Hi Geert-san,
> From: Geert Uytterhoeven, Sent: Wednesday, May 3, 2023 9:39 PM
>
> Hi Shimoda-san,
>
> CC linux-pci
>
> On Wed, Apr 26, 2023 at 10:28 AM Yoshihiro Shimoda
> <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > Add iommu-map and iommu-map-mask properties into PCIe host nodes.
> > Note that iommu-map-mask should be zero because the IPMMU assigns
> > one micro TLB ID only to the PCIe host.
> >
> > Also change dma-ranges arguments for IOMMU. Notes that the dma-ranges
> > can be used if IOMMU is disabled.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>
> Thanks for your patch!
>
> This is not really my area of expertise, but you can still find some
> questions and comments below...
>
> > ---
> > Changes from v1:
> >
<snip URL>
> > - Drop iommus property.
> > - Add iommu-map-mask property.
> > - Revise the commit description.
> >
> > arch/arm64/boot/dts/renesas/r8a77951.dtsi | 12 ++++++++----
> > arch/arm64/boot/dts/renesas/r8a77960.dtsi | 12 ++++++++----
> > arch/arm64/boot/dts/renesas/r8a77961.dtsi | 12 ++++++++----
> > arch/arm64/boot/dts/renesas/r8a77965.dtsi | 12 ++++++++----
> > arch/arm64/boot/dts/renesas/r8a77990.dtsi | 6 ++++--
> > 5 files changed, 36 insertions(+), 18 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/renesas/r8a77951.dtsi b/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> > index 10b91e9733bf..2adec8b6c93f 100644
> > --- a/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> > +++ b/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> > @@ -2778,8 +2778,8 @@ pciec0: pcie@fe000000 {
> > <0x02000000 0 0xfe200000 0 0xfe200000 0 0x00200000>,
> > <0x02000000 0 0x30000000 0 0x30000000 0 0x08000000>,
> > <0x42000000 0 0x38000000 0 0x38000000 0 0x08000000>;
> > - /* Map all possible DDR as inbound ranges */
> > - dma-ranges = <0x42000000 0 0x40000000 0 0x40000000 0 0x40000000>;
> > + /* Map all possible DDR/IOMMU as inbound ranges */
> > + dma-ranges = <0x42000000 0 0x00000000 0 0x00000000 1 0x00000000>;
>
> So this is limited to the first 4 GiB of DDR (DDR0), i.e. to 32-bit
> address space? Shouldn't this include DDR1/2/3?
This controller can access within 32-bit address space only. So, we cannot include
DDR1/2/3.
> > interrupts = <GIC_SPI 116 IRQ_TYPE_LEVEL_HIGH>,
> > <GIC_SPI 117 IRQ_TYPE_LEVEL_HIGH>,
> > <GIC_SPI 118 IRQ_TYPE_LEVEL_HIGH>;
> > @@ -2790,6 +2790,8 @@ pciec0: pcie@fe000000 {
> > clock-names = "pcie", "pcie_bus";
> > power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
> > resets = <&cpg 319>;
> > + iommu-map = <0 &ipmmu_hc 0 0x10000>;
>
> Reading
<snip URL>
> the above means you map 65536 RIDs n in the range 0..65535
> to <&ipmmu_hc n>, while only micro-TLBs 0 and 1 are assigned to PCIe?
Yes. pciec0's ID is 0, and pciec1's ID is 1.
> Hence I think this should be:
>
> iommu-map = <0 &ipmmu_hc 0 1>;
I got it.
> > + iommu-map-mask = <0>;
> > status = "disabled";
> > };
> >
> > @@ -2805,8 +2807,8 @@ pciec1: pcie@ee800000 {
> > <0x02000000 0 0xeea00000 0 0xeea00000 0 0x00200000>,
> > <0x02000000 0 0xc0000000 0 0xc0000000 0 0x08000000>,
> > <0x42000000 0 0xc8000000 0 0xc8000000 0 0x08000000>;
> > - /* Map all possible DDR as inbound ranges */
> > - dma-ranges = <0x42000000 0 0x40000000 0 0x40000000 0 0x40000000>;
> > + /* Map all possible DDR/IOMMU as inbound ranges */
> > + dma-ranges = <0x42000000 0 0x00000000 0 0x00000000 1 0x00000000>;
>
> Likewise.
>
> > interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
> > <GIC_SPI 149 IRQ_TYPE_LEVEL_HIGH>,
> > <GIC_SPI 150 IRQ_TYPE_LEVEL_HIGH>;
> > @@ -2817,6 +2819,8 @@ pciec1: pcie@ee800000 {
> > clock-names = "pcie", "pcie_bus";
> > power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
> > resets = <&cpg 318>;
> > + iommu-map = <0 &ipmmu_hc 1 0x10000>;
>
> Likewise, the above means you map 65536 RIDs n in the range 0..65535
> to <&ipmmu_hc (1 + n)>?
>
> Hence I think this should be:
>
> iommu-map = <0 &ipmmu_hc 1 1>;
I got it.
> > + iommu-map-mask = <0>;
> > status = "disabled";
> > };
>
> Same comment for all other changes.
I'll fix all files.
> In addition, we need similar changes to r8a774{a1,b1,c0,e1}.dtsi,
> and slightly different changes (using ipmmu_vi0 uTLB 5) to r8a77980.dtsi.
I got it. I also modify these files.
Best regards,
Yoshihiro Shimoda
> 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
