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Date: Fri, 17 Oct 2025 08:20:08 +0200
From: Christoph Hellwig <hch@lst.de>
To: Leon Romanovsky <leon@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>, Keith Busch <kbusch@kernel.org>,
	Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-nvme@lists.infradead.org
Subject: Re: [PATCH 2/3] nvme-pci: unmap MMIO pages with appropriate
 interface
Message-ID: <20251017062008.GB402@lst.de>
References: <20251017-block-with-mmio-v1-0-3f486904db5e@nvidia.com> <20251017-block-with-mmio-v1-2-3f486904db5e@nvidia.com>
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On Fri, Oct 17, 2025 at 08:31:59AM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
> 
> Block layer maps MMIO memory through dma_map_phys() interface
> with help of DMA_ATTR_MMIO attribute. There is a need to unmap
> that memory with the appropriate unmap function, something which
> wasn't possible before adding new REQ attribute to block layer in
> previous patch.

DMA_ATTR_MMIO only gets set in the following patch as far as I can
tell.

The more logical way would be to simply convert to dma_unmap_phys
here and then add the flag in one go as suggested last round.