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author | Timothy Pearson <tpearson@raptorengineering.com> | 2017-08-23 14:45:25 -0500 |
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committer | Timothy Pearson <tpearson@raptorengineering.com> | 2017-08-23 14:45:25 -0500 |
commit | fcbb27b0ec6dcbc5a5108cb8fb19eae64593d204 (patch) | |
tree | 22962a4387943edc841c72a4e636a068c66d58fd /drivers/pci/search.c | |
download | ast2050-linux-kernel-fcbb27b0ec6dcbc5a5108cb8fb19eae64593d204.zip ast2050-linux-kernel-fcbb27b0ec6dcbc5a5108cb8fb19eae64593d204.tar.gz |
Initial import of modified Linux 2.6.28 tree
Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y
Diffstat (limited to 'drivers/pci/search.c')
-rw-r--r-- | drivers/pci/search.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/pci/search.c b/drivers/pci/search.c new file mode 100644 index 0000000..5af8bd5 --- /dev/null +++ b/drivers/pci/search.c @@ -0,0 +1,419 @@ +/* + * 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 (pdev->is_pcie) + return NULL; + while (1) { + if (!pdev->bus->self) + break; + pdev = pdev->bus->self; + /* a p2p bridge */ + if (!pdev->is_pcie) { + 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; +} + +#ifdef CONFIG_PCI_LEGACY +/** + * 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. + * + * NOTE: Do not use this function any more; use pci_get_slot() instead, as + * the PCI device returned by this function can disappear at any moment in + * time. + */ +struct pci_dev *pci_find_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 (dev->bus->number == bus && dev->devfn == devfn) { + pci_dev_put(dev); + return dev; + } + } + return NULL; +} +EXPORT_SYMBOL(pci_find_slot); + +/** + * 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, + struct pci_dev *from) +{ + struct pci_dev *pdev; + + pci_dev_get(from); + pdev = pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); + pci_dev_put(pdev); + return pdev; +} +EXPORT_SYMBOL(pci_find_device); +#endif /* CONFIG_PCI_LEGACY */ + +/** + * 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; +} + +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_bus_and_slot); +EXPORT_SYMBOL(pci_get_class); |