From: Joerg Roedel <joro@8bytes.org>
To: Zach Pfeffer <zpfeffer@codeaurora.org>
Cc: Hari Kanigeri <hari.kanigeri@gmail.com>,
Daniel Walker <dwalker@codeaurora.org>,
Andi Kleen <andi@firstfloor.org>,
Randy Dunlap <randy.dunlap@oracle.com>,
mel@csn.ul.ie, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-arm-msm@vger.kernel.org, linux-omap@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC 3/3] mm: iommu: The Virtual Contiguous Memory Manager
Date: Sat, 10 Jul 2010 16:36:35 +0200 [thread overview]
Message-ID: <20100710143635.GA10080@8bytes.org> (raw)
In-Reply-To: <4C2D908E.9030309@codeaurora.org>
On Fri, Jul 02, 2010 at 12:09:02AM -0700, Zach Pfeffer wrote:
> Hari Kanigeri wrote:
> >> He demonstrated the usage of his code in one of the emails he sent out
> >> initially. Did you go over that, and what (or how many) step would you
> >> use with the current code to do the same thing?
> >
> > -- So is this patch set adding layers and abstractions to help the User ?
> >
> > If the idea is to share some memory across multiple devices, I guess
> > you can achieve the same by calling the map function provided by iommu
> > module and sharing the mapped address to the 10's or 100's of devices
> > to access the buffers. You would only need a dedicated virtual pool
> > per IOMMU device to manage its virtual memory allocations.
>
> Yeah, you can do that. My idea is to get away from explicit addressing
> and encapsulate the "device address to physical address" link into a
> mapping.
The DMA-API already does this with the help of IOMMUs if they are
present. What is the benefit of your approach over that?
Joerg
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next prev parent reply other threads:[~2010-07-10 14:36 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-30 5:55 [RFC 1/3] mm: iommu: An API to unify IOMMU, CPU and device memory management Zach Pfeffer
2010-06-30 5:55 ` [RFC 2/3] mm: iommu: A physical allocator for the VCMM Zach Pfeffer
2010-06-30 5:55 ` [RFC 3/3] mm: iommu: The Virtual Contiguous Memory Manager Zach Pfeffer
2010-07-01 17:17 ` Randy Dunlap
2010-07-01 18:02 ` Andi Kleen
2010-07-01 19:28 ` Daniel Walker
2010-07-01 19:38 ` Andi Kleen
2010-07-01 19:42 ` Daniel Walker
2010-07-01 22:15 ` Hari Kanigeri
2010-07-02 7:09 ` Zach Pfeffer
2010-07-10 14:36 ` Joerg Roedel [this message]
2010-07-13 5:21 ` Zach Pfeffer
2010-07-14 19:34 ` Joerg Roedel
2010-07-15 1:18 ` Zach Pfeffer
2010-07-01 22:00 ` Zach Pfeffer
2010-07-01 22:05 ` Daniel Walker
2010-07-02 7:33 ` Zach Pfeffer
2010-07-10 14:56 ` Joerg Roedel
2010-07-13 5:46 ` Zach Pfeffer
2010-07-13 5:59 ` FUJITA Tomonori
2010-07-13 8:20 ` Alan Cox
2010-07-13 8:30 ` FUJITA Tomonori
2010-07-13 8:42 ` Alan Cox
2010-07-13 8:45 ` FUJITA Tomonori
2010-07-13 9:02 ` Russell King - ARM Linux
2010-07-14 1:59 ` FUJITA Tomonori
2010-07-22 3:50 ` Zach Pfeffer
2010-07-22 4:47 ` FUJITA Tomonori
2010-07-22 16:33 ` Zach Pfeffer
2010-07-22 7:51 ` Russell King - ARM Linux
2010-07-22 16:13 ` Zach Pfeffer
2010-07-13 12:06 ` Zach Pfeffer
2010-07-01 22:51 ` Hari Kanigeri
2010-07-02 7:29 ` Zach Pfeffer
2010-07-01 23:00 ` Andi Kleen
2010-07-02 6:17 ` Zach Pfeffer
2010-07-02 8:22 ` Andi Kleen
2010-07-02 18:42 ` Zach Pfeffer
2010-07-10 15:11 ` Joerg Roedel
2010-07-13 5:52 ` Zach Pfeffer
2010-07-03 6:36 ` Zach Pfeffer
2010-07-10 14:54 ` Joerg Roedel
2010-07-13 5:27 ` Zach Pfeffer
2010-07-01 20:59 ` Paul Walmsley
2010-07-01 21:48 ` Randy Dunlap
2010-06-30 23:40 ` [RFC 1/3] mm: iommu: An API to unify IOMMU, CPU and device memory management Randy Dunlap
2010-07-01 7:16 ` Zach Pfeffer
2010-07-02 7:00 ` Paul Mundt
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