2 files changed, 5 insertions, 4 deletions

diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt
index cf3e205e0b7e..3f1d3fca62bb 100644
--- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt
+++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt
@@ -34,8 +34,9 @@ Properties of the host controller node:
 - #size-cells    : Must be 2.
 
 - reg            : The Configuration Space base address and size, as accessed
-                   from the parent bus.
-
+                   from the parent bus.  The base address corresponds to
+                   the first bus in the "bus-range" property.  If no
+                   "bus-range" is specified, this will be bus 0 (the default).
 
 Properties of the /chosen node:
 
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index 895c0e39ca3b..5434c90db243 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -169,6 +169,7 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
         struct resource *bus_range;
         struct device *dev = pci->host.dev.parent;
         struct device_node *np = dev->of_node;
+        u32 sz = 1 << pci->cfg.ops->bus_shift;
 
         err = of_address_to_resource(np, 0, &pci->cfg.res);
         if (err) {
@@ -196,10 +197,9 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
         bus_range = pci->cfg.bus_range;
         for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
                 u32 idx = busn - bus_range->start;
-                u32 sz = 1 << pci->cfg.ops->bus_shift;
 
                 pci->cfg.win[idx] = devm_ioremap(dev,
-                                                 pci->cfg.res.start + busn * sz,
+                                                 pci->cfg.res.start + idx * sz,
                                                  sz);
                 if (!pci->cfg.win[idx])
                         return -ENOMEM;