1 files changed, 61 insertions, 0 deletions

diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 6b16ead1da58..ad9749463d4f 100644
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -875,6 +875,56 @@ static void print_version(void)
                 printk(KERN_INFO "%s", version);
 }
 
+struct vdc_check_port_data {
+        int     dev_no;
+        char    *type;
+};
+
+static int vdc_device_probed(struct device *dev, void *arg)
+{
+        struct vio_dev *vdev = to_vio_dev(dev);
+        struct vdc_check_port_data *port_data;
+
+        port_data = (struct vdc_check_port_data *)arg;
+
+        if ((vdev->dev_no == port_data->dev_no) &&
+            (!(strcmp((char *)&vdev->type, port_data->type))) &&
+                dev_get_drvdata(dev)) {
+                /* This device has already been configured
+                 * by vdc_port_probe()
+                 */
+                return 1;
+        } else {
+                return 0;
+        }
+}
+
+/* Determine whether the VIO device is part of an mpgroup
+ * by locating all the virtual-device-port nodes associated
+ * with the parent virtual-device node for the VIO device
+ * and checking whether any of these nodes are vdc-ports
+ * which have already been configured.
+ *
+ * Returns true if this device is part of an mpgroup and has
+ * already been probed.
+ */
+static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
+{
+        struct vdc_check_port_data port_data;
+        struct device *dev;
+
+        port_data.dev_no = vdev->dev_no;
+        port_data.type = (char *)&vdev->type;
+
+        dev = device_find_child(vdev->dev.parent, &port_data,
+                                vdc_device_probed);
+
+        if (dev)
+                return true;
+
+        return false;
+}
+
 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 {
         struct mdesc_handle *hp;
@@ -893,6 +943,14 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
                 goto err_out_release_mdesc;
         }
 
+        /* Check if this device is part of an mpgroup */
+        if (vdc_port_mpgroup_check(vdev)) {
+                printk(KERN_WARNING
+                        "VIO: Ignoring extra vdisk port %s",
+                        dev_name(&vdev->dev));
+                goto err_out_release_mdesc;
+        }
+
         port = kzalloc(sizeof(*port), GFP_KERNEL);
         err = -ENOMEM;
         if (!port) {
@@ -943,6 +1001,9 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
         if (err)
                 goto err_out_free_tx_ring;
 
+        /* Note that the device driver_data is used to determine
+         * whether the port has been probed.
+         */
         dev_set_drvdata(&vdev->dev, port);
 
         mdesc_release(hp);