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Date:   Tue, 4 May 2021 09:30:05 +0100
From:   Will Deacon <will@kernel.org>
To:     Vikram Sethi <vsethi@nvidia.com>
Cc:     Alex Williamson <alex.williamson@redhat.com>,
        Mark Kettenis <mark.kettenis@xs4all.nl>,
        Marc Zyngier <maz@kernel.org>,
        Shanker Donthineni <sdonthineni@nvidia.com>,
        "catalin.marinas@arm.com" <catalin.marinas@arm.com>,
        "christoffer.dall@arm.com" <christoffer.dall@arm.com>,
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        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        Jason Sequeira <jsequeira@nvidia.com>
Subject: Re: [RFC 1/2] vfio/pci: keep the prefetchable attribute of a BAR
 region in VMA
Message-ID: <20210504083005.GA12290@willie-the-truck>
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On Mon, May 03, 2021 at 10:03:59PM +0000, Vikram Sethi wrote:
> Will/Catalin, perhaps you could explain your thought process on why you chose
> Normal NC for ioremap_wc on the armv8 linux port instead of Device GRE or other
> Device Gxx. 

I think a combination of: compatibility with 32-bit Arm, the need to
support unaligned accesses and the potential for higher performance.

Furthermore, ioremap() already gives you a Device memory type, and we're
tight on MAIR space.

Will