[RFC][PATCH 1/2] mm: cma: Export cma symbols for cma heap as a module

[John Stultz]

On Mon, Oct 28, 2019 at 1:03 PM John Stultz <john.stultz at linaro.org> wrote:
>
> On Mon, Oct 28, 2019 at 12:12 PM <sspatil at google.com> wrote:
> > On Fri, Oct 25, 2019 at 11:48:33PM +0000, John Stultz wrote:
> > > --- a/kernel/dma/contiguous.c
> > > +++ b/kernel/dma/contiguous.c
> > > @@ -31,6 +31,7 @@
> > >  #endif
> > >
> > >  struct cma *dma_contiguous_default_area;
> > > +EXPORT_SYMBOL(dma_contiguous_default_area);
> >
> > I didn't need to do this for the (out-of-tree) ion cma heap [1].
> > Any reason why you had to?
>
> Its likely due to the changes I made in the separate
> non-default-CMA-region patch set. Earlier I had gotten away with just
> your change, but in testing before I sent this series, I hit the build
> error and quickly added the export before sending.

And just to clarify this point, I was mistaken and it wasn't the
non-default-CMA-region patch set, but the fact that I'm using
dev_get_cma_area(NULL) to get the default CMA area to register, rather
then trying to register every CMA area via cma_for_each_area() as is
done in ION.  I actually could probably drop the cma_for_each_area
export for the dmabuf heaps usage.

thanks
-john