Loading...
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);
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_get_base_class - searching for a PCI device by matching against the base class code only
368 * @class: search for a PCI device with this base class code
369 * @from: Previous PCI device found in search, or %NULL for new search.
370 *
371 * Iterates through the list of known PCI devices. If a PCI device is found
372 * with a matching base class code, the reference count to the device is
373 * incremented. See pci_match_one_device() to figure out how does this works.
374 * A new search is initiated by passing %NULL as the @from argument.
375 * Otherwise if @from is not %NULL, searches continue from next device on the
376 * global list. The reference count for @from is always decremented if it is
377 * not %NULL.
378 *
379 * Returns:
380 * A pointer to a matched PCI device, %NULL Otherwise.
381 */
382struct pci_dev *pci_get_base_class(unsigned int class, struct pci_dev *from)
383{
384 struct pci_device_id id = {
385 .vendor = PCI_ANY_ID,
386 .device = PCI_ANY_ID,
387 .subvendor = PCI_ANY_ID,
388 .subdevice = PCI_ANY_ID,
389 .class_mask = 0xFF0000,
390 .class = class << 16,
391 };
392
393 return pci_get_dev_by_id(&id, from);
394}
395EXPORT_SYMBOL(pci_get_base_class);
396
397/**
398 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
399 * @ids: A pointer to a null terminated list of struct pci_device_id structures
400 * that describe the type of PCI device the caller is trying to find.
401 *
402 * Obvious fact: You do not have a reference to any device that might be found
403 * by this function, so if that device is removed from the system right after
404 * this function is finished, the value will be stale. Use this function to
405 * find devices that are usually built into a system, or for a general hint as
406 * to if another device happens to be present at this specific moment in time.
407 */
408int pci_dev_present(const struct pci_device_id *ids)
409{
410 struct pci_dev *found = NULL;
411
412 while (ids->vendor || ids->subvendor || ids->class_mask) {
413 found = pci_get_dev_by_id(ids, NULL);
414 if (found) {
415 pci_dev_put(found);
416 return 1;
417 }
418 ids++;
419 }
420
421 return 0;
422}
423EXPORT_SYMBOL(pci_dev_present);