/* * 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); /* * find the upstream PCIe-to-PCI bridge of a PCI device * if the device is PCIE, return NULL * if the device isn't connected to a PCIe bridge (that is its parent is a * legacy PCI bridge and the bridge is directly connected to bus 0), return its * parent */ struct pci_dev * pci_find_upstream_pcie_bridge(struct pci_dev *pdev) { struct pci_dev *tmp = NULL; if (pci_is_pcie(pdev)) return NULL; while (1) { if (pci_is_root_bus(pdev->bus)) break; pdev = pdev->bus->self; /* a p2p bridge */ if (!pci_is_pcie(pdev)) { tmp = pdev; continue; } /* PCI device should connect to a PCIe bridge */ if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) { /* Busted hardware? */ WARN_ON_ONCE(1); return NULL; } return pdev; } return tmp; } 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_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_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot * @domain: PCI domain/segment on which the PCI device resides. * @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 domain, 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_domain_bus_and_slot(int domain, 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) == domain && (dev->bus->number == bus && dev->devfn == devfn)) return dev; } return NULL; } EXPORT_SYMBOL(pci_get_domain_bus_and_slot); static int match_pci_dev_by_id(struct device *dev, void *data) { struct pci_dev *pdev = to_pci_dev(dev); struct pci_device_id *id = data; if (pci_match_one_device(id, pdev)) return 1; return 0; } /* * pci_get_dev_by_id - begin or continue searching for a PCI device by id * @id: pointer to struct pci_device_id to match for the device * @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 id 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. * * This is an internal function for use by the other search functions in * this file. */ static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id, struct pci_dev *from) { struct device *dev; struct device *dev_start = NULL; struct pci_dev *pdev = NULL; WARN_ON(in_interrupt()); if (from) dev_start = &from->dev; dev = bus_find_device(&pci_bus_type, dev_start, (void *)id, match_pci_dev_by_id); if (dev) pdev = to_pci_dev(dev); if (from) pci_dev_put(from); return pdev; } /** * 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 pci_dev *pdev; struct pci_device_id *id; /* * 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(no_pci_devices())) return NULL; id = kzalloc(sizeof(*id), GFP_KERNEL); if (!id) return NULL; id->vendor = vendor; id->device = device; id->subvendor = ss_vendor; id->subdevice = ss_device; pdev = pci_get_dev_by_id(id, from); kfree(id); return pdev; } /** * 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_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 pci_dev *dev; struct pci_device_id *id; id = kzalloc(sizeof(*id), GFP_KERNEL); if (!id) return NULL; id->vendor = id->device = id->subvendor = id->subdevice = PCI_ANY_ID; id->class_mask = PCI_ANY_ID; id->class = class; dev = pci_get_dev_by_id(id, from); kfree(id); return dev; } /** * 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) { struct pci_dev *found = NULL; WARN_ON(in_interrupt()); while (ids->vendor || ids->subvendor || ids->class_mask) { found = pci_get_dev_by_id(ids, NULL); if (found) goto exit; ids++; } exit: if (found) return 1; return 0; } EXPORT_SYMBOL(pci_dev_present); /* 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_subsys); EXPORT_SYMBOL(pci_get_slot); EXPORT_SYMBOL(pci_get_class);