5 files changed, 109 insertions, 81 deletions

diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile
index b8f8740a3e44..a1055965fbee 100644
--- a/arch/riscv/errata/Makefile
+++ b/arch/riscv/errata/Makefile
@@ -1,2 +1,2 @@
-obj-y	+= alternative.o
 obj-$(CONFIG_ERRATA_SIFIVE) += sifive/
+obj-$(CONFIG_ERRATA_THEAD) += thead/
diff --git a/arch/riscv/errata/alternative.c b/arch/riscv/errata/alternative.c
deleted file mode 100644
index e8b4a0fe488c..000000000000
--- a/arch/riscv/errata/alternative.c
+++ /dev/null
@@ -1,75 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * alternative runtime patching
- * inspired by the ARM64 and x86 version
- *
- * Copyright (C) 2021 Sifive.
- */
-
-#include <linux/init.h>
-#include <linux/cpu.h>
-#include <linux/uaccess.h>
-#include <asm/alternative.h>
-#include <asm/sections.h>
-#include <asm/vendorid_list.h>
-#include <asm/sbi.h>
-#include <asm/csr.h>
-
-static struct cpu_manufacturer_info_t {
-	unsigned long vendor_id;
-	unsigned long arch_id;
-	unsigned long imp_id;
-} cpu_mfr_info;
-
-static void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end,
-				 unsigned long archid,
-				 unsigned long impid) __initdata;
-
-static inline void __init riscv_fill_cpu_mfr_info(void)
-{
-#ifdef CONFIG_RISCV_M_MODE
-	cpu_mfr_info.vendor_id = csr_read(CSR_MVENDORID);
-	cpu_mfr_info.arch_id = csr_read(CSR_MARCHID);
-	cpu_mfr_info.imp_id = csr_read(CSR_MIMPID);
-#else
-	cpu_mfr_info.vendor_id = sbi_get_mvendorid();
-	cpu_mfr_info.arch_id = sbi_get_marchid();
-	cpu_mfr_info.imp_id = sbi_get_mimpid();
-#endif
-}
-
-static void __init init_alternative(void)
-{
-	riscv_fill_cpu_mfr_info();
-
-	switch (cpu_mfr_info.vendor_id) {
-#ifdef CONFIG_ERRATA_SIFIVE
-	case SIFIVE_VENDOR_ID:
-		vendor_patch_func = sifive_errata_patch_func;
-		break;
-#endif
-	default:
-		vendor_patch_func = NULL;
-	}
-}
-
-/*
- * This is called very early in the boot process (directly after we run
- * a feature detect on the boot CPU). No need to worry about other CPUs
- * here.
- */
-void __init apply_boot_alternatives(void)
-{
-	/* If called on non-boot cpu things could go wrong */
-	WARN_ON(smp_processor_id() != 0);
-
-	init_alternative();
-
-	if (!vendor_patch_func)
-		return;
-
-	vendor_patch_func((struct alt_entry *)__alt_start,
-			  (struct alt_entry *)__alt_end,
-			  cpu_mfr_info.arch_id, cpu_mfr_info.imp_id);
-}
-
diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index f5e5ae70e829..672f02b21ce0 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/string.h>
 #include <linux/bug.h>
 #include <asm/patch.h>
@@ -54,7 +55,8 @@ static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = {
 	},
 };
 
-static u32 __init sifive_errata_probe(unsigned long archid, unsigned long impid)
+static u32 __init_or_module sifive_errata_probe(unsigned long archid,
+						unsigned long impid)
 {
 	int idx;
 	u32 cpu_req_errata = 0;
@@ -66,7 +68,7 @@ static u32 __init sifive_errata_probe(unsigned long archid, unsigned long impid)
 	return cpu_req_errata;
 }
 
-static void __init warn_miss_errata(u32 miss_errata)
+static void __init_or_module warn_miss_errata(u32 miss_errata)
 {
 	int i;
 
@@ -79,14 +81,22 @@ static void __init warn_miss_errata(u32 miss_errata)
 	pr_warn("----------------------------------------------------------------\n");
 }
 
-void __init sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
-				     unsigned long archid, unsigned long impid)
+void __init_or_module sifive_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_req_errata = sifive_errata_probe(archid, impid);
+	u32 cpu_req_errata;
 	u32 cpu_apply_errata = 0;
 	u32 tmp;
 
+	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+		return;
+
+	cpu_req_errata = sifive_errata_probe(archid, impid);
+
 	for (alt = begin; alt < end; alt++) {
 		if (alt->vendor_id != SIFIVE_VENDOR_ID)
 			continue;
diff --git a/arch/riscv/errata/thead/Makefile b/arch/riscv/errata/thead/Makefile
new file mode 100644
index 000000000000..137e700d9d3f
--- /dev/null
+++ b/arch/riscv/errata/thead/Makefile
@@ -0,0 +1,11 @@
+ifdef CONFIG_RISCV_ALTERNATIVE_EARLY
+CFLAGS_errata.o := -mcmodel=medany
+ifdef CONFIG_FTRACE
+CFLAGS_REMOVE_errata.o = $(CC_FLAGS_FTRACE)
+endif
+ifdef CONFIG_KASAN
+KASAN_SANITIZE_errata.o := n
+endif
+endif
+
+obj-y += errata.o
diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
new file mode 100644
index 000000000000..e5d75270b99c
--- /dev/null
+++ b/arch/riscv/errata/thead/errata.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Heiko Stuebner <heiko@sntech.de>
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <asm/alternative.h>
+#include <asm/cacheflush.h>
+#include <asm/errata_list.h>
+#include <asm/patch.h>
+#include <asm/vendorid_list.h>
+
+struct errata_info {
+	char name[ERRATA_STRING_LENGTH_MAX];
+	bool (*check_func)(unsigned long arch_id, unsigned long impid);
+	unsigned int stage;
+};
+
+static bool errata_mt_check_func(unsigned long  arch_id, unsigned long impid)
+{
+	if (arch_id != 0 || impid != 0)
+		return false;
+	return true;
+}
+
+static const struct errata_info errata_list[ERRATA_THEAD_NUMBER] = {
+	{
+		.name = "memory-types",
+		.stage = RISCV_ALTERNATIVES_EARLY_BOOT,
+		.check_func = errata_mt_check_func
+	},
+};
+
+static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid)
+{
+	const struct errata_info *info;
+	u32 cpu_req_errata = 0;
+	int idx;
+
+	for (idx = 0; idx < ERRATA_THEAD_NUMBER; idx++) {
+		info = &errata_list[idx];
+
+		if ((stage == RISCV_ALTERNATIVES_MODULE ||
+		     info->stage == stage) && info->check_func(archid, impid))
+			cpu_req_errata |= (1U << idx);
+	}
+
+	return cpu_req_errata;
+}
+
+void __init_or_module thead_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_req_errata = thead_errata_probe(stage, archid, impid);
+	u32 tmp;
+
+	for (alt = begin; alt < end; alt++) {
+		if (alt->vendor_id != THEAD_VENDOR_ID)
+			continue;
+		if (alt->errata_id >= ERRATA_THEAD_NUMBER)
+			continue;
+
+		tmp = (1U << alt->errata_id);
+		if (cpu_req_errata & tmp) {
+			/* On vm-alternatives, the mmu isn't running yet */
+			if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+				memcpy((void *)__pa_symbol(alt->old_ptr),
+				       (void *)__pa_symbol(alt->alt_ptr), alt->alt_len);
+			else
+				patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
+		}
+	}
+
+	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+		local_flush_icache_all();
+}