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From:   Roman Shaposhnik <roman@zededa.com>
Date:   Wed, 20 May 2020 16:51:23 -0700
Message-ID: <CAMmSBy9VBxjSCRcfyiZ-RY8eyYOooeNfCqrvirhWzfpSbAQyuw@mail.gmail.com>
Subject: Re: [PATCH 00/10] fix swiotlb-xen for RPi4
To:     Stefano Stabellini <sstabellini@kernel.org>
Cc:     Juergen Gross <jgross@suse.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Konrad Wilk <konrad.wilk@oracle.com>,
        Xen-devel <xen-devel@lists.xenproject.org>,
        linux-kernel@vger.kernel.org, tamas@tklengyel.com
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On Wed, May 20, 2020 at 4:45 PM Stefano Stabellini
<sstabellini@kernel.org> wrote:
>
> Hi all,
>
> This series is a collection of fixes to get Linux running on the RPi4 as
> dom0.
>
> Conceptually there are only two significant changes:
>
> - make sure not to call virt_to_page on vmalloc virt addresses (patch
>   #1)
> - use phys_to_dma and dma_to_phys to translate phys to/from dma
>   addresses (all other patches)
>
> In particular in regards to the second part, the RPi4 is the first
> board where Xen can run that has the property that dma addresses are
> different from physical addresses, and swiotlb-xen was written with the
> assumption that phys addr == dma addr.
>
> This series adds the phys_to_dma and dma_to_phys calls to make it work.

Great to see this! Stefano, any chance you can put it in a branch some place
so I can test the final version?

Thanks,
Roman.