[openib-general] Re: [PATCH] arch/xx/pci: remap_pfn_range -> io_remap_pfn_range

[Greg KH]

On Thu, Jul 28, 2005 at 12:57:51PM +0100, Ian Pratt wrote:
> > >     Greg> Hm, you do realize that io_remap_pfn_range() is the same
> > >     Greg> thing as remap_pfn_range() on i386, right?
> > > 
> > >     Greg> So, why would this patch change anything?
> > > 
> > > It's not the same thing under Xen.  I think this patch 
> > fixes userspace 
> > > access to PCI memory for XenLinux.
> > 
> > But Xen is a separate arch, and hence, will get different pci 
> > arch specific functions, right?
> > 
> > In short, what is this patch trying to fix?  What is the 
> > problem anyone is seeing with the existing code?
> 
> As I understand it, remap_pfn_range should be used for mapping pages
> that are backed by memory, and io_remap_pfn_range should be used for
> mapping MMIO regions.
> There's a distinciton between the two for architectures like Sparc and
> xen/x86. 

I agree, but not for i386, which is what the patch was trying to change.

If this is a fix for xen, fine, then say so in the changelog information
for the patch, as it is, no such information was given.

thanks,

greg k-h