[PATCH RFC 05/15] powerpc/eeh: Sync eeh_pe_get_parent()

[Sam Bobroff]

Synchronize access to eeh_pe.

Signed-off-by: Sam Bobroff <sbobroff at linux.ibm.com>
---
 arch/powerpc/kernel/eeh_pe.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index b89ed46f14e6..0486d3c6ff20 100644
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -469,10 +469,12 @@ struct eeh_pe *eeh_pe_find(struct pci_controller *phb,
  * The whole PEs existing in the system are organized as hierarchy
  * tree. The function is used to retrieve the parent PE according
  * to the parent EEH device.
+ * Returns a referenced PE.
  */
 static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
 {
 	struct eeh_dev *parent;
+	struct eeh_pe *pe;
 	struct pci_dn *pdn = eeh_dev_to_pdn(edev);
 
 	/*
@@ -490,8 +492,14 @@ static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
 		if (!parent)
 			return NULL;
 
-		if (parent->pe)
-			return parent->pe;
+		if (parent->pe) {
+			/* TODO: Unsafe until eeh_dev can be synchronized
+			 * with eeh_pe.
+			 */
+			pe = parent->pe;
+			eeh_get_pe(pe);
+			return pe;
+		}
 
 		pdn = pdn->parent;
 	}
-- 
2.22.0.216.g00a2a96fc9