2 * PCI searching functions.
4 * Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
6 * Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
7 * Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
10 #include <linux/pci.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
16 DECLARE_RWSEM(pci_bus_sem
);
17 EXPORT_SYMBOL_GPL(pci_bus_sem
);
20 * find the upstream PCIe-to-PCI bridge of a PCI device
21 * if the device is PCIE, return NULL
22 * if the device isn't connected to a PCIe bridge (that is its parent is a
23 * legacy PCI bridge and the bridge is directly connected to bus 0), return its
27 pci_find_upstream_pcie_bridge(struct pci_dev
*pdev
)
29 struct pci_dev
*tmp
= NULL
;
31 if (pci_is_pcie(pdev
))
34 if (pci_is_root_bus(pdev
->bus
))
36 pdev
= pdev
->bus
->self
;
38 if (!pci_is_pcie(pdev
)) {
42 /* PCI device should connect to a PCIe bridge */
43 if (pci_pcie_type(pdev
) != PCI_EXP_TYPE_PCI_BRIDGE
) {
44 /* Busted hardware? */
54 static struct pci_bus
*pci_do_find_bus(struct pci_bus
*bus
, unsigned char busnr
)
56 struct pci_bus
*child
;
59 if(bus
->number
== busnr
)
62 list_for_each_entry(tmp
, &bus
->children
, node
) {
63 child
= pci_do_find_bus(tmp
, busnr
);
71 * pci_find_bus - locate PCI bus from a given domain and bus number
72 * @domain: number of PCI domain to search
73 * @busnr: number of desired PCI bus
75 * Given a PCI bus number and domain number, the desired PCI bus is located
76 * in the global list of PCI buses. If the bus is found, a pointer to its
77 * data structure is returned. If no bus is found, %NULL is returned.
79 struct pci_bus
* pci_find_bus(int domain
, int busnr
)
81 struct pci_bus
*bus
= NULL
;
82 struct pci_bus
*tmp_bus
;
84 while ((bus
= pci_find_next_bus(bus
)) != NULL
) {
85 if (pci_domain_nr(bus
) != domain
)
87 tmp_bus
= pci_do_find_bus(bus
, busnr
);
95 * pci_find_next_bus - begin or continue searching for a PCI bus
96 * @from: Previous PCI bus found, or %NULL for new search.
98 * Iterates through the list of known PCI buses. A new search is
99 * initiated by passing %NULL as the @from argument. Otherwise if
100 * @from is not %NULL, searches continue from next device on the
104 pci_find_next_bus(const struct pci_bus
*from
)
107 struct pci_bus
*b
= NULL
;
109 WARN_ON(in_interrupt());
110 down_read(&pci_bus_sem
);
111 n
= from
? from
->node
.next
: pci_root_buses
.next
;
112 if (n
!= &pci_root_buses
)
113 b
= list_entry(n
, struct pci_bus
, node
);
114 up_read(&pci_bus_sem
);
119 * pci_get_slot - locate PCI device for a given PCI slot
120 * @bus: PCI bus on which desired PCI device resides
121 * @devfn: encodes number of PCI slot in which the desired PCI
122 * device resides and the logical device number within that slot
123 * in case of multi-function devices.
125 * Given a PCI bus and slot/function number, the desired PCI device
126 * is located in the list of PCI devices.
127 * If the device is found, its reference count is increased and this
128 * function returns a pointer to its data structure. The caller must
129 * decrement the reference count by calling pci_dev_put().
130 * If no device is found, %NULL is returned.
132 struct pci_dev
*pci_get_slot(struct pci_bus
*bus
, unsigned int devfn
)
136 WARN_ON(in_interrupt());
137 down_read(&pci_bus_sem
);
139 list_for_each_entry(dev
, &bus
->devices
, bus_list
) {
140 if (dev
->devfn
== devfn
)
147 up_read(&pci_bus_sem
);
152 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
153 * @domain: PCI domain/segment on which the PCI device resides.
154 * @bus: PCI bus on which desired PCI device resides
155 * @devfn: encodes number of PCI slot in which the desired PCI device
156 * resides and the logical device number within that slot in case of
157 * multi-function devices.
159 * Given a PCI domain, bus, and slot/function number, the desired PCI
160 * device is located in the list of PCI devices. If the device is
161 * found, its reference count is increased and this function returns a
162 * pointer to its data structure. The caller must decrement the
163 * reference count by calling pci_dev_put(). If no device is found,
166 struct pci_dev
*pci_get_domain_bus_and_slot(int domain
, unsigned int bus
,
169 struct pci_dev
*dev
= NULL
;
171 for_each_pci_dev(dev
) {
172 if (pci_domain_nr(dev
->bus
) == domain
&&
173 (dev
->bus
->number
== bus
&& dev
->devfn
== devfn
))
178 EXPORT_SYMBOL(pci_get_domain_bus_and_slot
);
180 static int match_pci_dev_by_id(struct device
*dev
, void *data
)
182 struct pci_dev
*pdev
= to_pci_dev(dev
);
183 struct pci_device_id
*id
= data
;
185 if (pci_match_one_device(id
, pdev
))
191 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
192 * @id: pointer to struct pci_device_id to match for the device
193 * @from: Previous PCI device found in search, or %NULL for new search.
195 * Iterates through the list of known PCI devices. If a PCI device is found
196 * with a matching id a pointer to its device structure is returned, and the
197 * reference count to the device is incremented. Otherwise, %NULL is returned.
198 * A new search is initiated by passing %NULL as the @from argument. Otherwise
199 * if @from is not %NULL, searches continue from next device on the global
200 * list. The reference count for @from is always decremented if it is not
203 * This is an internal function for use by the other search functions in
206 static struct pci_dev
*pci_get_dev_by_id(const struct pci_device_id
*id
,
207 struct pci_dev
*from
)
210 struct device
*dev_start
= NULL
;
211 struct pci_dev
*pdev
= NULL
;
213 WARN_ON(in_interrupt());
215 dev_start
= &from
->dev
;
216 dev
= bus_find_device(&pci_bus_type
, dev_start
, (void *)id
,
217 match_pci_dev_by_id
);
219 pdev
= to_pci_dev(dev
);
226 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
227 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
228 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
229 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
230 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
231 * @from: Previous PCI device found in search, or %NULL for new search.
233 * Iterates through the list of known PCI devices. If a PCI device is found
234 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
235 * device structure is returned, and the reference count to the device is
236 * incremented. Otherwise, %NULL is returned. A new search is initiated by
237 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
238 * searches continue from next device on the global list.
239 * The reference count for @from is always decremented if it is not %NULL.
241 struct pci_dev
*pci_get_subsys(unsigned int vendor
, unsigned int device
,
242 unsigned int ss_vendor
, unsigned int ss_device
,
243 struct pci_dev
*from
)
245 struct pci_device_id id
= {
248 .subvendor
= ss_vendor
,
249 .subdevice
= ss_device
,
252 return pci_get_dev_by_id(&id
, from
);
256 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
257 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
258 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
259 * @from: Previous PCI device found in search, or %NULL for new search.
261 * Iterates through the list of known PCI devices. If a PCI device is
262 * found with a matching @vendor and @device, the reference count to the
263 * device is incremented and a pointer to its device structure is returned.
264 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
265 * as the @from argument. Otherwise if @from is not %NULL, searches continue
266 * from next device on the global list. The reference count for @from is
267 * always decremented if it is not %NULL.
270 pci_get_device(unsigned int vendor
, unsigned int device
, struct pci_dev
*from
)
272 return pci_get_subsys(vendor
, device
, PCI_ANY_ID
, PCI_ANY_ID
, from
);
276 * pci_get_class - begin or continue searching for a PCI device by class
277 * @class: search for a PCI device with this class designation
278 * @from: Previous PCI device found in search, or %NULL for new search.
280 * Iterates through the list of known PCI devices. If a PCI device is
281 * found with a matching @class, the reference count to the device is
282 * incremented and a pointer to its device structure is returned.
283 * Otherwise, %NULL is returned.
284 * A new search is initiated by passing %NULL as the @from argument.
285 * Otherwise if @from is not %NULL, searches continue from next device
286 * on the global list. The reference count for @from is always decremented
287 * if it is not %NULL.
289 struct pci_dev
*pci_get_class(unsigned int class, struct pci_dev
*from
)
291 struct pci_device_id id
= {
292 .vendor
= PCI_ANY_ID
,
293 .device
= PCI_ANY_ID
,
294 .subvendor
= PCI_ANY_ID
,
295 .subdevice
= PCI_ANY_ID
,
296 .class_mask
= PCI_ANY_ID
,
300 return pci_get_dev_by_id(&id
, from
);
304 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
305 * @ids: A pointer to a null terminated list of struct pci_device_id structures
306 * that describe the type of PCI device the caller is trying to find.
308 * Obvious fact: You do not have a reference to any device that might be found
309 * by this function, so if that device is removed from the system right after
310 * this function is finished, the value will be stale. Use this function to
311 * find devices that are usually built into a system, or for a general hint as
312 * to if another device happens to be present at this specific moment in time.
314 int pci_dev_present(const struct pci_device_id
*ids
)
316 struct pci_dev
*found
= NULL
;
318 WARN_ON(in_interrupt());
319 while (ids
->vendor
|| ids
->subvendor
|| ids
->class_mask
) {
320 found
= pci_get_dev_by_id(ids
, NULL
);
330 EXPORT_SYMBOL(pci_dev_present
);
332 /* For boot time work */
333 EXPORT_SYMBOL(pci_find_bus
);
334 EXPORT_SYMBOL(pci_find_next_bus
);
336 EXPORT_SYMBOL(pci_get_device
);
337 EXPORT_SYMBOL(pci_get_subsys
);
338 EXPORT_SYMBOL(pci_get_slot
);
339 EXPORT_SYMBOL(pci_get_class
);