@@ -1081,6 +1081,37 @@ struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
}
EXPORT_SYMBOL(pci_scan_single_device);
+static unsigned next_ari_fn(struct pci_dev *dev, unsigned fn)
+{
+ u16 cap;
+ unsigned pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
+ if (!pos)
+ return 0;
+ pci_read_config_word(dev, pos + 4, &cap);
+ return cap >> 8;
+}
+
+static unsigned next_trad_fn(struct pci_dev *dev, unsigned fn)
+{
+ return (fn + 1) % 8;
+}
+
+static unsigned no_next_fn(struct pci_dev *dev, unsigned fn)
+{
+ return 0;
+}
+
+static int only_one_child(struct pci_bus *bus)
+{
+ struct pci_dev *parent = bus->self;
+ if (!parent || !pci_is_pcie(parent))
+ return 0;
+ if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
+ parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)
+ return 1;
+ return 0;
+}
+
/**
* pci_scan_slot - scan a PCI slot on a bus for devices.
* @bus: PCI bus to scan
@@ -1094,21 +1125,28 @@ EXPORT_SYMBOL(pci_scan_single_device);
*/
int pci_scan_slot(struct pci_bus *bus, int devfn)
{
- int fn, nr = 0;
+ unsigned fn, nr = 0;
struct pci_dev *dev;
+ unsigned (*next_fn)(struct pci_dev *, unsigned) = no_next_fn;
+
+ if (only_one_child(bus) && (devfn > 0))
+ return 0; /* Already scanned the entire slot */
dev = pci_scan_single_device(bus, devfn);
if (dev && !dev->is_added) /* new device? */
nr++;
- if (dev && dev->multifunction) {
- for (fn = 1; fn < 8; fn++) {
- dev = pci_scan_single_device(bus, devfn + fn);
- if (dev) {
- if (!dev->is_added)
- nr++;
- dev->multifunction = 1;
- }
+ if (pci_ari_enabled(bus))
+ next_fn = next_ari_fn;
+ else if (dev && dev->multifunction)
+ next_fn = next_trad_fn;
+
+ for (fn = next_fn(dev, 0); fn > 0; fn = next_fn(dev, fn)) {
+ dev = pci_scan_single_device(bus, devfn + fn);
+ if (dev) {
+ if (!dev->is_added)
+ nr++;
+ dev->multifunction = 1;
}
}