From: Joerg.Roedel@amd•com ('Joerg Roedel')
To: linux-arm-kernel@lists•infradead.org
Subject: Changing IOMMU-API for generic DMA-mapping supported by the hardware
Date: Thu, 24 Nov 2011 16:27:47 +0100 [thread overview]
Message-ID: <20111124152747.GG11876@amd.com> (raw)
In-Reply-To: <023b01ccaaa7$ef16c910$cd445b30$%szyprowski@samsung.com>
On Thu, Nov 24, 2011 at 01:52:33PM +0100, Marek Szyprowski wrote:
> In my DMA-mapping IOMMU integration I've used a dma_iommu_mapping structure,
> which contains a pointer to iommu domain, a bitmap and a lock. Maybe we
> should consider extending iommu domain with allocation bitmap (or other
> structure that hold information about used/unused iova ranges)? From the
> DMA-mapping (as a IOMMU client) perspective we only need 2 more callbacks
> in IOMMU API: alloc_iova_range() and free_iova_range().
>
> Each IOMMU implementation can provide these calls based on internal bitmap
> allocator which will also cover the issue with reserved ranges. What do you
> think about such solution?
Hmm, the main point of a generic DMA-mapping implementation is that a
common address-allocator will be used. Today every IOMMU driver that
implements the DMA-API has its own allocator, this is something to unify
between for all drivers.
The allocator information can be stored in the default iommu_domain. We
need a user-private pointer there, but that is easy to add.
Joerg
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next prev parent reply other threads:[~2011-11-24 15:27 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-17 11:27 [PATCH v4 0/7] iommu: split mapping to page sizes as supported by the hardware Ohad Ben-Cohen
2011-10-17 11:27 ` [PATCH v4 1/7] iommu/core: stop converting bytes to page order back and forth Ohad Ben-Cohen
2011-10-17 11:27 ` [PATCH v4 2/7] iommu/core: split mapping to page sizes as supported by the hardware Ohad Ben-Cohen
2011-11-10 6:17 ` Kai Huang
2011-11-10 7:31 ` Ohad Ben-Cohen
2011-11-10 12:16 ` cody
2011-11-10 13:08 ` Joerg Roedel
2011-11-10 14:35 ` cody
2011-11-10 14:51 ` Joerg Roedel
2011-11-10 15:28 ` David Woodhouse
2011-11-10 17:09 ` Joerg Roedel
2011-11-10 19:28 ` David Woodhouse
2011-11-11 12:58 ` Joerg Roedel
2011-11-11 13:27 ` David Woodhouse
2011-11-11 14:18 ` Joerg Roedel
[not found] ` <20111111131728.GG13213@amd.com>
2011-11-24 12:52 ` Changing IOMMU-API for generic DMA-mapping " Marek Szyprowski
2011-11-24 15:27 ` 'Joerg Roedel' [this message]
2011-11-10 21:12 ` [PATCH v4 2/7] iommu/core: split mapping to page sizes as " Stepan Moskovchenko
2011-11-11 13:24 ` Joerg Roedel
2011-11-12 2:04 ` Stepan Moskovchenko
2011-11-13 1:43 ` KyongHo Cho
2011-10-17 11:27 ` [PATCH v4 3/7] iommu/omap: announce supported page sizes Ohad Ben-Cohen
2011-10-17 11:27 ` [PATCH v4 4/7] iommu/msm: " Ohad Ben-Cohen
2011-10-17 11:27 ` [PATCH v4 5/7] iommu/amd: " Ohad Ben-Cohen
2011-10-17 11:27 ` [PATCH v4 6/7] iommu/intel: " Ohad Ben-Cohen
2011-10-17 11:27 ` [PATCH v4 7/7] iommu/core: remove the temporary pgsize settings Ohad Ben-Cohen
2011-11-08 12:57 ` [PATCH v4 0/7] iommu: split mapping to page sizes as supported by the hardware Ohad Ben-Cohen
2011-11-08 14:01 ` Joerg Roedel
2011-11-08 14:03 ` Ohad Ben-Cohen
2011-11-08 16:23 ` Joerg Roedel
2011-11-08 16:43 ` Ohad Ben-Cohen
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