Re: [PATCH 2/4] riscv: errata: Add StarFive alternative ports
From: Samuel Holland
Date: Fri Mar 15 2024 - 19:13:47 EST
On 2024-03-14 1:12 AM, Joshua Yeong wrote:
> Add required ports of the Alternative scheme for
> StarFive CPU cores.
>
> Signed-off-by: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
> ---
> arch/riscv/Kconfig.errata | 21 ++++++
> arch/riscv/errata/Makefile | 1 +
> arch/riscv/errata/starfive/Makefile | 1 +
> arch/riscv/errata/starfive/errata.c | 95 ++++++++++++++++++++++++++++
> arch/riscv/include/asm/alternative.h | 3 +
> arch/riscv/include/asm/errata_list.h | 5 ++
> arch/riscv/kernel/alternative.c | 5 ++
> 7 files changed, 131 insertions(+)
> create mode 100644 arch/riscv/errata/starfive/Makefile
> create mode 100644 arch/riscv/errata/starfive/errata.c
>
> diff --git a/arch/riscv/Kconfig.errata b/arch/riscv/Kconfig.errata
> index 910ba8837add..1438dd09533b 100644
> --- a/arch/riscv/Kconfig.errata
> +++ b/arch/riscv/Kconfig.errata
> @@ -53,6 +53,16 @@ config ERRATA_SIFIVE_CIP_1200
>
> If you don't know what to do here, say "Y".
>
> +config ERRATA_STARFIVE
> + bool "StarFive errata"
> + depends on RISCV_ALTERNATIVE
> + help
> + All StarFive errata Kconfig depend on this Kconfig. Disabling
> + this Kconfig will disable all StarFive errata. Please say "Y"
> + here if your platform uses StarFive CPU cores.
> +
> + Otherwise, please say "N" here to avoid unnecessary overhead.
> +
> config ERRATA_STARFIVE_JH7100
> bool "StarFive JH7100 support"
> depends on ARCH_STARFIVE
> @@ -72,6 +82,17 @@ config ERRATA_STARFIVE_JH7100
> Say "Y" if you want to support the BeagleV Starlight and/or
> StarFive VisionFive V1 boards.
>
> +config ERRATA_STARFIVE_CMO
> + bool "Apply StarFive cache management errata"
> + depends on ERRATA_STARFIVE && MMU
> + select RISCV_DMA_NONCOHERENT
> + default y
> + help
> + This will apply the cache management errata to handle the
> + non-standard handling on non-coherent operations on StarFive cores.
> +
> + If you don't know what to do here, say "Y".
> +
> config ERRATA_THEAD
> bool "T-HEAD errata"
> depends on RISCV_ALTERNATIVE
> diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile
> index 8a2739485123..4713a686b9f7 100644
> --- a/arch/riscv/errata/Makefile
> +++ b/arch/riscv/errata/Makefile
> @@ -4,4 +4,5 @@ endif
>
> obj-$(CONFIG_ERRATA_ANDES) += andes/
> obj-$(CONFIG_ERRATA_SIFIVE) += sifive/
> +obj-$(CONFIG_ERRATA_STARFIVE) += starfive/
> obj-$(CONFIG_ERRATA_THEAD) += thead/
> diff --git a/arch/riscv/errata/starfive/Makefile b/arch/riscv/errata/starfive/Makefile
> new file mode 100644
> index 000000000000..2d644e19caef
> --- /dev/null
> +++ b/arch/riscv/errata/starfive/Makefile
> @@ -0,0 +1 @@
> +obj-y += errata.o
> diff --git a/arch/riscv/errata/starfive/errata.c b/arch/riscv/errata/starfive/errata.c
> new file mode 100644
> index 000000000000..3ee360cd5e81
> --- /dev/null
> +++ b/arch/riscv/errata/starfive/errata.c
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Erratas to be applied for StarFive CPU cores
> + *
> + * Copyright (C) 2024 Shanghai StarFive Technology Co., Ltd.
> + *
> + * Author: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/memory.h>
> +#include <linux/module.h>
> +
> +#include <asm/alternative.h>
> +#include <asm/cacheflush.h>
> +#include <asm/errata_list.h>
> +#include <asm/patch.h>
> +#include <asm/processor.h>
> +#include <asm/sbi.h>
> +#include <asm/vendorid_list.h>
> +
> +#define STARFIVE_JH8100_DUBHE90_MARCHID 0x80000000DB000090UL
> +#define STARFIVE_JH8100_DUBHE90_MIMPID 0x0000000020230930UL
> +#define STARFIVE_JH8100_DUBHE80_MARCHID 0x80000000DB000080UL
> +#define STARFIVE_JH8100_DUBHE80_MIMPID 0x0000000020230831UL
> +#define STARFIVE_JH8100_L3 0x40
> +
> +static bool errata_probe_cmo(unsigned int stage, unsigned long arch_id,
> + unsigned long impid)
> +{
> + if (!IS_ENABLED(CONFIG_ERRATA_STARFIVE_CMO))
> + return false;
> +
> + if ((arch_id != STARFIVE_JH8100_DUBHE90_MARCHID ||
> + impid != STARFIVE_JH8100_DUBHE90_MIMPID) &&
> + (arch_id != STARFIVE_JH8100_DUBHE80_MARCHID ||
> + impid != STARFIVE_JH8100_DUBHE80_MIMPID))
> + return false;
> +
> + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> + return false;
> +
> + riscv_cbom_block_size = STARFIVE_JH8100_L3;
> + riscv_noncoherent_supported();
This patch doesn't add any alternatives, so you don't need to use the errata
framework. Please move these two lines to the cache driver -- see
drivers/cache/sifive_ccache.c -- and then you can drop this patch.
Regards,
Samuel
> +
> + return true;
> +}
> +
> +static u32 starfive_errata_probe(unsigned int stage,
> + unsigned long archid, unsigned long impid)
> +{
> + u32 cpu_req_errata = 0;
> +
> + if (errata_probe_cmo(stage, archid, impid))
> + cpu_req_errata |= BIT(ERRATA_STARFIVE_CMO);
> +
> + return cpu_req_errata;
> +}
> +
> +void __init_or_module starfive_errata_patch_func(struct alt_entry *begin,
> + struct alt_entry *end,
> + unsigned long archid,
> + unsigned long impid,
> + unsigned int stage)
> +{
> + struct alt_entry *alt;
> + u32 cpu_apply_errata = 0;
> + u32 tmp;
> + u32 cpu_req_errata;
> +
> + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> + return;
> +
> + cpu_req_errata = starfive_errata_probe(stage, archid, impid);
> +
> + for (alt = begin; alt < end; alt++) {
> + if (alt->vendor_id != STARFIVE_VENDOR_ID)
> + continue;
> + if (alt->patch_id >= ERRATA_STARFIVE_NUMBER)
> + continue;
> +
> + tmp = (1U << alt->patch_id);
> + if (cpu_req_errata & tmp) {
> + mutex_lock(&text_mutex);
> + patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt),
> + alt->alt_len);
> + mutex_unlock(&text_mutex);
> + cpu_apply_errata |= tmp;
> + }
> + }
> +
> + if (stage != RISCV_ALTERNATIVES_MODULE &&
> + cpu_apply_errata != cpu_req_errata) {
> + pr_warn("WARNING: Missing StarFive errata patches! \n");
> + }
> +}
> diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h
> index 3c2b59b25017..8f5e6883db97 100644
> --- a/arch/riscv/include/asm/alternative.h
> +++ b/arch/riscv/include/asm/alternative.h
> @@ -51,6 +51,9 @@ void andes_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
> void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
> unsigned long archid, unsigned long impid,
> unsigned int stage);
> +void starfive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
> + unsigned long archid, unsigned long impid,
> + unsigned int stage);
> void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
> unsigned long archid, unsigned long impid,
> unsigned int stage);
> diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h
> index ea33288f8a25..1cd5ba3a1466 100644
> --- a/arch/riscv/include/asm/errata_list.h
> +++ b/arch/riscv/include/asm/errata_list.h
> @@ -22,6 +22,11 @@
> #define ERRATA_SIFIVE_NUMBER 2
> #endif
>
> +#ifdef CONFIG_ERRATA_STARFIVE
> +#define ERRATA_STARFIVE_CMO 0
> +#define ERRATA_STARFIVE_NUMBER 1
> +#endif
> +
> #ifdef CONFIG_ERRATA_THEAD
> #define ERRATA_THEAD_PBMT 0
> #define ERRATA_THEAD_PMU 1
> diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
> index 319a1da0358b..deedd4b76472 100644
> --- a/arch/riscv/kernel/alternative.c
> +++ b/arch/riscv/kernel/alternative.c
> @@ -52,6 +52,11 @@ static void riscv_fill_cpu_mfr_info(struct cpu_manufacturer_info_t *cpu_mfr_info
> cpu_mfr_info->patch_func = sifive_errata_patch_func;
> break;
> #endif
> +#ifdef CONFIG_ERRATA_STARFIVE
> + case STARFIVE_VENDOR_ID:
> + cpu_mfr_info->patch_func = starfive_errata_patch_func;
> + break;
> +#endif
> #ifdef CONFIG_ERRATA_THEAD
> case THEAD_VENDOR_ID:
> cpu_mfr_info->patch_func = thead_errata_patch_func;