Re: [PATCH 3/9] ARM: dma-mapping: convert DMA direction into IOMMU protection attributes
From: Will Deacon <hidden>
Date: 2013-06-25 12:34:14
Also in:
linux-arm-kernel, linux-devicetree, linux-iommu
Possibly related (same subject, not in this thread)
- 2013-06-25 · Re: [PATCH 3/9] ARM: dma-mapping: convert DMA direction into IOMMU protection attributes · Hiroshi Doyu <hidden>
- 2013-06-25 · Re: [PATCH 3/9] ARM: dma-mapping: convert DMA direction into IOMMU protection attributes · Will Deacon <hidden>
- 2013-06-25 · Re: [PATCH 3/9] ARM: dma-mapping: convert DMA direction into IOMMU protection attributes · Hiroshi Doyu <hidden>
On Tue, Jun 25, 2013 at 12:52:26PM +0100, Hiroshi Doyu wrote:
Will Deacon [off-list ref] wrote @ Tue, 25 Jun 2013 13:37:14 +0200: ...quoted
quoted
Do we need similar changes for map_sg case as well? They still passes '0' as prot.Yes, we could use the same trick there (probably worth moving the logic into a helper function for translating dma_data_direction into IOMMU_* values). There are also iommu_map calls when allocating DMA buffers, but I think 0 is the right thing to pass there (i.e. no permission until pages have been explicitly mapped). Although, to be honest, I don't see why we need to map the buffer at all when we allocate it.Yes, I thought too. I have a patch for that as below. If you like, I'll rebase and send for merge with the one which changes dma-mapping.c.
Yes, please send the series and I'll take a look. Marek's already picked up my original patch, so it's better if you can base against a stable branch from him. Will