pci: Additional search functions

In order to finish converting to pci_get_* interfaces we need to add a couple
of bits of missing functionaility

pci_get_bus_and_slot() provides the equivalent to pci_find_slot()
(pci_get_slot is already taken as a name for something similar but not the
same)

pci_get_device_reverse() is the equivalent of pci_find_device_reverse but
refcounting

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/search.c

@@ -139,6 +139,31 @@ struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn)
 	return dev;
 }
 
+/**
+ * pci_get_bus_and_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. 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 (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
@@ -274,6 +299,45 @@ 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_find_device_reverse - begin or continue searching for a PCI device by vendor/device id
@@ -382,12 +446,16 @@ int pci_dev_present(const struct pci_device_id *ids)
 }
 EXPORT_SYMBOL(pci_dev_present);
 
-EXPORT_SYMBOL(pci_find_bus);
-EXPORT_SYMBOL(pci_find_next_bus);
 EXPORT_SYMBOL(pci_find_device);
 EXPORT_SYMBOL(pci_find_device_reverse);
 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);

include/linux/pci.h

@@ -452,13 +452,14 @@ struct pci_dev *pci_find_slot (unsigned int bus, unsigned int devfn);
 int pci_find_capability (struct pci_dev *dev, int cap);
 int pci_find_next_capability (struct pci_dev *dev, u8 pos, int cap);
 int pci_find_ext_capability (struct pci_dev *dev, int cap);
-struct pci_bus * pci_find_next_bus(const struct pci_bus *from);
+struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
 
 struct pci_dev *pci_get_device (unsigned int vendor, unsigned int device, struct pci_dev *from);
 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 *pci_get_slot (struct pci_bus *bus, unsigned int devfn);
+struct pci_dev *pci_get_bus_and_slot (unsigned int bus, unsigned int devfn);
 struct pci_dev *pci_get_class (unsigned int class, struct pci_dev *from);
 int pci_dev_present(const struct pci_device_id *ids);