[PATCH 05/10] PCI/P2PDMA: Export pci_p2pdma_map_type() function

[Jason Gunthorpe]

On Fri, Jul 25, 2025 at 10:30:46AM -0600, Logan Gunthorpe wrote:
> 
> 
> On 2025-07-24 02:13, Leon Romanovsky wrote:
> > On Thu, Jul 24, 2025 at 10:03:13AM +0200, Christoph Hellwig wrote:
> >> On Wed, Jul 23, 2025 at 04:00:06PM +0300, Leon Romanovsky wrote:
> >>> From: Leon Romanovsky <leonro at nvidia.com>
> >>>
> >>> Export the pci_p2pdma_map_type() function to allow external modules
> >>> and subsystems to determine the appropriate mapping type for P2PDMA
> >>> transfers between a provider and target device.
> >>
> >> External modules have no business doing this.
> > 
> > VFIO PCI code is built as module. There is no way to access PCI p2p code
> > without exporting functions in it.
> 
> The solution that would make more sense to me would be for either
> dma_iova_try_alloc() or another helper in dma-iommu.c to handle the
> P2PDMA case.

This has nothing to do with dma-iommu.c, the decisions here still need
to be made even if dma-iommu.c is not compiled in.

It could be exported from the main dma code, but I think it would just
be a 1 line wrapper around the existing function? I'd rather rename
the functions and leave them in the p2pdma.c files...

Jason