summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--include/linux/crc64.h11
-rw-r--r--lib/.gitignore2
-rw-r--r--lib/Kconfig8
-rw-r--r--lib/Makefile11
-rw-r--r--lib/crc64.c56
-rw-r--r--lib/gen_crc64table.c68
6 files changed, 156 insertions, 0 deletions
diff --git a/include/linux/crc64.h b/include/linux/crc64.h
new file mode 100644
index 000000000000..c756e65a1b58
--- /dev/null
+++ b/include/linux/crc64.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * See lib/crc64.c for the related specification and polynomial arithmetic.
+ */
+#ifndef _LINUX_CRC64_H
+#define _LINUX_CRC64_H
+
+#include <linux/types.h>
+
+u64 __pure crc64_be(u64 crc, const void *p, size_t len);
+#endif /* _LINUX_CRC64_H */
diff --git a/lib/.gitignore b/lib/.gitignore
index 09aae85418ab..f2a39c9e5485 100644
--- a/lib/.gitignore
+++ b/lib/.gitignore
@@ -2,5 +2,7 @@
# Generated files
#
gen_crc32table
+gen_crc64table
crc32table.h
+crc64table.h
oid_registry_data.c
diff --git a/lib/Kconfig b/lib/Kconfig
index 706836ec314d..9c10b9852563 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -170,6 +170,14 @@ config CRC32_BIT
endchoice
+config CRC64
+ tristate "CRC64 functions"
+ help
+ This option is provided for the case where no in-kernel-tree
+ modules require CRC64 functions, but a module built outside
+ the kernel tree does. Such modules that use library CRC64
+ functions require M here.
+
config CRC4
tristate "CRC4 functions"
help
diff --git a/lib/Makefile b/lib/Makefile
index d95bb2525101..9baefb6cb1a1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -103,6 +103,7 @@ obj-$(CONFIG_CRC16) += crc16.o
obj-$(CONFIG_CRC_T10DIF)+= crc-t10dif.o
obj-$(CONFIG_CRC_ITU_T) += crc-itu-t.o
obj-$(CONFIG_CRC32) += crc32.o
+obj-$(CONFIG_CRC64) += crc64.o
obj-$(CONFIG_CRC32_SELFTEST) += crc32test.o
obj-$(CONFIG_CRC4) += crc4.o
obj-$(CONFIG_CRC7) += crc7.o
@@ -217,7 +218,9 @@ obj-$(CONFIG_FONT_SUPPORT) += fonts/
obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o
hostprogs-y := gen_crc32table
+hostprogs-y += gen_crc64table
clean-files := crc32table.h
+clean-files += crc64table.h
$(obj)/crc32.o: $(obj)/crc32table.h
@@ -227,6 +230,14 @@ quiet_cmd_crc32 = GEN $@
$(obj)/crc32table.h: $(obj)/gen_crc32table
$(call cmd,crc32)
+$(obj)/crc64.o: $(obj)/crc64table.h
+
+quiet_cmd_crc64 = GEN $@
+ cmd_crc64 = $< > $@
+
+$(obj)/crc64table.h: $(obj)/gen_crc64table
+ $(call cmd,crc64)
+
#
# Build a fast OID lookip registry from include/linux/oid_registry.h
#
diff --git a/lib/crc64.c b/lib/crc64.c
new file mode 100644
index 000000000000..0ef8ae6ac047
--- /dev/null
+++ b/lib/crc64.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Normal 64-bit CRC calculation.
+ *
+ * This is a basic crc64 implementation following ECMA-182 specification,
+ * which can be found from,
+ * http://www.ecma-international.org/publications/standards/Ecma-182.htm
+ *
+ * Dr. Ross N. Williams has a great document to introduce the idea of CRC
+ * algorithm, here the CRC64 code is also inspired by the table-driven
+ * algorithm and detail example from this paper. This paper can be found
+ * from,
+ * http://www.ross.net/crc/download/crc_v3.txt
+ *
+ * crc64table[256] is the lookup table of a table-driven 64-bit CRC
+ * calculation, which is generated by gen_crc64table.c in kernel build
+ * time. The polynomial of crc64 arithmetic is from ECMA-182 specification
+ * as well, which is defined as,
+ *
+ * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
+ * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
+ * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
+ * x^7 + x^4 + x + 1
+ *
+ * Copyright 2018 SUSE Linux.
+ * Author: Coly Li <colyli@suse.de>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include "crc64table.h"
+
+MODULE_DESCRIPTION("CRC64 calculations");
+MODULE_LICENSE("GPL v2");
+
+/**
+ * crc64_be - Calculate bitwise big-endian ECMA-182 CRC64
+ * @crc: seed value for computation. 0 or (u64)~0 for a new CRC calculation,
+ or the previous crc64 value if computing incrementally.
+ * @p: pointer to buffer over which CRC64 is run
+ * @len: length of buffer @p
+ */
+u64 __pure crc64_be(u64 crc, const void *p, size_t len)
+{
+ size_t i, t;
+
+ const unsigned char *_p = p;
+
+ for (i = 0; i < len; i++) {
+ t = ((crc >> 56) ^ (*_p++)) & 0xFF;
+ crc = crc64table[t] ^ (crc << 8);
+ }
+
+ return crc;
+}
+EXPORT_SYMBOL_GPL(crc64_be);
diff --git a/lib/gen_crc64table.c b/lib/gen_crc64table.c
new file mode 100644
index 000000000000..9011926e4162
--- /dev/null
+++ b/lib/gen_crc64table.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generate lookup table for the table-driven CRC64 calculation.
+ *
+ * gen_crc64table is executed in kernel build time and generates
+ * lib/crc64table.h. This header is included by lib/crc64.c for
+ * the table-driven CRC64 calculation.
+ *
+ * See lib/crc64.c for more information about which specification
+ * and polynomial arithmetic that gen_crc64table.c follows to
+ * generate the lookup table.
+ *
+ * Copyright 2018 SUSE Linux.
+ * Author: Coly Li <colyli@suse.de>
+ */
+#include <inttypes.h>
+#include <stdio.h>
+
+#include <linux/swab.h>
+
+#define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL
+
+static uint64_t crc64_table[256] = {0};
+
+static void generate_crc64_table(void)
+{
+ 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) ^ CRC64_ECMA182_POLY;
+ else
+ crc <<= 1;
+ c <<= 1;
+ }
+
+ crc64_table[i] = crc;
+ }
+}
+
+static void print_crc64_table(void)
+{
+ int i;
+
+ 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");
+ for (i = 0; i < 256; i++) {
+ printf("\t0x%016" PRIx64 "ULL", crc64_table[i]);
+ if (i & 0x1)
+ printf(",\n");
+ else
+ printf(", ");
+ }
+ printf("};\n");
+}
+
+int main(int argc, char *argv[])
+{
+ generate_crc64_table();
+ print_crc64_table();
+ return 0;
+}