Re: DMA API issues

[Takashi Iwai]

At Mon, 21 Jun 2004 20:26:39 -0700 (PDT),
Linus Torvalds wrote:
> 
> On Mon, 21 Jun 2004, Linus Torvalds wrote:
> > 
> > The argument at some point was that some architectures may not even _have_
> > a "struct page" for DMA memory, since it's not "normal" memory (ie "slow
> > memory" on m68k). However, I thought we all agreed that such a "struct
> > page" could be furnished if that architecture wants so support mmap'ing.
> 
> .. which is not to say that we shouldn't have a "pci_mmap_pages()" thing
> _too_. Pretty clearly the easiest interface often is to just map the pages
> at mmap() time, and then we should just have a helper function to do that. 
> 
> I thought we did one already, but hey, maybe not.

I don't think we have such.

Russell has once proposed a similar one (but not pci-specific), and I
believe it makes sense for many drivers.  We can hide the
architecture-specific cache handling inside the helper function, too.


Takashi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/