PCI: designware: Fix I/O transfers by using CPU (not realio) address

pp->io_base, which is the input of the outbound IO address translation
unit, should be the CPU address.  It was incorrectly programmed to the
realio address.

We should pass global_io_offset rather than sys->io_offset to
pci_ioremap_io(), so we map the new window into the first available spot in
the Linux view of the I/O space.

We must also pass CPU address instead of realio address to pci_ioremap_io().

This patch fixes above issue.  It has been tested with Lecroy PTC in AIC
mode and Pericom PI7C9X2G303EL PCIe switch, which does not work otherwise.

Tested-by: Mohit Kumar <mohit.kumar@st.com>
Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Marek Vasut <marex@denx.de
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Cc: Richard Zhu <Hong-Xing.Zhu@freescale.com>
diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index fc97f5a..4a08d30 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -418,6 +418,7 @@
 					   + global_io_offset);
 			pp->config.io_size = resource_size(&pp->io);
 			pp->config.io_bus_addr = range.pci_addr;
+			pp->io_base = range.cpu_addr;
 		}
 		if (restype == IORESOURCE_MEM) {
 			of_pci_range_to_resource(&range, np, &pp->mem);
@@ -443,7 +444,6 @@
 
 	pp->cfg0_base = pp->cfg.start;
 	pp->cfg1_base = pp->cfg.start + pp->config.cfg0_size;
-	pp->io_base = pp->io.start;
 	pp->mem_base = pp->mem.start;
 
 	pp->va_cfg0_base = devm_ioremap(pp->dev, pp->cfg0_base,
@@ -613,7 +613,6 @@
 	return ret;
 }
 
-
 static int dw_pcie_valid_config(struct pcie_port *pp,
 				struct pci_bus *bus, int dev)
 {
@@ -707,7 +706,7 @@
 
 	if (global_io_offset < SZ_1M && pp->config.io_size > 0) {
 		sys->io_offset = global_io_offset - pp->config.io_bus_addr;
-		pci_ioremap_io(sys->io_offset, pp->io.start);
+		pci_ioremap_io(global_io_offset, pp->io_base);
 		global_io_offset += SZ_64K;
 		pci_add_resource_offset(&sys->resources, &pp->io,
 					sys->io_offset);