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From: dwalker@fifo99.com
To: Jochen Schaeuble <psionic@psionic.de>
Cc: linux-mtd@lists.infradead.org, Joern Engel <joern@wh.fh-wedel.de>
Subject: slram on mapped ram areas
Date: Thu, 9 Oct 2014 16:17:07 +0000	[thread overview]
Message-ID: <20141009161707.GA18921@fifo99.com> (raw)

Hi,

It seems that slram was made for access parts of memory not used by the system,
or not mapped (right terminology?). I wanted to use it on memory which is mapped
or memory that can be used by the system. The problem I have is that the system I
work on places a filesystem image in memory someplace, and send the physical address
and size of the area as boot parameters. The memory where the images ends up is not
special memory.

I made the following changes to your driver (somewhat condensed),

1) Added memblock_reserve() on the memory region
2) Added an insert_resource() call to the memory
3) Altered the driver to not use ioremap, instead use __va() conditionally.

This worked. I was able to access the memory via the typical mtd
userspace interface.

So is this something acceptable to add to the slram driver?

Should it go someplace else?

Does the functionality to do this exists someplace already ?

I just wanted to send out feelers before I send any patches..

Daniel

             reply	other threads:[~2014-10-09 16:17 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-09 16:17 dwalker [this message]
2014-10-21  0:05 ` slram on mapped ram areas Brian Norris
2014-10-22 15:32   ` dwalker

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