Re: [PATCH v3 6/7] riscv: dts: add initial canmv-k230 and k230-evb dts

Palmer Dabbelt
2024-03-05T15:54:20Z

On Mon, 04 Mar 2024 13:06:00 PST (-0800), cyy@cyyself.name wrote:
> Add initial dts for CanMV-K230 and K230-EVB powered by Canaan Kendryte
> K230 SoC [1].
>
> Some key consideration:
> - Only place BigCore which is 1.6GHz RV64GCBV
>
> The existence of cache coherence between the two cores remains unknown
> since they have dedicated L2 caches. And the factory SDK uses it for
> other OS by default. I don't know whether the two CPUs on K230 SoC
> can be used in one system. So only place BigCore here.
>
> Meanwhile, although docs from Canaan said 1.6GHz Core with Vector is
> CPU1, the csr.mhartid of this core is 0.
>
> - Support for "zba" "zbb" "zbc" "zbs" are tested by hand
>
> The user manual of C908 from T-Head does not document it specifically.
> It just said it supports B extension V1.0-rc1. [2]

I'm seeing

3.1.6 Vector instruction set (RVV)
For more information, see RISC-V “V”Vector Extension, Version
1.0-rc1-20210608
URL：https://github.com/riscv/riscv-v-spec/releases/download/v1.0-rc1/riscv-v-spec-1.0-rc1.pdf

3.1.7 Bit operation instruction set (RV64B)
For more information, see ：RISC-V Bit-Manipulation ISA-extensions,
Version 1.0.0, 2021-06-12: public review
URL：https://github.com/riscv/riscv-bitmanip/releases/download/1.0.0/bitmanip-1.0.0.pdf

so I think maybe that's vector 1.0-rc1 and the final bitmanip?

> I have tested it by using this [3] which attempts to execute "add.uw",
> "andn", "clmulr", "bclr" and they doesn't traps on K230. But on JH7110,
> "clmulr" and "bclr" will trap.
>
> - Support for "zicbom" is tested by hand
>
> Have tested with some out-of-tree drivers from [4] that need DMA and they
> do not come to the dts currently.
>
> - Cache parameters are inferred from T-Head docs [2] and Canaan docs [1]
>
> L1i: 32KB, VIPT 4-Way set-associative, 64B Cacheline
> L1d: 32KB, VIPT 4-Way set-associative, 64B Cacheline
> L2: 256KB, PIPT 16-way set-associative, 64B Cacheline
>
> The numbers of cache sets are calculated from these parameters.
>
> - MMU only supports Sv39
>
> Since T-Head docs [2] say C908 should support Sv48. However, it will fail
> during the kernel probe when running Linux on K230. I also tested it by
> hand on M-Mode software, writing Sv48 to satp.mode will not trap but will
> leave the csr unchanged. While writing Sv39 it will take effect. It shows
> that this CPU does not support Sv48.

I think that only works due to a bug in our sv48 probing routines --
unless I'm missing something, we mixed up the sv57 and sv48 probing and
if sv57 fails to probe then we disable sv48 as well. So I think we
probably need some cleanup in there.

> - Svpbmt and T-Head MAEE both supported
>
> T-Head C908 does support both Svpbmt and T-Head MAEE for page-based memory
> attributes and is controlled by csr.mxstatus. If the kernel wants to use
> svpbmt, the m-mode software should set BIT(21) of csr.mxstatus to zero
> before entering the s-mode kernel. Otherwise, the kernel will not boot as 0
> on T-Head MAEE represent to NonCachable Memory and it will lose dirty cache
> lines modification that haven't been written back to the memory.

So I guess we need the bootloader to just be accurate here? ie:
whatever extension it tells S-mode kernels is enabled is how S-mode
behaves, and then this should just work itself out.

> [1] https://developer.canaan-creative.com/k230/dev/zh/00_hardware/K230_datasheet.html#chapter-1-introduction
> [2] https://occ-intl-prod.oss-ap-southeast-1.aliyuncs.com/resource//1699268369347/XuanTie-C908-UserManual.pdf
> [3] https://github.com/cyyself/rvb_test
> [4] https://github.com/cyyself/linux/tree/k230-mainline
>
> Signed-off-by: Yangyu Chen <cyy@cyyself.name>
> ---
> arch/riscv/boot/dts/canaan/Makefile | 2 +
> arch/riscv/boot/dts/canaan/k230-canmv.dts | 24 ++++
> arch/riscv/boot/dts/canaan/k230-evb.dts | 24 ++++
> arch/riscv/boot/dts/canaan/k230.dtsi | 140 ++++++++++++++++++++++
> 4 files changed, 190 insertions(+)
> create mode 100644 arch/riscv/boot/dts/canaan/k230-canmv.dts
> create mode 100644 arch/riscv/boot/dts/canaan/k230-evb.dts
> create mode 100644 arch/riscv/boot/dts/canaan/k230.dtsi
>
> diff --git a/arch/riscv/boot/dts/canaan/Makefile b/arch/riscv/boot/dts/canaan/Makefile
> index 987d1f0c41f0..7d54ea5c6f3d 100644
> --- a/arch/riscv/boot/dts/canaan/Makefile
> +++ b/arch/riscv/boot/dts/canaan/Makefile
> @@ -1,6 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
> dtb-$(CONFIG_ARCH_CANAAN) += canaan_kd233.dtb
> dtb-$(CONFIG_ARCH_CANAAN) += k210_generic.dtb
> +dtb-$(CONFIG_ARCH_CANAAN) += k230-canmv.dtb
> +dtb-$(CONFIG_ARCH_CANAAN) += k230-evb.dtb
> dtb-$(CONFIG_ARCH_CANAAN) += sipeed_maix_bit.dtb
> dtb-$(CONFIG_ARCH_CANAAN) += sipeed_maix_dock.dtb
> dtb-$(CONFIG_ARCH_CANAAN) += sipeed_maix_go.dtb
> diff --git a/arch/riscv/boot/dts/canaan/k230-canmv.dts b/arch/riscv/boot/dts/canaan/k230-canmv.dts
> new file mode 100644
> index 000000000000..3ab5c8de11a8
> --- /dev/null
> +++ b/arch/riscv/boot/dts/canaan/k230-canmv.dts
> @@ -0,0 +1,24 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +/*
> + * Copyright (C) 2024 Yangyu Chen <cyy@cyyself.name>
> + */
> +
> +#include "k230.dtsi"
> +
> +/ {
> + model = "Canaan CanMV-K230";
> + compatible = "canaan,canmv-k230", "canaan,kendryte-k230";
> +
> + chosen {
> + stdout-path = "serial0:115200n8";
> + };
> +
> + ddr: memory@0 {
> + device_type = "memory";
> + reg = <0x0 0x0 0x0 0x1fdff000>;
> + };
> +};
> +
> +&uart0 {
> + status = "okay";
> +};
> diff --git a/arch/riscv/boot/dts/canaan/k230-evb.dts b/arch/riscv/boot/dts/canaan/k230-evb.dts
> new file mode 100644
> index 000000000000..42720113c566
> --- /dev/null
> +++ b/arch/riscv/boot/dts/canaan/k230-evb.dts
> @@ -0,0 +1,24 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +/*
> + * Copyright (C) 2024 Yangyu Chen <cyy@cyyself.name>
> + */
> +
> +#include "k230.dtsi"
> +
> +/ {
> + model = "Kendryte K230 EVB";
> + compatible = "canaan,k230-usip-lp3-evb", "canaan,kendryte-k230";
> +
> + chosen {
> + stdout-path = "serial0:115200n8";
> + };
> +
> + ddr: memory@0 {
> + device_type = "memory";
> + reg = <0x0 0x0 0x0 0x1fdff000>;
> + };
> +};
> +
> +&uart0 {
> + status = "okay";
> +};
> diff --git a/arch/riscv/boot/dts/canaan/k230.dtsi b/arch/riscv/boot/dts/canaan/k230.dtsi
> new file mode 100644
> index 000000000000..0bcff67b78a8
> --- /dev/null
> +++ b/arch/riscv/boot/dts/canaan/k230.dtsi
> @@ -0,0 +1,140 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +/*
> + * Copyright (C) 2024 Yangyu Chen <cyy@cyyself.name>
> + */
> +
> +#include <dt-bindings/interrupt-controller/irq.h>
> +
> +/dts-v1/;
> +/ {
> + #address-cells = <2>;
> + #size-cells = <2>;
> + compatible = "canaan,kendryte-k230";
> +
> + aliases {
> + serial0 = &uart0;
> + };
> +
> + cpus {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + timebase-frequency = <27000000>;
> +
> + cpu@0 {
> + compatible = "thead,c908", "riscv";
> + device_type = "cpu";
> + reg = <0>;
> + riscv,isa = "rv64imafdcv_zba_zbb_zbc_zbs_zicbom_svpbmt";
> + riscv,isa-base = "rv64i";
> + riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "v", "zba", "zbb",
> + "zbc", "zbs", "zicbom", "zicntr", "zicsr",
> + "zifencei", "zihpm", "svpbmt";
> + riscv,cbom-block-size = <64>;
> + d-cache-block-size = <64>;
> + d-cache-sets = <128>;
> + d-cache-size = <32768>;
> + i-cache-block-size = <64>;
> + i-cache-sets = <128>;
> + i-cache-size = <32768>;
> + next-level-cache = <&l2_cache>;
> + mmu-type = "riscv,sv39";
> +
> + cpu0_intc: interrupt-controller {
> + compatible = "riscv,cpu-intc";
> + interrupt-controller;
> + #interrupt-cells = <1>;
> + };
> + };
> +
> + l2_cache: l2-cache {
> + compatible = "cache";
> + cache-block-size = <64>;
> + cache-level = <2>;
> + cache-size = <262144>;
> + cache-sets = <256>;
> + cache-unified;
> + };
> + };
> +
> + apb_clk: apb-clk-clock {
> + compatible = "fixed-clock";
> + clock-frequency = <50000000>;
> + clock-output-names = "apb_clk";
> + #clock-cells = <0>;
> + };
> +
> + soc {
> + compatible = "simple-bus";
> + interrupt-parent = <&plic>;
> + #address-cells = <2>;
> + #size-cells = <2>;
> + dma-noncoherent;
> + ranges;
> +
> + plic: interrupt-controller@f00000000 {
> + compatible = "canaan,k230-plic" ,"thead,c900-plic";
> + reg = <0xf 0x00000000 0x0 0x04000000>;
> + interrupts-extended = <&cpu0_intc 11>, <&cpu0_intc 9>;
> + interrupt-controller;
> + #address-cells = <0>;
> + #interrupt-cells = <2>;
> + riscv,ndev = <208>;
> + };
> +
> + clint: timer@f04000000 {
> + compatible = "canaan,k230-clint", "thead,c900-clint";
> + reg = <0xf 0x04000000 0x0 0x04000000>;
> + interrupts-extended = <&cpu0_intc 3>, <&cpu0_intc 7>;
> + };
> +
> + uart0: serial@91400000 {
> + compatible = "snps,dw-apb-uart";
> + reg = <0x0 0x91400000 0x0 0x1000>;
> + clocks = <&apb_clk>;
> + interrupts = <16 IRQ_TYPE_LEVEL_HIGH>;
> + reg-io-width = <4>;
> + reg-shift = <2>;
> + status = "disabled";
> + };
> +
> + uart1: serial@91401000 {
> + compatible = "snps,dw-apb-uart";
> + reg = <0x0 0x91401000 0x0 0x1000>;
> + clocks = <&apb_clk>;
> + interrupts = <17 IRQ_TYPE_LEVEL_HIGH>;
> + reg-io-width = <4>;
> + reg-shift = <2>;
> + status = "disabled";
> + };
> +
> + uart2: serial@91402000 {
> + compatible = "snps,dw-apb-uart";
> + reg = <0x0 0x91402000 0x0 0x1000>;
> + clocks = <&apb_clk>;
> + interrupts = <18 IRQ_TYPE_LEVEL_HIGH>;
> + reg-io-width = <4>;
> + reg-shift = <2>;
> + status = "disabled";
> + };
> +
> + uart3: serial@91403000 {
> + compatible = "snps,dw-apb-uart";
> + reg = <0x0 0x91403000 0x0 0x1000>;
> + clocks = <&apb_clk>;
> + interrupts = <19 IRQ_TYPE_LEVEL_HIGH>;
> + reg-io-width = <4>;
> + reg-shift = <2>;
> + status = "disabled";
> + };
> +
> + uart4: serial@91404000 {
> + compatible = "snps,dw-apb-uart";
> + reg = <0x0 0x91404000 0x0 0x1000>;
> + clocks = <&apb_clk>;
> + interrupts = <20 IRQ_TYPE_LEVEL_HIGH>;
> + reg-io-width = <4>;
> + reg-shift = <2>;
> + status = "disabled";
> + };
> + };
> +};