[POWERPC] ibmebus: Prevent bus_id collisions

Previously, ibmebus derived a device's bus_id from its location code.
The location code is not guaranteed to be unique, so we might get bus_id
collisions if two devices share the same location code.  The OFDT
full_name, however, is unique, so we use that instead (truncating it
on the left if it is too long).

Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 9 insertions, 21 deletions

diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index 9a8c9af43b22..d6a38cd5018e 100644
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -188,33 +188,21 @@ static struct ibmebus_dev* __devinit ibmebus_register_device_node(
         struct device_node *dn)
 {
         struct ibmebus_dev *dev;
-        const char *loc_code;
-        int length;
-
-        loc_code = of_get_property(dn, "ibm,loc-code", NULL);
-        if (!loc_code) {
-                printk(KERN_WARNING "%s: node %s missing 'ibm,loc-code'\n",
-                       __FUNCTION__, dn->name ? dn->name : "<unknown>");
-                return ERR_PTR(-EINVAL);
-        }
-
-        if (strlen(loc_code) == 0) {
-                printk(KERN_WARNING "%s: 'ibm,loc-code' is invalid\n",
-                       __FUNCTION__);
-                return ERR_PTR(-EINVAL);
-        }
+        int i, len, bus_len;
 
         dev = kzalloc(sizeof(struct ibmebus_dev), GFP_KERNEL);
-        if (!dev) {
+        if (!dev)
                 return ERR_PTR(-ENOMEM);
-        }
 
         dev->ofdev.node = of_node_get(dn);
 
-        length = strlen(loc_code);
-        memcpy(dev->ofdev.dev.bus_id, loc_code
-                + (length - min(length, BUS_ID_SIZE - 1)),
-                min(length, BUS_ID_SIZE - 1));
+        len = strlen(dn->full_name + 1);
+        bus_len = min(len, BUS_ID_SIZE - 1);
+        memcpy(dev->ofdev.dev.bus_id, dn->full_name + 1
+               + (len - bus_len), bus_len);
+        for (i = 0; i < bus_len; i++)
+                if (dev->ofdev.dev.bus_id[i] == '/')
+                        dev->ofdev.dev.bus_id[i] = '_';
 
         /* Register with generic device framework. */
         if (ibmebus_register_device_common(dev, dn->name) != 0) {