diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 4374836b033b4..62f17c015f9fb 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -792,7 +792,7 @@ static int pnv_ioda_deconfigure_pe(struct pnv_phb *phb, struct pnv_ioda_pe *pe)
 		fcomp = OPAL_IGNORE_RID_FUNCTION_NUMBER;
 		parent = pe->pbus->self;
 		if (pe->flags & PNV_IODA_PE_BUS_ALL)
-			count = pe->pbus->busn_res.end - pe->pbus->busn_res.start + 1;
+			count = resource_size(&pe->pbus->busn_res);
 		else
 			count = 1;
 
@@ -874,7 +874,7 @@ static int pnv_ioda_configure_pe(struct pnv_phb *phb, struct pnv_ioda_pe *pe)
 		fcomp = OPAL_IGNORE_RID_FUNCTION_NUMBER;
 		parent = pe->pbus->self;
 		if (pe->flags & PNV_IODA_PE_BUS_ALL)
-			count = pe->pbus->busn_res.end - pe->pbus->busn_res.start + 1;
+			count = resource_size(&pe->pbus->busn_res);
 		else
 			count = 1;