pci: Abolish pci_find_root_bus()

pci_find_root_bus() takes a domain parameter.  Currently PCI root buses
with domain other than 0 can't be created, so this is more or less a long
winded way of retrieving the main PCI root bus.  Numbered domains don't
actually properly cover the (non x86) possibilities for multiple PCI root
buses, so this patch for now enforces the domain == 0 restriction in other
places to replace pci_find_root_bus() with an explicit
pci_find_primary_bus().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 15 insertions, 4 deletions

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index adf4da5b95..fc99e3bf69 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -246,12 +246,12 @@ static void pci_host_bus_register(int domain, PCIBus *bus)
     QLIST_INSERT_HEAD(&host_buses, host, next);
 }
 
-PCIBus *pci_find_root_bus(int domain)
+PCIBus *pci_find_primary_bus(void)
 {
     struct PCIHostBus *host;
 
     QLIST_FOREACH(host, &host_buses, next) {
-        if (host->domain == domain) {
+        if (host->domain == 0) {
             return host->bus;
         }
     }
@@ -583,20 +583,31 @@ int pci_parse_devaddr(const char *addr, int *domp, int *busp,
 
 PCIBus *pci_get_bus_devfn(int *devfnp, const char *devaddr)
 {
+    PCIBus *root = pci_find_primary_bus();
     int dom, bus;
     unsigned slot;
 
+    if (!root) {
+        fprintf(stderr, "No primary PCI bus\n");
+        return NULL;
+    }
+
     if (!devaddr) {
         *devfnp = -1;
-        return pci_find_bus_nr(pci_find_root_bus(0), 0);
+        return pci_find_bus_nr(root, 0);
     }
 
     if (pci_parse_devaddr(devaddr, &dom, &bus, &slot, NULL) < 0) {
         return NULL;
     }
 
+    if (dom != 0) {
+        fprintf(stderr, "No support for non-zero PCI domains\n");
+        return NULL;
+    }
+
     *devfnp = PCI_DEVFN(slot, 0);
-    return pci_find_bus_nr(pci_find_root_bus(dom), bus);
+    return pci_find_bus_nr(root, bus);
 }
 
 static void pci_init_cmask(PCIDevice *dev)