On Tue, May 28, 2013 at 12:40:20PM -0600, Alex Williamson wrote:
> +bool iommu_pci_is_pcie_bridge(struct pci_dev *pdev)
> +{
> + if (!pdev->subordinate)
> + return false;
> +
> + if (pci_is_pcie(pdev))
> + return true;
> +
> +#ifdef CONFIG_PCI_QUIRKS
> + /*
> + * If we're not on the root bus, look one device upstream of the
> + * current device. If that device is PCIe and is not a PCIe-to-PCI
> + * bridge, then the current device is effectively PCIe as it must
> + * be the PCIe-to-PCI bridge. This handles several bridges that
> + * violate the PCIe spec by not exposing a PCIe capability:
> + * https://bugzilla.kernel.org/show_bug.cgi?id=44881
> + */
> + if (!pci_is_root_bus(pdev->bus)) {
> + struct pci_dev *parent = pdev->bus->self;
> +
> + if (pci_is_pcie(parent) &&
> + pci_pcie_type(parent) != PCI_EXP_TYPE_PCI_BRIDGE)
> + return true;
> + }
Hmm, that looks a bit dangerous. Do we have a list of PCI
vendor/device-ids of these broken bridges to match against instead of
some open-coded heuristics?
That would probably also help to bring this into the PCI code.
Joerg
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