[PATCH] rapidio: fix multi-switch enumeration

[Alexandre Bounine]

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.

This patch can be applied to the kernel version 2.6.19.  

Signed-off-by: Alexandre Bounine <alexandreb@xxxxxxxxxx>

---

This patch was tested using existing sRIO development platforms (SRDP) connected
to create multi-switch configurations. Test environment includes Tsi568 and
Tsi578 SRIO switch devices from Tundra Semiconductor and endpoints based on
Freescale's MPC8548 processors.


diff -pNur linux-2.6.19/drivers/rapidio/rio-scan.c linux-2.6.19-tun/drivers/rapidio/rio-scan.c
--- linux-2.6.19/drivers/rapidio/rio-scan.c	2006-11-29 16:57:37.000000000 -0500
+++ linux-2.6.19-tun/drivers/rapidio/rio-scan.c	2007-01-30 17:44:51.000000000 -0500
@@ -326,14 +326,17 @@ static struct rio_dev *rio_setup_device(
 	rio_mport_read_config_32(port, destid, hopcount, RIO_DST_OPS_CAR,
 				 &rdev->dst_ops);
 
-	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)
-	    && do_enum) {
-		rio_set_device_id(port, destid, hopcount, next_destid);
-		rdev->destid = next_destid++;
-		if (next_destid == port->host_deviceid)
-			next_destid++;
+	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)) {
+		if (do_enum) {
+			rio_set_device_id(port, destid, hopcount, next_destid);
+			rdev->destid = next_destid++;
+			if (next_destid == port->host_deviceid)
+				next_destid++;
+		} else
+			rdev->destid = rio_get_device_id(port, destid, hopcount);
 	} else
-		rdev->destid = rio_get_device_id(port, destid, hopcount);
+		/* Switch device has an associated destID */
+		rdev->destid = RIO_INVALID_DESTID;
 
 	/* If a PE has both switch and other functions, show it as a switch */
 	if (rio_is_switch(rdev)) {
@@ -347,7 +350,7 @@ static struct rio_dev *rio_setup_device(
 		}
 		rswitch->switchid = next_switchid;
 		rswitch->hopcount = hopcount;
-		rswitch->destid = 0xffff;
+		rswitch->destid = destid;
 		/* Initialize switch route table */
 		for (rdid = 0; rdid < RIO_MAX_ROUTE_ENTRIES; rdid++)
 			rswitch->route_table[rdid] = RIO_INVALID_ROUTE;
@@ -422,7 +425,7 @@ rio_sport_is_active(struct rio_mport *po
 /**
  * rio_route_add_entry- Add a route entry to a switch routing table
  * @mport: Master port to send transaction
- * @rdev: Switch device
+ * @rswitch: Switch device
  * @table: Routing table ID
  * @route_destid: Destination ID to be routed
  * @route_port: Port number to be routed
@@ -434,18 +437,18 @@ rio_sport_is_active(struct rio_mport *po
  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
  * on failure.
  */
-static int rio_route_add_entry(struct rio_mport *mport, struct rio_dev *rdev,
+static int rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswitch,
 			       u16 table, u16 route_destid, u8 route_port)
 {
-	return rdev->rswitch->add_entry(mport, rdev->rswitch->destid,
-					rdev->rswitch->hopcount, table,
+	return rswitch->add_entry(mport, rswitch->destid,
+					rswitch->hopcount, table,
 					route_destid, route_port);
 }
 
 /**
  * rio_route_get_entry- Read a route entry in a switch routing table
  * @mport: Master port to send transaction
- * @rdev: Switch device
+ * @rswitch: Switch device
  * @table: Routing table ID
  * @route_destid: Destination ID to be routed
  * @route_port: Pointer to read port number into
@@ -458,11 +461,11 @@ static int rio_route_add_entry(struct ri
  * on failure.
  */
 static int
-rio_route_get_entry(struct rio_mport *mport, struct rio_dev *rdev, u16 table,
+rio_route_get_entry(struct rio_mport *mport, struct rio_switch *rswitch, u16 table,
 		    u16 route_destid, u8 * route_port)
 {
-	return rdev->rswitch->get_entry(mport, rdev->rswitch->destid,
-					rdev->rswitch->hopcount, table,
+	return rswitch->get_entry(mport, rswitch->destid,
+					rswitch->hopcount, table,
 					route_destid, route_port);
 }
 
@@ -552,6 +555,8 @@ static int rio_enum_peer(struct rio_net 
 	int port_num;
 	int num_ports;
 	int cur_destid;
+	int sw_destid;
+	int sw_inport;
 	struct rio_dev *rdev;
 	u16 destid;
 	int tmp;
@@ -594,15 +599,17 @@ static int rio_enum_peer(struct rio_net 
 
 	if (rio_is_switch(rdev)) {
 		next_switchid++;
+		sw_inport = rio_get_swpinfo_inport(port, RIO_ANY_DESTID, hopcount);
+		rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
+				    port->host_deviceid, sw_inport);
+		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;
 
 		for (destid = 0; destid < next_destid; destid++) {
-			rio_route_add_entry(port, rdev, RIO_GLOBAL_TABLE,
-					    destid, rio_get_swpinfo_inport(port,
-									   RIO_ANY_DESTID,
-									   hopcount));
-			rdev->rswitch->route_table[destid] =
-			    rio_get_swpinfo_inport(port, RIO_ANY_DESTID,
-						   hopcount);
+			if (destid == port->host_deviceid)
+				continue;
+			rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
+					    destid, sw_inport);
+			rdev->rswitch->route_table[destid] = sw_inport;
 		}
 
 		num_ports =
@@ -610,9 +617,9 @@ static int rio_enum_peer(struct rio_net 
 		pr_debug(
 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
+		sw_destid = next_destid;
 		for (port_num = 0; port_num < num_ports; port_num++) {
-			if (rio_get_swpinfo_inport
-			    (port, RIO_ANY_DESTID, hopcount) == port_num)
+			if (sw_inport == port_num)
 				continue;
 
 			cur_destid = next_destid;
@@ -622,7 +629,7 @@ static int rio_enum_peer(struct rio_net 
 				pr_debug(
 				    "RIO: scanning device on port %d\n",
 				    port_num);
-				rio_route_add_entry(port, rdev,
+				rio_route_add_entry(port, rdev->rswitch,
 						    RIO_GLOBAL_TABLE,
 						    RIO_ANY_DESTID, port_num);
 
@@ -633,7 +640,9 @@ static int rio_enum_peer(struct rio_net 
 				if (next_destid > cur_destid) {
 					for (destid = cur_destid;
 					     destid < next_destid; destid++) {
-						rio_route_add_entry(port, rdev,
+						if (destid == port->host_deviceid)
+							continue;
+						rio_route_add_entry(port, rdev->rswitch,
 								    RIO_GLOBAL_TABLE,
 								    destid,
 								    port_num);
@@ -641,10 +650,18 @@ static int rio_enum_peer(struct rio_net 
 						    route_table[destid] =
 						    port_num;
 					}
-					rdev->rswitch->destid = cur_destid;
 				}
 			}
 		}
+
+		/* Check for empty switch */
+		if (next_destid == sw_destid) {
+			next_destid++;
+			if (next_destid == port->host_deviceid)
+				next_destid++;
+		}
+
+		rdev->rswitch->destid = sw_destid;
 	} else
 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
 		    rio_name(rdev), rdev->vid, rdev->did);
@@ -721,7 +738,7 @@ rio_disc_peer(struct rio_net *net, struc
 				    port_num);
 				for (ndestid = 0; ndestid < RIO_ANY_DESTID;
 				     ndestid++) {
-					rio_route_get_entry(port, rdev,
+					rio_route_get_entry(port, rdev->rswitch,
 							    RIO_GLOBAL_TABLE,
 							    ndestid,
 							    &route_port);
@@ -798,6 +815,44 @@ static struct rio_net __devinit *rio_all
 }
 
 /**
+ * rio_update_route_tables- Updates route tables in switches
+ * @port: Master port associated with the RIO network
+ *
+ * For each enumerated device, ensure that each switch in a system
+ * has correct routing entries. Add routes for devices that where
+ * unknown dirung the first enumeration pass through the switch.
+ */
+static void rio_update_route_tables(struct rio_mport *port)
+{
+	struct rio_dev *rdev;
+	struct rio_switch *rswitch;
+	u8 sport;
+	u16 destid;
+
+	list_for_each_entry(rdev, &rio_devices, global_list) {
+		
+		destid = (rio_is_switch(rdev))?rdev->rswitch->destid:rdev->destid; 
+
+		list_for_each_entry(rswitch, &rio_switches, node) {
+
+			if (rio_is_switch(rdev)	&& (rdev->rswitch == rswitch))
+				continue;
+
+			if (RIO_INVALID_ROUTE == rswitch->route_table[destid]) {
+
+				sport = rio_get_swpinfo_inport(port,
+						rswitch->destid, rswitch->hopcount);
+
+				if (rswitch->add_entry)	{
+					rio_route_add_entry(port, rswitch, RIO_GLOBAL_TABLE, destid, sport);
+					rswitch->route_table[destid] = sport;
+				}
+			}
+		}
+	}
+}
+
+/**
  * rio_enum_mport- Start enumeration through a master port
  * @mport: Master port to send transactions
  *
@@ -838,6 +893,7 @@ int rio_enum_mport(struct rio_mport *mpo
 			rc = -EBUSY;
 			goto out;
 		}
+		rio_update_route_tables(mport);
 		rio_clear_locks(mport);
 	} else {
 		printk(KERN_INFO "RIO: master port %d link inactive\n",
@@ -865,8 +921,8 @@ static void rio_build_route_tables(void)
 	    if (rio_is_switch(rdev))
 		for (i = 0; i < RIO_MAX_ROUTE_ENTRIES; i++) {
 			if (rio_route_get_entry
-			    (rdev->net->hport, rdev, RIO_GLOBAL_TABLE, i,
-			     &sport) < 0)
+			    (rdev->net->hport, rdev->rswitch, RIO_GLOBAL_TABLE,
+			     i, &sport) < 0)
 				continue;
 			rdev->rswitch->route_table[i] = sport;
 		}
diff -pNur linux-2.6.19/include/linux/rio.h linux-2.6.19-tun/include/linux/rio.h
--- linux-2.6.19/include/linux/rio.h	2006-11-29 16:57:37.000000000 -0500
+++ linux-2.6.19-tun/include/linux/rio.h	2007-01-30 17:45:34.000000000 -0500
@@ -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

---

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