From 906d66df18faa4aac8d898ae6920d1014694a932 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Fri, 8 Dec 2006 02:36:25 -0800 Subject: [PATCH] [PATCH] crc32: replace bitreverse by bitrev32 This patch replaces bitreverse() by bitrev32. The only users of bitreverse() are crc32 itself and via-velocity. Cc: Jeff Garzik Cc: Matt Domsch Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/net/via-velocity.c | 2 +- include/linux/crc32.h | 4 ++-- lib/Kconfig | 1 + lib/crc32.c | 28 +++++----------------------- 4 files changed, 9 insertions(+), 26 deletions(-) diff --git a/drivers/net/via-velocity.c b/drivers/net/via-velocity.c index 74f894795a..4587f23f4e 100644 --- a/drivers/net/via-velocity.c +++ b/drivers/net/via-velocity.c @@ -3132,7 +3132,7 @@ static u16 wol_calc_crc(int size, u8 * pattern, u8 *mask_pattern) } /* Finally, invert the result once to get the correct data */ crc = ~crc; - return bitreverse(crc) >> 16; + return bitrev32(crc) >> 16; } /** diff --git a/include/linux/crc32.h b/include/linux/crc32.h index 56c0645789..e20dd1f9b4 100644 --- a/include/linux/crc32.h +++ b/include/linux/crc32.h @@ -6,10 +6,10 @@ #define _LINUX_CRC32_H #include +#include extern u32 crc32_le(u32 crc, unsigned char const *p, size_t len); extern u32 crc32_be(u32 crc, unsigned char const *p, size_t len); -extern u32 bitreverse(u32 in); #define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)data, length) @@ -21,7 +21,7 @@ extern u32 bitreverse(u32 in); * is in bit nr 0], thus it must be reversed before use. Except for * nics that bit swap the result internally... */ -#define ether_crc(length, data) bitreverse(crc32_le(~0, data, length)) +#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length)) #define ether_crc_le(length, data) crc32_le(~0, data, length) #endif /* _LINUX_CRC32_H */ diff --git a/lib/Kconfig b/lib/Kconfig index 0d68355908..47b172df3e 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -26,6 +26,7 @@ config CRC16 config CRC32 tristate "CRC32 functions" default y + select BITREVERSE help This option is provided for the case where no in-kernel-tree modules require CRC32 functions, but a module built outside the diff --git a/lib/crc32.c b/lib/crc32.c index 285fd9bc61..bfc33314c7 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -235,23 +235,8 @@ u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len) } #endif -/** - * bitreverse - reverse the order of bits in a u32 value - * @x: value to be bit-reversed - */ -u32 bitreverse(u32 x) -{ - x = (x >> 16) | (x << 16); - x = (x >> 8 & 0x00ff00ff) | (x << 8 & 0xff00ff00); - x = (x >> 4 & 0x0f0f0f0f) | (x << 4 & 0xf0f0f0f0); - x = (x >> 2 & 0x33333333) | (x << 2 & 0xcccccccc); - x = (x >> 1 & 0x55555555) | (x << 1 & 0xaaaaaaaa); - return x; -} - EXPORT_SYMBOL(crc32_le); EXPORT_SYMBOL(crc32_be); -EXPORT_SYMBOL(bitreverse); /* * A brief CRC tutorial. @@ -400,10 +385,7 @@ buf_dump(char const *prefix, unsigned char const *buf, size_t len) static void bytereverse(unsigned char *buf, size_t len) { while (len--) { - unsigned char x = *buf; - x = (x >> 4) | (x << 4); - x = (x >> 2 & 0x33) | (x << 2 & 0xcc); - x = (x >> 1 & 0x55) | (x << 1 & 0xaa); + unsigned char x = bitrev8(*buf); *buf++ = x; } } @@ -460,11 +442,11 @@ static u32 test_step(u32 init, unsigned char *buf, size_t len) /* Now swap it around for the other test */ bytereverse(buf, len + 4); - init = bitreverse(init); - crc2 = bitreverse(crc1); - if (crc1 != bitreverse(crc2)) + init = bitrev32(init); + crc2 = bitrev32(crc1); + if (crc1 != bitrev32(crc2)) printf("\nBit reversal fail: 0x%08x -> 0x%08x -> 0x%08x\n", - crc1, crc2, bitreverse(crc2)); + crc1, crc2, bitrev32(crc2)); crc1 = crc32_le(init, buf, len); if (crc1 != crc2) printf("\nCRC endianness fail: 0x%08x != 0x%08x\n", crc1, -- 2.39.5