1 files changed, 119 insertions, 0 deletions
diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
new file mode 100644
index 000000000000..3d9a32d791f7
--- /dev/null
+++ b/arch/riscv/errata/sifive/errata.c
@@ -0,0 +1,119 @@
+// 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[32];
+	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 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->patch_id >= ERRATA_SIFIVE_NUMBER) {
+			WARN(1, "This errata id:%d is not in kernel errata list", alt->patch_id);
+			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)
+		warn_miss_errata(cpu_req_errata - cpu_apply_errata);
+}