Re: [PATCH v4 3/7] riscv: errata: Add Andes alternative ports

[Heiko Stübner]

Am Donnerstag, 24. November 2022, 18:22:03 CET schrieb Prabhakar:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> 
> Add required ports of the Alternative scheme for Andes CPU cores.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> RFC v3 -> v4
> * New patch
> ---

> diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile
> index a1055965fbee..81828e80f6dc 100644
> --- a/arch/riscv/errata/Makefile
> +++ b/arch/riscv/errata/Makefile
> @@ -1,2 +1,3 @@
>  obj-$(CONFIG_ERRATA_SIFIVE) += sifive/
>  obj-$(CONFIG_ERRATA_THEAD) += thead/
> +obj-$(CONFIG_ERRATA_ANDES) += andes/

alphabetical sorting please


> diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c
> new file mode 100644
> index 000000000000..ec3e052ca8c7
> --- /dev/null
> +++ b/arch/riscv/errata/andes/errata.c
> @@ -0,0 +1,68 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Erratas to be applied for Andes CPU cores
> + *
> + *  Copyright (C) 2022 Renesas Electronics Corporation.
> + *
> + * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +#include <asm/alternative.h>
> +#include <asm/cacheflush.h>
> +#include <asm/errata_list.h>
> +#include <asm/patch.h>
> +#include <asm/vendorid_list.h>
> +
> +static bool errata_probe_iocp(unsigned int stage, unsigned long arch_id, unsigned long impid)
> +{
> +	if (!IS_ENABLED(CONFIG_ERRATA_ANDES_CMO))
> +		return false;
> +
> +	if (arch_id != 0x8000000000008a45 || impid != 0x500)
> +		return false;
> +
> +	riscv_cbom_block_size = 1;

as this is mainly to make the core cbo code happy, maybe add a comment
above that line to explain.


> +	riscv_noncoherent_supported();
> +
> +	return true;
> +}
> +

> diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h
> index 6511dd73e812..d8012af30cbd 100644
> --- a/arch/riscv/include/asm/alternative.h
> +++ b/arch/riscv/include/asm/alternative.h
> @@ -46,6 +46,9 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
>  void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
>  			     unsigned long archid, unsigned long impid,
>  			     unsigned int stage);
> +void andes_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
> +			     unsigned long archid, unsigned long impid,
> +			     unsigned int stage);

again alphabetical please (i.e. above sifive)


> diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h
> index 4180312d2a70..2ba7e6e74540 100644
> --- a/arch/riscv/include/asm/errata_list.h
> +++ b/arch/riscv/include/asm/errata_list.h
> @@ -9,6 +9,11 @@
>  #include <asm/csr.h>
>  #include <asm/vendorid_list.h>
>  
> +#ifdef CONFIG_ERRATA_ANDES
> +#define ERRATA_ANDESTECH_NO_IOCP	0
> +#define ERRATA_ANDESTECH_NUMBER		1
> +#endif
> +
>  #ifdef CONFIG_ERRATA_SIFIVE
>  #define	ERRATA_SIFIVE_CIP_453 0
>  #define	ERRATA_SIFIVE_CIP_1200 1
> diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
> index a7d26a00beea..4ded3e9aa3bc 100644
> --- a/arch/riscv/kernel/alternative.c
> +++ b/arch/riscv/kernel/alternative.c
> @@ -47,6 +47,11 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf
>  	case THEAD_VENDOR_ID:
>  		cpu_mfr_info->patch_func = thead_errata_patch_func;
>  		break;
> +#endif
> +#ifdef CONFIG_ERRATA_ANDES
> +	case ANDESTECH_VENDOR_ID:
> +		cpu_mfr_info->patch_func = andes_errata_patch_func;
> +		break;

and again alphabetical please


Thanks
Heiko