[PATCH 2/4] riscv: errata: Add StarFive alternative ports

From: Joshua Yeong
Date: Thu Mar 14 2024 - 02:28:43 EST

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();
+
+ 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;
--
2.25.1