powerpc/eeh: Fix PE location code

[ Upstream commit 7e56f627768da4e6480986b5145dc3422bc448a5 ]

In eeh_pe_loc_get(), the PE location code is retrieved from the
"ibm,loc-code" property of the device node for the bridge of the
PE's primary bus. It's not correct because the property indicates
the parent PE's location code.

This reads the correct PE location code from "ibm,io-base-loc-code"
or "ibm,slot-location-code" property of PE parent bus's device node.

Cc: stable@vger.kernel.org # v3.16+
Fixes: 357b2f3dd9b7 ("powerpc/eeh: Dump PE location code")
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index 35f0b62..22f6d95 100644 (file)
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -861,32 +861,29 @@ void eeh_pe_restore_bars(struct eeh_pe *pe)
 const char *eeh_pe_loc_get(struct eeh_pe *pe)
 {
        struct pci_bus *bus = eeh_pe_bus_get(pe);
-       struct device_node *dn = pci_bus_to_OF_node(bus);
+       struct device_node *dn;
        const char *loc = NULL;
 
-       if (!dn)
-               goto out;
+       while (bus) {
+               dn = pci_bus_to_OF_node(bus);
+               if (!dn) {
+                       bus = bus->parent;
+                       continue;
+               }
 
-       /* PHB PE or root PE ? */
-       if (pci_is_root_bus(bus)) {
-               loc = of_get_property(dn, "ibm,loc-code", NULL);
-               if (!loc)
+               if (pci_is_root_bus(bus))
                        loc = of_get_property(dn, "ibm,io-base-loc-code", NULL);
+               else
+                       loc = of_get_property(dn, "ibm,slot-location-code",
+                                             NULL);
+
                if (loc)
-                       goto out;
+                       return loc;
 
-               /* Check the root port */
-               dn = dn->child;
-               if (!dn)
-                       goto out;
+               bus = bus->parent;
        }
 
-       loc = of_get_property(dn, "ibm,loc-code", NULL);
-       if (!loc)
-               loc = of_get_property(dn, "ibm,slot-location-code", NULL);
-
-out:
-       return loc ? loc : "N/A";
+       return "N/A";
 }
 
 /**