Various changes to make it easier to subclass the PCI bus device.

- Make the pci devclass a global variable.
- Add child devices in pci_attach() instead of pci_probe().  Change
  pci_probe() to just check for a valid bus number from the associated
  bridge and return -1000 if successful.  This allows subclasses of the
  PCI bus driver to override the generic driver.
- Move the code to load the vendor data into its own public function.
  Really though, doing this at attach is just plain wrong.  This should
  really be done in the module load routine instead.  As a side effect,
  the 'busno' variable in pci_attach() is now no longer static (minor
  bug that was harmless so far.)
- Change pci_add_children() to take an extra argument that is the size of
  the device info structure passed to pci_read_device() and make it public
  so subclasses of the PCI bus can call it in their attach routines.
- Move the bits to attach a probed PCI child to a PCI bus into a global
  pci_add_child() function.  This will allow subclasses that can detect
  a PCI device not found in the normal PCI probe to add those devices in
  their own attach routine.  (I have seen this in the ACPI tree on my
  laptop for example.)  As a side effect, change the static function
  pci_add_resources() to get the busno, slot, and func from the passed
  in dinfo structure instead of requiring them as function arguments.

Tested on:	i386, alpha, ia64, sparc64

2 files changed, 61 insertions, 30 deletions

diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index 1a2119b..96553cf 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -73,10 +73,9 @@ static int		pci_porten(device_t pcib, int b, int s, int f);
 static int		pci_memen(device_t pcib, int b, int s, int f);
 static int		pci_add_map(device_t pcib, int b, int s, int f, int reg, 
 				    struct resource_list *rl);
-static void		pci_add_resources(device_t pcib, int b, int s, int f, 
-					  device_t dev);
-static void		pci_add_children(device_t dev, int busno);
+static void		pci_add_resources(device_t pcib, device_t dev);
 static int		pci_probe(device_t dev);
+static int		pci_attach(device_t dev);
 static int		pci_describe_parse_line(char **ptr, int *vendor, 
 						int *device, char **desc);
 static char		*pci_describe_device(device_t dev);
@@ -85,7 +84,7 @@ static int		pci_modevent(module_t mod, int what, void *arg);
 static device_method_t pci_methods[] = {
 	/* Device interface */
 	DEVMETHOD(device_probe,		pci_probe),
-	DEVMETHOD(device_attach,	bus_generic_attach),
+	DEVMETHOD(device_attach,	pci_attach),
 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
 	DEVMETHOD(device_suspend,	bus_generic_suspend),
 	DEVMETHOD(device_resume,	bus_generic_resume),
@@ -127,7 +126,7 @@ static driver_t pci_driver = {
 	0,			/* no softc */
 };
 
-static devclass_t	pci_devclass;
+devclass_t	pci_devclass;
 DRIVER_MODULE(pci, pcib, pci_driver, pci_devclass, pci_modevent, 0);
 DRIVER_MODULE(pci, acpi_pcib, pci_driver, pci_devclass, pci_modevent, 0);
 MODULE_VERSION(pci, 1);
@@ -741,14 +740,17 @@ pci_add_map(device_t pcib, int b, int s, int f, int reg,
 }
 
 static void
-pci_add_resources(device_t pcib, int b, int s, int f, device_t dev)
+pci_add_resources(device_t pcib, device_t dev)
 {
 	struct pci_devinfo *dinfo = device_get_ivars(dev);
 	pcicfgregs *cfg = &dinfo->cfg;
 	struct resource_list *rl = &dinfo->resources;
 	struct pci_quirk *q;
-	int i;
+	int b, i, f, s;
 
+	b = cfg->bus;
+	s = cfg->slot;
+	f = cfg->func;
 	for (i = 0; i < cfg->nummaps;) {
 		i += pci_add_map(pcib, b, s, f, PCIR_MAPS + i*4, rl);
 	}
@@ -773,44 +775,59 @@ pci_add_resources(device_t pcib, int b, int s, int f, device_t dev)
 	}
 }
 
-static void
-pci_add_children(device_t dev, int busno)
+void
+pci_add_children(device_t dev, int busno, size_t dinfo_size)
 {
 	device_t pcib = device_get_parent(dev);
+	struct pci_devinfo *dinfo;
 	int maxslots;
-	int s, f;
+	int s, f, pcifunchigh;
 
-	maxslots = PCIB_MAXSLOTS(pcib);
-	
+	KASSERT(dinfo_size >= sizeof(struct pci_devinfo),
+	    ("dinfo_size too small"));
+	maxslots = PCIB_MAXSLOTS(pcib);	
 	for (s = 0; s <= maxslots; s++) {
-		int pcifunchigh = 0;
+		pcifunchigh = 0;
 		for (f = 0; f <= pcifunchigh; f++) {
-			struct pci_devinfo *dinfo = pci_read_device(pcib,
-			    busno, s, f, sizeof(struct pci_devinfo));
+			dinfo = pci_read_device(pcib, busno, s, f, dinfo_size);
 			if (dinfo != NULL) {
 				if (dinfo->cfg.mfdev)
 					pcifunchigh = PCI_FUNCMAX;
-
-				dinfo->cfg.dev = device_add_child(dev, NULL, -1);
-				device_set_ivars(dinfo->cfg.dev, dinfo);
-				pci_add_resources(pcib, busno, s, f,
-						  dinfo->cfg.dev);
-				pci_print_verbose(dinfo);
+				pci_add_child(dev, dinfo);
 			}
 		}
 	}
 }
 
+void
+pci_add_child(device_t bus, struct pci_devinfo *dinfo)
+{
+	device_t pcib;
+
+	pcib = device_get_parent(bus);
+	dinfo->cfg.dev = device_add_child(bus, NULL, -1);
+	device_set_ivars(dinfo->cfg.dev, dinfo);
+	pci_add_resources(pcib, dinfo->cfg.dev);
+	pci_print_verbose(dinfo);
+}
+
 static int
 pci_probe(device_t dev)
 {
-	static int once, busno;
-	caddr_t vendordata, info;
 
+	if (pcib_get_bus(dev) < 0)
+		return (ENXIO);
+	
 	device_set_desc(dev, "PCI bus");
 
-	if (bootverbose)
-		device_printf(dev, "physical bus=%d\n", pcib_get_bus(dev));
+	/* Allow other subclasses to override this driver. */
+	return (-1000);
+}
+
+static int
+pci_attach(device_t dev)
+{
+	int busno;
 
 	/*
 	 * Since there can be multiple independantly numbered PCI
@@ -819,9 +836,20 @@ pci_probe(device_t dev)
 	 * pcib what our bus number is.
 	 */
 	busno = pcib_get_bus(dev);
-	if (busno < 0)
-		return (ENXIO);
-	pci_add_children(dev, busno);
+	if (bootverbose)
+		device_printf(dev, "physical bus=%d\n", busno);
+
+	pci_add_children(dev, busno, sizeof(struct pci_devinfo));
+
+	pci_load_vendor_data();
+	return (bus_generic_attach(dev));
+}
+
+void
+pci_load_vendor_data(void)
+{
+	caddr_t vendordata, info;
+	static int once;
 
 	if (!once) {
 		make_dev(&pcicdev, 0, UID_ROOT, GID_WHEEL, 0644, "pci");
@@ -836,8 +864,6 @@ pci_probe(device_t dev)
 		}
 		once++;
 	}
-
-	return (0);
 }
 
 int
diff --git a/sys/dev/pci/pci_private.h b/sys/dev/pci/pci_private.h
index cb43cef..c82e3f5 100644
--- a/sys/dev/pci/pci_private.h
+++ b/sys/dev/pci/pci_private.h
@@ -37,6 +37,10 @@
  * it with "subclass" busses.  A more generic subclassing mechanism would
  * be nice, but is not present in the tree at this time.
  */
+extern devclass_t pci_devclass;
+
+void		pci_add_children(device_t dev, int busno, size_t dinfo_size);
+void		pci_add_child(device_t bus, struct pci_devinfo *dinfo);
 int		pci_print_child(device_t dev, device_t child);
 void		pci_probe_nomatch(device_t dev, device_t child);
 int		pci_read_ivar(device_t dev, device_t child, int which,
@@ -64,5 +68,6 @@ struct pci_devinfo *pci_read_device(device_t pcib, int b, int s, int f,
 		    size_t size);
 void		pci_print_verbose(struct pci_devinfo *dinfo);
 int		pci_freecfg(struct pci_devinfo *dinfo);
+void		pci_load_vendor_data(void);
 
 #endif /* _PCI_PRIVATE_H_ */