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linux/drivers/pci/search.c

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/*
* PCI searching functions.
*
* Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
* David Mosberger-Tang
* Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
* Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
*/
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include "pci.h"
DECLARE_RWSEM(pci_bus_sem);
static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
{
struct pci_bus* child;
struct list_head *tmp;
if(bus->number == busnr)
return bus;
list_for_each(tmp, &bus->children) {
child = pci_do_find_bus(pci_bus_b(tmp), busnr);
if(child)
return child;
}
return NULL;
}
/**
* pci_find_bus - locate PCI bus from a given domain and bus number
* @domain: number of PCI domain to search
* @busnr: number of desired PCI bus
*
* Given a PCI bus number and domain number, the desired PCI bus is located
* in the global list of PCI buses. If the bus is found, a pointer to its
* data structure is returned. If no bus is found, %NULL is returned.
*/
struct pci_bus * pci_find_bus(int domain, int busnr)
{
struct pci_bus *bus = NULL;
struct pci_bus *tmp_bus;
while ((bus = pci_find_next_bus(bus)) != NULL) {
if (pci_domain_nr(bus) != domain)
continue;
tmp_bus = pci_do_find_bus(bus, busnr);
if (tmp_bus)
return tmp_bus;
}
return NULL;
}
/**
* pci_find_next_bus - begin or continue searching for a PCI bus
* @from: Previous PCI bus found, or %NULL for new search.
*
* Iterates through the list of known PCI busses. A new search is
* initiated by passing %NULL as the @from argument. Otherwise if
* @from is not %NULL, searches continue from next device on the
* global list.
*/
struct pci_bus *
pci_find_next_bus(const struct pci_bus *from)
{
struct list_head *n;
struct pci_bus *b = NULL;
WARN_ON(in_interrupt());
down_read(&pci_bus_sem);
n = from ? from->node.next : pci_root_buses.next;
if (n != &pci_root_buses)
b = pci_bus_b(n);
up_read(&pci_bus_sem);
return b;
}
/**
* pci_find_slot - locate PCI device from a given PCI slot
* @bus: number of PCI bus on which desired PCI device resides
* @devfn: encodes number of PCI slot in which the desired PCI
* device resides and the logical device number within that slot
* in case of multi-function devices.
*
* Given a PCI bus and slot/function number, the desired PCI device
* is located in system global list of PCI devices. If the device
* is found, a pointer to its data structure is returned. If no
* device is found, %NULL is returned.
*/
struct pci_dev *
pci_find_slot(unsigned int bus, unsigned int devfn)
{
struct pci_dev *dev = NULL;
while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
if (dev->bus->number == bus && dev->devfn == devfn)
return dev;
}
return NULL;
}
/**
* pci_get_slot - locate PCI device for a given PCI slot
* @bus: PCI bus on which desired PCI device resides
* @devfn: encodes number of PCI slot in which the desired PCI
* device resides and the logical device number within that slot
* in case of multi-function devices.
*
* Given a PCI bus and slot/function number, the desired PCI device
* is located in the list of PCI devices.
* If the device is found, its reference count is increased and this
* function returns a pointer to its data structure. The caller must
* decrement the reference count by calling pci_dev_put().
* If no device is found, %NULL is returned.
*/
struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn)
{
struct list_head *tmp;
struct pci_dev *dev;
WARN_ON(in_interrupt());
down_read(&pci_bus_sem);
list_for_each(tmp, &bus->devices) {
dev = pci_dev_b(tmp);
if (dev->devfn == devfn)
goto out;
}
dev = NULL;
out:
pci_dev_get(dev);
up_read(&pci_bus_sem);
return dev;
}
/**
* pci_get_bus_and_slot - locate PCI device from a given PCI bus & slot
* @bus: number of PCI bus on which desired PCI device resides
* @devfn: encodes number of PCI slot in which the desired PCI
* device resides and the logical device number within that slot
* in case of multi-function devices.
*
* Note: the bus/slot search is limited to PCI domain (segment) 0.
*
* Given a PCI bus and slot/function number, the desired PCI device
* is located in system global list of PCI devices. If the device
* is found, a pointer to its data structure is returned. If no
* device is found, %NULL is returned. The returned device has its
* reference count bumped by one.
*/
struct pci_dev * pci_get_bus_and_slot(unsigned int bus, unsigned int devfn)
{
struct pci_dev *dev = NULL;
while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
if (pci_domain_nr(dev->bus) == 0 &&
(dev->bus->number == bus && dev->devfn == devfn))
return dev;
}
return NULL;
}
/**
* pci_find_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices. If a PCI device is
* found with a matching @vendor, @device, @ss_vendor and @ss_device, a
* pointer to its device structure is returned. Otherwise, %NULL is returned.
* A new search is initiated by passing %NULL as the @from argument.
* Otherwise if @from is not %NULL, searches continue from next device
* on the global list.
*
* NOTE: Do not use this function any more; use pci_get_subsys() instead, as
* the PCI device returned by this function can disappear at any moment in
* time.
*/
static struct pci_dev * pci_find_subsys(unsigned int vendor,
unsigned int device,
unsigned int ss_vendor,
unsigned int ss_device,
const struct pci_dev *from)
{
struct list_head *n;
struct pci_dev *dev;
WARN_ON(in_interrupt());
/*
* pci_find_subsys() can be called on the ide_setup() path, super-early
* in boot. But the down_read() will enable local interrupts, which
* can cause some machines to crash. So here we detect and flag that
* situation and bail out early.
*/
if (unlikely(list_empty(&pci_devices)))
return NULL;
down_read(&pci_bus_sem);
n = from ? from->global_list.next : pci_devices.next;
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
(device == PCI_ANY_ID || dev->device == device) &&
(ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
(ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
goto exit;
n = n->next;
}
dev = NULL;
exit:
up_read(&pci_bus_sem);
return dev;
}
/**
* pci_find_device - begin or continue searching for a PCI device by vendor/device id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices. If a PCI device is found
* with a matching @vendor and @device, a pointer to its device structure is
* returned. Otherwise, %NULL is returned.
* A new search is initiated by passing %NULL as the @from argument.
* Otherwise if @from is not %NULL, searches continue from next device
* on the global list.
*
* NOTE: Do not use this function any more; use pci_get_device() instead, as
* the PCI device returned by this function can disappear at any moment in
* time.
*/
struct pci_dev *
pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from)
{
return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
}
/**
* pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices. If a PCI device is found
* with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
* device structure is returned, and the reference count to the device is
* incremented. Otherwise, %NULL is returned. A new search is initiated by
* passing %NULL as the @from argument. Otherwise if @from is not %NULL,
* searches continue from next device on the global list.
* The reference count for @from is always decremented if it is not %NULL.
*/
struct pci_dev *
pci_get_subsys(unsigned int vendor, unsigned int device,
unsigned int ss_vendor, unsigned int ss_device,
struct pci_dev *from)
{
struct list_head *n;
struct pci_dev *dev;
WARN_ON(in_interrupt());
/*
* pci_get_subsys() can potentially be called by drivers super-early
* in boot. But the down_read() will enable local interrupts, which
* can cause some machines to crash. So here we detect and flag that
* situation and bail out early.
*/
if (unlikely(list_empty(&pci_devices)))
return NULL;
down_read(&pci_bus_sem);
n = from ? from->global_list.next : pci_devices.next;
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
(device == PCI_ANY_ID || dev->device == device) &&
(ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
(ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
goto exit;
n = n->next;
}
dev = NULL;
exit:
dev = pci_dev_get(dev);
up_read(&pci_bus_sem);
pci_dev_put(from);
return dev;
}
/**
* pci_get_device - begin or continue searching for a PCI device by vendor/device id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices. If a PCI device is
* found with a matching @vendor and @device, the reference count to the
* device is incremented and a pointer to its device structure is returned.
* Otherwise, %NULL is returned. A new search is initiated by passing %NULL
* as the @from argument. Otherwise if @from is not %NULL, searches continue
* from next device on the global list. The reference count for @from is
* always decremented if it is not %NULL.
*/
struct pci_dev *
pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
{
return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
}
/**
* pci_get_device_reverse - begin or continue searching for a PCI device by vendor/device id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices in the reverse order of
* pci_get_device.
* If a PCI device is found with a matching @vendor and @device, the reference
* count to the device is incremented and a pointer to its device structure
* is returned Otherwise, %NULL is returned. A new search is initiated by
* passing %NULL as the @from argument. Otherwise if @from is not %NULL,
* searches continue from next device on the global list. The reference
* count for @from is always decremented if it is not %NULL.
*/
struct pci_dev *
pci_get_device_reverse(unsigned int vendor, unsigned int device, struct pci_dev *from)
{
struct list_head *n;
struct pci_dev *dev;
WARN_ON(in_interrupt());
down_read(&pci_bus_sem);
n = from ? from->global_list.prev : pci_devices.prev;
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
(device == PCI_ANY_ID || dev->device == device))
goto exit;
n = n->prev;
}
dev = NULL;
exit:
dev = pci_dev_get(dev);
up_read(&pci_bus_sem);
pci_dev_put(from);
return dev;
}
/**
* pci_get_class - begin or continue searching for a PCI device by class
* @class: search for a PCI device with this class designation
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices. If a PCI device is
* found with a matching @class, the reference count to the device is
* incremented and a pointer to its device structure is returned.
* Otherwise, %NULL is returned.
* A new search is initiated by passing %NULL as the @from argument.
* Otherwise if @from is not %NULL, searches continue from next device
* on the global list. The reference count for @from is always decremented
* if it is not %NULL.
*/
struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
{
struct list_head *n;
struct pci_dev *dev;
WARN_ON(in_interrupt());
down_read(&pci_bus_sem);
n = from ? from->global_list.next : pci_devices.next;
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if (dev->class == class)
goto exit;
n = n->next;
}
dev = NULL;
exit:
dev = pci_dev_get(dev);
up_read(&pci_bus_sem);
pci_dev_put(from);
return dev;
}
const struct pci_device_id *pci_find_present(const struct pci_device_id *ids)
{
struct pci_dev *dev;
const struct pci_device_id *found = NULL;
WARN_ON(in_interrupt());
down_read(&pci_bus_sem);
while (ids->vendor || ids->subvendor || ids->class_mask) {
list_for_each_entry(dev, &pci_devices, global_list) {
if ((found = pci_match_one_device(ids, dev)) != NULL)
goto exit;
}
ids++;
}
exit:
up_read(&pci_bus_sem);
return found;
}
/**
* pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
* @ids: A pointer to a null terminated list of struct pci_device_id structures
* that describe the type of PCI device the caller is trying to find.
*
* Obvious fact: You do not have a reference to any device that might be found
* by this function, so if that device is removed from the system right after
* this function is finished, the value will be stale. Use this function to
* find devices that are usually built into a system, or for a general hint as
* to if another device happens to be present at this specific moment in time.
*/
int pci_dev_present(const struct pci_device_id *ids)
{
return pci_find_present(ids) == NULL ? 0 : 1;
}
EXPORT_SYMBOL(pci_dev_present);
EXPORT_SYMBOL(pci_find_present);
EXPORT_SYMBOL(pci_find_device);
EXPORT_SYMBOL(pci_find_slot);
/* For boot time work */
EXPORT_SYMBOL(pci_find_bus);
EXPORT_SYMBOL(pci_find_next_bus);
/* For everyone */
EXPORT_SYMBOL(pci_get_device);
EXPORT_SYMBOL(pci_get_device_reverse);
EXPORT_SYMBOL(pci_get_subsys);
EXPORT_SYMBOL(pci_get_slot);
EXPORT_SYMBOL(pci_get_bus_and_slot);
EXPORT_SYMBOL(pci_get_class);
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