--- /dev/null
+########################################################################
+# 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.
+########################################################################
+# Function API:
+# UINT16 crc_t10dif_pcl(
+# UINT16 init_crc, //initial CRC value, 16 bits
+# const unsigned char *buf, //buffer pointer to calculate CRC on
+# UINT64 len //buffer length in bytes (64-bit data)
+# );
+#
+# 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 arg1 %rdi
+#define arg2 %rsi
+#define arg3 %rdx
+
+#define arg1_low32 %edi
+
+ENTRY(crc_t10dif_pcl)
+.align 16
+
+ # adjust the 16-bit initial_crc value, scale it to 32 bits
+ shl $16, arg1_low32
+
+ # Allocate Stack Space
+ mov %rsp, %rcx
+ sub $16*2, %rsp
+ # align stack to 16 byte boundary
+ and $~(0x10 - 1), %rsp
+
+ # check if smaller than 256
+ cmp $256, arg3
+
+ # for sizes less than 128, we can't fold 64B at a time...
+ jl _less_than_128
+
+
+ # load the initial crc value
+ movd arg1_low32, %xmm10 # initial crc
+
+ # crc value does not need to be byte-reflected, but it needs
+ # to be moved to the high part of the register.
+ # because data will be byte-reflected and will align with
+ # initial crc at correct place.
+ pslldq $12, %xmm10
+
+ movdqa SHUF_MASK(%rip), %xmm11
+ # receive the initial 64B data, xor the initial crc value
+ movdqu 16*0(arg2), %xmm0
+ movdqu 16*1(arg2), %xmm1
+ movdqu 16*2(arg2), %xmm2
+ movdqu 16*3(arg2), %xmm3
+ movdqu 16*4(arg2), %xmm4
+ movdqu 16*5(arg2), %xmm5
+ movdqu 16*6(arg2), %xmm6
+ movdqu 16*7(arg2), %xmm7
+
+ pshufb %xmm11, %xmm0
+ # XOR the initial_crc value
+ pxor %xmm10, %xmm0
+ pshufb %xmm11, %xmm1
+ pshufb %xmm11, %xmm2
+ pshufb %xmm11, %xmm3
+ pshufb %xmm11, %xmm4
+ pshufb %xmm11, %xmm5
+ pshufb %xmm11, %xmm6
+ pshufb %xmm11, %xmm7
+
+ movdqa rk3(%rip), %xmm10 #xmm10 has rk3 and rk4
+ #imm value of pclmulqdq instruction
+ #will determine which constant to use
+
+ #################################################################
+ # we subtract 256 instead of 128 to save one instruction from the loop
+ sub $256, arg3
+
+ # at this section of the code, there is 64*x+y (0<=y<64) bytes of
+ # buffer. The _fold_64_B_loop will fold 64B at a time
+ # until we have 64+y Bytes of buffer
+
+
+ # fold 64B at a time. This section of the code folds 4 xmm
+ # registers in parallel
+_fold_64_B_loop:
+
+ # update the buffer pointer
+ add $128, arg2 # buf += 64#
+
+ movdqu 16*0(arg2), %xmm9
+ movdqu 16*1(arg2), %xmm12
+ pshufb %xmm11, %xmm9
+ pshufb %xmm11, %xmm12
+ movdqa %xmm0, %xmm8
+ movdqa %xmm1, %xmm13
+ pclmulqdq $0x0 , %xmm10, %xmm0
+ pclmulqdq $0x11, %xmm10, %xmm8
+ pclmulqdq $0x0 , %xmm10, %xmm1
+ pclmulqdq $0x11, %xmm10, %xmm13
+ pxor %xmm9 , %xmm0
+ xorps %xmm8 , %xmm0
+ pxor %xmm12, %xmm1
+ xorps %xmm13, %xmm1
+
+ movdqu 16*2(arg2), %xmm9
+ movdqu 16*3(arg2), %xmm12
+ pshufb %xmm11, %xmm9
+ pshufb %xmm11, %xmm12
+ movdqa %xmm2, %xmm8
+ movdqa %xmm3, %xmm13
+ pclmulqdq $0x0, %xmm10, %xmm2
+ pclmulqdq $0x11, %xmm10, %xmm8
+ pclmulqdq $0x0, %xmm10, %xmm3
+ pclmulqdq $0x11, %xmm10, %xmm13
+ pxor %xmm9 , %xmm2
+ xorps %xmm8 , %xmm2
+ pxor %xmm12, %xmm3
+ xorps %xmm13, %xmm3
+
+ movdqu 16*4(arg2), %xmm9
+ movdqu 16*5(arg2), %xmm12
+ pshufb %xmm11, %xmm9
+ pshufb %xmm11, %xmm12
+ movdqa %xmm4, %xmm8
+ movdqa %xmm5, %xmm13
+ pclmulqdq $0x0, %xmm10, %xmm4
+ pclmulqdq $0x11, %xmm10, %xmm8
+ pclmulqdq $0x0, %xmm10, %xmm5
+ pclmulqdq $0x11, %xmm10, %xmm13
+ pxor %xmm9 , %xmm4
+ xorps %xmm8 , %xmm4
+ pxor %xmm12, %xmm5
+ xorps %xmm13, %xmm5
+
+ movdqu 16*6(arg2), %xmm9
+ movdqu 16*7(arg2), %xmm12
+ pshufb %xmm11, %xmm9
+ pshufb %xmm11, %xmm12
+ movdqa %xmm6 , %xmm8
+ movdqa %xmm7 , %xmm13
+ pclmulqdq $0x0 , %xmm10, %xmm6
+ pclmulqdq $0x11, %xmm10, %xmm8
+ pclmulqdq $0x0 , %xmm10, %xmm7
+ pclmulqdq $0x11, %xmm10, %xmm13
+ pxor %xmm9 , %xmm6
+ xorps %xmm8 , %xmm6
+ pxor %xmm12, %xmm7
+ xorps %xmm13, %xmm7
+
+ sub $128, arg3
+
+ # check if there is another 64B in the buffer to be able to fold
+ jge _fold_64_B_loop
+ ##################################################################
+
+
+ add $128, arg2
+ # at this point, the buffer pointer is pointing at the last y Bytes
+ # of the buffer the 64B of folded data is in 4 of the xmm
+ # registers: xmm0, xmm1, xmm2, xmm3
+
+
+ # fold the 8 xmm registers to 1 xmm register with different constants
+
+ movdqa rk9(%rip), %xmm10
+ movdqa %xmm0, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm0
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ xorps %xmm0, %xmm7
+
+ movdqa rk11(%rip), %xmm10
+ movdqa %xmm1, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm1
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ xorps %xmm1, %xmm7
+
+ movdqa rk13(%rip), %xmm10
+ movdqa %xmm2, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm2
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ pxor %xmm2, %xmm7
+
+ movdqa rk15(%rip), %xmm10
+ movdqa %xmm3, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm3
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ xorps %xmm3, %xmm7
+
+ movdqa rk17(%rip), %xmm10
+ movdqa %xmm4, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm4
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ pxor %xmm4, %xmm7
+
+ movdqa rk19(%rip), %xmm10
+ movdqa %xmm5, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm5
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ xorps %xmm5, %xmm7
+
+ movdqa rk1(%rip), %xmm10 #xmm10 has rk1 and rk2
+ #imm value of pclmulqdq instruction
+ #will determine which constant to use
+ movdqa %xmm6, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm6
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ pxor %xmm6, %xmm7
+
+
+ # instead of 64, we add 48 to the loop counter to save 1 instruction
+ # from the loop instead of a cmp instruction, we use the negative
+ # flag with the jl instruction
+ add $128-16, arg3
+ jl _final_reduction_for_128
+
+ # now we have 16+y bytes left to reduce. 16 Bytes is in register xmm7
+ # and the rest is in memory. We can fold 16 bytes at a time if y>=16
+ # continue folding 16B at a time
+
+_16B_reduction_loop:
+ movdqa %xmm7, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm7
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ movdqu (arg2), %xmm0
+ pshufb %xmm11, %xmm0
+ pxor %xmm0 , %xmm7
+ add $16, arg2
+ sub $16, arg3
+ # instead of a cmp instruction, we utilize the flags with the
+ # jge instruction equivalent of: cmp arg3, 16-16
+ # check if there is any more 16B in the buffer to be able to fold
+ jge _16B_reduction_loop
+
+ #now we have 16+z bytes left to reduce, where 0<= z < 16.
+ #first, we reduce the data in the xmm7 register
+
+
+_final_reduction_for_128:
+ # check if any more data to fold. If not, compute the CRC of
+ # the final 128 bits
+ add $16, arg3
+ je _128_done
+
+ # here we are getting data that is less than 16 bytes.
+ # since we know that there was data before the pointer, we can
+ # offset the input pointer before the actual point, to receive
+ # exactly 16 bytes. after that the registers need to be adjusted.
+_get_last_two_xmms:
+ movdqa %xmm7, %xmm2
+
+ movdqu -16(arg2, arg3), %xmm1
+ pshufb %xmm11, %xmm1
+
+ # get rid of the extra data that was loaded before
+ # load the shift constant
+ lea pshufb_shf_table+16(%rip), %rax
+ sub arg3, %rax
+ movdqu (%rax), %xmm0
+
+ # shift xmm2 to the left by arg3 bytes
+ pshufb %xmm0, %xmm2
+
+ # shift xmm7 to the right by 16-arg3 bytes
+ pxor mask1(%rip), %xmm0
+ pshufb %xmm0, %xmm7
+ pblendvb %xmm2, %xmm1 #xmm0 is implicit
+
+ # fold 16 Bytes
+ movdqa %xmm1, %xmm2
+ movdqa %xmm7, %xmm8
+ pclmulqdq $0x11, %xmm10, %xmm7
+ pclmulqdq $0x0 , %xmm10, %xmm8
+ pxor %xmm8, %xmm7
+ pxor %xmm2, %xmm7
+
+_128_done:
+ # compute crc of a 128-bit value
+ movdqa rk5(%rip), %xmm10 # rk5 and rk6 in xmm10
+ movdqa %xmm7, %xmm0
+
+ #64b fold
+ pclmulqdq $0x1, %xmm10, %xmm7
+ pslldq $8 , %xmm0
+ pxor %xmm0, %xmm7
+
+ #32b fold
+ movdqa %xmm7, %xmm0
+
+ pand mask2(%rip), %xmm0
+
+ psrldq $12, %xmm7
+ pclmulqdq $0x10, %xmm10, %xmm7
+ pxor %xmm0, %xmm7
+
+ #barrett reduction
+_barrett:
+ movdqa rk7(%rip), %xmm10 # rk7 and rk8 in xmm10
+ movdqa %xmm7, %xmm0
+ pclmulqdq $0x01, %xmm10, %xmm7
+ pslldq $4, %xmm7
+ pclmulqdq $0x11, %xmm10, %xmm7
+
+ pslldq $4, %xmm7
+ pxor %xmm0, %xmm7
+ pextrd $1, %xmm7, %eax
+
+_cleanup:
+ # scale the result back to 16 bits
+ shr $16, %eax
+ mov %rcx, %rsp
+ ret
+
+########################################################################
+
+.align 16
+_less_than_128:
+
+ # check if there is enough buffer to be able to fold 16B at a time
+ cmp $32, arg3
+ jl _less_than_32
+ movdqa SHUF_MASK(%rip), %xmm11
+
+ # now if there is, load the constants
+ movdqa rk1(%rip), %xmm10 # rk1 and rk2 in xmm10
+
+ movd arg1_low32, %xmm0 # get the initial crc value
+ pslldq $12, %xmm0 # align it to its correct place
+ movdqu (arg2), %xmm7 # load the plaintext
+ pshufb %xmm11, %xmm7 # byte-reflect the plaintext
+ pxor %xmm0, %xmm7
+
+
+ # update the buffer pointer
+ add $16, arg2
+
+ # update the counter. subtract 32 instead of 16 to save one
+ # instruction from the loop
+ sub $32, arg3
+
+ jmp _16B_reduction_loop
+
+
+.align 16
+_less_than_32:
+ # mov initial crc to the return value. this is necessary for
+ # zero-length buffers.
+ mov arg1_low32, %eax
+ test arg3, arg3
+ je _cleanup
+
+ movdqa SHUF_MASK(%rip), %xmm11
+
+ movd arg1_low32, %xmm0 # get the initial crc value
+ pslldq $12, %xmm0 # align it to its correct place
+
+ cmp $16, arg3
+ je _exact_16_left
+ jl _less_than_16_left
+
+ movdqu (arg2), %xmm7 # load the plaintext
+ pshufb %xmm11, %xmm7 # byte-reflect the plaintext
+ pxor %xmm0 , %xmm7 # xor the initial crc value
+ add $16, arg2
+ sub $16, arg3
+ movdqa rk1(%rip), %xmm10 # rk1 and rk2 in xmm10
+ jmp _get_last_two_xmms
+
+
+.align 16
+_less_than_16_left:
+ # use stack space to load data less than 16 bytes, zero-out
+ # the 16B in memory first.
+
+ pxor %xmm1, %xmm1
+ mov %rsp, %r11
+ movdqa %xmm1, (%r11)
+
+ cmp $4, arg3
+ jl _only_less_than_4
+
+ # backup the counter value
+ mov arg3, %r9
+ cmp $8, arg3
+ jl _less_than_8_left
+
+ # load 8 Bytes
+ mov (arg2), %rax
+ mov %rax, (%r11)
+ add $8, %r11
+ sub $8, arg3
+ add $8, arg2
+_less_than_8_left:
+
+ cmp $4, arg3
+ jl _less_than_4_left
+
+ # load 4 Bytes
+ mov (arg2), %eax
+ mov %eax, (%r11)
+ add $4, %r11
+ sub $4, arg3
+ add $4, arg2
+_less_than_4_left:
+
+ cmp $2, arg3
+ jl _less_than_2_left
+
+ # load 2 Bytes
+ mov (arg2), %ax
+ mov %ax, (%r11)
+ add $2, %r11
+ sub $2, arg3
+ add $2, arg2
+_less_than_2_left:
+ cmp $1, arg3
+ jl _zero_left
+
+ # load 1 Byte
+ mov (arg2), %al
+ mov %al, (%r11)
+_zero_left:
+ movdqa (%rsp), %xmm7
+ pshufb %xmm11, %xmm7
+ pxor %xmm0 , %xmm7 # xor the initial crc value
+
+ # shl r9, 4
+ lea pshufb_shf_table+16(%rip), %rax
+ sub %r9, %rax
+ movdqu (%rax), %xmm0
+ pxor mask1(%rip), %xmm0
+
+ pshufb %xmm0, %xmm7
+ jmp _128_done
+
+.align 16
+_exact_16_left:
+ movdqu (arg2), %xmm7
+ pshufb %xmm11, %xmm7
+ pxor %xmm0 , %xmm7 # xor the initial crc value
+
+ jmp _128_done
+
+_only_less_than_4:
+ cmp $3, arg3
+ jl _only_less_than_3
+
+ # load 3 Bytes
+ mov (arg2), %al
+ mov %al, (%r11)
+
+ mov 1(arg2), %al
+ mov %al, 1(%r11)
+
+ mov 2(arg2), %al
+ mov %al, 2(%r11)
+
+ movdqa (%rsp), %xmm7
+ pshufb %xmm11, %xmm7
+ pxor %xmm0 , %xmm7 # xor the initial crc value
+
+ psrldq $5, %xmm7
+
+ jmp _barrett
+_only_less_than_3:
+ cmp $2, arg3
+ jl _only_less_than_2
+
+ # load 2 Bytes
+ mov (arg2), %al
+ mov %al, (%r11)
+
+ mov 1(arg2), %al
+ mov %al, 1(%r11)
+
+ movdqa (%rsp), %xmm7
+ pshufb %xmm11, %xmm7
+ pxor %xmm0 , %xmm7 # xor the initial crc value
+
+ psrldq $6, %xmm7
+
+ jmp _barrett
+_only_less_than_2:
+
+ # load 1 Byte
+ mov (arg2), %al
+ mov %al, (%r11)
+
+ movdqa (%rsp), %xmm7
+ pshufb %xmm11, %xmm7
+ pxor %xmm0 , %xmm7 # xor the initial crc value
+
+ psrldq $7, %xmm7
+
+ jmp _barrett
+
+ENDPROC(crc_t10dif_pcl)
+
+.data
+
+# precomputed constants
+# these constants are precomputed from the poly:
+# 0x8bb70000 (0x8bb7 scaled to 32 bits)
+.align 16
+# Q = 0x18BB70000
+# rk1 = 2^(32*3) mod Q << 32
+# rk2 = 2^(32*5) mod Q << 32
+# rk3 = 2^(32*15) mod Q << 32
+# rk4 = 2^(32*17) mod Q << 32
+# rk5 = 2^(32*3) mod Q << 32
+# rk6 = 2^(32*2) mod Q << 32
+# rk7 = floor(2^64/Q)
+# rk8 = Q
+rk1:
+.quad 0x2d56000000000000
+rk2:
+.quad 0x06df000000000000
+rk3:
+.quad 0x9d9d000000000000
+rk4:
+.quad 0x7cf5000000000000
+rk5:
+.quad 0x2d56000000000000
+rk6:
+.quad 0x1368000000000000
+rk7:
+.quad 0x00000001f65a57f8
+rk8:
+.quad 0x000000018bb70000
+
+rk9:
+.quad 0xceae000000000000
+rk10:
+.quad 0xbfd6000000000000
+rk11:
+.quad 0x1e16000000000000
+rk12:
+.quad 0x713c000000000000
+rk13:
+.quad 0xf7f9000000000000
+rk14:
+.quad 0x80a6000000000000
+rk15:
+.quad 0x044c000000000000
+rk16:
+.quad 0xe658000000000000
+rk17:
+.quad 0xad18000000000000
+rk18:
+.quad 0xa497000000000000
+rk19:
+.quad 0x6ee3000000000000
+rk20:
+.quad 0xe7b5000000000000
+
+
+
+mask1:
+.octa 0x80808080808080808080808080808080
+mask2:
+.octa 0x00000000FFFFFFFFFFFFFFFFFFFFFFFF
+
+SHUF_MASK:
+.octa 0x000102030405060708090A0B0C0D0E0F
+
+pshufb_shf_table:
+# use these values for shift constants for the pshufb instruction
+# different alignments result in values as shown:
+# DDQ 0x008f8e8d8c8b8a898887868584838281 # shl 15 (16-1) / shr1
+# DDQ 0x01008f8e8d8c8b8a8988878685848382 # shl 14 (16-3) / shr2
+# DDQ 0x0201008f8e8d8c8b8a89888786858483 # shl 13 (16-4) / shr3
+# DDQ 0x030201008f8e8d8c8b8a898887868584 # shl 12 (16-4) / shr4
+# DDQ 0x04030201008f8e8d8c8b8a8988878685 # shl 11 (16-5) / shr5
+# DDQ 0x0504030201008f8e8d8c8b8a89888786 # shl 10 (16-6) / shr6
+# DDQ 0x060504030201008f8e8d8c8b8a898887 # shl 9 (16-7) / shr7
+# DDQ 0x07060504030201008f8e8d8c8b8a8988 # shl 8 (16-8) / shr8
+# DDQ 0x0807060504030201008f8e8d8c8b8a89 # shl 7 (16-9) / shr9
+# DDQ 0x090807060504030201008f8e8d8c8b8a # shl 6 (16-10) / shr10
+# DDQ 0x0a090807060504030201008f8e8d8c8b # shl 5 (16-11) / shr11
+# DDQ 0x0b0a090807060504030201008f8e8d8c # shl 4 (16-12) / shr12
+# DDQ 0x0c0b0a090807060504030201008f8e8d # shl 3 (16-13) / shr13
+# DDQ 0x0d0c0b0a090807060504030201008f8e # shl 2 (16-14) / shr14
+# DDQ 0x0e0d0c0b0a090807060504030201008f # shl 1 (16-15) / shr15
+.octa 0x8f8e8d8c8b8a89888786858483828100
+.octa 0x000e0d0c0b0a09080706050403020100
projects / linux.git / commitdiff