![Alan Stern](/assets/img/avatar_default.png)
This patch (as659) fixes a might_sleep problem in the PCI core, by moving a call to pci_dev_put() outside the scope of a spinlock. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
390 lines
13 KiB
C
390 lines
13 KiB
C
/*
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* PCI searching functions.
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*
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* Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
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* David Mosberger-Tang
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* Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
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* Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
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*/
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#include <linux/init.h>
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#include <linux/pci.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include "pci.h"
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DEFINE_SPINLOCK(pci_bus_lock);
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static struct pci_bus * __devinit
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pci_do_find_bus(struct pci_bus* bus, unsigned char busnr)
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{
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struct pci_bus* child;
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struct list_head *tmp;
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if(bus->number == busnr)
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return bus;
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list_for_each(tmp, &bus->children) {
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child = pci_do_find_bus(pci_bus_b(tmp), busnr);
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if(child)
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return child;
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}
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return NULL;
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}
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/**
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* pci_find_bus - locate PCI bus from a given domain and bus number
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* @domain: number of PCI domain to search
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* @busnr: number of desired PCI bus
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*
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* Given a PCI bus number and domain number, the desired PCI bus is located
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* in the global list of PCI buses. If the bus is found, a pointer to its
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* data structure is returned. If no bus is found, %NULL is returned.
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*/
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struct pci_bus * __devinit pci_find_bus(int domain, int busnr)
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{
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struct pci_bus *bus = NULL;
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struct pci_bus *tmp_bus;
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while ((bus = pci_find_next_bus(bus)) != NULL) {
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if (pci_domain_nr(bus) != domain)
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continue;
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tmp_bus = pci_do_find_bus(bus, busnr);
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if (tmp_bus)
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return tmp_bus;
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}
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return NULL;
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}
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/**
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* pci_find_next_bus - begin or continue searching for a PCI bus
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* @from: Previous PCI bus found, or %NULL for new search.
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*
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* Iterates through the list of known PCI busses. A new search is
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* initiated by passing %NULL to the @from argument. Otherwise if
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* @from is not %NULL, searches continue from next device on the
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* global list.
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*/
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struct pci_bus *
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pci_find_next_bus(const struct pci_bus *from)
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{
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struct list_head *n;
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struct pci_bus *b = NULL;
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WARN_ON(in_interrupt());
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spin_lock(&pci_bus_lock);
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n = from ? from->node.next : pci_root_buses.next;
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if (n != &pci_root_buses)
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b = pci_bus_b(n);
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spin_unlock(&pci_bus_lock);
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return b;
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}
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/**
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* pci_find_slot - locate PCI device from a given PCI slot
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* @bus: number of PCI bus on which desired PCI device resides
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* @devfn: encodes number of PCI slot in which the desired PCI
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* device resides and the logical device number within that slot
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* in case of multi-function devices.
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*
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* Given a PCI bus and slot/function number, the desired PCI device
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* is located in system global list of PCI devices. If the device
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* is found, a pointer to its data structure is returned. If no
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* device is found, %NULL is returned.
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*/
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struct pci_dev *
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pci_find_slot(unsigned int bus, unsigned int devfn)
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{
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struct pci_dev *dev = NULL;
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while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
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if (dev->bus->number == bus && dev->devfn == devfn)
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return dev;
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}
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return NULL;
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}
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/**
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* pci_get_slot - locate PCI device for a given PCI slot
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* @bus: PCI bus on which desired PCI device resides
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* @devfn: encodes number of PCI slot in which the desired PCI
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* device resides and the logical device number within that slot
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* in case of multi-function devices.
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*
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* Given a PCI bus and slot/function number, the desired PCI device
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* is located in the list of PCI devices.
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* If the device is found, its reference count is increased and this
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* function returns a pointer to its data structure. The caller must
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* decrement the reference count by calling pci_dev_put().
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* If no device is found, %NULL is returned.
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*/
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struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn)
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{
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struct list_head *tmp;
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struct pci_dev *dev;
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WARN_ON(in_interrupt());
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spin_lock(&pci_bus_lock);
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list_for_each(tmp, &bus->devices) {
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dev = pci_dev_b(tmp);
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if (dev->devfn == devfn)
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goto out;
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}
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dev = NULL;
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out:
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pci_dev_get(dev);
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spin_unlock(&pci_bus_lock);
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return dev;
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}
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/**
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* pci_find_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
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* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
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* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is
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* found with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
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* device structure is returned. Otherwise, %NULL is returned.
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* A new search is initiated by passing %NULL to the @from argument.
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* Otherwise if @from is not %NULL, searches continue from next device on the global list.
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*
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* NOTE: Do not use this function anymore, use pci_get_subsys() instead, as
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* the pci device returned by this function can disappear at any moment in
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* time.
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*/
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static struct pci_dev * pci_find_subsys(unsigned int vendor,
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unsigned int device,
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unsigned int ss_vendor,
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unsigned int ss_device,
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const struct pci_dev *from)
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{
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struct list_head *n;
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struct pci_dev *dev;
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WARN_ON(in_interrupt());
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spin_lock(&pci_bus_lock);
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n = from ? from->global_list.next : pci_devices.next;
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while (n && (n != &pci_devices)) {
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dev = pci_dev_g(n);
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if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
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(device == PCI_ANY_ID || dev->device == device) &&
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(ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
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(ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
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goto exit;
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n = n->next;
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}
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dev = NULL;
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exit:
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spin_unlock(&pci_bus_lock);
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return dev;
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}
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/**
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* pci_find_device - begin or continue searching for a PCI device by vendor/device id
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* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is
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* found with a matching @vendor and @device, a pointer to its device structure is
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* returned. Otherwise, %NULL is returned.
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* A new search is initiated by passing %NULL to the @from argument.
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* Otherwise if @from is not %NULL, searches continue from next device on the global list.
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*
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* NOTE: Do not use this function anymore, use pci_get_device() instead, as
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* the pci device returned by this function can disappear at any moment in
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* time.
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*/
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struct pci_dev *
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pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from)
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{
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return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
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}
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/**
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* pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
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* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
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* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is
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* found with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
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* device structure is returned, and the reference count to the device is
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* incremented. Otherwise, %NULL is returned. A new search is initiated by
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* passing %NULL to the @from argument. Otherwise if @from is not %NULL,
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* searches continue from next device on the global list.
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* The reference count for @from is always decremented if it is not %NULL.
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*/
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struct pci_dev *
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pci_get_subsys(unsigned int vendor, unsigned int device,
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unsigned int ss_vendor, unsigned int ss_device,
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struct pci_dev *from)
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{
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struct list_head *n;
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struct pci_dev *dev;
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WARN_ON(in_interrupt());
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spin_lock(&pci_bus_lock);
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n = from ? from->global_list.next : pci_devices.next;
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while (n && (n != &pci_devices)) {
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dev = pci_dev_g(n);
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if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
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(device == PCI_ANY_ID || dev->device == device) &&
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(ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
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(ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
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goto exit;
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n = n->next;
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}
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dev = NULL;
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exit:
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dev = pci_dev_get(dev);
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spin_unlock(&pci_bus_lock);
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pci_dev_put(from);
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return dev;
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}
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/**
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* pci_get_device - begin or continue searching for a PCI device by vendor/device id
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* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is
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* found with a matching @vendor and @device, the reference count to the
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* device is incremented and a pointer to its device structure is returned.
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* Otherwise, %NULL is returned. A new search is initiated by passing %NULL
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* to the @from argument. Otherwise if @from is not %NULL, searches continue
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* from next device on the global list. The reference count for @from is
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* always decremented if it is not %NULL.
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*/
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struct pci_dev *
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pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
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{
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return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
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}
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/**
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* pci_find_device_reverse - begin or continue searching for a PCI device by vendor/device id
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* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices in the reverse order of pci_find_device().
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* If a PCI device is found with a matching @vendor and @device, a pointer to
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* its device structure is returned. Otherwise, %NULL is returned.
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* A new search is initiated by passing %NULL to the @from argument.
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* Otherwise if @from is not %NULL, searches continue from previous device on the global list.
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*/
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struct pci_dev *
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pci_find_device_reverse(unsigned int vendor, unsigned int device, const struct pci_dev *from)
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{
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struct list_head *n;
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struct pci_dev *dev;
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WARN_ON(in_interrupt());
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spin_lock(&pci_bus_lock);
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n = from ? from->global_list.prev : pci_devices.prev;
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while (n && (n != &pci_devices)) {
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dev = pci_dev_g(n);
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if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
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(device == PCI_ANY_ID || dev->device == device))
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goto exit;
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n = n->prev;
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}
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dev = NULL;
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exit:
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spin_unlock(&pci_bus_lock);
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return dev;
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}
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/**
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* pci_get_class - begin or continue searching for a PCI device by class
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* @class: search for a PCI device with this class designation
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is
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* found with a matching @class, the reference count to the device is
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* incremented and a pointer to its device structure is returned.
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* Otherwise, %NULL is returned.
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* A new search is initiated by passing %NULL to the @from argument.
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* Otherwise if @from is not %NULL, searches continue from next device
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* on the global list. The reference count for @from is always decremented
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* if it is not %NULL.
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*/
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struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
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{
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struct list_head *n;
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struct pci_dev *dev;
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WARN_ON(in_interrupt());
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spin_lock(&pci_bus_lock);
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n = from ? from->global_list.next : pci_devices.next;
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while (n && (n != &pci_devices)) {
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dev = pci_dev_g(n);
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if (dev->class == class)
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goto exit;
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n = n->next;
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}
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dev = NULL;
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exit:
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dev = pci_dev_get(dev);
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spin_unlock(&pci_bus_lock);
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pci_dev_put(from);
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return dev;
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}
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/**
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* pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
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* @ids: A pointer to a null terminated list of struct pci_device_id structures
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* that describe the type of PCI device the caller is trying to find.
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*
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* Obvious fact: You do not have a reference to any device that might be found
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* by this function, so if that device is removed from the system right after
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* this function is finished, the value will be stale. Use this function to
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* find devices that are usually built into a system, or for a general hint as
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* to if another device happens to be present at this specific moment in time.
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*/
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int pci_dev_present(const struct pci_device_id *ids)
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{
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struct pci_dev *dev;
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int found = 0;
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WARN_ON(in_interrupt());
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spin_lock(&pci_bus_lock);
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while (ids->vendor || ids->subvendor || ids->class_mask) {
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list_for_each_entry(dev, &pci_devices, global_list) {
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if (pci_match_one_device(ids, dev)) {
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found = 1;
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goto exit;
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}
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}
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ids++;
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}
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exit:
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spin_unlock(&pci_bus_lock);
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return found;
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}
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EXPORT_SYMBOL(pci_dev_present);
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EXPORT_SYMBOL(pci_find_bus);
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EXPORT_SYMBOL(pci_find_next_bus);
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EXPORT_SYMBOL(pci_find_device);
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EXPORT_SYMBOL(pci_find_device_reverse);
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EXPORT_SYMBOL(pci_find_slot);
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EXPORT_SYMBOL(pci_get_device);
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EXPORT_SYMBOL(pci_get_subsys);
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EXPORT_SYMBOL(pci_get_slot);
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EXPORT_SYMBOL(pci_get_class);
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