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Date: Fri, 18 Aug 2006 23:52:47 -0700 (PDT)
From: Parav Pandit <paravpandit@yahoo.com>
Subject: ioremap() twice on same memory mapped area?
To: Linuxppc-embedded@ozlabs.org
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Hi,
   
  I have memory mapped device and two device drivers wants to use the same area for different external device.
  To access the same space there is a global spin lock to avoid any race condition.
   
  Question is:
  Can both the driver call the ioremap() on the same space and get the different virtual address? or ioremap() should fail?
   
  Regards,
  Parav Pandit
   

 		
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<div>Hi,</div>  <div>&nbsp;</div>  <div>I have memory mapped device and two device drivers wants to use the same area for different external device.</div>  <div>To access the same space there is a global spin lock to avoid any race condition.</div>  <div>&nbsp;</div>  <div>Question is:</div>  <div>Can both the driver call the ioremap() on the same space and get the different virtual address? or ioremap() should fail?</div>  <div>&nbsp;</div>  <div>Regards,</div>  <div>Parav Pandit</div>  <div>&nbsp;</div><p>&#32;
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From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dan@embeddedalley.com>
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From: Dan Malek <dan@embeddedalley.com>
Subject: Re: ioremap() twice on same memory mapped area?
Date: Sat, 19 Aug 2006 10:13:18 -0400
To: Parav Pandit <paravpandit@yahoo.com>
Cc: Linuxppc-embedded@ozlabs.org
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On Aug 19, 2006, at 2:52 AM, Parav Pandit wrote:

> Question is:
> Can both the driver call the ioremap() on the same space and get  
> the different virtual address?

Yes, and depending upon the implementation and optimizations,
they may also get the same virtual address.  It will work as you
intend.


	-- Dan