Loading...
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);
18/*
19 * find the upstream PCIe-to-PCI bridge of a PCI device
20 * if the device is PCIE, return NULL
21 * if the device isn't connected to a PCIe bridge (that is its parent is a
22 * legacy PCI bridge and the bridge is directly connected to bus 0), return its
23 * parent
24 */
25struct pci_dev *
26pci_find_upstream_pcie_bridge(struct pci_dev *pdev)
27{
28 struct pci_dev *tmp = NULL;
29
30 if (pci_is_pcie(pdev))
31 return NULL;
32 while (1) {
33 if (pci_is_root_bus(pdev->bus))
34 break;
35 pdev = pdev->bus->self;
36 /* a p2p bridge */
37 if (!pci_is_pcie(pdev)) {
38 tmp = pdev;
39 continue;
40 }
41 /* PCI device should connect to a PCIe bridge */
42 if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) {
43 /* Busted hardware? */
44 WARN_ON_ONCE(1);
45 return NULL;
46 }
47 return pdev;
48 }
49
50 return tmp;
51}
52
53static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
54{
55 struct pci_bus* child;
56 struct list_head *tmp;
57
58 if(bus->number == busnr)
59 return bus;
60
61 list_for_each(tmp, &bus->children) {
62 child = pci_do_find_bus(pci_bus_b(tmp), busnr);
63 if(child)
64 return child;
65 }
66 return NULL;
67}
68
69/**
70 * pci_find_bus - locate PCI bus from a given domain and bus number
71 * @domain: number of PCI domain to search
72 * @busnr: number of desired PCI bus
73 *
74 * Given a PCI bus number and domain number, the desired PCI bus is located
75 * in the global list of PCI buses. If the bus is found, a pointer to its
76 * data structure is returned. If no bus is found, %NULL is returned.
77 */
78struct pci_bus * pci_find_bus(int domain, int busnr)
79{
80 struct pci_bus *bus = NULL;
81 struct pci_bus *tmp_bus;
82
83 while ((bus = pci_find_next_bus(bus)) != NULL) {
84 if (pci_domain_nr(bus) != domain)
85 continue;
86 tmp_bus = pci_do_find_bus(bus, busnr);
87 if (tmp_bus)
88 return tmp_bus;
89 }
90 return NULL;
91}
92
93/**
94 * pci_find_next_bus - begin or continue searching for a PCI bus
95 * @from: Previous PCI bus found, or %NULL for new search.
96 *
97 * Iterates through the list of known PCI busses. A new search is
98 * initiated by passing %NULL as the @from argument. Otherwise if
99 * @from is not %NULL, searches continue from next device on the
100 * global list.
101 */
102struct pci_bus *
103pci_find_next_bus(const struct pci_bus *from)
104{
105 struct list_head *n;
106 struct pci_bus *b = NULL;
107
108 WARN_ON(in_interrupt());
109 down_read(&pci_bus_sem);
110 n = from ? from->node.next : pci_root_buses.next;
111 if (n != &pci_root_buses)
112 b = pci_bus_b(n);
113 up_read(&pci_bus_sem);
114 return b;
115}
116
117/**
118 * pci_get_slot - locate PCI device for a given PCI slot
119 * @bus: PCI bus on which desired PCI device resides
120 * @devfn: encodes number of PCI slot in which the desired PCI
121 * device resides and the logical device number within that slot
122 * in case of multi-function devices.
123 *
124 * Given a PCI bus and slot/function number, the desired PCI device
125 * is located in the list of PCI devices.
126 * If the device is found, its reference count is increased and this
127 * function returns a pointer to its data structure. The caller must
128 * decrement the reference count by calling pci_dev_put().
129 * If no device is found, %NULL is returned.
130 */
131struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn)
132{
133 struct list_head *tmp;
134 struct pci_dev *dev;
135
136 WARN_ON(in_interrupt());
137 down_read(&pci_bus_sem);
138
139 list_for_each(tmp, &bus->devices) {
140 dev = pci_dev_b(tmp);
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_dev *pdev;
247 struct pci_device_id *id;
248
249 /*
250 * pci_find_subsys() can be called on the ide_setup() path,
251 * super-early in boot. But the down_read() will enable local
252 * interrupts, which can cause some machines to crash. So here we
253 * detect and flag that situation and bail out early.
254 */
255 if (unlikely(no_pci_devices()))
256 return NULL;
257
258 id = kzalloc(sizeof(*id), GFP_KERNEL);
259 if (!id)
260 return NULL;
261 id->vendor = vendor;
262 id->device = device;
263 id->subvendor = ss_vendor;
264 id->subdevice = ss_device;
265
266 pdev = pci_get_dev_by_id(id, from);
267 kfree(id);
268
269 return pdev;
270}
271
272/**
273 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
274 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
275 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
276 * @from: Previous PCI device found in search, or %NULL for new search.
277 *
278 * Iterates through the list of known PCI devices. If a PCI device is
279 * found with a matching @vendor and @device, the reference count to the
280 * device is incremented and a pointer to its device structure is returned.
281 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
282 * as the @from argument. Otherwise if @from is not %NULL, searches continue
283 * from next device on the global list. The reference count for @from is
284 * always decremented if it is not %NULL.
285 */
286struct pci_dev *
287pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
288{
289 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
290}
291
292/**
293 * pci_get_class - begin or continue searching for a PCI device by class
294 * @class: search for a PCI device with this class designation
295 * @from: Previous PCI device found in search, or %NULL for new search.
296 *
297 * Iterates through the list of known PCI devices. If a PCI device is
298 * found with a matching @class, the reference count to the device is
299 * incremented and a pointer to its device structure is returned.
300 * Otherwise, %NULL is returned.
301 * A new search is initiated by passing %NULL as the @from argument.
302 * Otherwise if @from is not %NULL, searches continue from next device
303 * on the global list. The reference count for @from is always decremented
304 * if it is not %NULL.
305 */
306struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
307{
308 struct pci_dev *dev;
309 struct pci_device_id *id;
310
311 id = kzalloc(sizeof(*id), GFP_KERNEL);
312 if (!id)
313 return NULL;
314 id->vendor = id->device = id->subvendor = id->subdevice = PCI_ANY_ID;
315 id->class_mask = PCI_ANY_ID;
316 id->class = class;
317
318 dev = pci_get_dev_by_id(id, from);
319 kfree(id);
320 return dev;
321}
322
323/**
324 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
325 * @ids: A pointer to a null terminated list of struct pci_device_id structures
326 * that describe the type of PCI device the caller is trying to find.
327 *
328 * Obvious fact: You do not have a reference to any device that might be found
329 * by this function, so if that device is removed from the system right after
330 * this function is finished, the value will be stale. Use this function to
331 * find devices that are usually built into a system, or for a general hint as
332 * to if another device happens to be present at this specific moment in time.
333 */
334int pci_dev_present(const struct pci_device_id *ids)
335{
336 struct pci_dev *found = NULL;
337
338 WARN_ON(in_interrupt());
339 while (ids->vendor || ids->subvendor || ids->class_mask) {
340 found = pci_get_dev_by_id(ids, NULL);
341 if (found)
342 goto exit;
343 ids++;
344 }
345exit:
346 if (found)
347 return 1;
348 return 0;
349}
350EXPORT_SYMBOL(pci_dev_present);
351
352/* For boot time work */
353EXPORT_SYMBOL(pci_find_bus);
354EXPORT_SYMBOL(pci_find_next_bus);
355/* For everyone */
356EXPORT_SYMBOL(pci_get_device);
357EXPORT_SYMBOL(pci_get_subsys);
358EXPORT_SYMBOL(pci_get_slot);
359EXPORT_SYMBOL(pci_get_class);
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);