PCI: generic: Fix address window calculation for non-zero starting bus

Make the offset from the beginning of the "reg" property be from the
starting bus number, rather than zero.  Hoist the invariant size
calculation out of the mapping for loop.

Update host-generic-pci.txt to clarify the semantics of the "reg" property
with respect to non-zero starting bus numbers.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rob Herring <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt
index cf3e205e0b7e0de18e8e6650bdc347d996807960..3f1d3fca62bbf6a62afd1d270d271582c6c2e20e 100644 (file)
--- 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 895c0e39ca3b9ccbc0e4172c6ca0d6716ef2d08d..5434c90db24345bc73ad5e00ecc00d599c40ddaf 100644 (file)
--- 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;