From: Scott Moser <smoser@redhat.com>
Date: Thu, 1 Nov 2007 14:38:07 -0400
Subject: [ppc64] eHEA: ibm,loc-code not unique
Message-id: Pine.LNX.4.64.0711011437220.30676@squad5-lp1.lab.boston.redhat.com
O-Subject: [PATCH RHEL5u2] bz271821 ibm,loc-code not unique for eHEA/eHCA adapters
Bugzilla: 271821

Bug 271821 [1]
---------------

Description:
-----------
Each eHEA/eHCA adapter is shown in the Open Firmware Device Tree and has
an attribute called ibm,loc-code. The IBMEBUS driver uses this loc-code to
create entries for each adapter in the sysfs. The ibm,loc-code is not
unique. For some machine configurations with multiple eHEA/eHCA adapters
this causes problems when the IBMEBUS driver tries to create the same
sysfs entries twice.

This patch will change ibmebus to use the device-tree name for bus ID
instead of the location code. The device-tree name is unique (enforced by
OFDT specs), so this will prevent bus ID collisions.

Kernel Version:
--------------
Patch built against 2.6.18-54

Upstream Status:
---------------
This is a backport of upstream commit
d8612417b2f78767b96ca434b50d23e5cdfcde07

Test Status:
----
To ensure cross platform build, a brew scratch build has been done against
2.6.18-54 at [2].

I've booted the kernel above and done hotplug add and remove for the ehea
devices.  I've verified that the entries created in sysfs
(/sys/devices/ibmebus/) are named like lhea@23c00100 rather than with the
ibm,loc-code (which looks like 789D.001.DQDMLYY-P1).

Please review patch below for RHEL5u2
--
[1]:https://bugzilla.redhat.com/show_bug.cgi?id=271821
--
 arch/powerpc/kernel/ibmebus.c |   27 ++++++++-------------------
 1 file changed, 8 insertions(+), 19 deletions(-)

Acked-by: Pete Zaitcev <zaitcev@redhat.com>
---
 arch/powerpc/kernel/ibmebus.c |   27 ++++++++-------------------
 1 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index 74e40f9..0880a15 100644
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -185,21 +185,7 @@ static struct ibmebus_dev* __devinit ibmebus_register_device_node(
 	struct device_node *dn)
 {
 	struct ibmebus_dev *dev;
-	char *loc_code;
-	int length;
-
-	loc_code = (char *)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) {
@@ -208,10 +194,13 @@ static struct ibmebus_dev* __devinit ibmebus_register_device_node(
 
 	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) {
-- 
1.5.3.5.645.gbb47