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authorTimothy Pearson <tpearson@raptorengineering.com>2017-08-23 14:45:25 -0500
committerTimothy Pearson <tpearson@raptorengineering.com>2017-08-23 14:45:25 -0500
commitfcbb27b0ec6dcbc5a5108cb8fb19eae64593d204 (patch)
tree22962a4387943edc841c72a4e636a068c66d58fd /drivers/pci/search.c
downloadast2050-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.c419
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);
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