From d8e81d6e6093738c23b457b607c44a75a6952dc8 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 23 Jan 2019 09:24:25 +0100 Subject: spapr/pci: Fix primary bus number for PCI bridges While looking at the s390x implementation, looks like spapr has a similar BUG when building the topology. The primary bus number corresponds always to the bus number of the bus the bridge is attached to. Right now, if we have two bridges attached to the same bus (e.g. root bus) this is however not the case. The first bridge will have primary bus 0, the second bridge primary bus 1, which is wrong. Fix the assignment. While at it, drop setting the PCI_SUBORDINATE_BUS temporarily to 0xff. Setting it temporarily to that value (as discussed e.g. in [1]), is only relevant for a running system that probes the buses. The value is effectively unused for us just doing a DFS. [1] http://www.science.unitn.it/~fiorella/guidelinux/tlk/node76.html Signed-off-by: David Hildenbrand Reviewed-by: Alexey Kardashevskiy Signed-off-by: David Gibson --- hw/ppc/spapr_pci.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index b74f263..5cdc985 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -2030,8 +2030,6 @@ static void spapr_phb_pci_enumerate_bridge(PCIBus *bus, PCIDevice *pdev, void *opaque) { unsigned int *bus_no = opaque; - unsigned int primary = *bus_no; - unsigned int subordinate = 0xff; PCIBus *sec_bus = NULL; if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) != @@ -2040,7 +2038,7 @@ static void spapr_phb_pci_enumerate_bridge(PCIBus *bus, PCIDevice *pdev, } (*bus_no)++; - pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1); + pci_default_write_config(pdev, PCI_PRIMARY_BUS, pci_dev_bus_num(pdev), 1); pci_default_write_config(pdev, PCI_SECONDARY_BUS, *bus_no, 1); pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, *bus_no, 1); @@ -2049,7 +2047,6 @@ static void spapr_phb_pci_enumerate_bridge(PCIBus *bus, PCIDevice *pdev, return; } - pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, subordinate, 1); pci_for_each_device(sec_bus, pci_bus_num(sec_bus), spapr_phb_pci_enumerate_bridge, bus_no); pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, *bus_no, 1); -- cgit v1.1