Does kmalloc on MPC82xx work correctly with GFP_DMA?
Dan Malek
dan at embeddededge.com
Tue Oct 19 01:31:12 EST 2004
On Oct 18, 2004, at 5:30 AM, Conor McLoughlin wrote:
> I have been looking at the ethernet device driver (fcc_enet) for the
> mpc82xx platform. This allocates buffer descriptors using kmalloc with
> the GFP_DMA flag.
Yes.
> As far as I can see on my platform, this allocates
> from the regular kernel memory (0xCxxxxxxx). As the attributes of this
> block of memory are controlled by the block address translation
> registers,
No, the kmalloc() space is not covered by BATs (but, that isn't
relevant for this discussion).
> this cannot be DMA safe, can it?
Yes, it is DMA safe. That's why this driver works :-)
-- Dan
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