1 files changed, 88 insertions, 0 deletions
diff --git a/lib/crc/gen_crc64table.c b/lib/crc/gen_crc64table.c
new file mode 100644
index 000000000000..f2be9f62bab7
--- /dev/null
+++ b/lib/crc/gen_crc64table.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This host program runs at kernel build time and generates the lookup tables
+ * used by the generic CRC64 code.
+ *
+ * Copyright 2018 SUSE Linux.
+ *   Author: Coly Li <colyli@suse.de>
+ */
+#include <inttypes.h>
+#include <stdio.h>
+
+#define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL
+#define CRC64_NVME_POLY 0x9A6C9329AC4BC9B5ULL
+
+static uint64_t crc64_table[256] = {0};
+static uint64_t crc64_nvme_table[256] = {0};
+
+static void generate_reflected_crc64_table(uint64_t table[256], uint64_t poly)
+{
+	uint64_t i, j, c, crc;
+
+	for (i = 0; i < 256; i++) {
+		crc = 0ULL;
+		c = i;
+
+		for (j = 0; j < 8; j++) {
+			if ((crc ^ (c >> j)) & 1)
+				crc = (crc >> 1) ^ poly;
+			else
+				crc >>= 1;
+		}
+		table[i] = crc;
+	}
+}
+
+static void generate_crc64_table(uint64_t table[256], uint64_t poly)
+{
+	uint64_t i, j, c, crc;
+
+	for (i = 0; i < 256; i++) {
+		crc = 0;
+		c = i << 56;
+
+		for (j = 0; j < 8; j++) {
+			if ((crc ^ c) & 0x8000000000000000ULL)
+				crc = (crc << 1) ^ poly;
+			else
+				crc <<= 1;
+			c <<= 1;
+		}
+
+		table[i] = crc;
+	}
+}
+
+static void output_table(uint64_t table[256])
+{
+	int i;
+
+	for (i = 0; i < 256; i++) {
+		printf("\t0x%016" PRIx64 "ULL", table[i]);
+		if (i & 0x1)
+			printf(",\n");
+		else
+			printf(", ");
+	}
+	printf("};\n");
+}
+
+static void print_crc64_tables(void)
+{
+	printf("/* this file is generated - do not edit */\n\n");
+	printf("#include <linux/types.h>\n");
+	printf("#include <linux/cache.h>\n\n");
+	printf("static const u64 ____cacheline_aligned crc64table[256] = {\n");
+	output_table(crc64_table);
+
+	printf("\nstatic const u64 ____cacheline_aligned crc64nvmetable[256] = {\n");
+	output_table(crc64_nvme_table);
+}
+
+int main(int argc, char *argv[])
+{
+	generate_crc64_table(crc64_table, CRC64_ECMA182_POLY);
+	generate_reflected_crc64_table(crc64_nvme_table, CRC64_NVME_POLY);
+	print_crc64_tables();
+	return 0;
+}