Re: [PATCH 4/8] dma: mmp_pdma: Add SpacemiT PDMA support with 64-bit addressing

Guodong Xu
2025-06-19T02:38:04Z

On Tue, Jun 17, 2025 at 2:02 PM Vinod Koul <vkoul@kernel.org> wrote:
>
> On 11-06-25, 20:57, Guodong Xu wrote:
> > Extend the MMP PDMA driver to support SpacemiT PDMA controllers with
> > 64-bit physical addressing capabilities, as used in the K1 SoC. This
> > change introduces a flexible architecture that maintains compatibility
> > with existing 32-bit Marvell platforms while adding 64-bit support.
> >
> > Key changes:
> > - Add struct mmp_pdma_config to abstract platform-specific behaviors
> > - Implement 64-bit address support through:
> > * New high address registers (DDADRH, DSADRH, DTADRH)
> > * DCSR_LPAEEN bit for Long Physical Address Extension mode
> > * Helper functions for 32/64-bit address handling
> > - Add "spacemit,pdma-1.0" compatible string with associated config
> > - Extend descriptor structure to support 64-bit addresses
> > - Refactor address handling code to be platform-agnostic
> > - Add proper DMA mask configuration for both 32-bit and 64-bit modes
> >
> > The implementation uses a configuration-based approach to keeps all
> > platform-specific code isolated in config structures. It maintains clean
> > separation between 32-bit and 64-bit code paths, provides consistent
> > API for both addressing modes and preserves backward compatibility.
>
> I would ask for this to be split, first to to driver changes for adding
> new ops and then adding new soc support. This way the two changes are
> independent

Hi, Vinod

Thank you for the feedback. I agree with that.
I'll send v2 with this split approach.

-
Guodong

>
> --
> ~Vinod