[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>

diff --git a/drivers/rapidio/rio-scan.c b/drivers/rapidio/rio-scan.c
index 7bf7b2c..f935c1f 100644 (file)
--- a/drivers/rapidio/rio-scan.c
+++ b/drivers/rapidio/rio-scan.c
@@ -326,14 +326,17 @@ static struct rio_dev *rio_setup_device(struct rio_net *net,
        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(struct rio_net *net,
                }
                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 *port, u16 destid, u8 hopcount, int sport)
 /**
  * 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 *port, u16 destid, u8 hopcount, int sport)
  * %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 rio_mport *mport, struct rio_dev *rdev,
  * 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 *net, struct rio_mport *port,
        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 *net, struct rio_mport *port,
 
        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 *net, struct rio_mport *port,
                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 *net, struct rio_mport *port,
                                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 *net, struct rio_mport *port,
                                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 *net, struct rio_mport *port,
                                                    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, struct rio_mport *port, u16 destid,
                                    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);
@@ -797,6 +814,44 @@ static struct rio_net __devinit *rio_alloc_net(struct rio_mport *port)
        return net;
 }
 
+/**
+ * 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 *mport)
                        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 --git a/include/linux/rio.h b/include/linux/rio.h
index d938570..68e3f68 100644 (file)
--- a/include/linux/rio.h
+++ b/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