Re: PCI resource problems caused by improper address rounding

Andrew Morton
2007-12-22T09:21:19Z

On Sat, 22 Dec 2007 01:12:18 -0800 Andrew Morton <akpm@linux-foundation.org> wrote:

> On Thu, 20 Dec 2007 11:46:16 +0300 Ivan Kokshaysky <ink@jurassic.park.msu.ru> wrote:
>
> > PCI: do respect full 64-bit address for bridge prefetch window
> >
> > Prevent the prefetch window from being programmed with a bogus address
> > when its respective resource gets allocated above the 4G mark.
> >
> > Note that we cannot yet guarantee correct resource allocations
> > above 4G, though it might work in some simple cases.
> >
>
> So.. did we agree that this patch is good to go?

Oh, I see Greg merged a differnet patch.

> > --- a/drivers/pci/setup-bus.c
> > +++ b/drivers/pci/setup-bus.c
> > @@ -208,8 +208,11 @@ pci_setup_bridge(struct pci_bus *bus)
> > }
> > pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
> >
> > - /* Clear out the upper 32 bits of PREF base. */
> > - pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 0);
> > + /* Set up the upper 32 bits of PREF base/limit. */
> > + l = region.start >> 16 >> 16;
>
> We have the little upper_32_bits() helper for this.
>

Which could use this.

--- a/drivers/pci/setup-bus.c~gregkh-pci-pci-fix-bus-resource-assignment-on-32-bits-with-64b-resources-cleanup
+++ a/drivers/pci/setup-bus.c
@@ -206,10 +206,8 @@ pci_setup_bridge(struct pci_bus *bus)
if (bus->resource[2]->flags & IORESOURCE_PREFETCH) {
l = (region.start >> 16) & 0xfff0;
l |= region.end & 0xfff00000;
-#ifdef CONFIG_RESOURCES_64BIT
- bu = region.start >> 32;
- lu = region.end >> 32;
-#endif
+ bu = upper_32_bits(region.start);
+ lu = upper_32_bits(region.end);
DBG(KERN_INFO " PREFETCH window: 0x%016llx-0x%016llx\n",
(unsigned long long)region.start,
(unsigned long long)region.end);