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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Tue, 29 Jan 2019 16:28:57 -0500
Message-ID: <CADnq5_NOm8DkHWCw-s9B4+n=9qezS8kg9TXDK0fz9nP1vFB+mw@mail.gmail.com>
Subject: Re: [RFC PATCH 1/5] pci/p2p: add a function to test peer to peer capability
To:     Logan Gunthorpe <logang@deltatee.com>
Cc:     Jerome Glisse <jglisse@redhat.com>, linux-mm <linux-mm@kvack.org>,
        Joerg Roedel <jroedel@suse.de>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Felix Kuehling <Felix.Kuehling@amd.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>, Christoph Hellwig <hch@lst.de>,
        iommu@lists.linux-foundation.org,
        Jason Gunthorpe <jgg@mellanox.com>,
        Linux PCI <linux-pci@vger.kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Christian Koenig <christian.koenig@amd.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>
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On Tue, Jan 29, 2019 at 3:25 PM Logan Gunthorpe <logang@deltatee.com> wrote=
:
>
>
>
> On 2019-01-29 12:56 p.m., Alex Deucher wrote:
> > On Tue, Jan 29, 2019 at 12:47 PM <jglisse@redhat.com> wrote:
> >>
> >> From: J=C3=A9r=C3=B4me Glisse <jglisse@redhat.com>
> >>
> >> device_test_p2p() return true if two devices can peer to peer to
> >> each other. We add a generic function as different inter-connect
> >> can support peer to peer and we want to genericaly test this no
> >> matter what the inter-connect might be. However this version only
> >> support PCIE for now.
> >>
> >
> > What about something like these patches:
> > https://cgit.freedesktop.org/~deathsimple/linux/commit/?h=3Dp2p&id=3D4f=
ab9ff69cb968183f717551441b475fabce6c1c
> > https://cgit.freedesktop.org/~deathsimple/linux/commit/?h=3Dp2p&id=3Df9=
0b12d41c277335d08c9dab62433f27c0fadbe5
> > They are a bit more thorough.
>
> Those new functions seem to have a lot of overlap with the code that is
> already upstream in p2pdma.... Perhaps you should be improving the
> p2pdma functions if they aren't suitable for what you want already
> instead of creating new ones.

Could be.  Those patches are pretty old.  They probably need to be
rebased on the latest upstream p2p stuff.

Alex