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Date: Thu, 18 Jul 2024 05:49:10 +0200
From: Christoph Hellwig <hch@lst.de>
To: Leon Romanovsky <leon@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Leon Romanovsky <leonro@nvidia.com>,
	Easwar Hariharan <eahariha@linux.microsoft.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux.dev,
	Jason Gunthorpe <jgg@nvidia.com>
Subject: Re: [PATCH v2 1/2] dma: call unconditionally to unmap_page and
 unmap_sg callbacks
Message-ID: <20240718034910.GB31912@lst.de>
References: <cover.1721219730.git.leon@kernel.org> <f9f0e270c077c5a3225f114bf9f7df18a6f9693a.1721219730.git.leon@kernel.org>
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On Wed, Jul 17, 2024 at 03:37:10PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
> 
> Almost all users of ->map_page()/map_sg() callbacks implement
> ->unmap_page()/unmap_sg() callbacks too. One user which doesn't do it,
> is dummy DMA ops interface, and the use of this interface is to fail
> the operation and in such case, there won't be any call to
> ->unmap_page()/unmap_sg().
> 
> This patch removes the existence checks of ->unmap_page()/unmap_sg()
> and calls to it directly to create symmetrical interface to
> ->map_page()/map_sg().

I don't think you even need this any more, do you?