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Date: Wed, 29 Oct 2008 11:34:08 +0100
From: "Matteo Facchinetti @ Sirius Electronic Systems S.R.L."
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Subject: [Xenomai-core] rtdm_mmap_to_user() remapping problem on powerpc
	arch.
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To: xenomai@xenomai.org

Hi all,

I'm using framework RTDM to develop my driver on embedded system mpc5200 
based.
(kernel 2.6.24.4 (powerpc arch) - xenomai 2.4.3).

I've need to use rtdm_mmap_to_user() to share a kmalloc() kernel memory 
in userspace.
For this, I'm using the example in  
http://www.captain.at/xenomai-real-time-driver-example.php.

Running a similar example I've discovered a problem in kmalloc remapping.
The only way that I've found, to make remapping correctly, is to 
allocate an entire kernel mem page with __get_freepage() instead of 
kmalloc().

I think that could be a bug in powerpc arch.
what do you think about?