blob: a20ce7d5e2a718551554a1e860457b852756d97b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Bjorn Helgaasf7625982013-11-14 11:28:18 -07002 * PCI searching functions.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/pci.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090011#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/module.h>
13#include <linux/interrupt.h>
14#include "pci.h"
15
Zhang Yanmind71374d2006-06-02 12:35:43 +080016DECLARE_RWSEM(pci_bus_sem);
Amos Kongce29ca32012-05-23 10:20:35 -060017EXPORT_SYMBOL_GPL(pci_bus_sem);
18
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070019/*
Alex Williamsonc25dc822014-05-22 17:07:30 -060020 * 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_DEVID(pdev->bus->number, pdev->devfn), data);
36 if (ret)
37 return ret;
38
Alex Williamson31c2b812014-05-22 17:07:43 -060039 /*
40 * If the device is broken and uses an alias requester ID for
41 * DMA, iterate over that too.
42 */
43 if (unlikely(pdev->dev_flags & PCI_DEV_FLAGS_DMA_ALIAS_DEVFN)) {
44 ret = fn(pdev, PCI_DEVID(pdev->bus->number,
45 pdev->dma_alias_devfn), data);
46 if (ret)
47 return ret;
48 }
49
Alex Williamsonc25dc822014-05-22 17:07:30 -060050 for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
51 struct pci_dev *tmp;
52
53 /* Skip virtual buses */
54 if (!bus->self)
55 continue;
56
57 tmp = bus->self;
58
59 /*
60 * PCIe-to-PCI/X bridges alias transactions from downstream
61 * devices using the subordinate bus number (PCI Express to
62 * PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases
63 * where the upstream bus is PCI/X we alias to the bridge
64 * (there are various conditions in the previous reference
65 * where the bridge may take ownership of transactions, even
66 * when the secondary interface is PCI-X).
67 */
68 if (pci_is_pcie(tmp)) {
69 switch (pci_pcie_type(tmp)) {
70 case PCI_EXP_TYPE_ROOT_PORT:
71 case PCI_EXP_TYPE_UPSTREAM:
72 case PCI_EXP_TYPE_DOWNSTREAM:
73 continue;
74 case PCI_EXP_TYPE_PCI_BRIDGE:
75 ret = fn(tmp,
76 PCI_DEVID(tmp->subordinate->number,
77 PCI_DEVFN(0, 0)), data);
78 if (ret)
79 return ret;
80 continue;
81 case PCI_EXP_TYPE_PCIE_BRIDGE:
82 ret = fn(tmp,
83 PCI_DEVID(tmp->bus->number,
84 tmp->devfn), data);
85 if (ret)
86 return ret;
87 continue;
88 }
89 } else {
Alex Williamsonc8fe16e2014-05-28 14:57:02 -060090 if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS)
91 ret = fn(tmp,
92 PCI_DEVID(tmp->subordinate->number,
93 PCI_DEVFN(0, 0)), data);
94 else
95 ret = fn(tmp,
96 PCI_DEVID(tmp->bus->number,
97 tmp->devfn), data);
Alex Williamsonc25dc822014-05-22 17:07:30 -060098 if (ret)
99 return ret;
100 }
101 }
102
103 return ret;
104}
105
Sam Ravnborg96bde062007-03-26 21:53:30 -0800106static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
Yijing Wang94e6a9b2014-02-13 21:14:03 +0800108 struct pci_bus *child;
109 struct pci_bus *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
Ryan Desfosses3c78bc62014-04-18 20:13:49 -0400111 if (bus->number == busnr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 return bus;
113
Yijing Wang94e6a9b2014-02-13 21:14:03 +0800114 list_for_each_entry(tmp, &bus->children, node) {
115 child = pci_do_find_bus(tmp, busnr);
Ryan Desfosses3c78bc62014-04-18 20:13:49 -0400116 if (child)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 return child;
118 }
119 return NULL;
120}
121
122/**
123 * pci_find_bus - locate PCI bus from a given domain and bus number
124 * @domain: number of PCI domain to search
125 * @busnr: number of desired PCI bus
126 *
127 * Given a PCI bus number and domain number, the desired PCI bus is located
128 * in the global list of PCI buses. If the bus is found, a pointer to its
129 * data structure is returned. If no bus is found, %NULL is returned.
130 */
Ryan Desfosses3c78bc62014-04-18 20:13:49 -0400131struct pci_bus *pci_find_bus(int domain, int busnr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132{
133 struct pci_bus *bus = NULL;
134 struct pci_bus *tmp_bus;
135
136 while ((bus = pci_find_next_bus(bus)) != NULL) {
137 if (pci_domain_nr(bus) != domain)
138 continue;
139 tmp_bus = pci_do_find_bus(bus, busnr);
140 if (tmp_bus)
141 return tmp_bus;
142 }
143 return NULL;
144}
Ryan Desfossesb7fe9432014-04-25 14:32:25 -0600145EXPORT_SYMBOL(pci_find_bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146
147/**
148 * pci_find_next_bus - begin or continue searching for a PCI bus
149 * @from: Previous PCI bus found, or %NULL for new search.
150 *
Bjorn Helgaasf7625982013-11-14 11:28:18 -0700151 * Iterates through the list of known PCI buses. A new search is
Randy Dunlapd75763d2006-07-30 03:03:41 -0700152 * initiated by passing %NULL as the @from argument. Otherwise if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 * @from is not %NULL, searches continue from next device on the
154 * global list.
155 */
Ryan Desfosses3c78bc62014-04-18 20:13:49 -0400156struct pci_bus *pci_find_next_bus(const struct pci_bus *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157{
158 struct list_head *n;
159 struct pci_bus *b = NULL;
160
161 WARN_ON(in_interrupt());
Zhang Yanmind71374d2006-06-02 12:35:43 +0800162 down_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 n = from ? from->node.next : pci_root_buses.next;
164 if (n != &pci_root_buses)
Yijing Wang94e6a9b2014-02-13 21:14:03 +0800165 b = list_entry(n, struct pci_bus, node);
Zhang Yanmind71374d2006-06-02 12:35:43 +0800166 up_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 return b;
168}
Ryan Desfossesb7fe9432014-04-25 14:32:25 -0600169EXPORT_SYMBOL(pci_find_next_bus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171/**
172 * pci_get_slot - locate PCI device for a given PCI slot
173 * @bus: PCI bus on which desired PCI device resides
Bjorn Helgaasf7625982013-11-14 11:28:18 -0700174 * @devfn: encodes number of PCI slot in which the desired PCI
175 * device resides and the logical device number within that slot
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 * in case of multi-function devices.
177 *
Bjorn Helgaasf7625982013-11-14 11:28:18 -0700178 * Given a PCI bus and slot/function number, the desired PCI device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 * is located in the list of PCI devices.
180 * If the device is found, its reference count is increased and this
181 * function returns a pointer to its data structure. The caller must
182 * decrement the reference count by calling pci_dev_put().
183 * If no device is found, %NULL is returned.
184 */
Bjorn Helgaas66455f52012-08-17 15:53:27 -0600185struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 struct pci_dev *dev;
188
189 WARN_ON(in_interrupt());
Zhang Yanmind71374d2006-06-02 12:35:43 +0800190 down_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
Bjorn Helgaas66455f52012-08-17 15:53:27 -0600192 list_for_each_entry(dev, &bus->devices, bus_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 if (dev->devfn == devfn)
194 goto out;
195 }
196
197 dev = NULL;
198 out:
199 pci_dev_get(dev);
Zhang Yanmind71374d2006-06-02 12:35:43 +0800200 up_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 return dev;
202}
Ryan Desfossesb7fe9432014-04-25 14:32:25 -0600203EXPORT_SYMBOL(pci_get_slot);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205/**
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600206 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
207 * @domain: PCI domain/segment on which the PCI device resides.
208 * @bus: PCI bus on which desired PCI device resides
209 * @devfn: encodes number of PCI slot in which the desired PCI device
210 * resides and the logical device number within that slot in case of
211 * multi-function devices.
Alan Cox29f3eb62006-10-16 16:20:21 -0700212 *
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600213 * Given a PCI domain, bus, and slot/function number, the desired PCI
214 * device is located in the list of PCI devices. If the device is
215 * found, its reference count is increased and this function returns a
216 * pointer to its data structure. The caller must decrement the
217 * reference count by calling pci_dev_put(). If no device is found,
218 * %NULL is returned.
Alan Cox29f3eb62006-10-16 16:20:21 -0700219 */
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600220struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
221 unsigned int devfn)
Alan Cox29f3eb62006-10-16 16:20:21 -0700222{
223 struct pci_dev *dev = NULL;
224
Kulikov Vasiliy4e344b12010-07-03 20:04:39 +0400225 for_each_pci_dev(dev) {
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600226 if (pci_domain_nr(dev->bus) == domain &&
227 (dev->bus->number == bus && dev->devfn == devfn))
Alan Cox29f3eb62006-10-16 16:20:21 -0700228 return dev;
229 }
230 return NULL;
231}
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600232EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
Alan Cox29f3eb62006-10-16 16:20:21 -0700233
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800234static int match_pci_dev_by_id(struct device *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800236 struct pci_dev *pdev = to_pci_dev(dev);
237 struct pci_device_id *id = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800239 if (pci_match_one_device(id, pdev))
240 return 1;
241 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800244/*
245 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
246 * @id: pointer to struct pci_device_id to match for the device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 * @from: Previous PCI device found in search, or %NULL for new search.
248 *
Randy Dunlapd75763d2006-07-30 03:03:41 -0700249 * Iterates through the list of known PCI devices. If a PCI device is found
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800250 * with a matching id a pointer to its device structure is returned, and the
251 * reference count to the device is incremented. Otherwise, %NULL is returned.
252 * A new search is initiated by passing %NULL as the @from argument. Otherwise
253 * if @from is not %NULL, searches continue from next device on the global
254 * list. The reference count for @from is always decremented if it is not
255 * %NULL.
256 *
257 * This is an internal function for use by the other search functions in
258 * this file.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 */
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800260static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
Greg KHb08508c2008-08-26 08:20:34 -0700261 struct pci_dev *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262{
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800263 struct device *dev;
264 struct device *dev_start = NULL;
265 struct pci_dev *pdev = NULL;
266
267 WARN_ON(in_interrupt());
Matthew Wilcoxc4ed02f2008-10-20 19:13:08 -0600268 if (from)
269 dev_start = &from->dev;
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800270 dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
271 match_pci_dev_by_id);
272 if (dev)
273 pdev = to_pci_dev(dev);
Markus Elfringff0387c2014-11-10 21:02:17 -0700274 pci_dev_put(from);
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800275 return pdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276}
277
278/**
279 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
280 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
281 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
282 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
283 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
284 * @from: Previous PCI device found in search, or %NULL for new search.
285 *
Randy Dunlapd75763d2006-07-30 03:03:41 -0700286 * Iterates through the list of known PCI devices. If a PCI device is found
287 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 * device structure is returned, and the reference count to the device is
289 * incremented. Otherwise, %NULL is returned. A new search is initiated by
Randy Dunlapd75763d2006-07-30 03:03:41 -0700290 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 * searches continue from next device on the global list.
292 * The reference count for @from is always decremented if it is not %NULL.
293 */
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800294struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
295 unsigned int ss_vendor, unsigned int ss_device,
Greg KHb08508c2008-08-26 08:20:34 -0700296 struct pci_dev *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297{
Feng Tangb9443f42012-08-23 15:45:03 +0800298 struct pci_device_id id = {
299 .vendor = vendor,
300 .device = device,
301 .subvendor = ss_vendor,
302 .subdevice = ss_device,
303 };
Ard van Breemen6ae4adf2007-01-05 16:36:21 -0800304
Feng Tangb9443f42012-08-23 15:45:03 +0800305 return pci_get_dev_by_id(&id, from);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306}
Ryan Desfossesb7fe9432014-04-25 14:32:25 -0600307EXPORT_SYMBOL(pci_get_subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308
309/**
310 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
311 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
312 * @device: PCI 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.
314 *
315 * Iterates through the list of known PCI devices. If a PCI device is
316 * found with a matching @vendor and @device, the reference count to the
317 * device is incremented and a pointer to its device structure is returned.
318 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
Randy Dunlapd75763d2006-07-30 03:03:41 -0700319 * as the @from argument. Otherwise if @from is not %NULL, searches continue
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 * from next device on the global list. The reference count for @from is
321 * always decremented if it is not %NULL.
322 */
Ryan Desfosses3c78bc62014-04-18 20:13:49 -0400323struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
324 struct pci_dev *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325{
326 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
327}
Ryan Desfossesb7fe9432014-04-25 14:32:25 -0600328EXPORT_SYMBOL(pci_get_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Alan Cox29f3eb62006-10-16 16:20:21 -0700330/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 * pci_get_class - begin or continue searching for a PCI device by class
332 * @class: search for a PCI device with this class designation
333 * @from: Previous PCI device found in search, or %NULL for new search.
334 *
335 * Iterates through the list of known PCI devices. If a PCI device is
336 * found with a matching @class, the reference count to the device is
337 * incremented and a pointer to its device structure is returned.
338 * Otherwise, %NULL is returned.
Randy Dunlapd75763d2006-07-30 03:03:41 -0700339 * A new search is initiated by passing %NULL as the @from argument.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 * Otherwise if @from is not %NULL, searches continue from next device
341 * on the global list. The reference count for @from is always decremented
342 * if it is not %NULL.
343 */
344struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
345{
Feng Tangb9443f42012-08-23 15:45:03 +0800346 struct pci_device_id id = {
347 .vendor = PCI_ANY_ID,
348 .device = PCI_ANY_ID,
349 .subvendor = PCI_ANY_ID,
350 .subdevice = PCI_ANY_ID,
351 .class_mask = PCI_ANY_ID,
352 .class = class,
353 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
Feng Tangb9443f42012-08-23 15:45:03 +0800355 return pci_get_dev_by_id(&id, from);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356}
Ryan Desfossesb7fe9432014-04-25 14:32:25 -0600357EXPORT_SYMBOL(pci_get_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358
Greg Kroah-Hartman448432c2008-02-12 13:36:20 -0800359/**
360 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
361 * @ids: A pointer to a null terminated list of struct pci_device_id structures
362 * that describe the type of PCI device the caller is trying to find.
363 *
364 * Obvious fact: You do not have a reference to any device that might be found
365 * by this function, so if that device is removed from the system right after
366 * this function is finished, the value will be stale. Use this function to
367 * find devices that are usually built into a system, or for a general hint as
368 * to if another device happens to be present at this specific moment in time.
369 */
370int pci_dev_present(const struct pci_device_id *ids)
Alan Coxd86f90f2006-12-04 15:14:44 -0800371{
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800372 struct pci_dev *found = NULL;
Alan Coxd86f90f2006-12-04 15:14:44 -0800373
374 WARN_ON(in_interrupt());
Alan Coxd86f90f2006-12-04 15:14:44 -0800375 while (ids->vendor || ids->subvendor || ids->class_mask) {
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800376 found = pci_get_dev_by_id(ids, NULL);
Jiang Liud5af7d92013-01-21 13:20:45 -0800377 if (found) {
378 pci_dev_put(found);
379 return 1;
380 }
Alan Coxd86f90f2006-12-04 15:14:44 -0800381 ids++;
382 }
Jiang Liud5af7d92013-01-21 13:20:45 -0800383
Greg Kroah-Hartman448432c2008-02-12 13:36:20 -0800384 return 0;
Alan Coxd86f90f2006-12-04 15:14:44 -0800385}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386EXPORT_SYMBOL(pci_dev_present);