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

From: Palmer Dabbelt
Date: Tue Mar 05 2024 - 10:54:20 EST

On Mon, 04 Mar 2024 13:06:00 PST (-0800), cyy@xxxxxxxxxxxx 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@xxxxxxxxxxxx>
---
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@xxxxxxxxxxxx>
+ */
+
+#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@xxxxxxxxxxxx>
+ */
+
+#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@xxxxxxxxxxxx>
+ */
+
+#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";
+ };
+ };
+};