Messages in this thread | | | Date | Thu, 25 Aug 2011 23:18:42 -0700 | From | Yinghai Lu <> | Subject | Re: [PATCH 1/2] x86, ioapic: Reserve only 128 bytes for IOAPICs |
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On 08/25/2011 06:41 PM, H. Peter Anvin wrote: > On 08/25/2011 05:17 PM, Bjorn Helgaas wrote: >> >> If the OS allocated the next 128 bytes to another device, it sounds >> like it would cause a conflict on Intel boxes. This must be an area >> that differs between vendors. I haven't seen a spec that mentions 256 >> bytes as the required minimum MMIO size for IOAPICs, and apparently >> the AMD IOAPIC decodes 240 bytes or fewer. >> > > For what it's worth, it's probably a bad idea on x86 for the OS to > allocate addresses in the 0xFExxxxxx range... > for system with more than one ioapic controllers, could have ioapic address rather low. and those address are allocated to some pci devices BAR by BIOS.
Yinghai
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