clib: Generate dummy PCI bus numbers for 9x

clib/clib_pci.c

@@ -34,6 +34,7 @@ struct pci_access        *pacc;
 static struct pci_dev    *pdev = NULL;
 #    if defined(_WIN32) && (PCI_LIB_VERSION >= 0x030800)
 #        define DUMMY_CONFIG_SPACE
+static struct pci_dev    *dummy_buses[256] = {0};
 static const char         win_notice[] = "NOTICE:         These are dummy configuration registers generated by libpci, as it cannot access the real ones under Windows. It does not reflect the device's actual configuration.";
 #    endif
 #endif
@@ -139,6 +140,7 @@ static void
 pci_init_dev(uint8_t bus, uint8_t dev, uint8_t func)
 {
     struct pci_dev *other;
+    int             i;
     if (!pdev || (pdev->bus != bus) || (pdev->dev != dev) || (pdev->func != func)) {
         if (!pacc->devices) {
             libpci_scan_bus(pacc);
@@ -170,6 +172,24 @@ pci_init_dev(uint8_t bus, uint8_t dev, uint8_t func)
                         }
                     }
 
+                    /* Generate dummy bus numbers for 9x where the actual number cannot be obtained from cfgmgr32. */
+                    if (pdev->parent) {
+                        if (!pdev->bus) {
+                            for (i = 1; i < (sizeof(dummy_buses) / sizeof(dummy_buses[0])); i++) {
+                                if (dummy_buses[i] == pdev->parent) /* found bus */
+                                    break;
+                                if (!dummy_buses[i]) { /* create new bus here */
+                                    dummy_buses[i] = pdev->parent;
+                                    break;
+                                }
+                            }
+                            pdev->bus = i;
+                        } else {
+                            /* Flag this bus as taken, in the unlikely case that not all bus number lookups fail. */
+                            dummy_buses[i] = pdev->parent;
+                        }
+                    }
+
                     /* Set secondary bus number and cascade subordinate bus number to parents. */
                     other = pdev;
                     while (other->parent) {