Linux 2.6.26-rc6
[linux-2.6/kmemtrace.git] / drivers / pci / search.c
blob217814fef4ef4c7e5b3e4b54b96b1e70c7e2b7d4
1 /*
2 * PCI searching functions.
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 */
10 #include <linux/init.h>
11 #include <linux/pci.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include "pci.h"
16 DECLARE_RWSEM(pci_bus_sem);
18 * find the upstream PCIE-to-PCI bridge of a PCI device
19 * if the device is PCIE, return NULL
20 * if the device isn't connected to a PCIE bridge (that is its parent is a
21 * legacy PCI bridge and the bridge is directly connected to bus 0), return its
22 * parent
24 struct pci_dev *
25 pci_find_upstream_pcie_bridge(struct pci_dev *pdev)
27 struct pci_dev *tmp = NULL;
29 if (pdev->is_pcie)
30 return NULL;
31 while (1) {
32 if (!pdev->bus->self)
33 break;
34 pdev = pdev->bus->self;
35 /* a p2p bridge */
36 if (!pdev->is_pcie) {
37 tmp = pdev;
38 continue;
40 /* PCI device should connect to a PCIE bridge */
41 if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) {
42 /* Busted hardware? */
43 WARN_ON_ONCE(1);
44 return NULL;
46 return pdev;
49 return tmp;
52 static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
54 struct pci_bus* child;
55 struct list_head *tmp;
57 if(bus->number == busnr)
58 return bus;
60 list_for_each(tmp, &bus->children) {
61 child = pci_do_find_bus(pci_bus_b(tmp), busnr);
62 if(child)
63 return child;
65 return NULL;
68 /**
69 * pci_find_bus - locate PCI bus from a given domain and bus number
70 * @domain: number of PCI domain to search
71 * @busnr: number of desired PCI bus
73 * Given a PCI bus number and domain number, the desired PCI bus is located
74 * in the global list of PCI buses. If the bus is found, a pointer to its
75 * data structure is returned. If no bus is found, %NULL is returned.
77 struct pci_bus * pci_find_bus(int domain, int busnr)
79 struct pci_bus *bus = NULL;
80 struct pci_bus *tmp_bus;
82 while ((bus = pci_find_next_bus(bus)) != NULL) {
83 if (pci_domain_nr(bus) != domain)
84 continue;
85 tmp_bus = pci_do_find_bus(bus, busnr);
86 if (tmp_bus)
87 return tmp_bus;
89 return NULL;
92 /**
93 * pci_find_next_bus - begin or continue searching for a PCI bus
94 * @from: Previous PCI bus found, or %NULL for new search.
96 * Iterates through the list of known PCI busses. A new search is
97 * initiated by passing %NULL as the @from argument. Otherwise if
98 * @from is not %NULL, searches continue from next device on the
99 * global list.
101 struct pci_bus *
102 pci_find_next_bus(const struct pci_bus *from)
104 struct list_head *n;
105 struct pci_bus *b = NULL;
107 WARN_ON(in_interrupt());
108 down_read(&pci_bus_sem);
109 n = from ? from->node.next : pci_root_buses.next;
110 if (n != &pci_root_buses)
111 b = pci_bus_b(n);
112 up_read(&pci_bus_sem);
113 return b;
116 #ifdef CONFIG_PCI_LEGACY
118 * pci_find_slot - locate PCI device from a given PCI slot
119 * @bus: number of PCI bus on which desired PCI device resides
120 * @devfn: encodes number of PCI slot in which the desired PCI
121 * device resides and the logical device number within that slot
122 * in case of multi-function devices.
124 * Given a PCI bus and slot/function number, the desired PCI device
125 * is located in system global list of PCI devices. If the device
126 * is found, a pointer to its data structure is returned. If no
127 * device is found, %NULL is returned.
129 * NOTE: Do not use this function any more; use pci_get_slot() instead, as
130 * the PCI device returned by this function can disappear at any moment in
131 * time.
133 struct pci_dev *pci_find_slot(unsigned int bus, unsigned int devfn)
135 struct pci_dev *dev = NULL;
137 while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
138 if (dev->bus->number == bus && dev->devfn == devfn) {
139 pci_dev_put(dev);
140 return dev;
143 return NULL;
145 EXPORT_SYMBOL(pci_find_slot);
148 * pci_find_device - begin or continue searching for a PCI device by vendor/device id
149 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
150 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
151 * @from: Previous PCI device found in search, or %NULL for new search.
153 * Iterates through the list of known PCI devices. If a PCI device is found
154 * with a matching @vendor and @device, a pointer to its device structure is
155 * returned. Otherwise, %NULL is returned.
156 * A new search is initiated by passing %NULL as the @from argument.
157 * Otherwise if @from is not %NULL, searches continue from next device
158 * on the global list.
160 * NOTE: Do not use this function any more; use pci_get_device() instead, as
161 * the PCI device returned by this function can disappear at any moment in
162 * time.
164 struct pci_dev *pci_find_device(unsigned int vendor, unsigned int device,
165 const struct pci_dev *from)
167 struct pci_dev *pdev;
169 pdev = pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
170 pci_dev_put(pdev);
171 return pdev;
173 EXPORT_SYMBOL(pci_find_device);
174 #endif /* CONFIG_PCI_LEGACY */
177 * pci_get_slot - locate PCI device for a given PCI slot
178 * @bus: PCI bus on which desired PCI device resides
179 * @devfn: encodes number of PCI slot in which the desired PCI
180 * device resides and the logical device number within that slot
181 * in case of multi-function devices.
183 * Given a PCI bus and slot/function number, the desired PCI device
184 * is located in the list of PCI devices.
185 * If the device is found, its reference count is increased and this
186 * function returns a pointer to its data structure. The caller must
187 * decrement the reference count by calling pci_dev_put().
188 * If no device is found, %NULL is returned.
190 struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn)
192 struct list_head *tmp;
193 struct pci_dev *dev;
195 WARN_ON(in_interrupt());
196 down_read(&pci_bus_sem);
198 list_for_each(tmp, &bus->devices) {
199 dev = pci_dev_b(tmp);
200 if (dev->devfn == devfn)
201 goto out;
204 dev = NULL;
205 out:
206 pci_dev_get(dev);
207 up_read(&pci_bus_sem);
208 return dev;
212 * pci_get_bus_and_slot - locate PCI device from a given PCI bus & slot
213 * @bus: number of PCI bus on which desired PCI device resides
214 * @devfn: encodes number of PCI slot in which the desired PCI
215 * device resides and the logical device number within that slot
216 * in case of multi-function devices.
218 * Note: the bus/slot search is limited to PCI domain (segment) 0.
220 * Given a PCI bus and slot/function number, the desired PCI device
221 * is located in system global list of PCI devices. If the device
222 * is found, a pointer to its data structure is returned. If no
223 * device is found, %NULL is returned. The returned device has its
224 * reference count bumped by one.
227 struct pci_dev * pci_get_bus_and_slot(unsigned int bus, unsigned int devfn)
229 struct pci_dev *dev = NULL;
231 while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
232 if (pci_domain_nr(dev->bus) == 0 &&
233 (dev->bus->number == bus && dev->devfn == devfn))
234 return dev;
236 return NULL;
239 static int match_pci_dev_by_id(struct device *dev, void *data)
241 struct pci_dev *pdev = to_pci_dev(dev);
242 struct pci_device_id *id = data;
244 if (pci_match_one_device(id, pdev))
245 return 1;
246 return 0;
250 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
251 * @id: pointer to struct pci_device_id to match for the device
252 * @from: Previous PCI device found in search, or %NULL for new search.
254 * Iterates through the list of known PCI devices. If a PCI device is found
255 * with a matching id a pointer to its device structure is returned, and the
256 * reference count to the device is incremented. Otherwise, %NULL is returned.
257 * A new search is initiated by passing %NULL as the @from argument. Otherwise
258 * if @from is not %NULL, searches continue from next device on the global
259 * list. The reference count for @from is always decremented if it is not
260 * %NULL.
262 * This is an internal function for use by the other search functions in
263 * this file.
265 static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
266 const struct pci_dev *from)
268 struct device *dev;
269 struct device *dev_start = NULL;
270 struct pci_dev *pdev = NULL;
272 WARN_ON(in_interrupt());
273 if (from) {
274 /* FIXME
275 * take the cast off, when bus_find_device is made const.
277 dev_start = (struct device *)&from->dev;
279 dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
280 match_pci_dev_by_id);
281 if (dev)
282 pdev = to_pci_dev(dev);
283 return pdev;
287 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
288 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
289 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
290 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
291 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
292 * @from: Previous PCI device found in search, or %NULL for new search.
294 * Iterates through the list of known PCI devices. If a PCI device is found
295 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
296 * device structure is returned, and the reference count to the device is
297 * incremented. Otherwise, %NULL is returned. A new search is initiated by
298 * passing %NULL as the @from argument. Otherwise if @from is not %NULL,
299 * searches continue from next device on the global list.
300 * The reference count for @from is always decremented if it is not %NULL.
302 struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
303 unsigned int ss_vendor, unsigned int ss_device,
304 const struct pci_dev *from)
306 struct pci_dev *pdev;
307 struct pci_device_id *id;
310 * pci_find_subsys() can be called on the ide_setup() path,
311 * super-early in boot. But the down_read() will enable local
312 * interrupts, which can cause some machines to crash. So here we
313 * detect and flag that situation and bail out early.
315 if (unlikely(no_pci_devices()))
316 return NULL;
318 id = kzalloc(sizeof(*id), GFP_KERNEL);
319 if (!id)
320 return NULL;
321 id->vendor = vendor;
322 id->device = device;
323 id->subvendor = ss_vendor;
324 id->subdevice = ss_device;
326 pdev = pci_get_dev_by_id(id, from);
327 kfree(id);
329 return pdev;
333 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
334 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
335 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
336 * @from: Previous PCI device found in search, or %NULL for new search.
338 * Iterates through the list of known PCI devices. If a PCI device is
339 * found with a matching @vendor and @device, the reference count to the
340 * device is incremented and a pointer to its device structure is returned.
341 * Otherwise, %NULL is returned. A new search is initiated by passing %NULL
342 * as the @from argument. Otherwise if @from is not %NULL, searches continue
343 * from next device on the global list. The reference count for @from is
344 * always decremented if it is not %NULL.
346 struct pci_dev *
347 pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
349 return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
353 * pci_get_class - begin or continue searching for a PCI device by class
354 * @class: search for a PCI device with this class designation
355 * @from: Previous PCI device found in search, or %NULL for new search.
357 * Iterates through the list of known PCI devices. If a PCI device is
358 * found with a matching @class, the reference count to the device is
359 * incremented and a pointer to its device structure is returned.
360 * Otherwise, %NULL is returned.
361 * A new search is initiated by passing %NULL as the @from argument.
362 * Otherwise if @from is not %NULL, searches continue from next device
363 * on the global list. The reference count for @from is always decremented
364 * if it is not %NULL.
366 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
368 struct pci_dev *dev;
369 struct pci_device_id *id;
371 id = kzalloc(sizeof(*id), GFP_KERNEL);
372 if (!id)
373 return NULL;
374 id->vendor = id->device = id->subvendor = id->subdevice = PCI_ANY_ID;
375 id->class_mask = PCI_ANY_ID;
376 id->class = class;
378 dev = pci_get_dev_by_id(id, from);
379 kfree(id);
380 return dev;
384 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
385 * @ids: A pointer to a null terminated list of struct pci_device_id structures
386 * that describe the type of PCI device the caller is trying to find.
388 * Obvious fact: You do not have a reference to any device that might be found
389 * by this function, so if that device is removed from the system right after
390 * this function is finished, the value will be stale. Use this function to
391 * find devices that are usually built into a system, or for a general hint as
392 * to if another device happens to be present at this specific moment in time.
394 int pci_dev_present(const struct pci_device_id *ids)
396 struct pci_dev *found = NULL;
398 WARN_ON(in_interrupt());
399 while (ids->vendor || ids->subvendor || ids->class_mask) {
400 found = pci_get_dev_by_id(ids, NULL);
401 if (found)
402 goto exit;
403 ids++;
405 exit:
406 if (found)
407 return 1;
408 return 0;
410 EXPORT_SYMBOL(pci_dev_present);
412 /* For boot time work */
413 EXPORT_SYMBOL(pci_find_bus);
414 EXPORT_SYMBOL(pci_find_next_bus);
415 /* For everyone */
416 EXPORT_SYMBOL(pci_get_device);
417 EXPORT_SYMBOL(pci_get_subsys);
418 EXPORT_SYMBOL(pci_get_slot);
419 EXPORT_SYMBOL(pci_get_bus_and_slot);
420 EXPORT_SYMBOL(pci_get_class);