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/init.h>
11 #include <linux/pci.h>
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/interrupt.h>
17 DECLARE_RWSEM(pci_bus_sem
);
18 EXPORT_SYMBOL_GPL(pci_bus_sem
);
21 * pci_for_each_dma_alias - Iterate over DMA aliases for a device
22 * @pdev: starting downstream device
23 * @fn: function to call for each alias
24 * @data: opaque data to pass to @fn
26 * Starting @pdev, walk up the bus calling @fn for each possible alias
27 * of @pdev at the root bus.
29 int pci_for_each_dma_alias(struct pci_dev
*pdev
,
30 int (*fn
)(struct pci_dev
*pdev
,
31 u16 alias
, void *data
), void *data
)
36 ret
= fn(pdev
, PCI_DEVID(pdev
->bus
->number
, pdev
->devfn
), data
);
41 * If the device is broken and uses an alias requester ID for
42 * DMA, iterate over that too.
44 if (unlikely(pdev
->dev_flags
& PCI_DEV_FLAGS_DMA_ALIAS_DEVFN
)) {
45 ret
= fn(pdev
, PCI_DEVID(pdev
->bus
->number
,
46 pdev
->dma_alias_devfn
), data
);
51 for (bus
= pdev
->bus
; !pci_is_root_bus(bus
); bus
= bus
->parent
) {
54 /* Skip virtual buses */
61 * PCIe-to-PCI/X bridges alias transactions from downstream
62 * devices using the subordinate bus number (PCI Express to
63 * PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases
64 * where the upstream bus is PCI/X we alias to the bridge
65 * (there are various conditions in the previous reference
66 * where the bridge may take ownership of transactions, even
67 * when the secondary interface is PCI-X).
69 if (pci_is_pcie(tmp
)) {
70 switch (pci_pcie_type(tmp
)) {
71 case PCI_EXP_TYPE_ROOT_PORT
:
72 case PCI_EXP_TYPE_UPSTREAM
:
73 case PCI_EXP_TYPE_DOWNSTREAM
:
75 case PCI_EXP_TYPE_PCI_BRIDGE
:
77 PCI_DEVID(tmp
->subordinate
->number
,
78 PCI_DEVFN(0, 0)), data
);
82 case PCI_EXP_TYPE_PCIE_BRIDGE
:
84 PCI_DEVID(tmp
->bus
->number
,
91 ret
= fn(tmp
, PCI_DEVID(tmp
->bus
->number
, tmp
->devfn
),
102 * find the upstream PCIe-to-PCI bridge of a PCI device
103 * if the device is PCIE, return NULL
104 * if the device isn't connected to a PCIe bridge (that is its parent is a
105 * legacy PCI bridge and the bridge is directly connected to bus 0), return its
109 pci_find_upstream_pcie_bridge(struct pci_dev
*pdev
)
111 struct pci_dev
*tmp
= NULL
;
113 if (pci_is_pcie(pdev
))
116 if (pci_is_root_bus(pdev
->bus
))
118 pdev
= pdev
->bus
->self
;
120 if (!pci_is_pcie(pdev
)) {
124 /* PCI device should connect to a PCIe bridge */
125 if (pci_pcie_type(pdev
) != PCI_EXP_TYPE_PCI_BRIDGE
) {
126 /* Busted hardware? */
136 static struct pci_bus
*pci_do_find_bus(struct pci_bus
*bus
, unsigned char busnr
)
138 struct pci_bus
*child
;
141 if(bus
->number
== busnr
)
144 list_for_each_entry(tmp
, &bus
->children
, node
) {
145 child
= pci_do_find_bus(tmp
, busnr
);
153 * pci_find_bus - locate PCI bus from a given domain and bus number
154 * @domain: number of PCI domain to search
155 * @busnr: number of desired PCI bus
157 * Given a PCI bus number and domain number, the desired PCI bus is located
158 * in the global list of PCI buses. If the bus is found, a pointer to its
159 * data structure is returned. If no bus is found, %NULL is returned.
161 struct pci_bus
* pci_find_bus(int domain
, int busnr
)
163 struct pci_bus
*bus
= NULL
;
164 struct pci_bus
*tmp_bus
;
166 while ((bus
= pci_find_next_bus(bus
)) != NULL
) {
167 if (pci_domain_nr(bus
) != domain
)
169 tmp_bus
= pci_do_find_bus(bus
, busnr
);
177 * pci_find_next_bus - begin or continue searching for a PCI bus
178 * @from: Previous PCI bus found, or %NULL for new search.
180 * Iterates through the list of known PCI buses. A new search is
181 * initiated by passing %NULL as the @from argument. Otherwise if
182 * @from is not %NULL, searches continue from next device on the
186 pci_find_next_bus(const struct pci_bus
*from
)
189 struct pci_bus
*b
= NULL
;
191 WARN_ON(in_interrupt());
192 down_read(&pci_bus_sem
);
193 n
= from
? from
->node
.next
: pci_root_buses
.next
;
194 if (n
!= &pci_root_buses
)
195 b
= list_entry(n
, struct pci_bus
, node
);
196 up_read(&pci_bus_sem
);
201 * pci_get_slot - locate PCI device for a given PCI slot
202 * @bus: PCI bus on which desired PCI device resides
203 * @devfn: encodes number of PCI slot in which the desired PCI
204 * device resides and the logical device number within that slot
205 * in case of multi-function devices.
207 * Given a PCI bus and slot/function number, the desired PCI device
208 * is located in the list of PCI devices.
209 * If the device is found, its reference count is increased and this
210 * function returns a pointer to its data structure. The caller must
211 * decrement the reference count by calling pci_dev_put().
212 * If no device is found, %NULL is returned.
214 struct pci_dev
*pci_get_slot(struct pci_bus
*bus
, unsigned int devfn
)
218 WARN_ON(in_interrupt());
219 down_read(&pci_bus_sem
);
221 list_for_each_entry(dev
, &bus
->devices
, bus_list
) {
222 if (dev
->devfn
== devfn
)
229 up_read(&pci_bus_sem
);
234 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
235 * @domain: PCI domain/segment on which the PCI device resides.
236 * @bus: PCI bus on which desired PCI device resides
237 * @devfn: encodes number of PCI slot in which the desired PCI device
238 * resides and the logical device number within that slot in case of
239 * multi-function devices.
241 * Given a PCI domain, bus, and slot/function number, the desired PCI
242 * device is located in the list of PCI devices. If the device is
243 * found, its reference count is increased and this function returns a
244 * pointer to its data structure. The caller must decrement the
245 * reference count by calling pci_dev_put(). If no device is found,
248 struct pci_dev
*pci_get_domain_bus_and_slot(int domain
, unsigned int bus
,
251 struct pci_dev
*dev
= NULL
;
253 for_each_pci_dev(dev
) {
254 if (pci_domain_nr(dev
->bus
) == domain
&&
255 (dev
->bus
->number
== bus
&& dev
->devfn
== devfn
))
260 EXPORT_SYMBOL(pci_get_domain_bus_and_slot
);
262 static int match_pci_dev_by_id(struct device
*dev
, void *data
)
264 struct pci_dev
*pdev
= to_pci_dev(dev
);
265 struct pci_device_id
*id
= data
;
267 if (pci_match_one_device(id
, pdev
))
273 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
274 * @id: pointer to struct pci_device_id to match for the device
275 * @from: Previous PCI device found in search, or %NULL for new search.
277 * Iterates through the list of known PCI devices. If a PCI device is found
278 * with a matching id a pointer to its device structure is returned, and the
279 * reference count to the device is incremented. Otherwise, %NULL is returned.
280 * A new search is initiated by passing %NULL as the @from argument. Otherwise
281 * if @from is not %NULL, searches continue from next device on the global
282 * list. The reference count for @from is always decremented if it is not
285 * This is an internal function for use by the other search functions in
288 static struct pci_dev
*pci_get_dev_by_id(const struct pci_device_id
*id
,
289 struct pci_dev
*from
)
292 struct device
*dev_start
= NULL
;
293 struct pci_dev
*pdev
= NULL
;
295 WARN_ON(in_interrupt());
297 dev_start
= &from
->dev
;
298 dev
= bus_find_device(&pci_bus_type
, dev_start
, (void *)id
,
299 match_pci_dev_by_id
);
301 pdev
= to_pci_dev(dev
);
308 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
309 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
310 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
311 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
312 * @ss_device: PCI subsystem 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.
315 * Iterates through the list of known PCI devices. If a PCI device is found
316 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
317 * device structure is returned, and the reference count to the device is
318 * incremented. Otherwise, %NULL is returned. A new search is initiated by
319 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
320 * searches continue from next device on the global list.
321 * The reference count for @from is always decremented if it is not %NULL.
323 struct pci_dev
*pci_get_subsys(unsigned int vendor
, unsigned int device
,
324 unsigned int ss_vendor
, unsigned int ss_device
,
325 struct pci_dev
*from
)
327 struct pci_device_id id
= {
330 .subvendor
= ss_vendor
,
331 .subdevice
= ss_device
,
334 return pci_get_dev_by_id(&id
, from
);
338 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
339 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
340 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
341 * @from: Previous PCI device found in search, or %NULL for new search.
343 * Iterates through the list of known PCI devices. If a PCI device is
344 * found with a matching @vendor and @device, the reference count to the
345 * device is incremented and a pointer to its device structure is returned.
346 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
347 * as the @from argument. Otherwise if @from is not %NULL, searches continue
348 * from next device on the global list. The reference count for @from is
349 * always decremented if it is not %NULL.
352 pci_get_device(unsigned int vendor
, unsigned int device
, struct pci_dev
*from
)
354 return pci_get_subsys(vendor
, device
, PCI_ANY_ID
, PCI_ANY_ID
, from
);
358 * pci_get_class - begin or continue searching for a PCI device by class
359 * @class: search for a PCI device with this class designation
360 * @from: Previous PCI device found in search, or %NULL for new search.
362 * Iterates through the list of known PCI devices. If a PCI device is
363 * found with a matching @class, the reference count to the device is
364 * incremented and a pointer to its device structure is returned.
365 * Otherwise, %NULL is returned.
366 * A new search is initiated by passing %NULL as the @from argument.
367 * Otherwise if @from is not %NULL, searches continue from next device
368 * on the global list. The reference count for @from is always decremented
369 * if it is not %NULL.
371 struct pci_dev
*pci_get_class(unsigned int class, struct pci_dev
*from
)
373 struct pci_device_id id
= {
374 .vendor
= PCI_ANY_ID
,
375 .device
= PCI_ANY_ID
,
376 .subvendor
= PCI_ANY_ID
,
377 .subdevice
= PCI_ANY_ID
,
378 .class_mask
= PCI_ANY_ID
,
382 return pci_get_dev_by_id(&id
, from
);
386 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
387 * @ids: A pointer to a null terminated list of struct pci_device_id structures
388 * that describe the type of PCI device the caller is trying to find.
390 * Obvious fact: You do not have a reference to any device that might be found
391 * by this function, so if that device is removed from the system right after
392 * this function is finished, the value will be stale. Use this function to
393 * find devices that are usually built into a system, or for a general hint as
394 * to if another device happens to be present at this specific moment in time.
396 int pci_dev_present(const struct pci_device_id
*ids
)
398 struct pci_dev
*found
= NULL
;
400 WARN_ON(in_interrupt());
401 while (ids
->vendor
|| ids
->subvendor
|| ids
->class_mask
) {
402 found
= pci_get_dev_by_id(ids
, NULL
);
412 EXPORT_SYMBOL(pci_dev_present
);
414 /* For boot time work */
415 EXPORT_SYMBOL(pci_find_bus
);
416 EXPORT_SYMBOL(pci_find_next_bus
);
418 EXPORT_SYMBOL(pci_get_device
);
419 EXPORT_SYMBOL(pci_get_subsys
);
420 EXPORT_SYMBOL(pci_get_slot
);
421 EXPORT_SYMBOL(pci_get_class
);