Re: [PATCH -v2 1/2] x86: Reserve [0xa0000, 0x100000] in e820 map

From: H. Peter Anvin
Date: Tue Apr 13 2010 - 17:59:08 EST


On 04/13/2010 02:42 PM, Yinghai wrote:
> On 04/13/2010 02:18 PM, H. Peter Anvin wrote:
>> On 04/13/2010 02:11 PM, Yinghai wrote:
>>>>
>>>> I guess the real question (which I haven't looked at myself) is if the
>>>> E820_RESERVED -> BUSY will cause an explicitly assigned BAR from being
>>>> moved. That's bad, not so much for this particular range, but from BARs
>>>> which may be assigned by SMM. Hacking that up in a simulator
>>>> (Qemu/Bochs) and testing it is probably on the to do list...
>>>
>>> no, if some device BAR fall in that range, it should still use that range, and will not be relocated.
>>>
>>> will update the change log.
>>>
>>
>> Good, that's what we want.
>
> the driver for that device later can not use pci_request_region(). because that region is BUSY already.
>

That's not good (in general - for devices in this particular range it's
not such a big deal, but it is potentially really bad for devices marked
reserved for them not to be moved.)

We have talked about a need to resolve this before.

-hpa

--
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/