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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
10#include <linux/init.h>
11#include <linux/pci.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090012#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/module.h>
14#include <linux/interrupt.h>
15#include "pci.h"
16
Zhang Yanmind71374d2006-06-02 12:35:43 +080017DECLARE_RWSEM(pci_bus_sem);
Amos Kongce29ca32012-05-23 10:20:35 -060018EXPORT_SYMBOL_GPL(pci_bus_sem);
19
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070020/*
Stefan Assmann45e829e2009-12-03 06:49:24 -050021 * find the upstream PCIe-to-PCI bridge of a PCI device
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070022 * if the device is PCIE, return NULL
Stefan Assmann45e829e2009-12-03 06:49:24 -050023 * if the device isn't connected to a PCIe bridge (that is its parent is a
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070024 * legacy PCI bridge and the bridge is directly connected to bus 0), return its
25 * parent
26 */
27struct pci_dev *
28pci_find_upstream_pcie_bridge(struct pci_dev *pdev)
29{
30 struct pci_dev *tmp = NULL;
31
Kenji Kaneshige5f4d91a2009-11-11 14:36:17 +090032 if (pci_is_pcie(pdev))
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070033 return NULL;
34 while (1) {
Kenji Kaneshige6e3f36d2009-05-26 16:06:10 +090035 if (pci_is_root_bus(pdev->bus))
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070036 break;
37 pdev = pdev->bus->self;
38 /* a p2p bridge */
Kenji Kaneshige5f4d91a2009-11-11 14:36:17 +090039 if (!pci_is_pcie(pdev)) {
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070040 tmp = pdev;
41 continue;
42 }
Stefan Assmann45e829e2009-12-03 06:49:24 -050043 /* PCI device should connect to a PCIe bridge */
Yijing Wang62f87c02012-07-24 17:20:03 +080044 if (pci_pcie_type(pdev) != PCI_EXP_TYPE_PCI_BRIDGE) {
Keshavamurthy, Anil S994a65e2007-10-21 16:41:46 -070045 /* Busted hardware? */
46 WARN_ON_ONCE(1);
47 return NULL;
48 }
49 return pdev;
50 }
51
52 return tmp;
53}
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Sam Ravnborg96bde062007-03-26 21:53:30 -080055static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
57 struct pci_bus* child;
58 struct list_head *tmp;
59
60 if(bus->number == busnr)
61 return bus;
62
63 list_for_each(tmp, &bus->children) {
64 child = pci_do_find_bus(pci_bus_b(tmp), busnr);
65 if(child)
66 return child;
67 }
68 return NULL;
69}
70
71/**
72 * pci_find_bus - locate PCI bus from a given domain and bus number
73 * @domain: number of PCI domain to search
74 * @busnr: number of desired PCI bus
75 *
76 * Given a PCI bus number and domain number, the desired PCI bus is located
77 * in the global list of PCI buses. If the bus is found, a pointer to its
78 * data structure is returned. If no bus is found, %NULL is returned.
79 */
Randy Dunlapc8439cfc2006-07-18 14:33:16 -070080struct pci_bus * pci_find_bus(int domain, int busnr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070081{
82 struct pci_bus *bus = NULL;
83 struct pci_bus *tmp_bus;
84
85 while ((bus = pci_find_next_bus(bus)) != NULL) {
86 if (pci_domain_nr(bus) != domain)
87 continue;
88 tmp_bus = pci_do_find_bus(bus, busnr);
89 if (tmp_bus)
90 return tmp_bus;
91 }
92 return NULL;
93}
94
95/**
96 * pci_find_next_bus - begin or continue searching for a PCI bus
97 * @from: Previous PCI bus found, or %NULL for new search.
98 *
Bjorn Helgaasf7625982013-11-14 11:28:18 -070099 * Iterates through the list of known PCI buses. A new search is
Randy Dunlapd75763d2006-07-30 03:03:41 -0700100 * initiated by passing %NULL as the @from argument. Otherwise if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 * @from is not %NULL, searches continue from next device on the
102 * global list.
103 */
Bjorn Helgaasf7625982013-11-14 11:28:18 -0700104struct pci_bus *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105pci_find_next_bus(const struct pci_bus *from)
106{
107 struct list_head *n;
108 struct pci_bus *b = NULL;
109
110 WARN_ON(in_interrupt());
Zhang Yanmind71374d2006-06-02 12:35:43 +0800111 down_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 n = from ? from->node.next : pci_root_buses.next;
113 if (n != &pci_root_buses)
114 b = pci_bus_b(n);
Zhang Yanmind71374d2006-06-02 12:35:43 +0800115 up_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 return b;
117}
118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119/**
120 * pci_get_slot - locate PCI device for a given PCI slot
121 * @bus: PCI bus on which desired PCI device resides
Bjorn Helgaasf7625982013-11-14 11:28:18 -0700122 * @devfn: encodes number of PCI slot in which the desired PCI
123 * device resides and the logical device number within that slot
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 * in case of multi-function devices.
125 *
Bjorn Helgaasf7625982013-11-14 11:28:18 -0700126 * Given a PCI bus and slot/function number, the desired PCI device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 * is located in the list of PCI devices.
128 * If the device is found, its reference count is increased and this
129 * function returns a pointer to its data structure. The caller must
130 * decrement the reference count by calling pci_dev_put().
131 * If no device is found, %NULL is returned.
132 */
Bjorn Helgaas66455f52012-08-17 15:53:27 -0600133struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 struct pci_dev *dev;
136
137 WARN_ON(in_interrupt());
Zhang Yanmind71374d2006-06-02 12:35:43 +0800138 down_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
Bjorn Helgaas66455f52012-08-17 15:53:27 -0600140 list_for_each_entry(dev, &bus->devices, bus_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 if (dev->devfn == devfn)
142 goto out;
143 }
144
145 dev = NULL;
146 out:
147 pci_dev_get(dev);
Zhang Yanmind71374d2006-06-02 12:35:43 +0800148 up_read(&pci_bus_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 return dev;
150}
151
152/**
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600153 * 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.
Alan Cox29f3eb62006-10-16 16:20:21 -0700159 *
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600160 * 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.
Alan Cox29f3eb62006-10-16 16:20:21 -0700166 */
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600167struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
168 unsigned int devfn)
Alan Cox29f3eb62006-10-16 16:20:21 -0700169{
170 struct pci_dev *dev = NULL;
171
Kulikov Vasiliy4e344b12010-07-03 20:04:39 +0400172 for_each_pci_dev(dev) {
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600173 if (pci_domain_nr(dev->bus) == domain &&
174 (dev->bus->number == bus && dev->devfn == devfn))
Alan Cox29f3eb62006-10-16 16:20:21 -0700175 return dev;
176 }
177 return NULL;
178}
Andrew Patterson3c299dc2009-10-12 13:14:00 -0600179EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
Alan Cox29f3eb62006-10-16 16:20:21 -0700180
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800181static int match_pci_dev_by_id(struct device *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800183 struct pci_dev *pdev = to_pci_dev(dev);
184 struct pci_device_id *id = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800186 if (pci_match_one_device(id, pdev))
187 return 1;
188 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189}
190
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800191/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 * @from: Previous PCI device found in search, or %NULL for new search.
195 *
Randy Dunlapd75763d2006-07-30 03:03:41 -0700196 * Iterates through the list of known PCI devices. If a PCI device is found
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800197 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 */
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800207static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
Greg KHb08508c2008-08-26 08:20:34 -0700208 struct pci_dev *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209{
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800210 struct device *dev;
211 struct device *dev_start = NULL;
212 struct pci_dev *pdev = NULL;
213
214 WARN_ON(in_interrupt());
Matthew Wilcoxc4ed02f2008-10-20 19:13:08 -0600215 if (from)
216 dev_start = &from->dev;
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800217 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);
Greg KHebca4f12008-08-21 13:47:58 -0700221 if (from)
222 pci_dev_put(from);
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800223 return pdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224}
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 *
Randy Dunlapd75763d2006-07-30 03:03:41 -0700234 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 * device structure is returned, and the reference count to the device is
237 * incremented. Otherwise, %NULL is returned. A new search is initiated by
Randy Dunlapd75763d2006-07-30 03:03:41 -0700238 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 * searches continue from next device on the global list.
240 * The reference count for @from is always decremented if it is not %NULL.
241 */
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800242struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
243 unsigned int ss_vendor, unsigned int ss_device,
Greg KHb08508c2008-08-26 08:20:34 -0700244 struct pci_dev *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245{
Feng Tangb9443f42012-08-23 15:45:03 +0800246 struct pci_device_id id = {
247 .vendor = vendor,
248 .device = device,
249 .subvendor = ss_vendor,
250 .subdevice = ss_device,
251 };
Ard van Breemen6ae4adf2007-01-05 16:36:21 -0800252
Feng Tangb9443f42012-08-23 15:45:03 +0800253 return pci_get_dev_by_id(&id, from);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254}
255
256/**
257 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
258 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
259 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
260 * @from: Previous PCI device found in search, or %NULL for new search.
261 *
262 * Iterates through the list of known PCI devices. If a PCI device is
263 * found with a matching @vendor and @device, the reference count to the
264 * device is incremented and a pointer to its device structure is returned.
265 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
Randy Dunlapd75763d2006-07-30 03:03:41 -0700266 * as the @from argument. Otherwise if @from is not %NULL, searches continue
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 * from next device on the global list. The reference count for @from is
268 * always decremented if it is not %NULL.
269 */
270struct pci_dev *
271pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
272{
273 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
274}
275
Alan Cox29f3eb62006-10-16 16:20:21 -0700276/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 * pci_get_class - begin or continue searching for a PCI device by class
278 * @class: search for a PCI device with this class designation
279 * @from: Previous PCI device found in search, or %NULL for new search.
280 *
281 * Iterates through the list of known PCI devices. If a PCI device is
282 * found with a matching @class, the reference count to the device is
283 * incremented and a pointer to its device structure is returned.
284 * Otherwise, %NULL is returned.
Randy Dunlapd75763d2006-07-30 03:03:41 -0700285 * A new search is initiated by passing %NULL as the @from argument.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 * Otherwise if @from is not %NULL, searches continue from next device
287 * on the global list. The reference count for @from is always decremented
288 * if it is not %NULL.
289 */
290struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
291{
Feng Tangb9443f42012-08-23 15:45:03 +0800292 struct pci_device_id id = {
293 .vendor = PCI_ANY_ID,
294 .device = PCI_ANY_ID,
295 .subvendor = PCI_ANY_ID,
296 .subdevice = PCI_ANY_ID,
297 .class_mask = PCI_ANY_ID,
298 .class = class,
299 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300
Feng Tangb9443f42012-08-23 15:45:03 +0800301 return pci_get_dev_by_id(&id, from);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302}
303
Greg Kroah-Hartman448432c2008-02-12 13:36:20 -0800304/**
305 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
306 * @ids: A pointer to a null terminated list of struct pci_device_id structures
307 * that describe the type of PCI device the caller is trying to find.
308 *
309 * Obvious fact: You do not have a reference to any device that might be found
310 * by this function, so if that device is removed from the system right after
311 * this function is finished, the value will be stale. Use this function to
312 * find devices that are usually built into a system, or for a general hint as
313 * to if another device happens to be present at this specific moment in time.
314 */
315int pci_dev_present(const struct pci_device_id *ids)
Alan Coxd86f90f2006-12-04 15:14:44 -0800316{
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800317 struct pci_dev *found = NULL;
Alan Coxd86f90f2006-12-04 15:14:44 -0800318
319 WARN_ON(in_interrupt());
Alan Coxd86f90f2006-12-04 15:14:44 -0800320 while (ids->vendor || ids->subvendor || ids->class_mask) {
Greg Kroah-Hartman95247b52008-02-13 11:03:58 -0800321 found = pci_get_dev_by_id(ids, NULL);
Jiang Liud5af7d92013-01-21 13:20:45 -0800322 if (found) {
323 pci_dev_put(found);
324 return 1;
325 }
Alan Coxd86f90f2006-12-04 15:14:44 -0800326 ids++;
327 }
Jiang Liud5af7d92013-01-21 13:20:45 -0800328
Greg Kroah-Hartman448432c2008-02-12 13:36:20 -0800329 return 0;
Alan Coxd86f90f2006-12-04 15:14:44 -0800330}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331EXPORT_SYMBOL(pci_dev_present);
332
Alan Cox29f3eb62006-10-16 16:20:21 -0700333/* For boot time work */
334EXPORT_SYMBOL(pci_find_bus);
335EXPORT_SYMBOL(pci_find_next_bus);
336/* For everyone */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337EXPORT_SYMBOL(pci_get_device);
338EXPORT_SYMBOL(pci_get_subsys);
339EXPORT_SYMBOL(pci_get_slot);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340EXPORT_SYMBOL(pci_get_class);