Re: Modpost warning on Alchemy

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello.

Maciej W. Rozycki wrote:

>>>So what is the issue with the size then?  How big is the area?

>>   I've already said: 4 gigs! At least in theory, actually it's 2 gigs due to

>  Oh, I mistook it for the base physical address, sorry.

    That's 24 gigs. :-)

>>a device # being limited to 0 thru 19 (address bits 11 thru 30 are used as
>>IDSELx).

>  It does not help too much with a 32-bit virtual address space indeed.  
> Though I gather it has to be very sparsely populated as 16MiB is enough to 
> cover the whole configuration space of a single PCI bus tree.  Thus it has 

    Hm, maybe 16 MiB would be enough indeed, as the Alchemy CPUs are known to 
not support bus masters behind PCI bridges...

> to be another example where the chip designer "forgot" to talk to software 
> people.  Or a shifter was traded for software performance and complexity. 
> ;-)

    I certainly agree here. :-)

>>   There was no need to tell me about how KSEG0/1/2 work -- that's why I
>>cosidered it wasting time. :-)

>  As I say -- the key is how you look at it.  There are other readers on 
> the list who may benefit; it is archived too.  In this sense I can hardly 
> consider it a waste of time.  And it was fun to explain and no fun shall 
> be ever considered of no use. :-)

    Depends on the source of fun. :-)

>   Maciej

WBR, Sergei