Hi Shimoda-san,
On Mon, Jan 23, 2023 at 2:35 AM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> Since R-Car Gen4 doens't have the main IPMMU IMSSTR register, but
> each cache IPMMU has own module id. So, update descriptions of
> renesas,ipmmu-main property for R-Car Gen4.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Thanks for your patch!
> ---
> The old R-Car S4-8 datasheet had described IPMMU IMSSTR register, but
> the latest datasheet undocumented the register. So, update the propeties
> description. Note that the second argument is not used on the driver.
DT describes hardware, not software policy.
> So no behavior change.
So where do we get the module id numbers to use, if they are no longer
documented in the Hardware Manual?
> --- a/Documentation/devicetree/bindings/iommu/renesas,ipmmu-vmsa.yaml
> +++ b/Documentation/devicetree/bindings/iommu/renesas,ipmmu-vmsa.yaml
> @@ -76,14 +76,15 @@ properties:
> items:
> - items:
> - description: phandle to main IPMMU
> - - description: the interrupt bit number associated with the particular
> - cache IPMMU device. The interrupt bit number needs to match the main
> - IPMMU IMSSTR register. Only used by cache IPMMU instances.
> + - description: The interrupt bit number or module id associated with
> + the particular cache IPMMU device. The interrupt bit number needs
> + to match the main IPMMU IMSSTR register. Only used by cache IPMMU
> + instances.
> description:
> Reference to the main IPMMU phandle plus 1 cell. The cell is
> - the interrupt bit number associated with the particular cache IPMMU
> - device. The interrupt bit number needs to match the main IPMMU IMSSTR
> - register. Only used by cache IPMMU instances.
> + the interrupt bit number or module id associated with the particular
> + cache IPMMU device. The interrupt bit number needs to match the main
> + IPMMU IMSSTR register. Only used by cache IPMMU instances.
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
