Re: virt_to_page/pci_map_page vs. pci_map_single

[Ihar 'Philips' Filipau]

Hi!

  Can any-one draw a conclusion?
  Which function should be used in which case?

  So this will be at least reflected in lkml archives ;-)

David S. Miller wrote:
> On Mon, 3 Nov 2003 14:02:57 -0800
> David Mosberger <davidm@xxxxxxxxxxxxxxxxx> wrote:
>
>
> > > > > > > On 03 Nov 2003 09:17:59 -0500, Jes Sorensen <jes@xxxxxxxxxxxxxxxxxx> said:
> >
> >  Jes> Hmmm, my brain has gotten ia64ified ;-) It's basically the normal
> >  Jes> mappings of the kernel, ie. the kernel text/data/bss segments as well
> >  Jes> as anything you do not get back as a dynamic mapping such as
> >  Jes> ioremap/vmalloc/kmap.
> >
> > I don't think it's safe to use virt_to_page() on static kernel
> > addresses (text, data, and bss).  For example, ia64 linux nowadays
> > uses a virtual mapping for the static kernel memory, so it's not part
> > of the identity-mapped segment.
>
>
> That's correct and it'll break on sparc64 for similar reasons.
>
> It's also not safe to do virt_to_page() on kernel stack addresses
> either.


--
Ihar 'Philips' Filipau  / with best regards from Saarbruecken.
--                                                           _ _ _
 "... and for $64000 question, could you get yourself       |_|*|_|
   vaguely familiar with the notion of on-topic posting?"   |_|_|*|
                                -- Al Viro @ LKML           |*|*|*|

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