From: Xingang Wang <wangxinga...@huawei.com>
This helps to find max bus number of a root bus.
Signed-off-by: Xingang Wang <wangxinga...@huawei.com>
Signed-off-by: Jiahui Cen <cenjia...@huawei.com>
---
hw/pci/pci.c | 33 +++++++++++++++++++++++++++++++++
include/hw/pci/pci.h | 1 +
2 files changed, 34 insertions(+)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index dc969989c9..ed92ce0971 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -516,6 +516,39 @@ int pci_bus_num(PCIBus *s)
return PCI_BUS_GET_CLASS(s)->bus_num(s);
}
+int pci_root_bus_max_bus(PCIBus *bus)
+{
+ PCIHostState *host;
+ int max_bus = 0;
+ int type;
+ int devfn;
+
+ if (!pci_bus_is_root(bus)) {
+ return 0;
+ }
+
+ host = PCI_HOST_BRIDGE(BUS(bus)->parent);
+ max_bus = pci_bus_num(host->bus);
+
+ for (devfn = 0; devfn < ARRAY_SIZE(host->bus->devices); devfn++) {
+ PCIDevice *dev = host->bus->devices[devfn];
+
+ if (!dev) {
+ continue;
+ }
+
+ type = dev->config[PCI_HEADER_TYPE] & ~PCI_HEADER_TYPE_MULTI_FUNCTION;
+ if (type == PCI_HEADER_TYPE_BRIDGE) {
+ uint8_t subordinate = dev->config[PCI_SUBORDINATE_BUS];
+ if (subordinate > max_bus) {
+ max_bus = subordinate;
+ }
+ }
+ }
+
+ return max_bus;
+}
+
int pci_bus_numa_node(PCIBus *bus)
{
return PCI_BUS_GET_CLASS(bus)->numa_node(bus);
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 1bc231480f..238b91817a 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -449,6 +449,7 @@ static inline PCIBus *pci_get_bus(const PCIDevice *dev)
return PCI_BUS(qdev_get_parent_bus(DEVICE(dev)));
}
int pci_bus_num(PCIBus *s);
+int pci_root_bus_max_bus(PCIBus *bus);
static inline int pci_dev_bus_num(const PCIDevice *dev)
{
return pci_bus_num(pci_get_bus(dev));
--
2.19.1
