diff options
Diffstat (limited to 'sys/x86/iommu/busdma_dmar.c')
| -rw-r--r-- | sys/x86/iommu/busdma_dmar.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/sys/x86/iommu/busdma_dmar.c b/sys/x86/iommu/busdma_dmar.c index 698a791..4efd7b8 100644 --- a/sys/x86/iommu/busdma_dmar.c +++ b/sys/x86/iommu/busdma_dmar.c @@ -98,6 +98,8 @@ dmar_get_requester(device_t dev, uint16_t *rid) devclass_t pci_class; device_t l, pci, pcib, pcip, pcibp, requester; int cap_offset; + uint16_t pcie_flags; + bool bridge_is_pcie; pci_class = devclass_find("pci"); l = requester = dev; @@ -144,13 +146,30 @@ dmar_get_requester(device_t dev, uint16_t *rid) } else { /* * Device is not PCIe, it cannot be seen as a - * requester by DMAR unit. + * requester by DMAR unit. Check whether the + * bridge is PCIe. */ - requester = pcibp; + bridge_is_pcie = pci_find_cap(pcib, PCIY_EXPRESS, + &cap_offset) == 0; + requester = pcib; - /* Check whether the bus above the bridge is PCIe. */ - if (pci_find_cap(pcibp, PCIY_EXPRESS, - &cap_offset) == 0) { + /* + * Check for a buggy PCIe/PCI bridge that + * doesn't report the express capability. If + * the bridge above it is express but isn't a + * PCI bridge, then we know pcib is actually a + * PCIe/PCI bridge. + */ + if (!bridge_is_pcie && pci_find_cap(pcibp, + PCIY_EXPRESS, &cap_offset) == 0) { + pcie_flags = pci_read_config(pcibp, + cap_offset + PCIER_FLAGS, 2); + if ((pcie_flags & PCIEM_FLAGS_TYPE) != + PCIEM_TYPE_PCI_BRIDGE) + bridge_is_pcie = true; + } + + if (bridge_is_pcie) { /* * The current device is not PCIe, but * the bridge above it is. This is a @@ -168,6 +187,7 @@ dmar_get_requester(device_t dev, uint16_t *rid) * non-taken transactions. */ *rid = PCI_RID(pci_get_bus(l), 0, 0); + l = pcibp; } else { /* * Neither the device nor the bridge @@ -177,8 +197,8 @@ dmar_get_requester(device_t dev, uint16_t *rid) * requester ID. */ *rid = pci_get_rid(pcib); + l = pcib; } - l = pcibp; } } return (requester); |
