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Date:   Thu, 20 Jan 2022 16:28:58 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Keith Busch <kbusch@kernel.org>
Cc:     Christoph Hellwig <hch@lst.de>, Jason Gunthorpe <jgg@nvidia.com>,
        Matthew Wilcox <willy@infradead.org>,
        linux-kernel@vger.kernel.org,
        Joao Martins <joao.m.martins@oracle.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Ming Lei <ming.lei@redhat.com>, linux-block@vger.kernel.org,
        netdev@vger.kernel.org, linux-mm@kvack.org,
        linux-rdma@vger.kernel.org, dri-devel@lists.freedesktop.org,
        nvdimm@lists.linux.dev
Subject: Re: Phyr Starter
Message-ID: <20220120152858.GA13263@lst.de>
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On Thu, Jan 20, 2022 at 07:27:36AM -0800, Keith Busch wrote:
> It doesn't look like IOMMU page sizes are exported, or even necessarily
> consistently sized on at least one arch (power).

At the DMA API layer dma_get_merge_boundary is the API for it.