Add a pcib_attach_child() method to manage adding the child "pci" device.

This allows the PCI-PCI bridge driver to save a reference to the child
device in its softc.

Note that this required moving the "pci" device creation out of
acpi_pcib_attach().  Instead, acpi_pcib_attach() is renamed to
acpi_pcib_fetch_prt() as it's sole action now is to fetch the PCI
interrupt routing table.

Differential Revision:	https://reviews.freebsd.org/D6021

sys/dev/acpica/acpi_pcib.c

@@ -126,11 +126,10 @@ prt_attach_devices(ACPI_PCI_ROUTING_TABLE *entry, void *arg)
 	ACPI_ADR_PCI_SLOT(entry->Address), entry->Pin);
 }
 
-int
-acpi_pcib_attach(device_t dev, ACPI_BUFFER *prt, int busno)
+void
+acpi_pcib_fetch_prt(device_t dev, ACPI_BUFFER *prt)
 {
     ACPI_STATUS status;
-    int error;
 
     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
 
@@ -148,20 +147,9 @@ acpi_pcib_attach(device_t dev, ACPI_BUFFER *prt, int busno)
 	    acpi_name(acpi_get_handle(dev)), AcpiFormatException(status));
 
     /*
-     * Attach the PCI bus proper.
-     */
-    if (device_add_child(dev, "pci", -1) == NULL) {
-	device_printf(device_get_parent(dev), "couldn't attach pci bus\n");
-	return_VALUE(ENXIO);
-    }
-
-    /*
-     * Now go scan the bus.
+     * Ensure all the link devices are attached.
      */
     prt_walk_table(prt, prt_attach_devices, dev);
-
-    error = bus_generic_attach(dev);
-    return_VALUE(error);
 }
 
 static void

sys/dev/acpica/acpi_pcib_acpi.c

@@ -502,7 +502,13 @@ acpi_pcib_acpi_attach(device_t dev)
     if (sc->ap_segment == 0 && sc->ap_bus == 0)
 	    bus0_seen = 1;
 
-    return (acpi_pcib_attach(dev, &sc->ap_prt, sc->ap_bus));
+    acpi_pcib_fetch_prt(dev, &sc->ap_prt);
+
+    if (device_add_child(dev, "pci", -1) == NULL) {
+	device_printf(device_get_parent(dev), "couldn't attach pci bus\n");
+	return (ENXIO);
+    }
+    return (bus_generic_attach(dev));
 }
 
 /*

sys/dev/acpica/acpi_pcib_pci.c

@@ -120,7 +120,9 @@ acpi_pcib_pci_attach(device_t dev)
     pcib_attach_common(dev);
     sc = device_get_softc(dev);
     sc->ap_handle = acpi_get_handle(dev);
-    return (acpi_pcib_attach(dev, &sc->ap_prt, sc->ap_pcibsc.bus.sec));
+    acpi_pcib_fetch_prt(dev, &sc->ap_prt);
+
+    return (pcib_attach_child(dev));
 }
 
 static int

sys/dev/acpica/acpi_pcibvar.h

@@ -35,7 +35,7 @@
 void	acpi_pci_link_add_reference(device_t dev, int index, device_t pcib,
     int slot, int pin);
 int	acpi_pci_link_route_interrupt(device_t dev, int index);
-int	acpi_pcib_attach(device_t bus, ACPI_BUFFER *prt, int busno);
+void	acpi_pcib_fetch_prt(device_t bus, ACPI_BUFFER *prt);
 int	acpi_pcib_route_interrupt(device_t pcib, device_t dev, int pin,
     ACPI_BUFFER *prtbuf);
 int	acpi_pcib_power_for_sleep(device_t pcib, device_t dev,

sys/dev/pci/pci_pci.c

@@ -1074,22 +1074,27 @@ pcib_attach_common(device_t dev)
     pci_enable_busmaster(dev);
 }
 
+int
+pcib_attach_child(device_t dev)
+{
+	struct pcib_softc *sc;
+
+	sc = device_get_softc(dev);
+	if (sc->bus.sec == 0) {
+		/* no secondary bus; we should have fixed this */
+		return(0);
+	}
+
+	sc->child = device_add_child(dev, "pci", -1);
+	return (bus_generic_attach(dev));
+}
+
 int
 pcib_attach(device_t dev)
 {
-    struct pcib_softc	*sc;
-    device_t		child;
 
     pcib_attach_common(dev);
-    sc = device_get_softc(dev);
-    if (sc->bus.sec != 0) {
-	child = device_add_child(dev, "pci", -1);
-	if (child != NULL)
-	    return(bus_generic_attach(dev));
-    }
-
-    /* no secondary bus; we should have fixed this */
-    return(0);
+    return (pcib_attach_child(dev));
 }
 
 int

sys/dev/pci/pcib_private.h

@@ -101,6 +101,7 @@ struct pcib_secbus {
 struct pcib_softc 
 {
     device_t	dev;
+    device_t	child;
     uint32_t	flags;		/* flags */
 #define	PCIB_SUBTRACTIVE	0x1
 #define	PCIB_DISABLE_MSI	0x2
@@ -144,6 +145,7 @@ void		pcib_setup_secbus(device_t dev, struct pcib_secbus *bus,
     int min_count);
 #endif
 int		pcib_attach(device_t dev);
+int		pcib_attach_child(device_t dev);
 void		pcib_attach_common(device_t dev);
 void		pcib_bridge_init(device_t dev);	
 #ifdef NEW_PCIB

sys/powerpc/ofw/ofw_pcib_pci.c

@@ -114,10 +114,7 @@ ofw_pcib_pci_attach(device_t dev)
 	    sizeof(cell_t));
 
 	pcib_attach_common(dev);
-
-	device_add_child(dev, "pci", -1);
-
-	return (bus_generic_attach(dev));
+	return (pcib_attach_child(dev));
 }
 
 static phandle_t

sys/sparc64/pci/ofw_pcib.c

@@ -149,8 +149,7 @@ ofw_pcib_attach(device_t dev)
 
 	ofw_pcib_gen_setup(dev);
 	pcib_attach_common(dev);
-	device_add_child(dev, "pci", -1);
-	return (bus_generic_attach(dev));
+	return (pcib_attach_child(dev));
 }
 
 static void