From c8fe16e3f96a9bb95a10cedb19d2be2d2d580940 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Wed, 28 May 2014 14:57:02 -0600 Subject: [PATCH] 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 Signed-off-by: Bjorn Helgaas --- drivers/pci/search.c | 10 ++++++++-- include/linux/pci.h | 2 ++ 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/pci/search.c b/drivers/pci/search.c index 2c19f3f40621..df38f73f091f 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -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; } 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 { -- GitLab