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

From: John Stultz
Date: Mon Oct 28 2019 - 18:24:10 EST

On Mon, Oct 28, 2019 at 11:39 AM John Stultz <john.stultz@xxxxxxxxxx> wrote:
> On Mon, Oct 28, 2019 at 12:46 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> >
> > On Fri, Oct 25, 2019 at 11:48:33PM +0000, John Stultz wrote:
> > > struct cma *dma_contiguous_default_area;
> > > +EXPORT_SYMBOL(dma_contiguous_default_area);
> >
> > Please CC the dma maintainer. And no, you have no business using this.
> Sure thing. And I'll look again to see why I was needing to pull that
> one in to get it to build.

Ah. So looking a bit closer, I'm needing this due to my using
dev_get_cma_area() to get the default cma area for the dmabuf

Do you have a suggestion for how to get a reference to the default CMA
area without exporting dma_contiguous_default_area? Would it be
preferred to move dev_get_cma_area() into the .c file and
EXPORT_SYMBOL_GPL that function?