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Date: Fri, 12 Jul 2024 06:49:37 +0200
From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Leon Romanovsky <leon@kernel.org>, Christoph Hellwig <hch@lst.de>,
	Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Jason Gunthorpe <jgg@nvidia.com>,
	Leon Romanovsky <leonro@nvidia.com>, linux-kernel@vger.kernel.org,
	iommu@lists.linux.dev
Subject: Re: [PATCH 2/2] dma: Add IOMMU static calls with clear default ops
Message-ID: <20240712044937.GA4709@lst.de>
References: <98d1821780028434ff55b5d2f1feea287409fbc4.1720693745.git.leon@kernel.org> <f2b699aea8fff5589a674da2a567fd593ed2d386.1720693745.git.leon@kernel.org> <28309b7f-9809-452f-95fe-3448c15bdf1b@arm.com>
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On Thu, Jul 11, 2024 at 07:23:20PM +0100, Robin Murphy wrote:
> If so, I'd much rather see this done properly, i.e. hook everything up 
> similarly to dma-direct and be able to drop CONFIG_DMA_OPS for "modern" 
> dma-direct/iommu-dma architectures entirely.

Yes.  That is much better than doing hacks based on missing ops.

Note that the media subsystems just added another abuse of dma_map_ops
in drivers/ in addition to the existing vdpa one that we'll need to
kill again to fully get rid of dma_map_ops for common setups (in
addition to merging swiotlb-xen into main swiotlb finally).