Re: [PATCH] 64-bit struct resource fields

[ebiederm@xmission.com (Eric W. Biederman)]

Dave Hansen <haveblue@us.ibm.com> writes:

> We need some way to replicate the e820 tables for kexec.  This modifies struct
> resource to use u64's for its start and end fields. This way we can export the
> whole e820 table on PAE machines.
> 
> resource->flags seems to be used often to mask out things in
> resource->start/end, so I think it needs to be u64 too.  

I don't see this in the parts of the kernel your patch changes, I will
have to look a little more and see if this is really true.  If it
is you probably should append ULL to the flag constants.

>But, Is it all right to
> 
> let things like pcibios_update_resource() truncate the resource addresses like
> they do?

The type of addresses for resources will always be equal or larger
than the resources they actually represent.  Until someone modifies
the pcibios_xxxx code to handle 64bit BARs it should only be
truncation of zeros and thus safe.  

I will see if I can scrutinize this carefully, and try it in the next
little while.  For now I am placing it on the back burner and going
to bed.  It looks like a good start though.

Eric