6 files changed, 268 insertions, 0 deletions
diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile
new file mode 100644
index 000000000..a1055965f
--- /dev/null
+++ b/arch/riscv/errata/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_ERRATA_SIFIVE) += sifive/
+obj-$(CONFIG_ERRATA_THEAD) += thead/
diff --git a/arch/riscv/errata/sifive/Makefile b/arch/riscv/errata/sifive/Makefile
new file mode 100644
index 000000000..2fde48db0
--- /dev/null
+++ b/arch/riscv/errata/sifive/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_ERRATA_SIFIVE_CIP_453) += errata_cip_453.o
+obj-y += errata.o
diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
new file mode 100644
index 000000000..c24a349dd
--- /dev/null
+++ b/arch/riscv/errata/sifive/errata.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Sifive.
+ */
+
+#include <linux/kernel.h>
+#include <linux/memory.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/bug.h>
+#include <asm/patch.h>
+#include <asm/alternative.h>
+#include <asm/vendorid_list.h>
+#include <asm/errata_list.h>
+
+struct errata_info_t {
+	char name[ERRATA_STRING_LENGTH_MAX];
+	bool (*check_func)(unsigned long  arch_id, unsigned long impid);
+};
+
+static bool errata_cip_453_check_func(unsigned long  arch_id, unsigned long impid)
+{
+	/*
+	 * Affected cores:
+	 * Architecture ID: 0x8000000000000007
+	 * Implement ID: 0x20181004 <= impid <= 0x20191105
+	 */
+	if (arch_id != 0x8000000000000007 ||
+	    (impid < 0x20181004 || impid > 0x20191105))
+		return false;
+	return true;
+}
+
+static bool errata_cip_1200_check_func(unsigned long  arch_id, unsigned long impid)
+{
+	/*
+	 * Affected cores:
+	 * Architecture ID: 0x8000000000000007 or 0x1
+	 * Implement ID: mimpid[23:0] <= 0x200630 and mimpid != 0x01200626
+	 */
+	if (arch_id != 0x8000000000000007 && arch_id != 0x1)
+		return false;
+	if ((impid & 0xffffff) > 0x200630 || impid == 0x1200626)
+		return false;
+	return true;
+}
+
+static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = {
+	{
+		.name = "cip-453",
+		.check_func = errata_cip_453_check_func
+	},
+	{
+		.name = "cip-1200",
+		.check_func = errata_cip_1200_check_func
+	},
+};
+
+static u32 __init_or_module sifive_errata_probe(unsigned long archid,
+						unsigned long impid)
+{
+	int idx;
+	u32 cpu_req_errata = 0;
+
+	for (idx = 0; idx < ERRATA_SIFIVE_NUMBER; idx++)
+		if (errata_list[idx].check_func(archid, impid))
+			cpu_req_errata |= (1U << idx);
+
+	return cpu_req_errata;
+}
+
+static void __init_or_module warn_miss_errata(u32 miss_errata)
+{
+	int i;
+
+	pr_warn("----------------------------------------------------------------\n");
+	pr_warn("WARNING: Missing the following errata may cause potential issues\n");
+	for (i = 0; i < ERRATA_SIFIVE_NUMBER; i++)
+		if (miss_errata & 0x1 << i)
+			pr_warn("\tSiFive Errata[%d]:%s\n", i, errata_list[i].name);
+	pr_warn("Please enable the corresponding Kconfig to apply them\n");
+	pr_warn("----------------------------------------------------------------\n");
+}
+
+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;
+	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;
+		if (alt->errata_id >= ERRATA_SIFIVE_NUMBER) {
+			WARN(1, "This errata id:%d is not in kernel errata list", alt->errata_id);
+			continue;
+		}
+
+		tmp = (1U << alt->errata_id);
+		if (cpu_req_errata & tmp) {
+			mutex_lock(&text_mutex);
+			patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
+			mutex_unlock(&text_mutex);
+			cpu_apply_errata |= tmp;
+		}
+	}
+	if (stage != RISCV_ALTERNATIVES_MODULE &&
+	    cpu_apply_errata != cpu_req_errata)
+		warn_miss_errata(cpu_req_errata - cpu_apply_errata);
+}
diff --git a/arch/riscv/errata/sifive/errata_cip_453.S b/arch/riscv/errata/sifive/errata_cip_453.S
new file mode 100644
index 000000000..f1b9623fe
--- /dev/null
+++ b/arch/riscv/errata/sifive/errata_cip_453.S
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 SiFive
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/alternative.h>
+
+.macro ADD_SIGN_EXT pt_reg badaddr tmp_reg
+	REG_L \badaddr, PT_BADADDR(\pt_reg)
+	li \tmp_reg,1
+	slli \tmp_reg,\tmp_reg,0x26
+	and \tmp_reg,\tmp_reg,\badaddr
+	beqz \tmp_reg, 1f
+	li \tmp_reg,-1
+	slli \tmp_reg,\tmp_reg,0x27
+	or \badaddr,\tmp_reg,\badaddr
+	REG_S \badaddr, PT_BADADDR(\pt_reg)
+1:
+.endm
+
+ENTRY(sifive_cip_453_page_fault_trp)
+	ADD_SIGN_EXT a0, t0, t1
+#ifdef CONFIG_MMU
+	la t0, do_page_fault
+#else
+	la t0, do_trap_unknown
+#endif
+	jr t0
+END(sifive_cip_453_page_fault_trp)
+
+ENTRY(sifive_cip_453_insn_fault_trp)
+	ADD_SIGN_EXT a0, t0, t1
+	la t0, do_trap_insn_fault
+	jr t0
+END(sifive_cip_453_insn_fault_trp)
diff --git a/arch/riscv/errata/thead/Makefile b/arch/riscv/errata/thead/Makefile
new file mode 100644
index 000000000..137e700d9
--- /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 000000000..32a34ed73
--- /dev/null
+++ b/arch/riscv/errata/thead/errata.c
@@ -0,0 +1,95 @@
+// 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/memory.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>
+
+static bool errata_probe_pbmt(unsigned int stage,
+			      unsigned long arch_id, unsigned long impid)
+{
+	if (!IS_ENABLED(CONFIG_ERRATA_THEAD_PBMT))
+		return false;
+
+	if (arch_id != 0 || impid != 0)
+		return false;
+
+	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT ||
+	    stage == RISCV_ALTERNATIVES_MODULE)
+		return true;
+
+	return false;
+}
+
+static bool errata_probe_cmo(unsigned int stage,
+			     unsigned long arch_id, unsigned long impid)
+{
+	if (!IS_ENABLED(CONFIG_ERRATA_THEAD_CMO))
+		return false;
+
+	if (arch_id != 0 || impid != 0)
+		return false;
+
+	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+		return false;
+
+	riscv_cbom_block_size = L1_CACHE_BYTES;
+	riscv_noncoherent_supported();
+	return true;
+}
+
+static u32 thead_errata_probe(unsigned int stage,
+			      unsigned long archid, unsigned long impid)
+{
+	u32 cpu_req_errata = 0;
+
+	if (errata_probe_pbmt(stage, archid, impid))
+		cpu_req_errata |= BIT(ERRATA_THEAD_PBMT);
+
+	if (errata_probe_cmo(stage, archid, impid))
+		cpu_req_errata |= BIT(ERRATA_THEAD_CMO);
+
+	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 {
+				mutex_lock(&text_mutex);
+				patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
+				mutex_unlock(&text_mutex);
+			}
+		}
+	}
+
+	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+		local_flush_icache_all();
+}