[1/4] crc32: Bolt on crc32c

Message ID	20111004235403.1560.55503.stgit@elm3c44.beaverton.ibm.com
State	Not Applicable, archived
Headers	show Return-Path: <linux-ext4-owner@vger.kernel.org> Subject: [PATCH 1/4] crc32: Bolt on crc32c To: Andreas Dilger <adilger.kernel@dilger.ca>, Herbert Xu <herbert@gondor.apana.org.au>, Theodore Tso <tytso@mit.edu>, David Miller <davem@davemloft.net>, "Darrick J. Wong" <djwong@us.ibm.com> From: "Darrick J. Wong" <djwong@us.ibm.com> Cc: Joakim Tjernlund <joakim.tjernlund@transmode.se>, Bob Pearson <rpearson@systemfabricworks.com>, linux-kernel <linux-kernel@vger.kernel.org>, Mingming Cao <cmm@us.ibm.com>, linux-crypto <linux-crypto@vger.kernel.org>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, linux-ext4@vger.kernel.org Date: Tue, 04 Oct 2011 16:54:03 -0700 Message-ID: <20111004235403.1560.55503.stgit@elm3c44.beaverton.ibm.com> In-Reply-To: <20111004235357.1560.12602.stgit@elm3c44.beaverton.ibm.com> References: <20111004235357.1560.12602.stgit@elm3c44.beaverton.ibm.com> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk

diff --git a/include/linux/crc32.h b/include/linux/crc32.h index 391a259..68267b6 100644 --- a/include/linux/crc32.h +++ b/include/linux/crc32.h @@ -11,6 +11,8 @@ 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 __crc32c_le(u32 crc, unsigned char const *p, size_t len); + #define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length) /* diff --git a/lib/Kconfig b/lib/Kconfig index 8e0bcbd..477be04 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -51,14 +51,14 @@ config CRC_ITU_T functions require M here. config CRC32 - tristate "CRC32 functions" + tristate "CRC32/CRC32c 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 - kernel tree does. Such modules that use library CRC32 functions - require M here. + modules require CRC32/CRC32c functions, but a module built outside + the kernel tree does. Such modules that use library CRC32/CRC32c + functions require M here. config CRC32_SELFTEST bool "CRC32 perform self test on init" diff --git a/lib/crc32.c b/lib/crc32.c index d56516d..8df9561 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -46,7 +46,7 @@ #include "crc32table.h" MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>"); -MODULE_DESCRIPTION("Ethernet CRC32 calculations"); +MODULE_DESCRIPTION("Various CRC32 calculations"); MODULE_LICENSE("GPL"); #if CRC_LE_BITS > 8 || CRC_BE_BITS > 8 @@ -135,46 +135,57 @@ 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; } + +u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_le_generic(crc, p, len, crc32table_le, CRCPOLY_LE); +} EXPORT_SYMBOL(crc32_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); +} +EXPORT_SYMBOL(__crc32c_le); + /** * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32 * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for @@ -182,7 +193,9 @@ 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 +203,40 @@ 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; } + +u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len) +{ + return crc32_be_generic(crc, p, len, crc32table_be, CRCPOLY_BE); +} EXPORT_SYMBOL(crc32_be); #ifdef CONFIG_CRC32_SELFTEST diff --git a/lib/crc32defs.h b/lib/crc32defs.h index 8181592..6fd1917 100644 --- a/lib/crc32defs.h +++ b/lib/crc32defs.h @@ -7,6 +7,13 @@ #define CRCPOLY_BE 0x04c11db7 /* + * This is the CRC32c polynomial, as outlined by Castagnoli. + * x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+ + * x^8+x^6+x^0 + */ +#define CRC32C_POLY_LE 0x82F63B78 + +/* * How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64. * For less performance-sensitive, use 4 or 8 to save table size. * For larger systems choose same as CPU architecture as default. diff --git a/lib/gen_crc32table.c b/lib/gen_crc32table.c index 0d9edd1..8f8d543 100644 --- a/lib/gen_crc32table.c +++ b/lib/gen_crc32table.c @@ -23,6 +23,7 @@ static uint32_t crc32table_le[LE_TABLE_ROWS][256]; static uint32_t crc32table_be[BE_TABLE_ROWS][256]; +static uint32_t crc32ctable_le[LE_TABLE_ROWS][256]; /** * crc32init_le() - allocate and initialize LE table data @@ -31,27 +32,38 @@ static uint32_t crc32table_be[BE_TABLE_ROWS][256]; * fact that crctable[i^j] = crctable[i] ^ crctable[j]. * */ -static void crc32init_le(void) +static void crc32init_le_generic(const uint32_t polynomial, + uint32_t (*tab)[256]) { unsigned i, j; uint32_t crc = 1; - crc32table_le[0][0] = 0; + tab[0][0] = 0; for (i = LE_TABLE_SIZE >> 1; i; i >>= 1) { - crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0); + crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0); for (j = 0; j < LE_TABLE_SIZE; j += 2 * i) - crc32table_le[0][i + j] = crc ^ crc32table_le[0][j]; + tab[0][i + j] = crc ^ tab[0][j]; } for (i = 0; i < LE_TABLE_SIZE; i++) { - crc = crc32table_le[0][i]; + crc = tab[0][i]; for (j = 1; j < LE_TABLE_ROWS; j++) { - crc = crc32table_le[0][crc & 0xff] ^ (crc >> 8); - crc32table_le[j][i] = crc; + crc = tab[0][crc & 0xff] ^ (crc >> 8); + tab[j][i] = crc; } } } +static void crc32init_le(void) +{ + crc32init_le_generic(CRCPOLY_LE, crc32table_le); +} + +static void crc32cinit_le(void) +{ + crc32init_le_generic(CRC32C_POLY_LE, crc32ctable_le); +} + /** * crc32init_be() - allocate and initialize BE table data */ @@ -114,6 +126,15 @@ int main(int argc, char** argv) BE_TABLE_SIZE, "tobe"); printf("};\n"); } + if (CRC_LE_BITS > 1) { + crc32cinit_le(); + printf("static const u32 __cacheline_aligned " + "crc32ctable_le[%d][%d] = {", + LE_TABLE_ROWS, LE_TABLE_SIZE); + output_table(crc32ctable_le, LE_TABLE_ROWS, + LE_TABLE_SIZE, "tole"); + printf("};\n"); + } return 0; }

[1/4] crc32: Bolt on crc32c

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