PCI: designware-ep: Make dw_pcie_ep_set_bar() handle 64-bit BARs properly

Since a 64-bit BAR consists of a BAR pair, we need to write to both
BARs in the BAR pair to setup the BAR properly.

Link: https://lkml.kernel.org/r/20180328115018.31921-7-niklas.cassel@axis.com
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
[lorenzo.pieralisi@arm.com: updated code according to review]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>

drivers/pci/dwc/pcie-designware-ep.c

@@ -138,8 +138,15 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
 		return ret;
 
 	dw_pcie_dbi_ro_wr_en(pci);
-	dw_pcie_writel_dbi2(pci, reg, size - 1);
+
+	dw_pcie_writel_dbi2(pci, reg, lower_32_bits(size - 1));
 	dw_pcie_writel_dbi(pci, reg, flags);
+
+	if (flags & PCI_BASE_ADDRESS_MEM_TYPE_64) {
+		dw_pcie_writel_dbi2(pci, reg + 4, upper_32_bits(size - 1));
+		dw_pcie_writel_dbi(pci, reg + 4, 0);
+	}
+
 	dw_pcie_dbi_ro_wr_dis(pci);
 
 	return 0;