Re: [PATCH] PCI/P2PDMA: Match interface changes to devm_memremap_pages()

From: Bjorn Helgaas
Date: Tue Dec 11 2018 - 08:56:31 EST

On Thu, Dec 06, 2018 at 03:17:00PM -0700, Logan Gunthorpe wrote:
> On 2018-12-06 1:46 p.m., Bjorn Helgaas wrote:
> > On Fri, Nov 30, 2018 at 03:59:11PM -0700, Logan Gunthorpe wrote:
> >> "mm-hmm-mark-hmm_devmem_add-add_resource-export_symbol_gpl.patch" in the
> >> mm tree breaks p2pdma. The patch was written and reviewed before p2pdma
> >> was merged so the necessary changes were not done to the call site in
> >> that code.
> >>
> >> Without this patch, all drivers will fail to register P2P resources
> >> because devm_memremap_pages() will return -EINVAL due to the 'kill'
> >> member of the pagemap structure not yet being set.
> >>
> >> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> >> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> >> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> >
> > Applied with Dan's reviewed-by to pci/peer-to-peer for v4.21, thanks!
> >
> > If the mm patch you mention gets merged for v4.20, let me know and I can
> > promote this to for-linus so v4.20 doesn't end up broken.
> Thanks Bjorn, but I think Andrew has also picked it up in the mm tree
> with the patch in question. My hope is that he squashes the two but I'm
> not sure what his intentions are. I mostly copied you for information
> purposes as this patch shouldn't even compile without Dan's patch.
> Though, I guess we'll find out what goes in after the merge window --
> you may not need to do anything.

OK, I dropped this because I don't have the matching mm patch. I agree,
it should be squashed so we avoid a bisection hole. Let me know if I
need to do anything else with this.