Messages in this thread Patch in this message | | | Date | Thu, 19 Oct 2006 01:42:23 +0900 | From | Akinobu Mita <> | Subject | [PATCH 2/6] crc32: replace bitreverse by bitrev32 |
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This patch replaces bitreverse() by bitrev32. The only users of bitreverse() are crc32 itself and via-velocity.
Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
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(-)
Index: work-fault-inject/drivers/net/via-velocity.c =================================================================== --- work-fault-inject.orig/drivers/net/via-velocity.c +++ work-fault-inject/drivers/net/via-velocity.c @@ -3132,7 +3132,7 @@ static u16 wol_calc_crc(int size, u8 * p } /* Finally, invert the result once to get the correct data */ crc = ~crc; - return bitreverse(crc) >> 16; + return bitrev32(crc) >> 16; } /** Index: work-fault-inject/include/linux/crc32.h =================================================================== --- work-fault-inject.orig/include/linux/crc32.h +++ work-fault-inject/include/linux/crc32.h @@ -6,10 +6,10 @@ #define _LINUX_CRC32_H #include <linux/types.h> +#include <linux/bitrev.h> 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 */ Index: work-fault-inject/lib/Kconfig =================================================================== --- work-fault-inject.orig/lib/Kconfig +++ work-fault-inject/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 Index: work-fault-inject/lib/crc32.c =================================================================== --- work-fault-inject.orig/lib/crc32.c +++ work-fault-inject/lib/crc32.c @@ -235,23 +235,8 @@ u32 __attribute_pure__ crc32_be(u32 crc, } #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 ch 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 /* 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, - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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