[SLOF] [PATCH 2/2] fdt: Fix update of "interrupt-controller" node at CAS

[Alexey Kardashevskiy]

On 30/01/2020 05:21, Greg Kurz wrote:
> Now that QEMU passes a full FDT at CAS without rebooting, a guest that
> has switched from XICS to XIVE ends up being presented an malformed
> "interrupt-controller" node in the DT:
> 
> # dtc -I fs -O dts /proc/device-tree
> <stdout>: Warning (unit_address_vs_reg): /interrupt-controller: node has a reg or ranges property, but no unit name
> ...
>         interrupt-controller {
>                 ibm,xive-eq-sizes = <0x10>;
>                 device_type = "power-ivpe";
>                 ibm,interrupt-server-ranges = <0x00 0x03>;
>                 compatible = "ibm,power-ivpe";
>                 #interrupt-cells = <0x02>;
>                 reg = <0x60302 0x31b0000 0x00 0x10000 0x60302 0x31a0000 0x00 0x10000>;
>                 phandle = <0xe7448a8>;
>                 ibm,xive-lisn-ranges = <0x00 0x03>;
>                 interrupt-controller;
>         };
> 
> The node should have its unit set to "60302031b0000" as reported by dtc.
> Also the node still has an "ibm,interrupt-server-ranges" property which
> only makes sense with XICS.
> 
> This happens because we find an existing "interrupt-controller" node,
> which describes a XICS controller, and we _wrongly_ decide to copy
> all the properties from the new node into it. Delete the existing node
> instead so that we create a new node with the appropriate properties
> and unit name.
> 
> Signed-off-by: Greg Kurz <groug at kaod.org>
> ---
>  board-qemu/slof/fdt.fs |   13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs
> index 2ceb366d4f68..1e2378124b09 100644
> --- a/board-qemu/slof/fdt.fs
> +++ b/board-qemu/slof/fdt.fs
> @@ -465,6 +465,19 @@ r> drop
>      ELSE
>  	drop
>      THEN
> +
> +    fdt-cas-pass 0= IF
> +	\ The guest might have asked to change the interrupt controller type. It doesn't
> +	\ make sense to merge the new node and the existing "interrupt-controller" node
> +	\ in this case. Delete the latter. A brand new one will be created with the
> +	\ appropriate properties and unit name.
> +	2dup " interrupt-controller" find-substr 0= IF
> +	    " interrupt-controller" find-node ?dup 0 <> IF
> +		fdt-debug IF ." Deleting existing node: " dup .node cr THEN
> +		delete-node
> +	    THEN
> +	THEN
> +    THEN

This does not look extremely nice but I really do not see a better way
now. Deleting all properties instead of deleting the node may have
problems with unit/space; deleting all nodes with QEMU-defined phandles
may also have undesired effects...

Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>



>      2dup find-node ?dup 0 <> IF
>  	set-node
>  	fdt-debug IF ." Setting node: " 2dup type cr THEN
> 





-- 
Alexey