From 85d8bf57131a21424b50e50884372e813345f09a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Beh=C3=BAn?= <marek.behun@nic.cz>
Date: Sun, 3 Sep 2017 17:00:23 +0200
Subject: [PATCH] lib: Add CRC32-C

This is needed for BTRFS.

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

 create mode 100644 lib/crc32c.c
---
 include/u-boot/crc.h |  4 ++++
 lib/Kconfig          |  3 +++
 lib/Makefile         |  1 +
 lib/crc32c.c         | 38 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+)
 create mode 100644 lib/crc32c.c

diff --git a/include/u-boot/crc.h b/include/u-boot/crc.h
index 6764d58..6d08f5d 100644
--- a/include/u-boot/crc.h
+++ b/include/u-boot/crc.h
@@ -28,4 +28,8 @@ uint32_t crc32_no_comp (uint32_t, const unsigned char *, uint);
 void crc32_wd_buf(const unsigned char *input, uint ilen,
 		    unsigned char *output, uint chunk_sz);
 
+/* lib/crc32c.c */
+void crc32c_init(uint32_t *, uint32_t);
+uint32_t crc32c_cal(uint32_t, const char *, int, uint32_t *);
+
 #endif /* _UBOOT_CRC_H */
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;
+	}
+}