[PATCH] mach-k3: common_fdt: create a reserved memory node

[Bryan Brattlof]

On February 27, 2025 thus sayeth Andrew Davis:
> On 2/27/25 11:14 AM, Bryan Brattlof wrote:
> > Some device trees may not have a reserved-memory node. Rather than
> > exiting early we should create a new reserved-memory node along with
> > the memory carveout for the firmware we (U-Boot) have placed.
> > 
> > Signed-off-by: Bryan Brattlof <bb at ti.com>
> > ---
> >   arch/arm/mach-k3/common_fdt.c | 7 +++----
> >   1 file changed, 3 insertions(+), 4 deletions(-)
> > 
> > diff --git a/arch/arm/mach-k3/common_fdt.c b/arch/arm/mach-k3/common_fdt.c
> > index 4a01671156687..361b0c0b31b09 100644
> > --- a/arch/arm/mach-k3/common_fdt.c
> > +++ b/arch/arm/mach-k3/common_fdt.c
> > @@ -122,10 +122,8 @@ int fdt_fixup_reserved(void *blob, const char *name,
> >   	/* Find reserved-memory */
> >   	nodeoffset = fdt_subnode_offset(blob, 0, "reserved-memory");
> > -	if (nodeoffset < 0) {
> > -		debug("Could not find reserved-memory node\n");
> > -		return 0;
> > -	}
> > +	if (nodeoffset < 0)
> 
> We could also reverse this check and put the node deleting logic
> below inside this block. Same effect but removes the need for
> a goto for flow control here (goto considered harmful etc..)
> 
> if (nodeoffset >= 0) {
>     /* Find existing matching subnode and remove it */
>     ...
> }
> 
> Might make the intention a bit much, so either way is fine with me,
> 

Ha it's funny you mentioned this. I had a previous version where I did 
just that but wasn't sure how people felt about adding another tab to 
such a large section. Then started looking at adding a fdt_* function
before landing on seeing what people thought about a goto label.

I guess I should take votes :)

~Bryan

> Acked-by: Andrew Davis <afd at ti.com>
> 
> > +		goto add_carveout;
> >   	/* Find existing matching subnode and remove it */
> >   	fdt_for_each_subnode(subnode, blob, nodeoffset) {
> > @@ -154,6 +152,7 @@ int fdt_fixup_reserved(void *blob, const char *name,
> >   		}
> >   	}
> > +add_carveout:
> >   	struct fdt_memory carveout = {
> >   		.start = new_address,
> >   		.end = new_address + new_size - 1,
> > 
> > ---
> > base-commit: b78f8677cde8b1dde31b66f5b780f2e9b62fba7f
> > change-id: 20250227-reserved-memory-85f5d409e6a7
> > 
> > Best regards,