Messages in this thread | | | From | "Imran Badr" <> | Subject | RE: Calculating kernel logical address .. | Date | Mon, 9 Sep 2002 10:06:46 -0700 |
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So, what you gurus suggest me to do? How can I get physical address of a user buffer (which was originally mmap'ed() from a kmalloc() allocation) and which would also be protable across multiple platforms?
Thanks. Imran.
-----Original Message----- From: David S. Miller [mailto:davem@redhat.com] Sent: Sunday, September 08, 2002 10:28 PM To: phillips@arcor.de Cc: imran.badr@cavium.com; linux-kernel@vger.kernel.org Subject: Re: Calculating kernel logical address ..
From: Daniel Phillips <phillips@arcor.de> Date: Mon, 9 Sep 2002 07:17:30 +0200
On Monday 09 September 2002 07:00, David S. Miller wrote: > Actually, KSEG0 the most Linux friendly design in the world > particularly in 64-bit mode.
That's easy to say until you try and work with it (I assume you have, and forgot). Just try to do a 3G/1G split on it, for example.
Maybe you missed the "64-bit mode" part of what I said. :-)
In 64-bit mode there is no need to do any kind of split. You just use the KSEG mapping with full cache coherency for all of physical memory as the PAGE_OFFSET area.
I forget if it was KSEG0 or some other number, but I know it works.
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