From 46c5801eaf86e83cb3a4142ad35188db5011fff0 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 23 Mar 2012 15:02:25 -0700 Subject: crc32: bolt on crc32c Reuse the existing crc32 code to stamp out a crc32c implementation. Signed-off-by: Darrick J. Wong Cc: Herbert Xu Cc: Bob Pearson Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/crc32.c | 79 +++++++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 56 insertions(+), 23 deletions(-) (limited to 'lib/crc32.c') diff --git a/lib/crc32.c b/lib/crc32.c index a1a5145a93ba..87678dd1141e 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -46,7 +46,7 @@ #include "crc32table.h" MODULE_AUTHOR("Matt Domsch "); -MODULE_DESCRIPTION("Ethernet CRC32 calculations"); +MODULE_DESCRIPTION("Various CRC32 calculations"); MODULE_LICENSE("GPL"); #if CRC_LE_BITS > 8 || CRC_BE_BITS > 8 @@ -135,45 +135,66 @@ crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256]) * @p: pointer to buffer over which CRC is run * @len: length of buffer @p */ -u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len) +static inline u32 __pure crc32_le_generic(u32 crc, unsigned char const *p, + size_t len, const u32 (*tab)[256], + u32 polynomial) { #if CRC_LE_BITS == 1 int i; while (len--) { crc ^= *p++; for (i = 0; i < 8; i++) - crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0); + crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0); } # elif CRC_LE_BITS == 2 while (len--) { crc ^= *p++; - crc = (crc >> 2) ^ crc32table_le[0][crc & 3]; - crc = (crc >> 2) ^ crc32table_le[0][crc & 3]; - crc = (crc >> 2) ^ crc32table_le[0][crc & 3]; - crc = (crc >> 2) ^ crc32table_le[0][crc & 3]; + crc = (crc >> 2) ^ tab[0][crc & 3]; + crc = (crc >> 2) ^ tab[0][crc & 3]; + crc = (crc >> 2) ^ tab[0][crc & 3]; + crc = (crc >> 2) ^ tab[0][crc & 3]; } # elif CRC_LE_BITS == 4 while (len--) { crc ^= *p++; - crc = (crc >> 4) ^ crc32table_le[0][crc & 15]; - crc = (crc >> 4) ^ crc32table_le[0][crc & 15]; + crc = (crc >> 4) ^ tab[0][crc & 15]; + crc = (crc >> 4) ^ tab[0][crc & 15]; } # elif CRC_LE_BITS == 8 /* aka Sarwate algorithm */ while (len--) { crc ^= *p++; - crc = (crc >> 8) ^ crc32table_le[0][crc & 255]; + crc = (crc >> 8) ^ tab[0][crc & 255]; } # else - const u32 (*tab)[] = crc32table_le; - crc = (__force u32) __cpu_to_le32(crc); crc = crc32_body(crc, p, len, tab); crc = __le32_to_cpu((__force __le32)crc); #endif return crc; } + +#if CRC_LE_BITS == 1 +u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_le_generic(crc, p, len, NULL, CRCPOLY_LE); +} +u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_le_generic(crc, p, len, NULL, CRC32C_POLY_LE); +} +#else +u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_le_generic(crc, p, len, crc32table_le, CRCPOLY_LE); +} +u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_le_generic(crc, p, len, crc32ctable_le, CRC32C_POLY_LE); +} +#endif EXPORT_SYMBOL(crc32_le); +EXPORT_SYMBOL(__crc32c_le); /** * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32 @@ -182,7 +203,9 @@ EXPORT_SYMBOL(crc32_le); * @p: pointer to buffer over which CRC is run * @len: length of buffer @p */ -u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len) +static inline u32 __pure crc32_be_generic(u32 crc, unsigned char const *p, + size_t len, const u32 (*tab)[256], + u32 polynomial) { #if CRC_BE_BITS == 1 int i; @@ -190,37 +213,47 @@ u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len) crc ^= *p++ << 24; for (i = 0; i < 8; i++) crc = - (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : + (crc << 1) ^ ((crc & 0x80000000) ? polynomial : 0); } # elif CRC_BE_BITS == 2 while (len--) { crc ^= *p++ << 24; - crc = (crc << 2) ^ crc32table_be[0][crc >> 30]; - crc = (crc << 2) ^ crc32table_be[0][crc >> 30]; - crc = (crc << 2) ^ crc32table_be[0][crc >> 30]; - crc = (crc << 2) ^ crc32table_be[0][crc >> 30]; + crc = (crc << 2) ^ tab[0][crc >> 30]; + crc = (crc << 2) ^ tab[0][crc >> 30]; + crc = (crc << 2) ^ tab[0][crc >> 30]; + crc = (crc << 2) ^ tab[0][crc >> 30]; } # elif CRC_BE_BITS == 4 while (len--) { crc ^= *p++ << 24; - crc = (crc << 4) ^ crc32table_be[0][crc >> 28]; - crc = (crc << 4) ^ crc32table_be[0][crc >> 28]; + crc = (crc << 4) ^ tab[0][crc >> 28]; + crc = (crc << 4) ^ tab[0][crc >> 28]; } # elif CRC_BE_BITS == 8 while (len--) { crc ^= *p++ << 24; - crc = (crc << 8) ^ crc32table_be[0][crc >> 24]; + crc = (crc << 8) ^ tab[0][crc >> 24]; } # else - const u32 (*tab)[] = crc32table_be; - crc = (__force u32) __cpu_to_be32(crc); crc = crc32_body(crc, p, len, tab); crc = __be32_to_cpu((__force __be32)crc); # endif return crc; } + +#if CRC_LE_BITS == 1 +u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_be_generic(crc, p, len, NULL, CRCPOLY_BE); +} +#else +u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_be_generic(crc, p, len, crc32table_be, CRCPOLY_BE); +} +#endif EXPORT_SYMBOL(crc32_be); #ifdef CONFIG_CRC32_SELFTEST -- cgit v1.2.3