PCI: Add support for PCIe-to-PCI bridge DMA alias quirks (c8fe16e3) · Commits · 戴 / test

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>

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 {

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