[PATCH] rapidio: fix multi-switch enumeration

This patch contains two fixes for RapisIO enumeration logic:

1. Fix enumeration in configurations with multiple switches. The patch adds:

   a. Enumeration of an empty switch.  Empty switch is a switch that
      does not have any endpoint devices attached to it (except host device
      or previous switch in a chain).  New code assigns a phony destination
      ID associated with the switch and sets up corresponding routes.

   b. Adds a second pass to the enumeration to setup routes to
      devices discovered after switch was scanned.

2. Fix enumeration failure when riohdid parameter has non-zero value.
   Current version fails to setup response path to the host when it has
   destination ID other that 0.

Signed-off-by: Alexandre Bounine <alexandreb@tundra.com>
Acked-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/rio.h

@@ -25,6 +25,7 @@
 
 #define RIO_ANY_DESTID		0xff
 #define RIO_NO_HOPCOUNT		-1
+#define RIO_INVALID_DESTID	0xffff
 
 #define RIO_MAX_MPORT_RESOURCES	16
 #define RIO_MAX_DEV_RESOURCES	16