Messages in this thread | | | Date | Mon, 14 Jun 2010 09:18:23 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH 2/4] x86: ioremap: fix physical address check |
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On Fri, 11 Jun 2010 10:43:27 -0700 "H. Peter Anvin" <hpa@zytor.com> wrote:
> On 06/11/2010 02:20 AM, Kenji Kaneshige wrote: > > If the physical address is too high to be handled by ioremap() in > > x86_32 PAE (e.g. more than 36-bit physical address), ioremap() must > > return error (NULL). However, current x86 ioremap try to map this too > > high physical address, and it causes unexpected behavior. > > What unexpected behavior? It is perfectly legitimately to map such a > high address in PAE mode. We have a 36-bit kernel-imposed limit on > *RAM* in 32-bit mode (because we can't manage more than that), but there > is no reason it should apply to I/O. >
I'm sorry for lack of study. How to access it via mapped area by ioremap() ?
Thanks, -Kame
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