Re: Covert DMA address to Virtual address on Linux PPC

shreeram <rs.shreeram@xxxxxxxxxxxxx> · Thu, 18 Sep 2008 10:23:48 +0530

bhanu jampala wrote:

  Hi All,

How do I convert a DMA buffer address to its respective virtual address
in Linux PPC world?

I am not finding appropriate functions to do that?

How are people doing it on PPC platforms?

What I trying to do:

This is for MCC i.e. Buffer Desc and buffer are in main memory (DMA
memory)

I have submitted some DMA buffer from a chunk of memory to Device.

Now at the end of successful receive, where I know the DMA address by
reading from the buffer Descriptors.

Now from this DMA address, how do I find out the Virtual address so
that I can perform a read on that buffer?

If you know the physical address of the device buffer you could use
mmap() to get the virtual address.

  Regards,

Mukund Jampala

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Regards,
R.S.Shree Ram
GDA Technologies Ltd.