Hi Detlev,
On Mon, Nov 14, 2022 at 8:48 PM Detlev Casanova
<detlev.casanova@xxxxxxxxxxxxx> wrote:
> The 0x3000000 bytes memory region starting at 0x54000000 is
> reserved for the lossy_decompression hardware that will try to
> decompress any data written in the region.
>
> Mark the region as no-map to prevent linux from using it as RAM.
>
> Signed-off-by: Detlev Casanova <detlev.casanova@xxxxxxxxxxxxx>
Thanks for your patch!
> --- a/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> @@ -290,6 +290,18 @@ CPU_SLEEP_1: cpu-sleep-1 {
> };
> };
>
> + reserved-memory {
> + #address-cells = <2>;
> + #size-cells = <2>;
> + ranges;
> +
> + /* device specific region for Lossy Decompression */
> + lossy_decompress: memory-region@54000000 {
> + no-map;
> + reg = <0x00000000 0x54000000 0x0 0x03000000>;
> + };
> + };
This depends on the firmware/boot loader stack. If it configures a
Lossy Decompression region, it should make sure to pass this
info through the various boot loader components to Linux,
just like is already done with the memory regions, RPC-IF state,
and OpTee configuration.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
