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Commit c8fe16e3 authored by Alex Williamson's avatar Alex Williamson Committed by Bjorn Helgaas
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PCI: Add support for PCIe-to-PCI bridge DMA alias quirks 



Several PCIe-to-PCI bridges fail to provide a PCIe capability, causing us
to handle them as conventional PCI devices when they really use the
requester ID of the secondary bus.  We need to differentiate these from
PCIe-to-PCI bridges that actually use the conventional PCI ID when a PCIe
capability is not present, such as those found on the root complex of may
Intel chipsets.  Add a dev_flag bit to identify devices to be handled as
standard PCIe-to-PCI bridges.

Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent cc346a47

drivers/pci/search.c

+8 −2
Original line number Diff line number Diff line
@@ -88,8 +88,14 @@ int pci_for_each_dma_alias(struct pci_dev *pdev, 
				continue;

			}

		} else {

			ret = fn(tmp, PCI_DEVID(tmp->bus->number, tmp->devfn),

				 data);

			if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS)

				ret = fn(tmp,

					 PCI_DEVID(tmp->subordinate->number,

						   PCI_DEVFN(0, 0)), data);

			else

				ret = fn(tmp,

					 PCI_DEVID(tmp->bus->number,

						   tmp->devfn), data);

			if (ret)

				return ret;

		}

include/linux/pci.h

+2 −0
Original line number Diff line number Diff line
@@ -173,6 +173,8 @@ enum pci_dev_flags { 
	PCI_DEV_FLAGS_ACS_ENABLED_QUIRK = (__force pci_dev_flags_t) (1 << 3),

	/* Flag to indicate the device uses dma_alias_devfn */

	PCI_DEV_FLAGS_DMA_ALIAS_DEVFN = (__force pci_dev_flags_t) (1 << 4),

	/* Use a PCIe-to-PCI bridge alias even if !pci_is_pcie */

	PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS = (__force pci_dev_flags_t) (1 << 5),

};



enum pci_irq_reroute_variant {