device structure is returned, and the reference count to the device is
237 * incremented. Otherwise, %NULL is returned. A new search is initiated by
238 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
239 * searches continue from next device on the global list.
240 * The reference count for @from is always decremented if it is not %NULL.
241 */
242struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
243 unsigned int ss_vendor, unsigned int ss_device,
244 struct pci_dev *from)
245{
246 struct pci_device_id id = {
247 .vendor = vendor,
248 .device = device,
249 .subvendor = ss_vendor,
250 .subdevice = ss_device,
251 };
252
253 return pci_get_dev_by_id(&id, from);
254}
255
256/**
257 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
258 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
259 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
260 * @from: Previous PCI device found in search, or %NULL for new search.
261 *
262 * Iterates through the list of known PCI devices. If a PCI device is
263 * found with a matching @vendor and @device, the reference count to the
264 * device is incremented and a pointer to its device structure is returned.
265 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
266 * as the @from argument. Otherwise if @from is not %NULL, searches continue
267 * from next device on the global list. The reference count for @from is
268 * always decremented if it is not %NULL.
269 */
270struct pci_dev *
271pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
272{
273 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
274}
275
276/**
277 * pci_get_class - begin or continue searching for a PCI device by class
278 * @class: search for a PCI device with this class designation
279 * @from: Previous PCI device found in search, or %NULL for new search.
280 *
281 * Iterates through the list of known PCI devices. If a PCI device is
282 * found with a matching @class, the reference count to the device is
283 * incremented and a pointer to its device structure is returned.
284 * Otherwise, %NULL is returned.
285 * A new search is initiated by passing %NULL as the @from argument.
286 * Otherwise if @from is not %NULL, searches continue from next device
287 * on the global list. The reference count for @from is always decremented
288 * if it is not %NULL.
289 */
290struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
291{
292 struct pci_device_id id = {
293 .vendor = PCI_ANY_ID,
294 .device = PCI_ANY_ID,
295 .subvendor = PCI_ANY_ID,
296 .subdevice = PCI_ANY_ID,
297 .class_mask = PCI_ANY_ID,
298 .class = class,
299 };
300
301 return pci_get_dev_by_id(&id, from);
302}
303
304/**
305 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
306 * @ids: A pointer to a null terminated list of struct pci_device_id structures
307 * that describe the type of PCI device the caller is trying to find.
308 *
309 * Obvious fact: You do not have a reference to any device that might be found
310 * by this function, so if that device is removed from the system right after
311 * this function is finished, the value will be stale. Use this function to
312 * find devices that are usually built into a system, or for a general hint as
313 * to if another device happens to be present at this specific moment in time.
314 */
315int pci_dev_present(const struct pci_device_id *ids)
316{
317 struct pci_dev *found = NULL;
318
319 WARN_ON(in_interrupt());
320 while (ids->vendor || ids->subvendor || ids->class_mask) {
321 found = pci_get_dev_by_id(ids, NULL);
322 if (found) {
323 pci_dev_put(found);
324 return 1;
325 }
326 ids++;
327 }
328
329 return 0;
330}
331EXPORT_SYMBOL(pci_dev_present);
332
333/* For boot time work */
334EXPORT_SYMBOL(pci_find_bus);
335EXPORT_SYMBOL(pci_find_next_bus);
336/* For everyone */
337EXPORT_SYMBOL(pci_get_device);
338EXPORT_SYMBOL(pci_get_subsys);
339EXPORT_SYMBOL(pci_get_slot);
340EXPORT_SYMBOL(pci_get_class);