crypto: arm/crct10dif-ce - cleanup and optimizations
The x86, arm, and arm64 asm implementations of crct10dif are very difficult to understand partly because many of the comments, labels, and macros are named incorrectly: the lengths mentioned are usually off by a factor of two from the actual code. Many other things are unnecessarily convoluted as well, e.g. there are many more fold constants than actually needed and some aren't fully reduced. This series therefore cleans up all these implementations to be much more maintainable. I also made some small optimizations where I saw opportunities, resulting in slightly better performance. This patch cleans up the arm version. (Also moved the constants to .rodata as suggested by Ard Biesheuvel.) Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers
Herbert Xu
parent
0974037fc5
commit
e7b3ed3380
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@ -2,12 +2,14 @@
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// Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
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//
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// Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
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// Copyright (C) 2019 Google LLC <ebiggers@google.com>
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//
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License version 2 as
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// published by the Free Software Foundation.
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//
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// Derived from the x86 version:
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//
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// Implement fast CRC-T10DIF computation with SSE and PCLMULQDQ instructions
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//
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@ -54,19 +56,11 @@
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// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// Function API:
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// UINT16 crc_t10dif_pcl(
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// UINT16 init_crc, //initial CRC value, 16 bits
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// const unsigned char *buf, //buffer pointer to calculate CRC on
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// UINT64 len //buffer length in bytes (64-bit data)
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// );
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//
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// Reference paper titled "Fast CRC Computation for Generic
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// Polynomials Using PCLMULQDQ Instruction"
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// URL: http://www.intel.com/content/dam/www/public/us/en/documents
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// /white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
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//
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//
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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@ -78,13 +72,14 @@
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#endif
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.text
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.arch armv7-a
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.fpu crypto-neon-fp-armv8
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arg1_low32 .req r0
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arg2 .req r1
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arg3 .req r2
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init_crc .req r0
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buf .req r1
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len .req r2
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qzr .req q13
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fold_consts_ptr .req ip
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q0l .req d0
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q0h .req d1
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@ -102,82 +97,35 @@
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q6h .req d13
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q7l .req d14
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q7h .req d15
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q8l .req d16
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q8h .req d17
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q9l .req d18
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q9h .req d19
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q10l .req d20
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q10h .req d21
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q11l .req d22
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q11h .req d23
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q12l .req d24
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q12h .req d25
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ENTRY(crc_t10dif_pmull)
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vmov.i8 qzr, #0 // init zero register
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FOLD_CONSTS .req q10
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FOLD_CONST_L .req q10l
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FOLD_CONST_H .req q10h
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// adjust the 16-bit initial_crc value, scale it to 32 bits
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lsl arg1_low32, arg1_low32, #16
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// Fold reg1, reg2 into the next 32 data bytes, storing the result back
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// into reg1, reg2.
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.macro fold_32_bytes, reg1, reg2
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vld1.64 {q11-q12}, [buf]!
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// check if smaller than 256
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cmp arg3, #256
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vmull.p64 q8, \reg1\()h, FOLD_CONST_H
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vmull.p64 \reg1, \reg1\()l, FOLD_CONST_L
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vmull.p64 q9, \reg2\()h, FOLD_CONST_H
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vmull.p64 \reg2, \reg2\()l, FOLD_CONST_L
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// for sizes less than 128, we can't fold 64B at a time...
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blt _less_than_128
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// load the initial crc value
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// crc value does not need to be byte-reflected, but it needs
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// to be moved to the high part of the register.
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// because data will be byte-reflected and will align with
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// initial crc at correct place.
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vmov s0, arg1_low32 // initial crc
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vext.8 q10, qzr, q0, #4
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// receive the initial 64B data, xor the initial crc value
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vld1.64 {q0-q1}, [arg2]!
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vld1.64 {q2-q3}, [arg2]!
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vld1.64 {q4-q5}, [arg2]!
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vld1.64 {q6-q7}, [arg2]!
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CPU_LE( vrev64.8 q0, q0 )
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CPU_LE( vrev64.8 q1, q1 )
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CPU_LE( vrev64.8 q2, q2 )
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CPU_LE( vrev64.8 q3, q3 )
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CPU_LE( vrev64.8 q4, q4 )
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CPU_LE( vrev64.8 q5, q5 )
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CPU_LE( vrev64.8 q6, q6 )
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CPU_LE( vrev64.8 q7, q7 )
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vswp d0, d1
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vswp d2, d3
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vswp d4, d5
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vswp d6, d7
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vswp d8, d9
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vswp d10, d11
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vswp d12, d13
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vswp d14, d15
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// XOR the initial_crc value
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veor.8 q0, q0, q10
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adr ip, rk3
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vld1.64 {q10}, [ip, :128] // xmm10 has rk3 and rk4
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//
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// we subtract 256 instead of 128 to save one instruction from the loop
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//
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sub arg3, arg3, #256
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// at this section of the code, there is 64*x+y (0<=y<64) bytes of
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// buffer. The _fold_64_B_loop will fold 64B at a time
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// until we have 64+y Bytes of buffer
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// fold 64B at a time. This section of the code folds 4 vector
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// registers in parallel
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_fold_64_B_loop:
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.macro fold64, reg1, reg2
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vld1.64 {q11-q12}, [arg2]!
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vmull.p64 q8, \reg1\()h, d21
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vmull.p64 \reg1, \reg1\()l, d20
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vmull.p64 q9, \reg2\()h, d21
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vmull.p64 \reg2, \reg2\()l, d20
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CPU_LE( vrev64.8 q11, q11 )
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CPU_LE( vrev64.8 q12, q12 )
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vswp d22, d23
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vswp d24, d25
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CPU_LE( vrev64.8 q11, q11 )
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CPU_LE( vrev64.8 q12, q12 )
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vswp q11l, q11h
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vswp q12l, q12h
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veor.8 \reg1, \reg1, q8
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veor.8 \reg2, \reg2, q9
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@ -185,229 +133,248 @@ CPU_LE( vrev64.8 q12, q12 )
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veor.8 \reg2, \reg2, q12
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.endm
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fold64 q0, q1
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fold64 q2, q3
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fold64 q4, q5
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fold64 q6, q7
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subs arg3, arg3, #128
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// check if there is another 64B in the buffer to be able to fold
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bge _fold_64_B_loop
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// at this point, the buffer pointer is pointing at the last y Bytes
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// of the buffer the 64B of folded data is in 4 of the vector
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// registers: v0, v1, v2, v3
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// fold the 8 vector registers to 1 vector register with different
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// constants
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adr ip, rk9
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vld1.64 {q10}, [ip, :128]!
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.macro fold16, reg, rk
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vmull.p64 q8, \reg\()l, d20
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vmull.p64 \reg, \reg\()h, d21
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.ifnb \rk
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vld1.64 {q10}, [ip, :128]!
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// Fold src_reg into dst_reg, optionally loading the next fold constants
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.macro fold_16_bytes, src_reg, dst_reg, load_next_consts
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vmull.p64 q8, \src_reg\()l, FOLD_CONST_L
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vmull.p64 \src_reg, \src_reg\()h, FOLD_CONST_H
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.ifnb \load_next_consts
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vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
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.endif
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veor.8 q7, q7, q8
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veor.8 q7, q7, \reg
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veor.8 \dst_reg, \dst_reg, q8
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veor.8 \dst_reg, \dst_reg, \src_reg
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.endm
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fold16 q0, rk11
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fold16 q1, rk13
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fold16 q2, rk15
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fold16 q3, rk17
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fold16 q4, rk19
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fold16 q5, rk1
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fold16 q6
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.macro __adrl, out, sym
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movw \out, #:lower16:\sym
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movt \out, #:upper16:\sym
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.endm
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// instead of 64, we add 48 to the loop counter to save 1 instruction
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// from the loop instead of a cmp instruction, we use the negative
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// flag with the jl instruction
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adds arg3, arg3, #(128-16)
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blt _final_reduction_for_128
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//
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// u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
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//
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// Assumes len >= 16.
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//
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ENTRY(crc_t10dif_pmull)
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// now we have 16+y bytes left to reduce. 16 Bytes is in register v7
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// and the rest is in memory. We can fold 16 bytes at a time if y>=16
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// continue folding 16B at a time
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// For sizes less than 256 bytes, we can't fold 128 bytes at a time.
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cmp len, #256
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blt .Lless_than_256_bytes
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_16B_reduction_loop:
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vmull.p64 q8, d14, d20
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vmull.p64 q7, d15, d21
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__adrl fold_consts_ptr, .Lfold_across_128_bytes_consts
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// Load the first 128 data bytes. Byte swapping is necessary to make
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// the bit order match the polynomial coefficient order.
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vld1.64 {q0-q1}, [buf]!
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vld1.64 {q2-q3}, [buf]!
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vld1.64 {q4-q5}, [buf]!
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vld1.64 {q6-q7}, [buf]!
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CPU_LE( vrev64.8 q0, q0 )
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CPU_LE( vrev64.8 q1, q1 )
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CPU_LE( vrev64.8 q2, q2 )
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CPU_LE( vrev64.8 q3, q3 )
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CPU_LE( vrev64.8 q4, q4 )
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CPU_LE( vrev64.8 q5, q5 )
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CPU_LE( vrev64.8 q6, q6 )
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CPU_LE( vrev64.8 q7, q7 )
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vswp q0l, q0h
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vswp q1l, q1h
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vswp q2l, q2h
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vswp q3l, q3h
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vswp q4l, q4h
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vswp q5l, q5h
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vswp q6l, q6h
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vswp q7l, q7h
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// XOR the first 16 data *bits* with the initial CRC value.
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vmov.i8 q8h, #0
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vmov.u16 q8h[3], init_crc
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veor q0h, q0h, q8h
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// Load the constants for folding across 128 bytes.
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vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
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// Subtract 128 for the 128 data bytes just consumed. Subtract another
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// 128 to simplify the termination condition of the following loop.
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sub len, len, #256
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// While >= 128 data bytes remain (not counting q0-q7), fold the 128
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// bytes q0-q7 into them, storing the result back into q0-q7.
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.Lfold_128_bytes_loop:
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fold_32_bytes q0, q1
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fold_32_bytes q2, q3
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fold_32_bytes q4, q5
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fold_32_bytes q6, q7
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subs len, len, #128
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bge .Lfold_128_bytes_loop
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// Now fold the 112 bytes in q0-q6 into the 16 bytes in q7.
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// Fold across 64 bytes.
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vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
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fold_16_bytes q0, q4
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fold_16_bytes q1, q5
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fold_16_bytes q2, q6
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fold_16_bytes q3, q7, 1
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// Fold across 32 bytes.
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fold_16_bytes q4, q6
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fold_16_bytes q5, q7, 1
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// Fold across 16 bytes.
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fold_16_bytes q6, q7
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// Add 128 to get the correct number of data bytes remaining in 0...127
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// (not counting q7), following the previous extra subtraction by 128.
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// Then subtract 16 to simplify the termination condition of the
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// following loop.
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adds len, len, #(128-16)
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// While >= 16 data bytes remain (not counting q7), fold the 16 bytes q7
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// into them, storing the result back into q7.
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blt .Lfold_16_bytes_loop_done
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.Lfold_16_bytes_loop:
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vmull.p64 q8, q7l, FOLD_CONST_L
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vmull.p64 q7, q7h, FOLD_CONST_H
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veor.8 q7, q7, q8
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vld1.64 {q0}, [arg2]!
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CPU_LE( vrev64.8 q0, q0 )
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vswp d0, d1
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vld1.64 {q0}, [buf]!
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CPU_LE( vrev64.8 q0, q0 )
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vswp q0l, q0h
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veor.8 q7, q7, q0
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subs arg3, arg3, #16
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subs len, len, #16
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bge .Lfold_16_bytes_loop
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// instead of a cmp instruction, we utilize the flags with the
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// jge instruction equivalent of: cmp arg3, 16-16
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// check if there is any more 16B in the buffer to be able to fold
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bge _16B_reduction_loop
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.Lfold_16_bytes_loop_done:
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// Add 16 to get the correct number of data bytes remaining in 0...15
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// (not counting q7), following the previous extra subtraction by 16.
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adds len, len, #16
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beq .Lreduce_final_16_bytes
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// now we have 16+z bytes left to reduce, where 0<= z < 16.
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// first, we reduce the data in the xmm7 register
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.Lhandle_partial_segment:
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// Reduce the last '16 + len' bytes where 1 <= len <= 15 and the first
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// 16 bytes are in q7 and the rest are the remaining data in 'buf'. To
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// do this without needing a fold constant for each possible 'len',
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// redivide the bytes into a first chunk of 'len' bytes and a second
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// chunk of 16 bytes, then fold the first chunk into the second.
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_final_reduction_for_128:
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// check if any more data to fold. If not, compute the CRC of
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// the final 128 bits
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adds arg3, arg3, #16
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beq _128_done
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// q0 = last 16 original data bytes
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add buf, buf, len
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sub buf, buf, #16
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vld1.64 {q0}, [buf]
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CPU_LE( vrev64.8 q0, q0 )
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vswp q0l, q0h
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// here we are getting data that is less than 16 bytes.
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// since we know that there was data before the pointer, we can
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// offset the input pointer before the actual point, to receive
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// exactly 16 bytes. after that the registers need to be adjusted.
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_get_last_two_regs:
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add arg2, arg2, arg3
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sub arg2, arg2, #16
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vld1.64 {q1}, [arg2]
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CPU_LE( vrev64.8 q1, q1 )
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vswp d2, d3
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// q1 = high order part of second chunk: q7 left-shifted by 'len' bytes.
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__adrl r3, .Lbyteshift_table + 16
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sub r3, r3, len
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vld1.8 {q2}, [r3]
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vtbl.8 q1l, {q7l-q7h}, q2l
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vtbl.8 q1h, {q7l-q7h}, q2h
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// get rid of the extra data that was loaded before
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// load the shift constant
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adr ip, tbl_shf_table + 16
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sub ip, ip, arg3
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vld1.8 {q0}, [ip]
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// q3 = first chunk: q7 right-shifted by '16-len' bytes.
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vmov.i8 q3, #0x80
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veor.8 q2, q2, q3
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vtbl.8 q3l, {q7l-q7h}, q2l
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vtbl.8 q3h, {q7l-q7h}, q2h
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// shift v2 to the left by arg3 bytes
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vtbl.8 d4, {d14-d15}, d0
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vtbl.8 d5, {d14-d15}, d1
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// Convert to 8-bit masks: 'len' 0x00 bytes, then '16-len' 0xff bytes.
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vshr.s8 q2, q2, #7
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// shift v7 to the right by 16-arg3 bytes
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vmov.i8 q9, #0x80
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veor.8 q0, q0, q9
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vtbl.8 d18, {d14-d15}, d0
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vtbl.8 d19, {d14-d15}, d1
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// q2 = second chunk: 'len' bytes from q0 (low-order bytes),
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// then '16-len' bytes from q1 (high-order bytes).
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vbsl.8 q2, q1, q0
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// blend
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vshr.s8 q0, q0, #7 // convert to 8-bit mask
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vbsl.8 q0, q2, q1
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// fold 16 Bytes
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vmull.p64 q8, d18, d20
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vmull.p64 q7, d19, d21
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veor.8 q7, q7, q8
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// Fold the first chunk into the second chunk, storing the result in q7.
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vmull.p64 q0, q3l, FOLD_CONST_L
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vmull.p64 q7, q3h, FOLD_CONST_H
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veor.8 q7, q7, q0
|
||||
veor.8 q7, q7, q2
|
||||
|
||||
_128_done:
|
||||
// compute crc of a 128-bit value
|
||||
vldr d20, rk5
|
||||
vldr d21, rk6 // rk5 and rk6 in xmm10
|
||||
.Lreduce_final_16_bytes:
|
||||
// Reduce the 128-bit value M(x), stored in q7, to the final 16-bit CRC.
|
||||
|
||||
// 64b fold
|
||||
vext.8 q0, qzr, q7, #8
|
||||
vmull.p64 q7, d15, d20
|
||||
veor.8 q7, q7, q0
|
||||
// Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'.
|
||||
vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
|
||||
|
||||
// 32b fold
|
||||
vext.8 q0, q7, qzr, #12
|
||||
vmov s31, s3
|
||||
vmull.p64 q0, d0, d21
|
||||
veor.8 q7, q0, q7
|
||||
// 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.
|
||||
vmull.p64 q0, q7h, FOLD_CONST_H // high bits * x^48 * (x^80 mod G(x))
|
||||
veor.8 q0h, q0h, q7l // + low bits * x^64
|
||||
|
||||
// barrett reduction
|
||||
_barrett:
|
||||
vldr d20, rk7
|
||||
vldr d21, rk8
|
||||
// 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.
|
||||
vmov.i8 q1, #0
|
||||
vmov s4, s3 // extract high 32 bits
|
||||
vmov s3, s5 // zero high 32 bits
|
||||
vmull.p64 q1, q1l, FOLD_CONST_L // high 32 bits * x^48 * (x^48 mod G(x))
|
||||
veor.8 q0, q0, q1 // + low bits
|
||||
|
||||
vmull.p64 q0, d15, d20
|
||||
vext.8 q0, qzr, q0, #12
|
||||
vmull.p64 q0, d1, d21
|
||||
vext.8 q0, qzr, q0, #12
|
||||
veor.8 q7, q7, q0
|
||||
vmov r0, s29
|
||||
// Load G(x) and floor(x^48 / G(x)).
|
||||
vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]
|
||||
|
||||
_cleanup:
|
||||
// scale the result back to 16 bits
|
||||
lsr r0, r0, #16
|
||||
// Use Barrett reduction to compute the final CRC value.
|
||||
vmull.p64 q1, q0h, FOLD_CONST_H // high 32 bits * floor(x^48 / G(x))
|
||||
vshr.u64 q1l, q1l, #32 // /= x^32
|
||||
vmull.p64 q1, q1l, FOLD_CONST_L // *= G(x)
|
||||
vshr.u64 q0l, q0l, #48
|
||||
veor.8 q0l, q0l, q1l // + low 16 nonzero bits
|
||||
// Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of q0.
|
||||
|
||||
vmov.u16 r0, q0l[0]
|
||||
bx lr
|
||||
|
||||
_less_than_128:
|
||||
teq arg3, #0
|
||||
beq _cleanup
|
||||
.Lless_than_256_bytes:
|
||||
// Checksumming a buffer of length 16...255 bytes
|
||||
|
||||
vmov.i8 q0, #0
|
||||
vmov s3, arg1_low32 // get the initial crc value
|
||||
__adrl fold_consts_ptr, .Lfold_across_16_bytes_consts
|
||||
|
||||
vld1.64 {q7}, [arg2]!
|
||||
CPU_LE( vrev64.8 q7, q7 )
|
||||
vswp d14, d15
|
||||
veor.8 q7, q7, q0
|
||||
// Load the first 16 data bytes.
|
||||
vld1.64 {q7}, [buf]!
|
||||
CPU_LE( vrev64.8 q7, q7 )
|
||||
vswp q7l, q7h
|
||||
|
||||
cmp arg3, #16
|
||||
beq _128_done // exactly 16 left
|
||||
// XOR the first 16 data *bits* with the initial CRC value.
|
||||
vmov.i8 q0h, #0
|
||||
vmov.u16 q0h[3], init_crc
|
||||
veor.8 q7h, q7h, q0h
|
||||
|
||||
// now if there is, load the constants
|
||||
vldr d20, rk1
|
||||
vldr d21, rk2 // rk1 and rk2 in xmm10
|
||||
// Load the fold-across-16-bytes constants.
|
||||
vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
|
||||
|
||||
// check if there is enough buffer to be able to fold 16B at a time
|
||||
subs arg3, arg3, #32
|
||||
addlt arg3, arg3, #16
|
||||
blt _get_last_two_regs
|
||||
b _16B_reduction_loop
|
||||
cmp len, #16
|
||||
beq .Lreduce_final_16_bytes // len == 16
|
||||
subs len, len, #32
|
||||
addlt len, len, #16
|
||||
blt .Lhandle_partial_segment // 17 <= len <= 31
|
||||
b .Lfold_16_bytes_loop // 32 <= len <= 255
|
||||
ENDPROC(crc_t10dif_pmull)
|
||||
|
||||
// precomputed constants
|
||||
// these constants are precomputed from the poly:
|
||||
// 0x8bb70000 (0x8bb7 scaled to 32 bits)
|
||||
.section ".rodata", "a"
|
||||
.align 4
|
||||
// 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
|
||||
|
||||
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
|
||||
rk1: .quad 0x2d56000000000000
|
||||
rk2: .quad 0x06df000000000000
|
||||
|
||||
tbl_shf_table:
|
||||
// use these values for shift constants for the tbl/tbx 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
|
||||
// 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))
|
||||
|
||||
// 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
|
||||
|
|
|
|||
|
|
@ -21,7 +21,7 @@
|
|||
|
||||
#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
|
||||
|
||||
asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u32 len);
|
||||
asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
|
||||
|
||||
static int crct10dif_init(struct shash_desc *desc)
|
||||
{
|
||||
|
|
|
|||
Loading…
Reference in New Issue