X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fceph%2Fsrc%2Fcommon%2Fcrc32c_ppc.c;fp=src%2Fceph%2Fsrc%2Fcommon%2Fcrc32c_ppc.c;h=43756e24ef81ce180841041a48ad5fe35b31a6b7;hb=812ff6ca9fcd3e629e49d4328905f33eee8ca3f5;hp=0000000000000000000000000000000000000000;hpb=15280273faafb77777eab341909a3f495cf248d9;p=stor4nfv.git diff --git a/src/ceph/src/common/crc32c_ppc.c b/src/ceph/src/common/crc32c_ppc.c new file mode 100644 index 0000000..43756e2 --- /dev/null +++ b/src/ceph/src/common/crc32c_ppc.c @@ -0,0 +1,148 @@ +/* Copyright (C) 2017 International Business Machines Corp. + * All rights reserved. + * + * 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. + */ +#define CRC_TABLE +#define FAST_ZERO_TABLE + +#include "acconfig.h" +#include "include/int_types.h" +#include "crc32c_ppc_constants.h" +#include "reverse.h" + +#include +#include + +#define VMX_ALIGN 16 +#define VMX_ALIGN_MASK (VMX_ALIGN-1) + +#ifdef REFLECT +static unsigned int crc32_align(unsigned int crc, unsigned char const *p, + unsigned long len) +{ + while (len--) + crc = crc_table[(crc ^ *p++) & 0xff] ^ (crc >> 8); + return crc; +} +#else +static unsigned int crc32_align(unsigned int crc, unsigned char const *p, + unsigned long len) +{ + while (len--) + crc = crc_table[((crc >> 24) ^ *p++) & 0xff] ^ (crc << 8); + return crc; +} +#endif + +#ifdef HAVE_POWER8 +static inline unsigned long polynomial_multiply(unsigned int a, unsigned int b) { + vector unsigned int va = {a, 0, 0, 0}; + vector unsigned int vb = {b, 0, 0, 0}; + vector unsigned long vt; + + __asm__("vpmsumw %0,%1,%2" : "=v"(vt) : "v"(va), "v"(vb)); + + return vt[0]; +} + +unsigned int barrett_reduction(unsigned long val); + +static inline unsigned int gf_multiply(unsigned int a, unsigned int b) { + return barrett_reduction(polynomial_multiply(a, b)); +} + +unsigned int append_zeros(unsigned int crc, unsigned long length) { + unsigned long i = 0; + + while (length) { + if (length & 1) { + crc = gf_multiply(crc, crc_zero[i]); + } + i++; + length /= 2; + } + + return crc; +} + + +unsigned int __crc32_vpmsum(unsigned int crc, unsigned char const *p, + unsigned long len); + +static uint32_t crc32_vpmsum(uint32_t crc, unsigned char const *data, + unsigned len) +{ + unsigned int prealign; + unsigned int tail; + +#ifdef CRC_XOR + crc ^= 0xffffffff; +#endif + + if (len < VMX_ALIGN + VMX_ALIGN_MASK) { + crc = crc32_align(crc, data, (unsigned long)len); + goto out; + } + + if ((unsigned long)data & VMX_ALIGN_MASK) { + prealign = VMX_ALIGN - ((unsigned long)data & VMX_ALIGN_MASK); + crc = crc32_align(crc, data, prealign); + len -= prealign; + data += prealign; + } + + crc = __crc32_vpmsum(crc, data, (unsigned long)len & ~VMX_ALIGN_MASK); + + tail = len & VMX_ALIGN_MASK; + if (tail) { + data += len & ~VMX_ALIGN_MASK; + crc = crc32_align(crc, data, tail); + } + +out: +#ifdef CRC_XOR + crc ^= 0xffffffff; +#endif + + return crc; +} + +/* This wrapper function works around the fact that crc32_vpmsum + * does not gracefully handle the case where the data pointer is NULL. + */ +uint32_t ceph_crc32c_ppc(uint32_t crc, unsigned char const *data, unsigned len) +{ + if (!data) { + /* Handle the NULL buffer case. */ +#ifdef REFLECT + crc = reverse_bits(crc); +#endif + + crc = append_zeros(crc, len); + +#ifdef REFLECT + crc = reverse_bits(crc); +#endif + } else { + /* Handle the valid buffer case. */ + crc = crc32_vpmsum(crc, data, (unsigned long)len); + } + return crc; +} + +#else /* HAVE_POWER8 */ + +/* This symbol has to exist on non-ppc architectures (and on legacy + * ppc systems using power7 or below) in order to compile properly + * there, even though it won't be called. + */ +uint32_t ceph_crc32c_ppc(uint32_t crc, unsigned char const *data, unsigned len) +{ + return 0; +} + +#endif /* HAVE_POWER8 */