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>,
linux-kernel@vger.kernel.org, iommu@lists.linux.dev
Subject: Re: [PATCH 2/2] dma: Add IOMMU static calls with clear default ops
Date: Sat, 13 Jul 2024 07:18:13 +0200 [thread overview]
Message-ID: <20240713051813.GA25733@lst.de> (raw)
In-Reply-To: <7ba30992-78aa-49e5-98bb-75c6b7ae8ce9@arm.com>
On Fri, Jul 12, 2024 at 03:21:55PM +0100, Robin Murphy wrote:
>> This is done to keep layering similar to existing in DMA subsystem. We
>> have special files and calls to dma-direct, it looks natural to have
>> special files and call to dma-iommu. It is not nice to call to drivers/iommu
>> from kernel/dma/mapping.c
>
> That's where I firmly disagree. In the DMA API aspect, iommu-dma is exactly
> a peer of dma-direct,
Exactly.
> however it lives in drivers/iommu for practical
> reasons because it's more closely coupled to IOMMU API internals in all
> other aspects of its implementation.
TBH I think kernel/dma/ would be the better place. But that's really the
least my concernes at the moment.
But the important point is that I would really prefer to avoid another
magic layer - just do direct calls like for dma-direct to keep it
understandable (and probably faster).
next prev parent reply other threads:[~2024-07-13 5:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-11 10:38 [PATCH 1/2] dma: call unconditionally to unmap_page and unmap_sg callbacks Leon Romanovsky
2024-07-11 10:38 ` [PATCH 2/2] dma: Add IOMMU static calls with clear default ops Leon Romanovsky
2024-07-11 17:27 ` Leon Romanovsky
2024-07-11 18:17 ` Easwar Hariharan
2024-07-11 18:45 ` Leon Romanovsky
2024-07-11 18:23 ` Robin Murphy
2024-07-11 18:57 ` Leon Romanovsky
2024-07-11 20:08 ` Robin Murphy
2024-07-12 5:50 ` Leon Romanovsky
2024-07-12 14:21 ` Robin Murphy
2024-07-13 5:18 ` Christoph Hellwig [this message]
2024-07-13 9:32 ` Leon Romanovsky
2024-07-12 4:49 ` Christoph Hellwig
2024-07-12 6:02 ` Leon Romanovsky
2024-07-12 20:51 ` Easwar Hariharan
2024-07-13 9:30 ` Leon Romanovsky
2024-07-11 18:02 ` [PATCH 1/2] dma: call unconditionally to unmap_page and unmap_sg callbacks Robin Murphy
2024-07-12 5:47 ` Leon Romanovsky
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