diff options
Diffstat (limited to 'lib/crc32.c')
| -rw-r--r-- | lib/crc32.c | 233 |
1 files changed, 12 insertions, 221 deletions
diff --git a/lib/crc32.c b/lib/crc32.c index 5649847d0a8d..ede6131f66fc 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -30,20 +30,6 @@ #include <linux/crc32poly.h> #include <linux/module.h> #include <linux/types.h> -#include <linux/sched.h> -#include "crc32defs.h" - -#if CRC_LE_BITS > 8 -# define tole(x) ((__force u32) cpu_to_le32(x)) -#else -# define tole(x) (x) -#endif - -#if CRC_BE_BITS > 8 -# define tobe(x) ((__force u32) cpu_to_be32(x)) -#else -# define tobe(x) (x) -#endif #include "crc32table.h" @@ -51,162 +37,21 @@ MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>"); MODULE_DESCRIPTION("Various CRC32 calculations"); MODULE_LICENSE("GPL"); -#if CRC_LE_BITS > 8 || CRC_BE_BITS > 8 - -/* implements slicing-by-4 or slicing-by-8 algorithm */ -static inline u32 __pure -crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256]) +u32 __pure crc32_le_base(u32 crc, const u8 *p, size_t len) { -# ifdef __LITTLE_ENDIAN -# define DO_CRC(x) crc = t0[(crc ^ (x)) & 255] ^ (crc >> 8) -# define DO_CRC4 (t3[(q) & 255] ^ t2[(q >> 8) & 255] ^ \ - t1[(q >> 16) & 255] ^ t0[(q >> 24) & 255]) -# define DO_CRC8 (t7[(q) & 255] ^ t6[(q >> 8) & 255] ^ \ - t5[(q >> 16) & 255] ^ t4[(q >> 24) & 255]) -# else -# define DO_CRC(x) crc = t0[((crc >> 24) ^ (x)) & 255] ^ (crc << 8) -# define DO_CRC4 (t0[(q) & 255] ^ t1[(q >> 8) & 255] ^ \ - t2[(q >> 16) & 255] ^ t3[(q >> 24) & 255]) -# define DO_CRC8 (t4[(q) & 255] ^ t5[(q >> 8) & 255] ^ \ - t6[(q >> 16) & 255] ^ t7[(q >> 24) & 255]) -# endif - const u32 *b; - size_t rem_len; -# ifdef CONFIG_X86 - size_t i; -# endif - const u32 *t0=tab[0], *t1=tab[1], *t2=tab[2], *t3=tab[3]; -# if CRC_LE_BITS != 32 - const u32 *t4 = tab[4], *t5 = tab[5], *t6 = tab[6], *t7 = tab[7]; -# endif - u32 q; - - /* Align it */ - if (unlikely((long)buf & 3 && len)) { - do { - DO_CRC(*buf++); - } while ((--len) && ((long)buf)&3); - } - -# if CRC_LE_BITS == 32 - rem_len = len & 3; - len = len >> 2; -# else - rem_len = len & 7; - len = len >> 3; -# endif - - b = (const u32 *)buf; -# ifdef CONFIG_X86 - --b; - for (i = 0; i < len; i++) { -# else - for (--b; len; --len) { -# endif - q = crc ^ *++b; /* use pre increment for speed */ -# if CRC_LE_BITS == 32 - crc = DO_CRC4; -# else - crc = DO_CRC8; - q = *++b; - crc ^= DO_CRC4; -# endif - } - len = rem_len; - /* And the last few bytes */ - if (len) { - u8 *p = (u8 *)(b + 1) - 1; -# ifdef CONFIG_X86 - for (i = 0; i < len; i++) - DO_CRC(*++p); /* use pre increment for speed */ -# else - do { - DO_CRC(*++p); /* use pre increment for speed */ - } while (--len); -# endif - } + while (len--) + crc = (crc >> 8) ^ crc32table_le[(crc & 255) ^ *p++]; return crc; -#undef DO_CRC -#undef DO_CRC4 -#undef DO_CRC8 } -#endif - +EXPORT_SYMBOL(crc32_le_base); -/** - * crc32_le_generic() - Calculate bitwise little-endian Ethernet AUTODIN II - * CRC32/CRC32C - * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for other - * uses, or the previous crc32/crc32c value if computing incrementally. - * @p: pointer to buffer over which CRC32/CRC32C is run - * @len: length of buffer @p - * @tab: little-endian Ethernet table - * @polynomial: CRC32/CRC32c LE polynomial - */ -static inline u32 __pure crc32_le_generic(u32 crc, unsigned char const *p, - size_t len, const u32 (*tab)[256], - u32 polynomial) +u32 __pure crc32c_le_base(u32 crc, const u8 *p, size_t len) { -#if CRC_LE_BITS == 1 - int i; - while (len--) { - crc ^= *p++; - for (i = 0; i < 8; i++) - crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0); - } -# elif CRC_LE_BITS == 2 - while (len--) { - crc ^= *p++; - 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) ^ 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) ^ tab[0][crc & 255]; - } -# else - crc = (__force u32) __cpu_to_le32(crc); - crc = crc32_body(crc, p, len, tab); - crc = __le32_to_cpu((__force __le32)crc); -#endif + while (len--) + crc = (crc >> 8) ^ crc32ctable_le[(crc & 255) ^ *p++]; return crc; } - -#if CRC_LE_BITS == 1 -u32 __pure __weak crc32_le(u32 crc, unsigned char const *p, size_t len) -{ - return crc32_le_generic(crc, p, len, NULL, CRC32_POLY_LE); -} -u32 __pure __weak __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 __weak crc32_le(u32 crc, unsigned char const *p, size_t len) -{ - return crc32_le_generic(crc, p, len, crc32table_le, CRC32_POLY_LE); -} -u32 __pure __weak __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); - -u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias(crc32_le); -u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias(__crc32c_le); -u32 __pure crc32_be_base(u32, unsigned char const *, size_t) __alias(crc32_be); +EXPORT_SYMBOL(crc32c_le_base); /* * This multiplies the polynomials x and y modulo the given modulus. @@ -281,64 +126,10 @@ u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len) EXPORT_SYMBOL(crc32_le_shift); EXPORT_SYMBOL(__crc32c_le_shift); -/** - * crc32_be_generic() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32 - * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for - * other uses, or the previous crc32 value if computing incrementally. - * @p: pointer to buffer over which CRC32 is run - * @len: length of buffer @p - * @tab: big-endian Ethernet table - * @polynomial: CRC32 BE polynomial - */ -static inline u32 __pure crc32_be_generic(u32 crc, unsigned char const *p, - size_t len, const u32 (*tab)[256], - u32 polynomial) +u32 __pure crc32_be_base(u32 crc, const u8 *p, size_t len) { -#if CRC_BE_BITS == 1 - int i; - while (len--) { - crc ^= *p++ << 24; - for (i = 0; i < 8; i++) - crc = - (crc << 1) ^ ((crc & 0x80000000) ? polynomial : - 0); - } -# elif CRC_BE_BITS == 2 - while (len--) { - crc ^= *p++ << 24; - 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) ^ tab[0][crc >> 28]; - crc = (crc << 4) ^ tab[0][crc >> 28]; - } -# elif CRC_BE_BITS == 8 - while (len--) { - crc ^= *p++ << 24; - crc = (crc << 8) ^ tab[0][crc >> 24]; - } -# else - crc = (__force u32) __cpu_to_be32(crc); - crc = crc32_body(crc, p, len, tab); - crc = __be32_to_cpu((__force __be32)crc); -# endif + while (len--) + crc = (crc << 8) ^ crc32table_be[(crc >> 24) ^ *p++]; return crc; } - -#if CRC_BE_BITS == 1 -u32 __pure __weak crc32_be(u32 crc, unsigned char const *p, size_t len) -{ - return crc32_be_generic(crc, p, len, NULL, CRC32_POLY_BE); -} -#else -u32 __pure __weak crc32_be(u32 crc, unsigned char const *p, size_t len) -{ - return crc32_be_generic(crc, p, len, crc32table_be, CRC32_POLY_BE); -} -#endif -EXPORT_SYMBOL(crc32_be); +EXPORT_SYMBOL(crc32_be_base); |