freebsd_network: Add pci_msix_table_bar().

Needed by the e1000 driver from FreeBSD 13. Tested in QEMU with e1000e.

src/libs/compat/freebsd_network/bus.cpp

@@ -846,6 +846,24 @@ pci_release_msi(device_t dev)
 }
 
 
+int
+pci_msix_table_bar(device_t dev)
+{
+	pci_info *info = &((struct root_device_softc *)dev->root->softc)->pci_info;
+
+	uint8 capability_offset;
+	if (gPci->find_pci_capability(info->bus, info->device, info->function,
+			PCI_cap_id_msix, &capability_offset) != B_OK)
+		return -1;
+
+	uint32 table_value = gPci->read_pci_config(info->bus, info->device, info->function,
+		capability_offset + PCI_msix_table, 4);
+
+	uint32 bar = table_value & PCI_msix_bir_mask;
+	return PCIR_BAR(bar);
+}
+
+
 int
 pci_msix_count(device_t dev)
 {

src/libs/compat/freebsd_network/compat/dev/pci/pcivar.h

@@ -51,6 +51,8 @@ int pci_find_extcap(device_t dev, int capability, int *capreg);
 int pci_msi_count(device_t dev);
 int pci_alloc_msi(device_t dev, int *count);
 int pci_release_msi(device_t dev);
+
+int pci_msix_table_bar(device_t dev);
 int pci_msix_count(device_t dev);
 int pci_alloc_msix(device_t dev, int *count);