On Aug 26, 2009, at 9:08 AM, Michael Ellerman wrote:
On Wed, 2009-08-26 at 22:29 +1000, Benjamin Herrenschmidt wrote:
On Mon, 2009-08-24 at 21:48 +0200, Christoph Hellwig wrote:
On Mon, Aug 24, 2009 at 11:17:14AM -0500, Becky Bruce wrote:
Previously, this was specified as a void *, but that's not
large enough on 32-bit systems with 36-bit physical
addressing support. Change the type to dma_addr_t so it
will scale based on the size of a dma address.
This looks extreml ugly to me. It seems like the typical use is to
store a pointer to a structure. So what about making the direct
dma case follow that general scheme instead?
E.g. declare a
struct direct_dma_data {
dma_addr_t direct_dma_offset;
};
and have one normal instace of it, and one per weird cell device.
Right, but we want to avoid a structure for the classic case of 32-
bit
systems with no iommu...
I wouldn't mind doing a union here.
That might be best, the patch as it stands is a horrible mess of
casts.
Let's be fair - the code before was a horrible mess of casts, I've
just moved them :)
Stashing a dma_addr_t into a void * is sort of gross, but storing a
pointer to some struct (a void *) in a dma_addr_t is _really_ gross :)
Both are revolting (and storing a dma_addr_t into a void * is really
gross when the void * is smaller than the dma_addr_t!!). A union
might not be a bad idea, though. I'll look at doing that instead.
-Becky
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