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: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9d4035c276f4..85ab35e974a9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -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 {