From: Arnd Bergmann <arnd@arndb•de>
To: linuxppc-embedded@ozlabs•org
Cc: Misbah khan <misbah_khan@engineer•com>
Subject: Re: how to allocate 9MB of memory in kernel ?
Date: Tue, 22 Jul 2008 17:12:51 +0200 [thread overview]
Message-ID: <200807221712.52030.arnd@arndb.de> (raw)
In-Reply-To: <18587466.post@talk.nabble.com>
On Tuesday 22 July 2008, Misbah khan wrote:
> First of all let me thank you for your valuable suggessions ...
>
> 1. I wanted to allocate 9MB in kernel and wanted that memory to be mapped to
> the physically continews SDRAM memory. but till now i could not found a way
> to do so ???
>
> 2. So i thought to use ioremap to map SDRAM and make it accessible to user
> using mmap technique but there is only one doubt and that is will it be
> secure and stable and whether it is a right way of doing ???
As I have told you a few times now, you *either* allocate the memory *or*
ioremap it, NOT BOTH!!!
If you SDRAM is you main memory, you need vmalloc and remap_vmalloc_range.
If the SDRAM is not your main memory but some I/O attached buffer, you need
ioremap/of_iomap and remap_pfn_range.
Arnd <><
next prev parent reply other threads:[~2008-07-22 15:18 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-17 7:26 how to allocate 9MB of memory in kernel ? Misbah khan
2008-07-17 7:51 ` Marco Stornelli
2008-07-17 8:34 ` Misbah khan
2008-07-17 9:04 ` Marco Stornelli
2008-07-17 7:56 ` Arnd Bergmann
2008-07-17 8:19 ` Misbah khan
2008-07-17 8:24 ` Arnd Bergmann
2008-07-18 4:44 ` Misbah khan
2008-07-18 6:50 ` Marco Stornelli
2008-07-18 8:48 ` Misbah khan
2008-07-18 14:57 ` Timur Tabi
2008-07-18 15:39 ` Arnd Bergmann
2008-07-22 5:23 ` Misbah khan
2008-07-22 6:43 ` Marco Stornelli
2008-07-22 9:31 ` Arnd Bergmann
2008-07-22 9:47 ` Marco Stornelli
2008-07-22 13:22 ` Misbah khan
2008-07-22 15:12 ` Arnd Bergmann [this message]
2008-07-23 7:30 ` Misbah khan
2008-07-23 12:47 ` Alessandro Rubini
2008-07-24 8:33 ` Misbah khan
2008-07-24 9:31 ` Arnd Bergmann
2008-07-25 8:43 ` Misbah khan
2008-07-25 8:50 ` Arnd Bergmann
2008-08-02 19:13 ` harihanv
2008-07-17 8:02 ` Sylvain Joyeau
2008-07-17 8:41 ` Misbah khan
[not found] <mailman.2280.1216290829.2883.linuxppc-embedded@ozlabs.org>
2008-07-17 20:15 ` Siva Prasad
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