powerpc/eeh: Trace PCI bus from PE
There're several types of PEs can be supported for now: PHB, Bus
and Device dependent PE. For PCI bus dependent PE, tracing the
corresponding PCI bus from PE (struct eeh_pe) would make the code
more efficient. The patch also enables the retrieval of PCI bus based
on the PCI bus dependent PE.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index 3d2dcf5..c963667 100644
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -365,6 +365,17 @@
pe->config_addr = edev->config_addr;
/*
+ * While doing PE reset, we probably hot-reset the
+ * upstream bridge. However, the PCI devices including
+ * the associated EEH devices might be removed when EEH
+ * core is doing recovery. So that won't safe to retrieve
+ * the bridge through downstream EEH device. We have to
+ * trace the parent PCI bus, then the upstream bridge.
+ */
+ if (eeh_probe_mode_dev())
+ pe->bus = eeh_dev_to_pci_dev(edev)->bus;
+
+ /*
* Put the new EEH PE into hierarchy tree. If the parent
* can't be found, the newly created PE will be attached
* to PHB directly. Otherwise, we have to associate the
@@ -641,12 +652,18 @@
bus = pe->phb->bus;
} else if (pe->type & EEH_PE_BUS ||
pe->type & EEH_PE_DEVICE) {
+ if (pe->bus) {
+ bus = pe->bus;
+ goto out;
+ }
+
edev = list_first_entry(&pe->edevs, struct eeh_dev, list);
pdev = eeh_dev_to_pci_dev(edev);
if (pdev)
bus = pdev->bus;
}
+out:
eeh_unlock();
return bus;