Re: [PATCH 02/11] PCI: Try to allocate mem64 above 4G at first

H. Peter Anvin
2012-05-29T20:51:13Z

On 05/29/2012 01:46 PM, Yinghai Lu wrote:
> On Tue, May 29, 2012 at 12:03 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>> On 05/29/2012 11:17 AM, Yinghai Lu wrote:
>>>
>>> pci bridge could support 16bits and 32bits io port.
>>> but we did not record if 32bits is supported.
>>>
>>
>> Okay, so this is the actual problem, no?
>
> their fw could not need kernel help to allocate io ports, or they are
> only use device that support 32bit ioport.
>

That barely parses, never mind makes sense.

>>
>>> so during allocating, could have allocated above 64k address to non
>>> 32bit bridge.
>>>
>>> but x86 is ok, because ioport.end always set to 0xffff.
>>> other arches with IO_SPACE_LIMIT with 0xffffffff or
>>> 0xffffffffffffffffUL may have problem.
>>
>> The latter is nonsense, the PCI-side address space is only 32 bits wide.
>>
> maybe they have unified io include ioport and mem io?
>

The bus-side address space should not be more than 32 bits no matter
what. As Bjorn indicates, you seem to be mixing up bus and cpu
addresses all over the place.

-hpa