From: Alex Williamson Date: Tue, 13 Jan 2015 18:26:50 +0000 (-0700) Subject: PCI: Add DMA alias quirk for Adaptec 3405 X-Git-Tag: firefly_0821_release~176^2~2382^2~4^5~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d3d2ab43ddae5f958461ac0a9a2b484a68194df5;p=firefly-linux-kernel-4.4.55.git PCI: Add DMA alias quirk for Adaptec 3405 The Adaptec 3405 is actually an Intel 80333 I/O processor where the exposed device at 0e.0 is actually the address translation unit of the I/O processor and a hidden, private device at 01.0 masters the DMA for the device. Create a fixed alias between the exposed and hidden devfn so we can enable the IOMMU. Scenarios like this are potentially likely for any device incorporating this I/O processor, so this little bit of abstraction with the fixed alias table should make future additions trivial. Without this fix, booting a system with the Intel IOMMU enabled and an Adaptec 3405 at 02:0e.0 results in a flood of errors like this: dmar: DRHD: handling fault status reg 3 dmar: DMAR:[DMA Write] Request device [02:01.0] fault addr ffbff000 DMAR:[fault reason 02] Present bit in context entry is clear [bhelgaas: changelog, comment] Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas CC: Adaptec OEM Raid Solutions --- diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 3fb378aa7c53..45bd8704c99d 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3562,6 +3562,44 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB388_ESD, quirk_dma_func1_alias); +/* + * Some devices DMA with the wrong devfn, not just the wrong function. + * quirk_fixed_dma_alias() uses this table to create fixed aliases, where + * the alias is "fixed" and independent of the device devfn. + * + * For example, the Adaptec 3405 is a PCIe card with an Intel 80333 I/O + * processor. To software, this appears as a PCIe-to-PCI/X bridge with a + * single device on the secondary bus. In reality, the single exposed + * device at 0e.0 is the Address Translation Unit (ATU) of the controller + * that provides a bridge to the internal bus of the I/O processor. The + * controller supports private devices, which can be hidden from PCI config + * space. In the case of the Adaptec 3405, a private device at 01.0 + * appears to be the DMA engine, which therefore needs to become a DMA + * alias for the device. + */ +static const struct pci_device_id fixed_dma_alias_tbl[] = { + { PCI_DEVICE_SUB(PCI_VENDOR_ID_ADAPTEC2, 0x0285, + PCI_VENDOR_ID_ADAPTEC2, 0x02bb), /* Adaptec 3405 */ + .driver_data = PCI_DEVFN(1, 0) }, + { 0 } +}; + +static void quirk_fixed_dma_alias(struct pci_dev *dev) +{ + const struct pci_device_id *id; + + id = pci_match_id(fixed_dma_alias_tbl, dev); + if (id) { + dev->dma_alias_devfn = id->driver_data; + dev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN; + dev_info(&dev->dev, "Enabling fixed DMA alias to %02x.%d\n", + PCI_SLOT(dev->dma_alias_devfn), + PCI_FUNC(dev->dma_alias_devfn)); + } +} + +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ADAPTEC2, 0x0285, quirk_fixed_dma_alias); + /* * A few PCIe-to-PCI bridges fail to expose a PCIe capability, resulting in * using the wrong DMA alias for the device. Some of these devices can be