From: Christoph Hellwig <hch@lst.de>
To: "T.J. Mercier" <tjmercier@google.com>
Cc: Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
isaacmanjarres@google.com,
Catalin Marinas <catalin.marinas@arm.com>,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dma-direct: Set SG_DMA_SWIOTLB flag for dma-direct
Date: Mon, 6 May 2024 07:29:55 +0200 [thread overview]
Message-ID: <20240506052955.GA4923@lst.de> (raw)
In-Reply-To: <20240503183713.1557480-1-tjmercier@google.com>
On Fri, May 03, 2024 at 06:37:12PM +0000, T.J. Mercier wrote:
> As of commit 861370f49ce4 ("iommu/dma: force bouncing if the size is
> not cacheline-aligned") sg_dma_mark_swiotlb is called when
> dma_map_sgtable takes the IOMMU path and uses SWIOTLB for some portion
> of a scatterlist. It is never set for the direct path, so drivers
> cannot always rely on sg_dma_is_swiotlb to return correctly after
> calling dma_map_sgtable. Fix this by calling sg_dma_mark_swiotlb in the
> direct path like it is in the IOMMU path.
I don't think this is the right thing to do. Despite it's name
sg_dma_mark_swiotlb really is dma-iommu specific, and doesn't make sense
in context of dma-direct. If anything we need to find a better name
for the flag.
next prev parent reply other threads:[~2024-05-06 5:30 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-03 18:37 [PATCH] dma-direct: Set SG_DMA_SWIOTLB flag for dma-direct T.J. Mercier
2024-05-04 8:53 ` Petr Tesařík
2024-05-09 13:28 ` Robin Murphy
2024-05-06 5:29 ` Christoph Hellwig [this message]
2024-05-06 16:00 ` T.J. Mercier
2024-05-06 16:02 ` Christoph Hellwig
2024-05-06 16:10 ` T.J. Mercier
2024-05-06 16:19 ` Christoph Hellwig
2024-05-06 16:39 ` T.J. Mercier
2024-05-07 5:43 ` Christoph Hellwig
2024-05-07 20:07 ` T.J. Mercier
2024-05-08 11:33 ` Christoph Hellwig
2024-05-09 12:54 ` Robin Murphy
2024-05-09 18:26 ` T.J. Mercier
2024-05-08 17:19 ` Catalin Marinas
2024-05-08 20:14 ` T.J. Mercier
2024-05-09 7:49 ` Catalin Marinas
2024-05-09 13:06 ` Christoph Hellwig
2024-05-09 18:32 ` T.J. Mercier
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