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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Well!... you can manage any way you want.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>1) You can store the virtual address in
the DpRAM, and convert to physical (should I say DMA mapped address) and then
pass it on to the device under consideration here.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>2) Other way would be… store the
physical address in DpRAM. Use that address for the device, and convert to
virtual before you use it in the code.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>My preference is for first option.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>- Siva<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> suresh suresh
[mailto:sureshtang@gmail.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, July 16, 2007 10:59
PM<br>
<b><span style='font-weight:bold'>To:</span></b> Scott Wood<br>
<b><span style='font-weight:bold'>Cc:</span></b> Siva Prasad;
linuxppc-embedded@ozlabs.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: Linuxppc-embedded
Digest, Vol 35, Issue 33</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Thanks....<br>
<br>
MPC8280 has internal memory space which contains Dualport(Dp) RAM. In the DpRAM
we allocate some tables and these has to store pointer of the buffers which are
allocated in external memory. Core will use this pointer to access the buffers,
basically these buffers are used for DMA.<br>
<br>
Using IMMR register we can get physical address of the internal memory. Now can
I store the address return by the kmalloc() function? or I should convert it
into physical?<br>
<br>
Please help me how to resove this address translation.<br>
<br>
<br>
Regards,<br>
Suresh<o:p></o:p></span></font></p>
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<p class=MsoNormal><span class=gmailquote><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>On 7/16/07, <b><span style='font-weight:bold'>Scott
Wood</span></b> <<a href="mailto:scottwood@freescale.com">scottwood@freescale.com</a>>
wrote:</span></font></span><o:p></o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Siva Prasad wrote:<br>
> It returns kernel virtual address. If you use this buffer space for DMA,<br>
> please use appropriate flags. You may use __pa(address) or<br>
> virt_to_phys() to convert virtual to physical. <br>
<br>
No, you may not -- physical and DMA addresses are not always identical.<br>
Use the DMA mapping API.<br>
<br>
-Scott<o:p></o:p></span></font></p>
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12.0pt'><o:p> </o:p></span></font></p>
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