Re: [PATCH v3 6/7] riscv: dts: starfive: Add initial StarFive JH7110 device tree

Conor Dooley
2022-12-28T22:49:16Z

[-- Attachment #1.1: Type: text/plain, Size: 3208 bytes --]

Hey,

On Tue, Dec 20, 2022 at 09:12:46AM +0800, Hal Feng wrote:
> From: Emil Renner Berthing <kernel@esmil.dk>
>
> Add initial device tree for the JH7110 RISC-V SoC by StarFive
> Technology Ltd.
>
> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
> Co-developed-by: Jianlong Huang <jianlong.huang@starfivetech.com>
> Signed-off-by: Jianlong Huang <jianlong.huang@starfivetech.com>
> Co-developed-by: Hal Feng <hal.feng@starfivetech.com>
> Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
> ---
> arch/riscv/boot/dts/starfive/jh7110.dtsi | 411 +++++++++++++++++++++++
> 1 file changed, 411 insertions(+)
> create mode 100644 arch/riscv/boot/dts/starfive/jh7110.dtsi
>
> diff --git a/arch/riscv/boot/dts/starfive/jh7110.dtsi b/arch/riscv/boot/dts/starfive/jh7110.dtsi
> new file mode 100644
> index 000000000000..64d260ea1f29
> --- /dev/null
> +++ b/arch/riscv/boot/dts/starfive/jh7110.dtsi
> @@ -0,0 +1,411 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +/*
> + * Copyright (C) 2022 StarFive Technology Co., Ltd.
> + * Copyright (C) 2022 Emil Renner Berthing <kernel@esmil.dk>
> + */
> +
> +/dts-v1/;
> +#include <dt-bindings/clock/starfive,jh7110-crg.h>
> +#include <dt-bindings/reset/starfive,jh7110-crg.h>
> +
> +/ {
> + compatible = "starfive,jh7110";
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + cpus {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + S76_0: cpu@0 {
> + compatible = "sifive,u74-mc", "riscv";

The label here says S76 but the compatible says u74-mc.
Which is correct? Your docs say S7 and S76, so I would imagine that it
is actually an S76?

> + reg = <0>;
> + d-cache-block-size = <64>;
> + d-cache-sets = <64>;
> + d-cache-size = <8192>;
> + d-tlb-sets = <1>;
> + d-tlb-size = <40>;
> + device_type = "cpu";
> + i-cache-block-size = <64>;
> + i-cache-sets = <64>;
> + i-cache-size = <16384>;
> + i-tlb-sets = <1>;
> + i-tlb-size = <40>;
> + mmu-type = "riscv,sv39";
> + next-level-cache = <&ccache>;
> + riscv,isa = "rv64imac";

While I was poking around trying to see if there was some logic behind
that compatible, I noticed that SiFive's docs for the S76 say it is
RV64GBC *but* the docs for the u74-mc say "4xRV64GBC and 1xRV64IMAC".
I assume that rv64imac is the correct one here?

> + tlb-split;
> + status = "disabled";
> +
> + cpu0_intc: interrupt-controller {
> + compatible = "riscv,cpu-intc";
> + interrupt-controller;
> + #interrupt-cells = <1>;
> + };
> + };
> +
> + U74_1: cpu@1 {
> + compatible = "sifive,u74-mc", "riscv";
> + reg = <1>;
> + d-cache-block-size = <64>;
> + d-cache-sets = <64>;
> + d-cache-size = <32768>;
> + d-tlb-sets = <1>;
> + d-tlb-size = <40>;
> + device_type = "cpu";
> + i-cache-block-size = <64>;
> + i-cache-sets = <64>;
> + i-cache-size = <32768>;
> + i-tlb-sets = <1>;
> + i-tlb-size = <40>;
> + mmu-type = "riscv,sv39";
> + next-level-cache = <&ccache>;
> + riscv,isa = "rv64imafdc";

That also begs the question:
Do your u74s support RV64GBC, as the (current) SiFive documentation
suggests?

Thanks,
Conor.

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

[-- Attachment #2: Type: text/plain, Size: 161 bytes --]