[U-Boot] [PATCH] mmc:dcache: Cache line size aligned internal MMC buffers

Mike Frysinger
2011-08-23T21:32:37Z

On Tuesday, August 23, 2011 17:09:37 Wolfgang Denk wrote:
> Mike Frysinger wrote:
> > On Tuesday, August 23, 2011 16:27:26 Anton Staaf wrote:
> > > So then, to guide our efforts, what is a more suitable solution?
> > > Would you prefer we stick with the existing path of calling memalign
> > > and passing it the cache size by directly calling
> > > get_dcache_line_size? Or would you prefer something more like a
> > > dma_buffer_malloc function that allocates on the heap a cache line
> > > size aligned buffer and returns it?
> >
> > memalign() is simply a malloc() with offset fudging, so
> > dma_buffer_malloc() is the way to go imo. anything that involves end
> > code having to figure out how to align things itself is asking for pain.
>
> I would like to avoid using any malloc code here. We have to keep in
> mind that such code changes will spread, and will be copied into
> driver code, file systems, etc. which might be used (and even
> required, for example for NAND or SDCard booting systems) before
> relocation - but malloc becomes available only after relocation.
>
> Why cannot we define a macro that declares a (sufficiently sized)
> buffer on the stack and provides and a pointer to a (correctly
> aligned) address in this buffer?

isnt that what i already posted and you NAK-ed ? :)

DMA_DECLARE_BUFFER(...)
-mike
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 836 bytes
Desc: This is a digitally signed message part.
Url : http://lists.denx.de/pipermail/u-boot/attachments/20110823/600a6891/attachment.pgp