[PATCH v4 01/10] riscv: Add initial support for P8700 SoC

[Uros Stajic]

On 9. 10. 25. 12:23, Yao Zi wrote:
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> 
> 
> On Tue, Aug 19, 2025 at 10:31:42AM +0000, Uros Stajic wrote:
>> From: Chao-ying Fu <cfu at mips.com>
>>
>> Add initial platform support for the P8700-F, a high-performance
>> multi-core RV64GC SoC with optional multi-cluster configuration and
>> hardware multithreading.
>>
>> This patch introduces the initial platform code necessary to support
>> the P8700 CPU in U-Boot.
>>
>> Signed-off-by: Chao-ying Fu <cfu at mips.com>
>> Signed-off-by: Uros Stajic <uros.stajic at htecgroup.com>
>> ---
>>   arch/riscv/Kconfig                          |   1 +
>>   arch/riscv/cpu/p8700/Kconfig                |  14 ++
>>   arch/riscv/cpu/p8700/Makefile               |   9 ++
>>   arch/riscv/cpu/p8700/cache.c                |  93 +++++++++++
>>   arch/riscv/cpu/p8700/cpu.c                  |  13 ++
>>   arch/riscv/cpu/p8700/dram.c                 |  37 +++++
>>   arch/riscv/cpu/p8700/p8700_platform_setup.S | 169 ++++++++++++++++++++
>>   arch/riscv/include/asm/arch-p8700/p8700.h   | 110 +++++++++++++
>>   8 files changed, 446 insertions(+)
>>   create mode 100644 arch/riscv/cpu/p8700/Kconfig
>>   create mode 100644 arch/riscv/cpu/p8700/Makefile
>>   create mode 100644 arch/riscv/cpu/p8700/cache.c
>>   create mode 100644 arch/riscv/cpu/p8700/cpu.c
>>   create mode 100644 arch/riscv/cpu/p8700/dram.c
>>   create mode 100644 arch/riscv/cpu/p8700/p8700_platform_setup.S
>>   create mode 100644 arch/riscv/include/asm/arch-p8700/p8700.h
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index 04eb0e6f23c..4eaf0e3db71 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -131,6 +131,7 @@ source "arch/riscv/cpu/jh7110/Kconfig"
>>   source "arch/riscv/cpu/k1/Kconfig"
>>   source "arch/riscv/cpu/k230/Kconfig"
>>   source "arch/riscv/cpu/th1520/Kconfig"
>> +source "arch/riscv/cpu/p8700/Kconfig"
>>
>>   # architecture-specific options below
>>
>> diff --git a/arch/riscv/cpu/p8700/Kconfig b/arch/riscv/cpu/p8700/Kconfig
>> new file mode 100644
>> index 00000000000..7023575a6be
>> --- /dev/null
>> +++ b/arch/riscv/cpu/p8700/Kconfig
>> @@ -0,0 +1,14 @@
>> +# SPDX-License-Identifier: GPL-2.0+
>> +#
>> +# Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
>> +
>> +config P8700_RISCV
>> +     bool
>> +     select ARCH_EARLY_INIT_R
>> +     imply CPU
>> +     imply CPU_RISCV
>> +     imply SIFIVE_CLINT if (RISCV_MMODE || SPL_RISCV_MMODE)
> 
> SIFIVE_CLINT has been renamed as RISCV_ACLINT back to 2023, and in
> PATCH 2 you change SIFIVE_CLINT to RISCV_ACLINT. I think you should
> squash the change into PATCH 1.
> 
>> +     imply CMD_CPU
>> +     imply SPL_CPU_SUPPORT
>> +     imply SPL_OPENSBI
>> +     imply SPL_LOAD_FIT
> 
> ...
> 
>> diff --git a/arch/riscv/cpu/p8700/p8700_platform_setup.S b/arch/riscv/cpu/p8700/p8700_platform_setup.S
>> new file mode 100644
>> index 00000000000..7c4475a03dd
>> --- /dev/null
>> +++ b/arch/riscv/cpu/p8700/p8700_platform_setup.S
> 
> Could this file be converted to C language? Then it'll be easier to
> maintain. I think nothing prevents this if you could put the
> initialization off until harts_early_init().
> 
> Futhermore I don't see this file is included in any of your Makefile,
> which is suspicious.
> 
> ...
> 
>> diff --git a/arch/riscv/include/asm/arch-p8700/p8700.h b/arch/riscv/include/asm/arch-p8700/p8700.h
>> new file mode 100644
>> index 00000000000..5ca9b4b9497
>> --- /dev/null
>> +++ b/arch/riscv/include/asm/arch-p8700/p8700.h
>> @@ -0,0 +1,110 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Copyright (C) 2021, Chao-ying Fu <cfu at mips.com>
>> + */
>> +
>> +#ifndef __P8700_H__
>> +#define __P8700_H__
>> +
>> +#define CSR_MIPSCONFIG7              0x7d7
>> +#define CSR_PMACFG0                  0x7e0
>> +
>> +#define MHARTID_HART_SHIFT   0
>> +#define MHARTID_HART_MASK    0xf
>> +#define MHARTID_CORE_SHIFT   4
>> +#define MHARTID_CORE_MASK    0xff
>> +#define MHARTID_CLUSTER_SHIFT        16
>> +#define MHARTID_CLUSTER_MASK 0xf
>> +
>> +#define MARCHID_UARCH_SHIFT  0
>> +#define MARCHID_UARCH_MASK   0xff
>> +#define MARCHID_CLASS_SHIFT  8
>> +#define MARCHID_CLASS_MASK   0xff
> 
> If you convert p8700_platform_setup.S to a C file, these macros could be
> simplified with GENMASK() and FIELD_GET/PUT().
> 
> Best regards,
> Yao Zi

Hi Yao Zi,

Thank you for the review and suggestions! The code from 
p8700_platform_setup.S has been moved into a C implementation in the 
newer revision and the initialization is now handled from 
harts_early_init().

Best regards,
Uros