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Date:   Wed, 19 Feb 2020 10:46:04 +0100
From:   Joerg Roedel <joro@8bytes.org>
To:     "Isaac J. Manjarres" <isaacm@codeaurora.org>
Cc:     iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        Liam Mark <lmark@codeaurora.org>, pratikp@codeaurora.org,
        kernel-team@android.com
Subject: Re: [RFC PATCH] iommu/dma: Allow drivers to reserve an iova range
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On Fri, Feb 14, 2020 at 02:58:16PM -0800, Isaac J. Manjarres wrote:
> From: Liam Mark <lmark@codeaurora.org>
> 
> Some devices have a memory map which contains gaps or holes.
> In order for the device to have as much IOVA space as possible,
> allow its driver to inform the DMA-IOMMU layer that it should
> not allocate addresses from these holes.
> 
> Change-Id: I15bd1d313d889c2572d0eb2adecf6bebde3267f7
> Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>

Ideally this is something put into the IOMMU firmware table by the
platform firmware. If its not there, a quirk is the best way to handle
this.

Regards,

	Joerg