Date: Sun, 1 Mar 2015 10:39:19 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r279486 - stable/10/sys/x86/iommu Message-ID: <201503011039.t21AdJ15074563@svn.freebsd.org>
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Author: kib Date: Sun Mar 1 10:39:19 2015 New Revision: 279486 URL: https://svnweb.freebsd.org/changeset/base/279486 Log: MFC r276949: (only to ease merging of r279117). MFC r279117: Revert r276949 and redo the fix for PCIe/PCI bridges, which do not follow specification and do not provide PCIe capability. Modified: stable/10/sys/x86/iommu/busdma_dmar.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/x86/iommu/busdma_dmar.c ============================================================================== --- stable/10/sys/x86/iommu/busdma_dmar.c Sun Mar 1 10:35:54 2015 (r279485) +++ stable/10/sys/x86/iommu/busdma_dmar.c Sun Mar 1 10:39:19 2015 (r279486) @@ -96,11 +96,13 @@ static device_t dmar_get_requester(device_t dev, uint16_t *rid) { devclass_t pci_class; - device_t pci, pcib, requester; + device_t l, pci, pcib, pcip, pcibp, requester; int cap_offset; + uint16_t pcie_flags; + bool bridge_is_pcie; pci_class = devclass_find("pci"); - requester = dev; + l = requester = dev; *rid = pci_get_rid(dev); @@ -110,19 +112,17 @@ dmar_get_requester(device_t dev, uint16_ * unit. */ for (;;) { - pci = device_get_parent(dev); - KASSERT(pci != NULL, ("NULL parent for pci%d:%d:%d:%d", - pci_get_domain(dev), pci_get_bus(dev), pci_get_slot(dev), - pci_get_function(dev))); + pci = device_get_parent(l); + KASSERT(pci != NULL, ("dmar_get_requester(%s): NULL parent " + "for %s", device_get_name(dev), device_get_name(l))); KASSERT(device_get_devclass(pci) == pci_class, - ("Non-pci parent for pci%d:%d:%d:%d", - pci_get_domain(dev), pci_get_bus(dev), pci_get_slot(dev), - pci_get_function(dev))); + ("dmar_get_requester(%s): non-pci parent %s for %s", + device_get_name(dev), device_get_name(pci), + device_get_name(l))); pcib = device_get_parent(pci); - KASSERT(pcib != NULL, ("NULL bridge for pci%d:%d:%d:%d", - pci_get_domain(dev), pci_get_bus(dev), pci_get_slot(dev), - pci_get_function(dev))); + KASSERT(pcib != NULL, ("dmar_get_requester(%s): NULL bridge " + "for %s", device_get_name(dev), device_get_name(pci))); /* * The parent of our "bridge" isn't another PCI bus, @@ -130,19 +130,46 @@ dmar_get_requester(device_t dev, uint16_ * port, and the requester ID won't be translated * further. */ - if (device_get_devclass(device_get_parent(pcib)) != pci_class) + pcip = device_get_parent(pcib); + if (device_get_devclass(pcip) != pci_class) break; + pcibp = device_get_parent(pcip); - if (pci_find_cap(dev, PCIY_EXPRESS, &cap_offset) != 0) { + if (pci_find_cap(l, PCIY_EXPRESS, &cap_offset) == 0) { + /* + * Do not stop the loop even if the target + * device is PCIe, because it is possible (but + * unlikely) to have a PCI->PCIe bridge + * somewhere in the hierarchy. + */ + l = pcib; + } 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. */ + bridge_is_pcie = pci_find_cap(pcib, PCIY_EXPRESS, + &cap_offset) == 0; requester = pcib; - /* Check whether the bus above is PCIe. */ - if (pci_find_cap(pcib, 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 @@ -159,7 +186,8 @@ dmar_get_requester(device_t dev, uint16_ * same page tables for taken and * non-taken transactions. */ - *rid = PCI_RID(pci_get_bus(dev), 0, 0); + *rid = PCI_RID(pci_get_bus(l), 0, 0); + l = pcibp; } else { /* * Neither the device nor the bridge @@ -169,15 +197,9 @@ dmar_get_requester(device_t dev, uint16_ * requester ID. */ *rid = pci_get_rid(pcib); + l = pcib; } } - /* - * Do not stop the loop even if the target device is - * PCIe, because it is possible (but unlikely) to have - * a PCI->PCIe bridge somewhere in the hierarchy. - */ - - dev = pcib; } return (requester); }
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