fs: ext4: Use CRC-16 implementation from linux/crc16.h

Implementation in linux/crc16.h provides standard CRC-16 algorithm with
polynomial x^16 + x^15 + x^2 + 1. Use it and remove duplicate ext4 CRC-16
specific code.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>

5 files changed, 6 insertions, 84 deletions

diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index c2544beee3a..6ae44a2d0a3 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -8,4 +8,4 @@
 #
 
 obj-y := ext4fs.o ext4_common.o dev.o
-obj-$(CONFIG_EXT4_WRITE) += ext4_write.o ext4_journal.o crc16.o
+obj-$(CONFIG_EXT4_WRITE) += ext4_write.o ext4_journal.o
diff --git a/fs/ext4/crc16.c b/fs/ext4/crc16.c
deleted file mode 100644
index 3afb34daefa..00000000000
--- a/fs/ext4/crc16.c
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- *      crc16.c
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2. See the file COPYING for more details.
- */
-
-#include <common.h>
-#include <asm/byteorder.h>
-#include <linux/stat.h>
-#include "crc16.h"
-
-/** CRC table for the CRC-16. The poly is 0x8005 (x16 + x15 + x2 + 1) */
-static __u16 const crc16_table[256] = {
-	0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
-	0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
-	0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
-	0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
-	0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
-	0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
-	0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
-	0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
-	0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
-	0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
-	0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
-	0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
-	0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
-	0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
-	0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
-	0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
-	0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
-	0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
-	0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
-	0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
-	0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
-	0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
-	0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
-	0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
-	0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
-	0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
-	0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
-	0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
-	0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
-	0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
-	0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
-	0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
-};
-
-/**
- * Compute the CRC-16 for the data buffer
-*/
-
-unsigned int ext2fs_crc16(unsigned int crc,
-	const void *buffer, unsigned int len)
-{
-	const unsigned char *cp = buffer;
-
-	while (len--)
-		crc = (((crc >> 8) & 0xffU) ^
-		       crc16_table[(crc ^ *cp++) & 0xffU]) & 0x0000ffffU;
-	return crc;
-}
diff --git a/fs/ext4/crc16.h b/fs/ext4/crc16.h
deleted file mode 100644
index 5fd113a56c0..00000000000
--- a/fs/ext4/crc16.h
+++ /dev/null
@@ -1,16 +0,0 @@
-/*
- * crc16.h - CRC-16 routine
- * Implements the standard CRC-16:
- *  Width 16
- *  Poly  0x8005 (x16 + x15 + x2 + 1)
- *  Init  0
- *
- * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
- * This source code is licensed under the GNU General Public License,
- * Version 2. See the file COPYING for more details.
- */
-#ifndef __CRC16_H
-#define __CRC16_H
-extern unsigned int ext2fs_crc16(unsigned int crc,
-	const void *buffer, unsigned int len);
-#endif
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index c52cc400e1f..d49ba4a9954 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -427,14 +427,14 @@ uint16_t ext4fs_checksum_update(uint32_t i)
 	if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
 		int offset = offsetof(struct ext2_block_group, bg_checksum);
 
-		crc = ext2fs_crc16(~0, fs->sb->unique_id,
+		crc = crc16(~0, (__u8 *)fs->sb->unique_id,
 				   sizeof(fs->sb->unique_id));
-		crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
-		crc = ext2fs_crc16(crc, desc, offset);
+		crc = crc16(crc, (__u8 *)&le32_i, sizeof(le32_i));
+		crc = crc16(crc, (__u8 *)desc, offset);
 		offset += sizeof(desc->bg_checksum);	/* skip checksum */
 		assert(offset == sizeof(*desc));
 		if (offset < fs->gdsize) {
-			crc = ext2fs_crc16(crc, (__u8 *)desc + offset,
+			crc = crc16(crc, (__u8 *)desc + offset,
 					   fs->gdsize - offset);
 		}
 	}
diff --git a/fs/ext4/ext4_common.h b/fs/ext4/ext4_common.h
index beaee9c80bd..504c708b064 100644
--- a/fs/ext4/ext4_common.h
+++ b/fs/ext4/ext4_common.h
@@ -27,7 +27,7 @@
 #include <linux/errno.h>
 #if defined(CONFIG_EXT4_WRITE)
 #include "ext4_journal.h"
-#include "crc16.h"
+#include <linux/crc16.h>
 #endif
 
 #define YES		1