Re: When is a kernel VA not a virt_to_xxx() address?
Jeff Garzik (jgarzik@mandrakesoft.com)
Mon, 13 Dec 1999 18:54:38 -0500
Bret Indrelee wrote:
>
> Hello,
>
> I'm having some problems setting up a DMA between a PCI device and kernel
> memory space. I haven't fully debugged it, but one of the areas that looks
> suspicious is obtaining the PCI address of a kernel buffer.
>
> I've allocated a buffer in kernel space using vmalloc(). I had originally
> thought that I could just do a virt_to_bus() in order to get the PCI address
> of the buffer. Looking through various other drivers, I'm seeing them go
> through the pgd/pmd/pte before calling virt_to_bus().
Bret,
Check out how the latest bttv and Zoran drivers use vmalloc. grep for
vmalloc in drivers/char.
--
Jeff Garzik | Just once, I wish we would encounter
Building 1024 | an alien menace that wasn't immune to
MandrakeSoft, Inc. | bullets. -- The Brigadier, "Dr. Who"
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/