From: Robert Hancock <hancockr@shaw.ca>
To: linux-kernel@vger.kernel.org
Cc: maciej.sosnowski@intel.com, dan.j.williams@intel.com
Subject: Re: DMA from memory to local bus
Date: Fri, 28 Nov 2008 21:24:40 -0600 [thread overview]
Message-ID: <4930B5F8.6020601@shaw.ca> (raw)
In-Reply-To: <62DDBB9E5E23CC4A929EE46F9427CEAF0162468D@BUDMLVEM04.e2k.ad.ge.com>
Hommel, Thomas (GE EntSol, Intelligent Platforms) wrote:
> Hi all,
> I'm currently developing a driver and want to make use of the DMA
> offload engine. Data has to be transferred from memory to a device on
> the local bus and vice versa.
> At a first look, the function dma_async_memcpy_buf_to_buf() seemed to be
> suitable, but it does not translate addresses correctly. Both addresses
> are treated as if they were in memory.
That would be the normal use of these things, I believe.. normally when
copying to/from a device the device does it itself with bus master DMA.
> In my configuration, the buffer is located in memory, but the device's
> I/O space is mapped into vmalloc space via ioremap(). How can I access
> the I/O space corectly from the DMA controller?
>
> Thanks for your help
> Thomas
prev parent reply other threads:[~2008-11-29 3:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-28 6:35 DMA from memory to local bus Hommel, Thomas (GE EntSol, Intelligent Platforms)
2008-11-29 3:24 ` Robert Hancock [this message]
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