/* * Copied from the kernel source code, lib/libcrc32c.c. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ #include #include #include "crypto/crc32c.h" #include "common/cpu-utils.h" static uint32_t crc32c_ref(uint32_t crc, unsigned char const *data, uint32_t length); static uint32_t (*crc32c_impl)(uint32_t crc, unsigned char const *data, uint32_t length) = crc32c_ref; #ifdef __x86_64__ #ifdef __GLIBC__ /* asmlinkage */ unsigned int crc_pcl(const unsigned char *buffer, int len, unsigned int crc_init); static unsigned int crc32c_pcl(uint32_t crc, unsigned char const *data, uint32_t len) { return crc_pcl(data, len, crc); } #endif /* * Based on a posting to lkml by Austin Zhang * * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal. * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE) * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at: * http://www.intel.com/products/processor/manuals/ * Intel(R) 64 and IA-32 Architectures Software Developer's Manual * Volume 2A: Instruction Set Reference, A-M */ #if __SIZEOF_LONG__ == 8 #define REX_PRE "0x48, " #define SCALE_F 8 #else #define REX_PRE #define SCALE_F 4 #endif static uint32_t crc32c_intel_le_hw_byte(uint32_t crc, unsigned char const *data, uint32_t length) { while (length--) { __asm__ __volatile__( ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1" :"=S"(crc) :"0"(crc), "c"(*data) ); data++; } return crc; } /* * Accelerated implementation using SSE 4.2 extension for instruction crc32c. * Steps through buffer one byte at at time, calculates reflected crc using * table. */ static uint32_t crc32c_sse42(uint32_t crc, unsigned char const *data, uint32_t length) { unsigned int iquotient = length / SCALE_F; unsigned int iremainder = length % SCALE_F; unsigned long *ptmp = (unsigned long *)data; while (iquotient--) { __asm__ __volatile__( ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;" :"=S"(crc) :"0"(crc), "c"(*ptmp) ); ptmp++; } if (iremainder) crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp, iremainder); return crc; } void crc32c_init_accel(void) { /* * Musl reports a problem with linkage, use the old implementation for * now. */ if (0) { #ifdef __GLIBC__ } else if (cpu_has_feature(CPU_FLAG_PCLMUL)) { /* printf("CRC32C: pcl\n"); */ crc32c_impl = crc32c_pcl; #endif } else if (cpu_has_feature(CPU_FLAG_SSE42)) { /* printf("CRC32c: intel\n"); */ crc32c_impl = crc32c_sse42; } else { /* printf("CRC32c: fallback\n"); */ crc32c_impl = crc32c_ref; } } #else void crc32c_init_accel(void) { crc32c_impl = crc32c_ref; } #endif /* __x86_64__ */ /* * This is the CRC-32C table * Generated with: * width = 32 bits * poly = 0x1EDC6F41 * reflect input bytes = true * reflect output bytes = true */ static const uint32_t crc32c_table[256] = { 0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L, 0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL, 0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL, 0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L, 0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL, 0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L, 0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L, 0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL, 0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL, 0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L, 0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L, 0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL, 0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L, 0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL, 0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL, 0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L, 0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L, 0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L, 0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L, 0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L, 0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L, 0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L, 0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L, 0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L, 0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L, 0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L, 0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L, 0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L, 0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L, 0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L, 0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L, 0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L, 0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL, 0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L, 0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L, 0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL, 0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L, 0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL, 0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL, 0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L, 0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L, 0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL, 0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL, 0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L, 0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL, 0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L, 0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L, 0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL, 0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L, 0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL, 0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL, 0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L, 0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL, 0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L, 0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L, 0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL, 0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL, 0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L, 0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L, 0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL, 0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L, 0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL, 0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL, 0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L }; /* * Fallback implementation. Step through buffer one byte at at time, calculates * reflected crc using table, can accept an unaligned buffer. */ static uint32_t crc32c_ref(uint32_t crc, unsigned char const *data, uint32_t length) { while (length--) crc = crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8); return crc; } uint32_t crc32c_le(uint32_t crc, unsigned char const *data, uint32_t length) { /* Use by-byte access for unaligned buffers */ if ((unsigned long)data % sizeof(unsigned long)) return crc32c_ref(crc, data, length); return crc32c_impl(crc, data, length); }