powerpc/powernv: Fetch frozen PE on top level

It should have been part of commit 1ad7a72c5 ("powerpc/eeh: Report
frozen parent PE prior to child PE"). There are 2 ways to report
EEH errors: proactively polling because of 0xFF's returned from
PCI config or IO read, or interrupt driven event. We missed to
report and handle parent frozen PE prior to child frozen PE for
the later case on PowerNV platform.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/eeh-ioda.c

@@ -886,14 +886,12 @@ static int ioda_eeh_get_pe(struct pci_controller *hose,
 	 * the master PE because slave PE is invisible
 	 * to EEH core.
 	 */
-	if (phb->get_pe_state) {
-		pnv_pe = &phb->ioda.pe_array[pe_no];
-		if (pnv_pe->flags & PNV_IODA_PE_SLAVE) {
-			pnv_pe = pnv_pe->master;
-			WARN_ON(!pnv_pe ||
-				!(pnv_pe->flags & PNV_IODA_PE_MASTER));
-			pe_no = pnv_pe->pe_number;
-		}
+	pnv_pe = &phb->ioda.pe_array[pe_no];
+	if (pnv_pe->flags & PNV_IODA_PE_SLAVE) {
+		pnv_pe = pnv_pe->master;
+		WARN_ON(!pnv_pe ||
+			!(pnv_pe->flags & PNV_IODA_PE_MASTER));
+		pe_no = pnv_pe->pe_number;
 	}
 
 	/* Find the PE according to PE# */
@@ -904,15 +902,37 @@ static int ioda_eeh_get_pe(struct pci_controller *hose,
 	if (!dev_pe)
 		return -EEXIST;
 
-	/*
-	 * At this point, we're sure the compound PE should
-	 * be put into frozen state.
-	 */
+	/* Freeze the (compound) PE */
 	*pe = dev_pe;
-	if (phb->freeze_pe &&
-	    !(dev_pe->state & EEH_PE_ISOLATED))
+	if (!(dev_pe->state & EEH_PE_ISOLATED))
 		phb->freeze_pe(phb, pe_no);
 
+	/*
+	 * At this point, we're sure the (compound) PE should
+	 * have been frozen. However, we still need poke until
+	 * hitting the frozen PE on top level.
+	 */
+	dev_pe = dev_pe->parent;
+	while (dev_pe && !(dev_pe->type & EEH_PE_PHB)) {
+		int ret;
+		int active_flags = (EEH_STATE_MMIO_ACTIVE |
+				    EEH_STATE_DMA_ACTIVE);
+
+		ret = eeh_ops->get_state(dev_pe, NULL);
+		if (ret <= 0 || (ret & active_flags) == active_flags) {
+			dev_pe = dev_pe->parent;
+			continue;
+		}
+
+		/* Frozen parent PE */
+		*pe = dev_pe;
+		if (!(dev_pe->state & EEH_PE_ISOLATED))
+			phb->freeze_pe(phb, dev_pe->addr);
+
+		/* Next one */
+		dev_pe = dev_pe->parent;
+	}
+
 	return 0;
 }