lib: Add CRC32-C

This is needed for BTRFS.

Signed-off-by: Marek Behun <marek.behun@nic.cz>

 create mode 100644 lib/crc32c.c

3 files changed, 42 insertions, 0 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 628ef8d..aef940f 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -146,6 +146,9 @@ config SHA_PROG_HW_ACCEL
 config MD5
 	bool
 
+config CRC32C
+	bool
+
 endmenu
 
 menu "Compression Support"
diff --git a/lib/Makefile b/lib/Makefile
index 8e1c9d1..80216c2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -71,6 +71,7 @@ obj-y += display_options.o
 CFLAGS_display_options.o := $(if $(BUILD_TAG),-DBUILD_TAG='"$(BUILD_TAG)"')
 obj-$(CONFIG_BCH) += bch.o
 obj-y += crc32.o
+obj-$(CONFIG_CRC32C) += crc32c.o
 obj-y += ctype.o
 obj-y += div64.o
 obj-y += hang.o
diff --git a/lib/crc32c.c b/lib/crc32c.c
new file mode 100644
index 0000000..322c08f
--- /dev/null
+++ b/lib/crc32c.c
@@ -0,0 +1,38 @@
+/*
+ * Copied from Linux kernel crypto/crc32c.c
+ * Copyright (c) 2004 Cisco Systems, Inc.
+ * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <compiler.h>
+
+uint32_t crc32c_cal(uint32_t crc, const char *data, int length,
+		    uint32_t *crc32c_table)
+{
+	while (length--)
+		crc = crc32c_table[(u8)(crc ^ *data++)] ^ (crc >> 8);
+
+	return crc;
+}
+
+void crc32c_init(uint32_t *crc32c_table, uint32_t pol)
+{
+	int i, j;
+	uint32_t v;
+	const uint32_t poly = pol; /* Bit-reflected CRC32C polynomial */
+
+	for (i = 0; i < 256; i++) {
+		v = i;
+		for (j = 0; j < 8; j++)
+			v = (v >> 1) ^ ((v & 1) ? poly : 0);
+
+		crc32c_table[i] = v;
+	}
+}