Linux 3.6-rc1
[deliverable/linux.git] / drivers / pci / search.c
CommitLineData
1da177e4
LT
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>
5a0e3ad6 12#include <linux/slab.h>
1da177e4
LT
13#include <linux/module.h>
14#include <linux/interrupt.h>
15#include "pci.h"
16
d71374da 17DECLARE_RWSEM(pci_bus_sem);
ce29ca3e
AK
18EXPORT_SYMBOL_GPL(pci_bus_sem);
19
994a65e2 20/*
45e829ea 21 * find the upstream PCIe-to-PCI bridge of a PCI device
994a65e2 22 * if the device is PCIE, return NULL
45e829ea 23 * if the device isn't connected to a PCIe bridge (that is its parent is a
994a65e2
KA
24 * 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
5f4d91a1 32 if (pci_is_pcie(pdev))
994a65e2
KA
33 return NULL;
34 while (1) {
6e3f36df 35 if (pci_is_root_bus(pdev->bus))
994a65e2
KA
36 break;
37 pdev = pdev->bus->self;
38 /* a p2p bridge */
5f4d91a1 39 if (!pci_is_pcie(pdev)) {
994a65e2
KA
40 tmp = pdev;
41 continue;
42 }
45e829ea 43 /* PCI device should connect to a PCIe bridge */
994a65e2
KA
44 if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) {
45 /* Busted hardware? */
46 WARN_ON_ONCE(1);
47 return NULL;
48 }
49 return pdev;
50 }
51
52 return tmp;
53}
1da177e4 54
96bde06a 55static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
1da177e4
LT
56{
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 */
c8439cfc 80struct pci_bus * pci_find_bus(int domain, int busnr)
1da177e4
LT
81{
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 *
99 * Iterates through the list of known PCI busses. A new search is
d75763d2 100 * initiated by passing %NULL as the @from argument. Otherwise if
1da177e4
LT
101 * @from is not %NULL, searches continue from next device on the
102 * global list.
103 */
104struct pci_bus *
105pci_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());
d71374da 111 down_read(&pci_bus_sem);
1da177e4
LT
112 n = from ? from->node.next : pci_root_buses.next;
113 if (n != &pci_root_buses)
114 b = pci_bus_b(n);
d71374da 115 up_read(&pci_bus_sem);
1da177e4
LT
116 return b;
117}
118
1da177e4
LT
119/**
120 * pci_get_slot - locate PCI device for a given PCI slot
121 * @bus: PCI bus on which desired PCI device resides
122 * @devfn: encodes number of PCI slot in which the desired PCI
123 * device resides and the logical device number within that slot
124 * in case of multi-function devices.
125 *
126 * Given a PCI bus and slot/function number, the desired PCI device
127 * 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 */
133struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn)
134{
135 struct list_head *tmp;
136 struct pci_dev *dev;
137
138 WARN_ON(in_interrupt());
d71374da 139 down_read(&pci_bus_sem);
1da177e4
LT
140
141 list_for_each(tmp, &bus->devices) {
142 dev = pci_dev_b(tmp);
143 if (dev->devfn == devfn)
144 goto out;
145 }
146
147 dev = NULL;
148 out:
149 pci_dev_get(dev);
d71374da 150 up_read(&pci_bus_sem);
1da177e4
LT
151 return dev;
152}
153
29f3eb64 154/**
3c299dc2
AP
155 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
156 * @domain: PCI domain/segment on which the PCI device resides.
157 * @bus: PCI bus on which desired PCI device resides
158 * @devfn: encodes number of PCI slot in which the desired PCI device
159 * resides and the logical device number within that slot in case of
160 * multi-function devices.
5463d9f0 161 *
3c299dc2
AP
162 * Given a PCI domain, bus, and slot/function number, the desired PCI
163 * device is located in the list of PCI devices. If the device is
164 * found, its reference count is increased and this function returns a
165 * pointer to its data structure. The caller must decrement the
166 * reference count by calling pci_dev_put(). If no device is found,
167 * %NULL is returned.
29f3eb64 168 */
3c299dc2
AP
169struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
170 unsigned int devfn)
29f3eb64
AC
171{
172 struct pci_dev *dev = NULL;
173
4e344b1c 174 for_each_pci_dev(dev) {
3c299dc2
AP
175 if (pci_domain_nr(dev->bus) == domain &&
176 (dev->bus->number == bus && dev->devfn == devfn))
29f3eb64
AC
177 return dev;
178 }
179 return NULL;
180}
3c299dc2 181EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
29f3eb64 182
95247b57 183static int match_pci_dev_by_id(struct device *dev, void *data)
1da177e4 184{
95247b57
GKH
185 struct pci_dev *pdev = to_pci_dev(dev);
186 struct pci_device_id *id = data;
1da177e4 187
95247b57
GKH
188 if (pci_match_one_device(id, pdev))
189 return 1;
190 return 0;
1da177e4
LT
191}
192
95247b57
GKH
193/*
194 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
195 * @id: pointer to struct pci_device_id to match for the device
1da177e4
LT
196 * @from: Previous PCI device found in search, or %NULL for new search.
197 *
d75763d2 198 * Iterates through the list of known PCI devices. If a PCI device is found
95247b57
GKH
199 * with a matching id a pointer to its device structure is returned, and the
200 * reference count to the device is incremented. Otherwise, %NULL is returned.
201 * A new search is initiated by passing %NULL as the @from argument. Otherwise
202 * if @from is not %NULL, searches continue from next device on the global
203 * list. The reference count for @from is always decremented if it is not
204 * %NULL.
205 *
206 * This is an internal function for use by the other search functions in
207 * this file.
1da177e4 208 */
95247b57 209static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
b08508c4 210 struct pci_dev *from)
1da177e4 211{
95247b57
GKH
212 struct device *dev;
213 struct device *dev_start = NULL;
214 struct pci_dev *pdev = NULL;
215
216 WARN_ON(in_interrupt());
c4ed02fa
MW
217 if (from)
218 dev_start = &from->dev;
95247b57
GKH
219 dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
220 match_pci_dev_by_id);
221 if (dev)
222 pdev = to_pci_dev(dev);
ebca4f1b
GK
223 if (from)
224 pci_dev_put(from);
95247b57 225 return pdev;
1da177e4
LT
226}
227
228/**
229 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
230 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
231 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
232 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
233 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
234 * @from: Previous PCI device found in search, or %NULL for new search.
235 *
d75763d2
RD
236 * Iterates through the list of known PCI devices. If a PCI device is found
237 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
1da177e4
LT
238 * device structure is returned, and the reference count to the device is
239 * incremented. Otherwise, %NULL is returned. A new search is initiated by
d75763d2 240 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
1da177e4
LT
241 * searches continue from next device on the global list.
242 * The reference count for @from is always decremented if it is not %NULL.
243 */
95247b57
GKH
244struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
245 unsigned int ss_vendor, unsigned int ss_device,
b08508c4 246 struct pci_dev *from)
1da177e4 247{
95247b57
GKH
248 struct pci_dev *pdev;
249 struct pci_device_id *id;
6ae4adf5
AB
250
251 /*
95247b57
GKH
252 * pci_find_subsys() can be called on the ide_setup() path,
253 * super-early in boot. But the down_read() will enable local
254 * interrupts, which can cause some machines to crash. So here we
255 * detect and flag that situation and bail out early.
6ae4adf5 256 */
35ef63f6 257 if (unlikely(no_pci_devices()))
6ae4adf5 258 return NULL;
95247b57
GKH
259
260 id = kzalloc(sizeof(*id), GFP_KERNEL);
261 if (!id)
262 return NULL;
263 id->vendor = vendor;
264 id->device = device;
265 id->subvendor = ss_vendor;
266 id->subdevice = ss_device;
267
268 pdev = pci_get_dev_by_id(id, from);
269 kfree(id);
270
271 return pdev;
1da177e4
LT
272}
273
274/**
275 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
276 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
277 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
278 * @from: Previous PCI device found in search, or %NULL for new search.
279 *
280 * Iterates through the list of known PCI devices. If a PCI device is
281 * found with a matching @vendor and @device, the reference count to the
282 * device is incremented and a pointer to its device structure is returned.
283 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
d75763d2 284 * as the @from argument. Otherwise if @from is not %NULL, searches continue
1da177e4
LT
285 * from next device on the global list. The reference count for @from is
286 * always decremented if it is not %NULL.
287 */
288struct pci_dev *
289pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
290{
291 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
292}
293
1da177e4
LT
294/**
295 * pci_get_class - begin or continue searching for a PCI device by class
296 * @class: search for a PCI device with this class designation
297 * @from: Previous PCI device found in search, or %NULL for new search.
298 *
299 * Iterates through the list of known PCI devices. If a PCI device is
300 * found with a matching @class, the reference count to the device is
301 * incremented and a pointer to its device structure is returned.
302 * Otherwise, %NULL is returned.
d75763d2 303 * A new search is initiated by passing %NULL as the @from argument.
1da177e4
LT
304 * Otherwise if @from is not %NULL, searches continue from next device
305 * on the global list. The reference count for @from is always decremented
306 * if it is not %NULL.
307 */
308struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
309{
1da177e4 310 struct pci_dev *dev;
95247b57 311 struct pci_device_id *id;
1da177e4 312
95247b57
GKH
313 id = kzalloc(sizeof(*id), GFP_KERNEL);
314 if (!id)
315 return NULL;
316 id->vendor = id->device = id->subvendor = id->subdevice = PCI_ANY_ID;
317 id->class_mask = PCI_ANY_ID;
318 id->class = class;
1da177e4 319
95247b57
GKH
320 dev = pci_get_dev_by_id(id, from);
321 kfree(id);
1da177e4
LT
322 return dev;
323}
324
448432c4
GKH
325/**
326 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
327 * @ids: A pointer to a null terminated list of struct pci_device_id structures
328 * that describe the type of PCI device the caller is trying to find.
329 *
330 * Obvious fact: You do not have a reference to any device that might be found
331 * by this function, so if that device is removed from the system right after
332 * this function is finished, the value will be stale. Use this function to
333 * find devices that are usually built into a system, or for a general hint as
334 * to if another device happens to be present at this specific moment in time.
335 */
336int pci_dev_present(const struct pci_device_id *ids)
d86f90f9 337{
95247b57 338 struct pci_dev *found = NULL;
d86f90f9
AC
339
340 WARN_ON(in_interrupt());
d86f90f9 341 while (ids->vendor || ids->subvendor || ids->class_mask) {
95247b57
GKH
342 found = pci_get_dev_by_id(ids, NULL);
343 if (found)
344 goto exit;
d86f90f9
AC
345 ids++;
346 }
3c92c57a 347exit:
448432c4
GKH
348 if (found)
349 return 1;
350 return 0;
1da177e4
LT
351}
352EXPORT_SYMBOL(pci_dev_present);
353
29f3eb64
AC
354/* For boot time work */
355EXPORT_SYMBOL(pci_find_bus);
356EXPORT_SYMBOL(pci_find_next_bus);
357/* For everyone */
1da177e4
LT
358EXPORT_SYMBOL(pci_get_device);
359EXPORT_SYMBOL(pci_get_subsys);
360EXPORT_SYMBOL(pci_get_slot);
361EXPORT_SYMBOL(pci_get_class);
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