[PATCH 4/5] fs: ext4: Use CRC-16 implementation from linux/crc16.h
Stefan Roese
sr at denx.de
Thu Apr 21 16:35:19 CEST 2022
On 4/12/22 11:20, Pali Rohár wrote:
> 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 at kernel.org>
Reviewed-by: Stefan Roese <sr at denx.de>
Thanks,
Stefan
> ---
> fs/ext4/Makefile | 2 +-
> fs/ext4/crc16.c | 62 -------------------------------------------
> fs/ext4/crc16.h | 16 -----------
> fs/ext4/ext4_common.c | 8 +++---
> fs/ext4/ext4_common.h | 2 +-
> 5 files changed, 6 insertions(+), 84 deletions(-)
> delete mode 100644 fs/ext4/crc16.c
> delete mode 100644 fs/ext4/crc16.h
>
> diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
> index c2544beee3a5..6ae44a2d0a34 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 3afb34daefa1..000000000000
> --- 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 5fd113a56c03..000000000000
> --- 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 at 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 c52cc400e1f2..d49ba4a9954d 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 beaee9c80bd6..504c708b0647 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
Viele Grüße,
Stefan Roese
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr at denx.de
More information about the U-Boot
mailing list