diff options
Diffstat (limited to 'arch/x86/lib/crc32c-3way.S')
| -rw-r--r-- | arch/x86/lib/crc32c-3way.S | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/arch/x86/lib/crc32c-3way.S b/arch/x86/lib/crc32c-3way.S new file mode 100644 index 000000000000..9b8770503bbc --- /dev/null +++ b/arch/x86/lib/crc32c-3way.S @@ -0,0 +1,360 @@ +/* + * Implement fast CRC32C with PCLMULQDQ instructions. (x86_64) + * + * The white papers on CRC32C calculations with PCLMULQDQ instruction can be + * downloaded from: + * http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/crc-iscsi-polynomial-crc32-instruction-paper.pdf + * http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-paper.pdf + * + * Copyright (C) 2012 Intel Corporation. + * Copyright 2024 Google LLC + * + * Authors: + * Wajdi Feghali <wajdi.k.feghali@intel.com> + * James Guilford <james.guilford@intel.com> + * David Cote <david.m.cote@intel.com> + * Tim Chen <tim.c.chen@linux.intel.com> + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include <linux/linkage.h> + +## ISCSI CRC 32 Implementation with crc32 and pclmulqdq Instruction + +# Define threshold below which buffers are considered "small" and routed to +# regular CRC code that does not interleave the CRC instructions. +#define SMALL_SIZE 200 + +# u32 crc32c_x86_3way(u32 crc, const u8 *buffer, size_t len); + +.text +SYM_FUNC_START(crc32c_x86_3way) +#define crc0 %edi +#define crc0_q %rdi +#define bufp %rsi +#define bufp_d %esi +#define len %rdx +#define len_dw %edx +#define n_misaligned %ecx /* overlaps chunk_bytes! */ +#define n_misaligned_q %rcx +#define chunk_bytes %ecx /* overlaps n_misaligned! */ +#define chunk_bytes_q %rcx +#define crc1 %r8 +#define crc2 %r9 + + cmp $SMALL_SIZE, len + jb .Lsmall + + ################################################################ + ## 1) ALIGN: + ################################################################ + mov bufp_d, n_misaligned + neg n_misaligned + and $7, n_misaligned # calculate the misalignment amount of + # the address + je .Laligned # Skip if aligned + + # Process 1 <= n_misaligned <= 7 bytes individually in order to align + # the remaining data to an 8-byte boundary. +.Ldo_align: + movq (bufp), %rax + add n_misaligned_q, bufp + sub n_misaligned_q, len +.Lalign_loop: + crc32b %al, crc0 # compute crc32 of 1-byte + shr $8, %rax # get next byte + dec n_misaligned + jne .Lalign_loop +.Laligned: + + ################################################################ + ## 2) PROCESS BLOCK: + ################################################################ + + cmp $128*24, len + jae .Lfull_block + +.Lpartial_block: + # Compute floor(len / 24) to get num qwords to process from each lane. + imul $2731, len_dw, %eax # 2731 = ceil(2^16 / 24) + shr $16, %eax + jmp .Lcrc_3lanes + +.Lfull_block: + # Processing 128 qwords from each lane. + mov $128, %eax + + ################################################################ + ## 3) CRC each of three lanes: + ################################################################ + +.Lcrc_3lanes: + xor crc1,crc1 + xor crc2,crc2 + mov %eax, chunk_bytes + shl $3, chunk_bytes # num bytes to process from each lane + sub $5, %eax # 4 for 4x_loop, 1 for special last iter + jl .Lcrc_3lanes_4x_done + + # Unroll the loop by a factor of 4 to reduce the overhead of the loop + # bookkeeping instructions, which can compete with crc32q for the ALUs. +.Lcrc_3lanes_4x_loop: + crc32q (bufp), crc0_q + crc32q (bufp,chunk_bytes_q), crc1 + crc32q (bufp,chunk_bytes_q,2), crc2 + crc32q 8(bufp), crc0_q + crc32q 8(bufp,chunk_bytes_q), crc1 + crc32q 8(bufp,chunk_bytes_q,2), crc2 + crc32q 16(bufp), crc0_q + crc32q 16(bufp,chunk_bytes_q), crc1 + crc32q 16(bufp,chunk_bytes_q,2), crc2 + crc32q 24(bufp), crc0_q + crc32q 24(bufp,chunk_bytes_q), crc1 + crc32q 24(bufp,chunk_bytes_q,2), crc2 + add $32, bufp + sub $4, %eax + jge .Lcrc_3lanes_4x_loop + +.Lcrc_3lanes_4x_done: + add $4, %eax + jz .Lcrc_3lanes_last_qword + +.Lcrc_3lanes_1x_loop: + crc32q (bufp), crc0_q + crc32q (bufp,chunk_bytes_q), crc1 + crc32q (bufp,chunk_bytes_q,2), crc2 + add $8, bufp + dec %eax + jnz .Lcrc_3lanes_1x_loop + +.Lcrc_3lanes_last_qword: + crc32q (bufp), crc0_q + crc32q (bufp,chunk_bytes_q), crc1 +# SKIP crc32q (bufp,chunk_bytes_q,2), crc2 ; Don't do this one yet + + ################################################################ + ## 4) Combine three results: + ################################################################ + + lea (K_table-8)(%rip), %rax # first entry is for idx 1 + pmovzxdq (%rax,chunk_bytes_q), %xmm0 # 2 consts: K1:K2 + lea (chunk_bytes,chunk_bytes,2), %eax # chunk_bytes * 3 + sub %rax, len # len -= chunk_bytes * 3 + + movq crc0_q, %xmm1 # CRC for block 1 + pclmulqdq $0x00, %xmm0, %xmm1 # Multiply by K2 + + movq crc1, %xmm2 # CRC for block 2 + pclmulqdq $0x10, %xmm0, %xmm2 # Multiply by K1 + + pxor %xmm2,%xmm1 + movq %xmm1, %rax + xor (bufp,chunk_bytes_q,2), %rax + mov crc2, crc0_q + crc32 %rax, crc0_q + lea 8(bufp,chunk_bytes_q,2), bufp + + ################################################################ + ## 5) If more blocks remain, goto (2): + ################################################################ + + cmp $128*24, len + jae .Lfull_block + cmp $SMALL_SIZE, len + jae .Lpartial_block + + ####################################################################### + ## 6) Process any remainder without interleaving: + ####################################################################### +.Lsmall: + test len_dw, len_dw + jz .Ldone + mov len_dw, %eax + shr $3, %eax + jz .Ldo_dword +.Ldo_qwords: + crc32q (bufp), crc0_q + add $8, bufp + dec %eax + jnz .Ldo_qwords +.Ldo_dword: + test $4, len_dw + jz .Ldo_word + crc32l (bufp), crc0 + add $4, bufp +.Ldo_word: + test $2, len_dw + jz .Ldo_byte + crc32w (bufp), crc0 + add $2, bufp +.Ldo_byte: + test $1, len_dw + jz .Ldone + crc32b (bufp), crc0 +.Ldone: + mov crc0, %eax + RET +SYM_FUNC_END(crc32c_x86_3way) + +.section .rodata, "a", @progbits + ################################################################ + ## PCLMULQDQ tables + ## Table is 128 entries x 2 words (8 bytes) each + ################################################################ +.align 8 +K_table: + .long 0x493c7d27, 0x00000001 + .long 0xba4fc28e, 0x493c7d27 + .long 0xddc0152b, 0xf20c0dfe + .long 0x9e4addf8, 0xba4fc28e + .long 0x39d3b296, 0x3da6d0cb + .long 0x0715ce53, 0xddc0152b + .long 0x47db8317, 0x1c291d04 + .long 0x0d3b6092, 0x9e4addf8 + .long 0xc96cfdc0, 0x740eef02 + .long 0x878a92a7, 0x39d3b296 + .long 0xdaece73e, 0x083a6eec + .long 0xab7aff2a, 0x0715ce53 + .long 0x2162d385, 0xc49f4f67 + .long 0x83348832, 0x47db8317 + .long 0x299847d5, 0x2ad91c30 + .long 0xb9e02b86, 0x0d3b6092 + .long 0x18b33a4e, 0x6992cea2 + .long 0xb6dd949b, 0xc96cfdc0 + .long 0x78d9ccb7, 0x7e908048 + .long 0xbac2fd7b, 0x878a92a7 + .long 0xa60ce07b, 0x1b3d8f29 + .long 0xce7f39f4, 0xdaece73e + .long 0x61d82e56, 0xf1d0f55e + .long 0xd270f1a2, 0xab7aff2a + .long 0xc619809d, 0xa87ab8a8 + .long 0x2b3cac5d, 0x2162d385 + .long 0x65863b64, 0x8462d800 + .long 0x1b03397f, 0x83348832 + .long 0xebb883bd, 0x71d111a8 + .long 0xb3e32c28, 0x299847d5 + .long 0x064f7f26, 0xffd852c6 + .long 0xdd7e3b0c, 0xb9e02b86 + .long 0xf285651c, 0xdcb17aa4 + .long 0x10746f3c, 0x18b33a4e + .long 0xc7a68855, 0xf37c5aee + .long 0x271d9844, 0xb6dd949b + .long 0x8e766a0c, 0x6051d5a2 + .long 0x93a5f730, 0x78d9ccb7 + .long 0x6cb08e5c, 0x18b0d4ff + .long 0x6b749fb2, 0xbac2fd7b + .long 0x1393e203, 0x21f3d99c + .long 0xcec3662e, 0xa60ce07b + .long 0x96c515bb, 0x8f158014 + .long 0xe6fc4e6a, 0xce7f39f4 + .long 0x8227bb8a, 0xa00457f7 + .long 0xb0cd4768, 0x61d82e56 + .long 0x39c7ff35, 0x8d6d2c43 + .long 0xd7a4825c, 0xd270f1a2 + .long 0x0ab3844b, 0x00ac29cf + .long 0x0167d312, 0xc619809d + .long 0xf6076544, 0xe9adf796 + .long 0x26f6a60a, 0x2b3cac5d + .long 0xa741c1bf, 0x96638b34 + .long 0x98d8d9cb, 0x65863b64 + .long 0x49c3cc9c, 0xe0e9f351 + .long 0x68bce87a, 0x1b03397f + .long 0x57a3d037, 0x9af01f2d + .long 0x6956fc3b, 0xebb883bd + .long 0x42d98888, 0x2cff42cf + .long 0x3771e98f, 0xb3e32c28 + .long 0xb42ae3d9, 0x88f25a3a + .long 0x2178513a, 0x064f7f26 + .long 0xe0ac139e, 0x4e36f0b0 + .long 0x170076fa, 0xdd7e3b0c + .long 0x444dd413, 0xbd6f81f8 + .long 0x6f345e45, 0xf285651c + .long 0x41d17b64, 0x91c9bd4b + .long 0xff0dba97, 0x10746f3c + .long 0xa2b73df1, 0x885f087b + .long 0xf872e54c, 0xc7a68855 + .long 0x1e41e9fc, 0x4c144932 + .long 0x86d8e4d2, 0x271d9844 + .long 0x651bd98b, 0x52148f02 + .long 0x5bb8f1bc, 0x8e766a0c + .long 0xa90fd27a, 0xa3c6f37a + .long 0xb3af077a, 0x93a5f730 + .long 0x4984d782, 0xd7c0557f + .long 0xca6ef3ac, 0x6cb08e5c + .long 0x234e0b26, 0x63ded06a + .long 0xdd66cbbb, 0x6b749fb2 + .long 0x4597456a, 0x4d56973c + .long 0xe9e28eb4, 0x1393e203 + .long 0x7b3ff57a, 0x9669c9df + .long 0xc9c8b782, 0xcec3662e + .long 0x3f70cc6f, 0xe417f38a + .long 0x93e106a4, 0x96c515bb + .long 0x62ec6c6d, 0x4b9e0f71 + .long 0xd813b325, 0xe6fc4e6a + .long 0x0df04680, 0xd104b8fc + .long 0x2342001e, 0x8227bb8a + .long 0x0a2a8d7e, 0x5b397730 + .long 0x6d9a4957, 0xb0cd4768 + .long 0xe8b6368b, 0xe78eb416 + .long 0xd2c3ed1a, 0x39c7ff35 + .long 0x995a5724, 0x61ff0e01 + .long 0x9ef68d35, 0xd7a4825c + .long 0x0c139b31, 0x8d96551c + .long 0xf2271e60, 0x0ab3844b + .long 0x0b0bf8ca, 0x0bf80dd2 + .long 0x2664fd8b, 0x0167d312 + .long 0xed64812d, 0x8821abed + .long 0x02ee03b2, 0xf6076544 + .long 0x8604ae0f, 0x6a45d2b2 + .long 0x363bd6b3, 0x26f6a60a + .long 0x135c83fd, 0xd8d26619 + .long 0x5fabe670, 0xa741c1bf + .long 0x35ec3279, 0xde87806c + .long 0x00bcf5f6, 0x98d8d9cb + .long 0x8ae00689, 0x14338754 + .long 0x17f27698, 0x49c3cc9c + .long 0x58ca5f00, 0x5bd2011f + .long 0xaa7c7ad5, 0x68bce87a + .long 0xb5cfca28, 0xdd07448e + .long 0xded288f8, 0x57a3d037 + .long 0x59f229bc, 0xdde8f5b9 + .long 0x6d390dec, 0x6956fc3b + .long 0x37170390, 0xa3e3e02c + .long 0x6353c1cc, 0x42d98888 + .long 0xc4584f5c, 0xd73c7bea + .long 0xf48642e9, 0x3771e98f + .long 0x531377e2, 0x80ff0093 + .long 0xdd35bc8d, 0xb42ae3d9 + .long 0xb25b29f2, 0x8fe4c34d + .long 0x9a5ede41, 0x2178513a + .long 0xa563905d, 0xdf99fc11 + .long 0x45cddf4e, 0xe0ac139e + .long 0xacfa3103, 0x6c23e841 + .long 0xa51b6135, 0x170076fa |