[PATCH] ARM: rpi: parse memory from vc fdt

[Sascha Hauer]

On Tue, Jan 10, 2023 at 08:56:13PM +0100, Ahmad Fatoum wrote:
> On 10.01.23 20:32, Marcin Niestroj wrote:
> > From: Marcin Niestroj <m.niestroj at emb.dev>
> > 
> > Currently for RaspberryPi platform there is only one memory bank
> > created, based on information fetched over mailbox. This is fine for
> > booting Barebox, but unfortunately all the other memory banks are not
> > propagated to Linux during boot, thus cannot be utilized. In fact, even
> > when using /vc.dtb as device-tree for Linux, all memory nodes in FDT are
> > deleted and new ones are created by Barebox by memory fixup mechanism,
> > using exising RAM information. As a result RaspberryPi 4 boots Linux
> > with 1GB RAM available, instead of 2GB (2 banks, each 1GB).
> > 
> > At the end of VideoCore FDT parsing, do the same as of_probe_memory() in
> > mem_initcall does, but for VideoCore provided devicetree/memory
> > information. During Linux boot this information is used for memory fixup
> > mechanism and in case of RaspberryPi 4 this results in 2 memory banks
> > being propagated:
> > 
> >   # ls /proc/device-tree/memory*
> >   /proc/device-tree/memory at 0:
> >   device_type  name         reg
> > 
> >   /proc/device-tree/memory at 40000000:
> >   device_type  name         reg
> > 
> > Signed-off-by: Marcin Niestroj <m.niestroj at emb.dev>
> 
> Thanks for your patch. I suggest this be applied to master.
> 
> I think it may be worthwhile in future to only query the mailbox
> interface for memory in PBL (lowlevel.c) for use as early mem and
> depend solely on DT in barebox proper.
> 
> > ---
> >  arch/arm/boards/raspberry-pi/rpi-common.c | 16 +++++++++++++++-
> >  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> > +		err = of_add_memory(memory, false);
> > +		if (err)
> > +			ret = err;
> 
> No one does anything wither either err or ret, so you can drop that.

Did that and applied to master.

Sascha

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