Messages in this thread | | | Date | Wed, 8 Mar 2006 13:57:34 -0800 | From | thockin@hockin ... | Subject | Re: proper way to assign fixed PCI resources to a "hotplug" device |
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On Thu, Mar 09, 2006 at 12:21:53AM +0300, Ivan Kokshaysky wrote: > On Wed, Mar 08, 2006 at 08:40:42AM -0800, thockin@hockin.org wrote: > > Assigned from what pool? BIOS most likely sizes the hole to be a pretty > > tight fit for all the resources it knows about. If there is suddenly a > > new resource, you're in trouble. > > This can only be true when device in question is behind a pci-to-pci > bridge (which is obviously not the case for ICH controllers you mentioned). > Otherwise we have plenty of MMIO space.
Not true. Plenty of root bridges have the same base/limit style configuration registers, but they are non-standard. Even worse - the MMIO hole thatthe chipset carves out, is not guaranteed to be big enough for some new random allocation.
> > We could teach linux about chipsets and let Linux re-do the whole > > PCI-allocation process. But that's not an easy task, and is probably a > > contentious idea. > > Linux knows how to do this for years. Actually, this is the way how alpha > and some other platforms work. Since 2.6.13, this pretty much applies to > x86 as well (we do respect BIOS PCI allocations, but we clean the things > up after BIOS quite aggressively - see pci_assign_unassigned_resources() call).
Cleaning up and re-doing are not the same thing. The plethora of x86 chipsets makes this unpleasant at best and more likely unworkable. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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