nfp: don't set aux pointers if ioremap failed

If ioremap of PCIe ctrl memory failed we can still get to it through
PCI config space, therefore we allow ioremap() to fail.  When if fails,
however, we must leave all the IOMEM pointers as NULL.  Currently we
would calculate csr and em pointers, adding offsets to the potential
NULL value and therefore making the NULL-checks throughout the code
ineffective.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c

@@ -639,19 +639,23 @@ static int enable_bars(struct nfp6000_pcie *nfp, u16 interface)
 		nfp6000_bar_write(nfp, bar, barcfg_msix_general);
 
 		nfp->expl.data = bar->iomem + NFP_PCIE_SRAM + 0x1000;
+
+		if (nfp->pdev->device == PCI_DEVICE_ID_NETRONOME_NFP4000 ||
+		    nfp->pdev->device == PCI_DEVICE_ID_NETRONOME_NFP6000) {
+			nfp->iomem.csr = bar->iomem + NFP_PCIE_BAR(0);
+		} else {
+			int pf = nfp->pdev->devfn & 7;
+
+			nfp->iomem.csr = bar->iomem + NFP_PCIE_BAR(pf);
+		}
+		nfp->iomem.em = bar->iomem + NFP_PCIE_EM;
 	}
 
 	if (nfp->pdev->device == PCI_DEVICE_ID_NETRONOME_NFP4000 ||
-	    nfp->pdev->device == PCI_DEVICE_ID_NETRONOME_NFP6000) {
-		nfp->iomem.csr = bar->iomem + NFP_PCIE_BAR(0);
+	    nfp->pdev->device == PCI_DEVICE_ID_NETRONOME_NFP6000)
 		expl_groups = 4;
-	} else {
-		int pf = nfp->pdev->devfn & 7;
-
-		nfp->iomem.csr = bar->iomem + NFP_PCIE_BAR(pf);
+	else
 		expl_groups = 1;
-	}
-	nfp->iomem.em = bar->iomem + NFP_PCIE_EM;
 
 	/* Configure, and lock, BAR0.1 for PCIe XPB (MSI-X PBA) */
 	bar = &nfp->bar[1];