diff options
| -rw-r--r-- | drivers/pci/probe.c | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 446e4a94d7d..dd64310a735 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -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; } } |