[+cc Arnd] And this one? On Fri, Oct 02, 2015 at 11:44:02AM -0700, David Daney wrote: > From: David Daney <david.daney@xxxxxxxxxx> > > There are two problems with the bus_max calculation: > > 1) The u8 data type can overflow for large config space windows. > > 2) The calculation is incorrect for a bus range that doesn't start at > zero. > > Since the configuration space is relative to bus zero, make bus_max > just be the size of the config window scaled by bus_shift. Then clamp > it to a maximum of 255, per PCI. Use a data type of int to avoid > overflow problems. > > 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@xxxxxxxxxx> > --- > Change from V3: Add to explanation of "reg" property in > host-generic-pci.txt. Add error message if "reg" property is too big. > > Documentation/devicetree/bindings/pci/host-generic-pci.txt | 6 +++++- > drivers/pci/host/pci-host-generic.c | 12 +++++++++--- > 2 files changed, 14 insertions(+), 4 deletions(-) > > diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt > index cf3e205..42303bb 100644 > --- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt > +++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt > @@ -34,7 +34,11 @@ 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 > + bus zero, even though the "bus-range" property may specify > + a different starting bus number. The driver must only map > + or access the portion of the Configuration Space that > + corresponds to the "bus-range" > > > Properties of the /chosen node: > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > index 216ded5..5cce837 100644 > --- a/drivers/pci/host/pci-host-generic.c > +++ b/drivers/pci/host/pci-host-generic.c > @@ -164,7 +164,7 @@ out_release_res: > static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci) > { > int err; > - u8 bus_max; > + int bus_max; > resource_size_t busn; > struct resource *bus_range; > struct device *dev = pci->host.dev.parent; > @@ -177,8 +177,14 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci) > } > > /* Limit the bus-range to fit within reg */ > - bus_max = pci->cfg.bus_range->start + > - (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1; > + bus_max = (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1; > + if (bus_max > 255) { > + dev_err(dev, > + "\"reg\" size corresponds to bus %d, truncating to 255\n", > + bus_max); > + bus_max = 255; > + } > + > pci->cfg.bus_range->end = min_t(resource_size_t, > pci->cfg.bus_range->end, bus_max); > > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html