[PATCH 1/2] riscv: cpu: cv1800b: Add support for cv1800b SoC

[Heinrich Schuchardt]

On 02.02.24 10:37, Kongyang Liu wrote:
> Add Sophgo cv1800b SoC to support RISC-V arch.
> 
> Signed-off-by: Kongyang Liu <seashell11234455 at gmail.com>
> 
> ---
> 
>   arch/riscv/Kconfig              |  1 +
>   arch/riscv/cpu/cv1800b/Kconfig  | 12 ++++++++++++
>   arch/riscv/cpu/cv1800b/Makefile |  6 ++++++
>   arch/riscv/cpu/cv1800b/cpu.c    | 22 ++++++++++++++++++++++
>   arch/riscv/cpu/cv1800b/dram.c   | 21 +++++++++++++++++++++
>   board/sophgo/milkv_duo/Kconfig  |  4 ++--
>   6 files changed, 64 insertions(+), 2 deletions(-)
>   create mode 100644 arch/riscv/cpu/cv1800b/Kconfig
>   create mode 100644 arch/riscv/cpu/cv1800b/Makefile
>   create mode 100644 arch/riscv/cpu/cv1800b/cpu.c
>   create mode 100644 arch/riscv/cpu/cv1800b/dram.c
> 
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index ac52c5e6da..2c92b0d9f6 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -93,6 +93,7 @@ source "board/xilinx/mbv/Kconfig"
>   
>   # platform-specific options below
>   source "arch/riscv/cpu/andesv5/Kconfig"
> +source "arch/riscv/cpu/cv1800b/Kconfig"
>   source "arch/riscv/cpu/fu540/Kconfig"
>   source "arch/riscv/cpu/fu740/Kconfig"
>   source "arch/riscv/cpu/generic/Kconfig"
> diff --git a/arch/riscv/cpu/cv1800b/Kconfig b/arch/riscv/cpu/cv1800b/Kconfig
> new file mode 100644
> index 0000000000..7225b1210c
> --- /dev/null
> +++ b/arch/riscv/cpu/cv1800b/Kconfig
> @@ -0,0 +1,12 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2024, Kongyang Liu <seashell11234455 at gmail.com>
> +
> +config SOPHGO_CV1800B
> +	bool
> +	select ARCH_EARLY_INIT_R
> +	select SYS_CACHE_SHIFT_6
> +	imply CPU
> +	imply CPU_RISCV
> +	imply RISCV_TIMER
> +	imply CMD_CPU
> diff --git a/arch/riscv/cpu/cv1800b/Makefile b/arch/riscv/cpu/cv1800b/Makefile
> new file mode 100644
> index 0000000000..da12e0f64e
> --- /dev/null
> +++ b/arch/riscv/cpu/cv1800b/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2024, Kongyang Liu <seashell11234455 at gmail.com>
> +
> +obj-y += dram.o
> +obj-y += cpu.o
> diff --git a/arch/riscv/cpu/cv1800b/cpu.c b/arch/riscv/cpu/cv1800b/cpu.c
> new file mode 100644
> index 0000000000..f13c18942f
> --- /dev/null
> +++ b/arch/riscv/cpu/cv1800b/cpu.c
> @@ -0,0 +1,22 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + */
> +
> +#include <irq_func.h>
> +#include <asm/cache.h>
> +
> +/*
> + * cleanup_before_linux() is called just before we call linux
> + * it prepares the processor for linux
> + *
> + * we disable interrupt and caches.
> + */
> +int cleanup_before_linux(void)
> +{
> +	disable_interrupts();
> +
> +	cache_flush();
> +
> +	return 0;
> +}

Thank you for enabling another board.

The same cleanup_before_linux() code can be found in:

arch/riscv/cpu/fu740/cpu.c
arch/riscv/cpu/andesv5/cpu.c
arch/riscv/cpu/fu540/cpu.c
arch/riscv/cpu/generic/cpu.c
arch/riscv/cpu/jh7110/cpu.c

We should try to avoid this code duplication.

disable_interrupts() is already called by bootm_disable_interrupts().

flushing the instruction cache after loading a binary is not 
architecture specific either. This is why bootm_load_os() calls 
flush_cache().

It should be sufficient to let weak function flush_dcache_range() in 
arch/riscv/lib/cache.c call flush_dcache_all(). And then remove all 
cleanup_before_linux() implementations.

Best regards

Heinrich


> diff --git a/arch/riscv/cpu/cv1800b/dram.c b/arch/riscv/cpu/cv1800b/dram.c
> new file mode 100644
> index 0000000000..91007c0a3d
> --- /dev/null
> +++ b/arch/riscv/cpu/cv1800b/dram.c
> @@ -0,0 +1,21 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + */
> +
> +#include <fdtdec.h>
> +#include <init.h>
> +#include <asm/global_data.h>
> +#include <linux/sizes.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +int dram_init(void)
> +{
> +	return fdtdec_setup_mem_size_base();
> +}
> +
> +int dram_init_banksize(void)
> +{
> +	return fdtdec_setup_memory_banksize();
> +}
> diff --git a/board/sophgo/milkv_duo/Kconfig b/board/sophgo/milkv_duo/Kconfig
> index 2a458f291c..040a7487f1 100644
> --- a/board/sophgo/milkv_duo/Kconfig
> +++ b/board/sophgo/milkv_duo/Kconfig
> @@ -7,7 +7,7 @@ config SYS_VENDOR
>   	default "sophgo"
>   
>   config SYS_CPU
> -	default "generic"
> +	default "cv1800b"
>   
>   config SYS_CONFIG_NAME
>   	default "milkv_duo"
> @@ -23,6 +23,6 @@ config ENV_SECT_SIZE
>   
>   config BOARD_SPECIFIC_OPTIONS
>   	def_bool y
> -	select GENERIC_RISCV
> +	select SOPHGO_CV1800B
>   
>   endif