Re: [PATCH 1/2] uio: introduce UIO_MEM_DMA_COHERENT type

[Chris Leech]

On Wed, Jan 31, 2024 at 1:29 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Jan 31, 2024 at 11:17:31AM -0800, Chris Leech wrote:
> > Add a UIO memtype specifically for sharing dma_alloc_coherent
> > memory with userspace, backed by dma_mmap_coherent.
> >
> > This is mainly for the bnx2/bnx2x/bnx2i "cnic" interface, although there
> > are a few other uio drivers which map dma_alloc_coherent memory and
> > could be converted to use dma_mmap_coherent as well.
>
> What other drivers could use this?  Patches doing the conversion would
> be welcome, otherwise, again, I am very loath to take this
> one-off-change for just a single driver that shouldn't be doing this in
> the first place :)

uio_pruss and uio_dmem_genirq both appear to mmap dma_alloc_coherent
memory as UIO_MEM_PHYS.  It might not be an issue on that platforms
where those are used, but I'd be happy to include untested patches to
convert them for better adherence to the DMA APIs.

(sorry for the double send on this Greg, missed the reply-all)

- Chris