Re: [PATCH v4 2/6] misc: sram: add ability to mark sram sections as reserved

From: Heiko Stübner
Date: Thu Aug 01 2013 - 12:35:40 EST

Am Montag, 29. Juli 2013, 23:39:45 schrieb Matt Sealey:
> On Mon, Jul 29, 2013 at 9:02 AM, Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> > Hi Heiko,
> >
> > Am Montag, den 29.07.2013, 15:12 +0200 schrieb Heiko Stübner:
> >> Some SoCs need parts of their sram for special purposes. So while being
> >> part of the peripheral, it should not be part of the genpool
> >> controlling the sram.
> >>
> >> Therefore add an option mmio-sram-reserved to keep arbitrary portions of
> >> the sram from being part of the pool.
> >>
> >> Suggested-by: Rob Herring <robherring2@xxxxxxxxx>
> >> Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
> >> Tested-by: Ulrich Prinz <ulrich.prinz@xxxxxxxxxxxxxx>
> >> ---
> >> Philipp: I didn't carry the ack, because the loop changed significantly
> >> again. So if it looks ok, could you re-ack it please?
> >
> > I'd prefer the first loop to contain the magic and produce a list of
> > useable chunks, instead of a list of reserved blocks. The second loop
> > could then iterate over the array and just call gen_pool_add_virt
> > repeatedly.
> >
> > regards
> > Philipp
> Agreed, however specifying chunks of memory should probably match the
> format of the standard memory@ node "available" property - mostly
> because it would be the same syntax and definition as defining any
> other chunk of memory, as OpenFirmware and device trees have been
> doing since the dark ages. In this case, why not re-use the
> "available" property name instead of creating a new one? Standard OF
> memory parsing code is then free for you to use to pull the chunks
> out.

Sound interesting, but could you give me a pointer to some sort of docs about
this "available" property in memory nodes?

Documentation/devicetree/booting-without-of.txt seems to be the only file
describing the memory node at all but only required properties, and not any
"available" property.

I've found a document on describing the memory node, but also not
mentioning any "available" property.

And does not seem to handle the memory node at all.

Thanks for any hints
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