334 lines
11 KiB
ArmAsm
334 lines
11 KiB
ArmAsm
########################################################################
|
|
# Implement fast CRC-T10DIF computation with SSE and PCLMULQDQ instructions
|
|
#
|
|
# Copyright (c) 2013, Intel Corporation
|
|
#
|
|
# Authors:
|
|
# Erdinc Ozturk <erdinc.ozturk@intel.com>
|
|
# Vinodh Gopal <vinodh.gopal@intel.com>
|
|
# James Guilford <james.guilford@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.
|
|
#
|
|
# * Neither the name of the Intel Corporation nor the names of its
|
|
# contributors may be used to endorse or promote products derived from
|
|
# this software without specific prior written permission.
|
|
#
|
|
#
|
|
# THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION ""AS IS"" AND ANY
|
|
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL CORPORATION OR
|
|
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
#
|
|
# Reference paper titled "Fast CRC Computation for Generic
|
|
# Polynomials Using PCLMULQDQ Instruction"
|
|
# URL: http://www.intel.com/content/dam/www/public/us/en/documents
|
|
# /white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
|
|
#
|
|
|
|
#include <linux/linkage.h>
|
|
|
|
.text
|
|
|
|
#define init_crc %edi
|
|
#define buf %rsi
|
|
#define len %rdx
|
|
|
|
#define FOLD_CONSTS %xmm10
|
|
#define BSWAP_MASK %xmm11
|
|
|
|
# Fold reg1, reg2 into the next 32 data bytes, storing the result back into
|
|
# reg1, reg2.
|
|
.macro fold_32_bytes offset, reg1, reg2
|
|
movdqu \offset(buf), %xmm9
|
|
movdqu \offset+16(buf), %xmm12
|
|
pshufb BSWAP_MASK, %xmm9
|
|
pshufb BSWAP_MASK, %xmm12
|
|
movdqa \reg1, %xmm8
|
|
movdqa \reg2, %xmm13
|
|
pclmulqdq $0x00, FOLD_CONSTS, \reg1
|
|
pclmulqdq $0x11, FOLD_CONSTS, %xmm8
|
|
pclmulqdq $0x00, FOLD_CONSTS, \reg2
|
|
pclmulqdq $0x11, FOLD_CONSTS, %xmm13
|
|
pxor %xmm9 , \reg1
|
|
xorps %xmm8 , \reg1
|
|
pxor %xmm12, \reg2
|
|
xorps %xmm13, \reg2
|
|
.endm
|
|
|
|
# Fold src_reg into dst_reg.
|
|
.macro fold_16_bytes src_reg, dst_reg
|
|
movdqa \src_reg, %xmm8
|
|
pclmulqdq $0x11, FOLD_CONSTS, \src_reg
|
|
pclmulqdq $0x00, FOLD_CONSTS, %xmm8
|
|
pxor %xmm8, \dst_reg
|
|
xorps \src_reg, \dst_reg
|
|
.endm
|
|
|
|
#
|
|
# u16 crc_t10dif_pcl(u16 init_crc, const *u8 buf, size_t len);
|
|
#
|
|
# Assumes len >= 16.
|
|
#
|
|
.align 16
|
|
SYM_FUNC_START(crc_t10dif_pcl)
|
|
|
|
movdqa .Lbswap_mask(%rip), BSWAP_MASK
|
|
|
|
# For sizes less than 256 bytes, we can't fold 128 bytes at a time.
|
|
cmp $256, len
|
|
jl .Lless_than_256_bytes
|
|
|
|
# Load the first 128 data bytes. Byte swapping is necessary to make the
|
|
# bit order match the polynomial coefficient order.
|
|
movdqu 16*0(buf), %xmm0
|
|
movdqu 16*1(buf), %xmm1
|
|
movdqu 16*2(buf), %xmm2
|
|
movdqu 16*3(buf), %xmm3
|
|
movdqu 16*4(buf), %xmm4
|
|
movdqu 16*5(buf), %xmm5
|
|
movdqu 16*6(buf), %xmm6
|
|
movdqu 16*7(buf), %xmm7
|
|
add $128, buf
|
|
pshufb BSWAP_MASK, %xmm0
|
|
pshufb BSWAP_MASK, %xmm1
|
|
pshufb BSWAP_MASK, %xmm2
|
|
pshufb BSWAP_MASK, %xmm3
|
|
pshufb BSWAP_MASK, %xmm4
|
|
pshufb BSWAP_MASK, %xmm5
|
|
pshufb BSWAP_MASK, %xmm6
|
|
pshufb BSWAP_MASK, %xmm7
|
|
|
|
# XOR the first 16 data *bits* with the initial CRC value.
|
|
pxor %xmm8, %xmm8
|
|
pinsrw $7, init_crc, %xmm8
|
|
pxor %xmm8, %xmm0
|
|
|
|
movdqa .Lfold_across_128_bytes_consts(%rip), FOLD_CONSTS
|
|
|
|
# Subtract 128 for the 128 data bytes just consumed. Subtract another
|
|
# 128 to simplify the termination condition of the following loop.
|
|
sub $256, len
|
|
|
|
# While >= 128 data bytes remain (not counting xmm0-7), fold the 128
|
|
# bytes xmm0-7 into them, storing the result back into xmm0-7.
|
|
.Lfold_128_bytes_loop:
|
|
fold_32_bytes 0, %xmm0, %xmm1
|
|
fold_32_bytes 32, %xmm2, %xmm3
|
|
fold_32_bytes 64, %xmm4, %xmm5
|
|
fold_32_bytes 96, %xmm6, %xmm7
|
|
add $128, buf
|
|
sub $128, len
|
|
jge .Lfold_128_bytes_loop
|
|
|
|
# Now fold the 112 bytes in xmm0-xmm6 into the 16 bytes in xmm7.
|
|
|
|
# Fold across 64 bytes.
|
|
movdqa .Lfold_across_64_bytes_consts(%rip), FOLD_CONSTS
|
|
fold_16_bytes %xmm0, %xmm4
|
|
fold_16_bytes %xmm1, %xmm5
|
|
fold_16_bytes %xmm2, %xmm6
|
|
fold_16_bytes %xmm3, %xmm7
|
|
# Fold across 32 bytes.
|
|
movdqa .Lfold_across_32_bytes_consts(%rip), FOLD_CONSTS
|
|
fold_16_bytes %xmm4, %xmm6
|
|
fold_16_bytes %xmm5, %xmm7
|
|
# Fold across 16 bytes.
|
|
movdqa .Lfold_across_16_bytes_consts(%rip), FOLD_CONSTS
|
|
fold_16_bytes %xmm6, %xmm7
|
|
|
|
# Add 128 to get the correct number of data bytes remaining in 0...127
|
|
# (not counting xmm7), following the previous extra subtraction by 128.
|
|
# Then subtract 16 to simplify the termination condition of the
|
|
# following loop.
|
|
add $128-16, len
|
|
|
|
# While >= 16 data bytes remain (not counting xmm7), fold the 16 bytes
|
|
# xmm7 into them, storing the result back into xmm7.
|
|
jl .Lfold_16_bytes_loop_done
|
|
.Lfold_16_bytes_loop:
|
|
movdqa %xmm7, %xmm8
|
|
pclmulqdq $0x11, FOLD_CONSTS, %xmm7
|
|
pclmulqdq $0x00, FOLD_CONSTS, %xmm8
|
|
pxor %xmm8, %xmm7
|
|
movdqu (buf), %xmm0
|
|
pshufb BSWAP_MASK, %xmm0
|
|
pxor %xmm0 , %xmm7
|
|
add $16, buf
|
|
sub $16, len
|
|
jge .Lfold_16_bytes_loop
|
|
|
|
.Lfold_16_bytes_loop_done:
|
|
# Add 16 to get the correct number of data bytes remaining in 0...15
|
|
# (not counting xmm7), following the previous extra subtraction by 16.
|
|
add $16, len
|
|
je .Lreduce_final_16_bytes
|
|
|
|
.Lhandle_partial_segment:
|
|
# Reduce the last '16 + len' bytes where 1 <= len <= 15 and the first 16
|
|
# bytes are in xmm7 and the rest are the remaining data in 'buf'. To do
|
|
# this without needing a fold constant for each possible 'len', redivide
|
|
# the bytes into a first chunk of 'len' bytes and a second chunk of 16
|
|
# bytes, then fold the first chunk into the second.
|
|
|
|
movdqa %xmm7, %xmm2
|
|
|
|
# xmm1 = last 16 original data bytes
|
|
movdqu -16(buf, len), %xmm1
|
|
pshufb BSWAP_MASK, %xmm1
|
|
|
|
# xmm2 = high order part of second chunk: xmm7 left-shifted by 'len' bytes.
|
|
lea .Lbyteshift_table+16(%rip), %rax
|
|
sub len, %rax
|
|
movdqu (%rax), %xmm0
|
|
pshufb %xmm0, %xmm2
|
|
|
|
# xmm7 = first chunk: xmm7 right-shifted by '16-len' bytes.
|
|
pxor .Lmask1(%rip), %xmm0
|
|
pshufb %xmm0, %xmm7
|
|
|
|
# xmm1 = second chunk: 'len' bytes from xmm1 (low-order bytes),
|
|
# then '16-len' bytes from xmm2 (high-order bytes).
|
|
pblendvb %xmm2, %xmm1 #xmm0 is implicit
|
|
|
|
# Fold the first chunk into the second chunk, storing the result in xmm7.
|
|
movdqa %xmm7, %xmm8
|
|
pclmulqdq $0x11, FOLD_CONSTS, %xmm7
|
|
pclmulqdq $0x00, FOLD_CONSTS, %xmm8
|
|
pxor %xmm8, %xmm7
|
|
pxor %xmm1, %xmm7
|
|
|
|
.Lreduce_final_16_bytes:
|
|
# Reduce the 128-bit value M(x), stored in xmm7, to the final 16-bit CRC
|
|
|
|
# Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'.
|
|
movdqa .Lfinal_fold_consts(%rip), FOLD_CONSTS
|
|
|
|
# Fold the high 64 bits into the low 64 bits, while also multiplying by
|
|
# x^64. This produces a 128-bit value congruent to x^64 * M(x) and
|
|
# whose low 48 bits are 0.
|
|
movdqa %xmm7, %xmm0
|
|
pclmulqdq $0x11, FOLD_CONSTS, %xmm7 # high bits * x^48 * (x^80 mod G(x))
|
|
pslldq $8, %xmm0
|
|
pxor %xmm0, %xmm7 # + low bits * x^64
|
|
|
|
# Fold the high 32 bits into the low 96 bits. This produces a 96-bit
|
|
# value congruent to x^64 * M(x) and whose low 48 bits are 0.
|
|
movdqa %xmm7, %xmm0
|
|
pand .Lmask2(%rip), %xmm0 # zero high 32 bits
|
|
psrldq $12, %xmm7 # extract high 32 bits
|
|
pclmulqdq $0x00, FOLD_CONSTS, %xmm7 # high 32 bits * x^48 * (x^48 mod G(x))
|
|
pxor %xmm0, %xmm7 # + low bits
|
|
|
|
# Load G(x) and floor(x^48 / G(x)).
|
|
movdqa .Lbarrett_reduction_consts(%rip), FOLD_CONSTS
|
|
|
|
# Use Barrett reduction to compute the final CRC value.
|
|
movdqa %xmm7, %xmm0
|
|
pclmulqdq $0x11, FOLD_CONSTS, %xmm7 # high 32 bits * floor(x^48 / G(x))
|
|
psrlq $32, %xmm7 # /= x^32
|
|
pclmulqdq $0x00, FOLD_CONSTS, %xmm7 # *= G(x)
|
|
psrlq $48, %xmm0
|
|
pxor %xmm7, %xmm0 # + low 16 nonzero bits
|
|
# Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of xmm0.
|
|
|
|
pextrw $0, %xmm0, %eax
|
|
ret
|
|
|
|
.align 16
|
|
.Lless_than_256_bytes:
|
|
# Checksumming a buffer of length 16...255 bytes
|
|
|
|
# Load the first 16 data bytes.
|
|
movdqu (buf), %xmm7
|
|
pshufb BSWAP_MASK, %xmm7
|
|
add $16, buf
|
|
|
|
# XOR the first 16 data *bits* with the initial CRC value.
|
|
pxor %xmm0, %xmm0
|
|
pinsrw $7, init_crc, %xmm0
|
|
pxor %xmm0, %xmm7
|
|
|
|
movdqa .Lfold_across_16_bytes_consts(%rip), FOLD_CONSTS
|
|
cmp $16, len
|
|
je .Lreduce_final_16_bytes # len == 16
|
|
sub $32, len
|
|
jge .Lfold_16_bytes_loop # 32 <= len <= 255
|
|
add $16, len
|
|
jmp .Lhandle_partial_segment # 17 <= len <= 31
|
|
SYM_FUNC_END(crc_t10dif_pcl)
|
|
|
|
.section .rodata, "a", @progbits
|
|
.align 16
|
|
|
|
# Fold constants precomputed from the polynomial 0x18bb7
|
|
# G(x) = x^16 + x^15 + x^11 + x^9 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + x^0
|
|
.Lfold_across_128_bytes_consts:
|
|
.quad 0x0000000000006123 # x^(8*128) mod G(x)
|
|
.quad 0x0000000000002295 # x^(8*128+64) mod G(x)
|
|
.Lfold_across_64_bytes_consts:
|
|
.quad 0x0000000000001069 # x^(4*128) mod G(x)
|
|
.quad 0x000000000000dd31 # x^(4*128+64) mod G(x)
|
|
.Lfold_across_32_bytes_consts:
|
|
.quad 0x000000000000857d # x^(2*128) mod G(x)
|
|
.quad 0x0000000000007acc # x^(2*128+64) mod G(x)
|
|
.Lfold_across_16_bytes_consts:
|
|
.quad 0x000000000000a010 # x^(1*128) mod G(x)
|
|
.quad 0x0000000000001faa # x^(1*128+64) mod G(x)
|
|
.Lfinal_fold_consts:
|
|
.quad 0x1368000000000000 # x^48 * (x^48 mod G(x))
|
|
.quad 0x2d56000000000000 # x^48 * (x^80 mod G(x))
|
|
.Lbarrett_reduction_consts:
|
|
.quad 0x0000000000018bb7 # G(x)
|
|
.quad 0x00000001f65a57f8 # floor(x^48 / G(x))
|
|
|
|
.section .rodata.cst16.mask1, "aM", @progbits, 16
|
|
.align 16
|
|
.Lmask1:
|
|
.octa 0x80808080808080808080808080808080
|
|
|
|
.section .rodata.cst16.mask2, "aM", @progbits, 16
|
|
.align 16
|
|
.Lmask2:
|
|
.octa 0x00000000FFFFFFFFFFFFFFFFFFFFFFFF
|
|
|
|
.section .rodata.cst16.bswap_mask, "aM", @progbits, 16
|
|
.align 16
|
|
.Lbswap_mask:
|
|
.octa 0x000102030405060708090A0B0C0D0E0F
|
|
|
|
.section .rodata.cst32.byteshift_table, "aM", @progbits, 32
|
|
.align 16
|
|
# For 1 <= len <= 15, the 16-byte vector beginning at &byteshift_table[16 - len]
|
|
# is the index vector to shift left by 'len' bytes, and is also {0x80, ...,
|
|
# 0x80} XOR the index vector to shift right by '16 - len' bytes.
|
|
.Lbyteshift_table:
|
|
.byte 0x0, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87
|
|
.byte 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f
|
|
.byte 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7
|
|
.byte 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe , 0x0
|