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

[Mike Frysinger <vapier@gentoo.org>]

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
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