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path: root/drivers/pci/search.c
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Diffstat (limited to 'drivers/pci/search.c')
-rw-r--r--drivers/pci/search.c62
1 files changed, 54 insertions, 8 deletions
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 53840634fbfc..e6e84dc62e82 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -282,6 +282,45 @@ static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
return pdev;
}
+static struct pci_dev *pci_get_dev_by_id_reverse(const struct pci_device_id *id,
+ struct pci_dev *from)
+{
+ struct device *dev;
+ struct device *dev_start = NULL;
+ struct pci_dev *pdev = NULL;
+
+ if (from)
+ dev_start = &from->dev;
+ dev = bus_find_device_reverse(&pci_bus_type, dev_start, (void *)id,
+ match_pci_dev_by_id);
+ if (dev)
+ pdev = to_pci_dev(dev);
+ pci_dev_put(from);
+ return pdev;
+}
+
+enum pci_search_direction {
+ PCI_SEARCH_FORWARD,
+ PCI_SEARCH_REVERSE,
+};
+
+static struct pci_dev *__pci_get_subsys(unsigned int vendor, unsigned int device,
+ unsigned int ss_vendor, unsigned int ss_device,
+ struct pci_dev *from, enum pci_search_direction dir)
+{
+ struct pci_device_id id = {
+ .vendor = vendor,
+ .device = device,
+ .subvendor = ss_vendor,
+ .subdevice = ss_device,
+ };
+
+ if (dir == PCI_SEARCH_FORWARD)
+ return pci_get_dev_by_id(&id, from);
+ else
+ return pci_get_dev_by_id_reverse(&id, from);
+}
+
/**
* 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
@@ -302,14 +341,8 @@ 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_device_id id = {
- .vendor = vendor,
- .device = device,
- .subvendor = ss_vendor,
- .subdevice = ss_device,
- };
-
- return pci_get_dev_by_id(&id, from);
+ return __pci_get_subsys(vendor, device, ss_vendor, ss_device, from,
+ PCI_SEARCH_FORWARD);
}
EXPORT_SYMBOL(pci_get_subsys);
@@ -334,6 +367,19 @@ struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
}
EXPORT_SYMBOL(pci_get_device);
+/*
+ * Same semantics as pci_get_device(), except walks the PCI device list
+ * in reverse discovery order.
+ */
+struct pci_dev *pci_get_device_reverse(unsigned int vendor,
+ unsigned int device,
+ struct pci_dev *from)
+{
+ return __pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from,
+ PCI_SEARCH_REVERSE);
+}
+EXPORT_SYMBOL(pci_get_device_reverse);
+
/**
* pci_get_class - begin or continue searching for a PCI device by class
* @class: search for a PCI device with this class designation